I am looking to do what GPSS did, make my own NATO pressure or somewhere thereabouts heavy OTM ammo.  I am going to have it contracted to a company that loads ammo in new cases.  They use Winchester cases for 223 Remington.  From what I read, this is ok and one of the better cases to use.

So what is the difference between the 75 grain Hornady, the 77 Noser, and the 77 Sierra?  Did I leave any out?  I can buy the cannulure tool.  I know that they all have different BC, but how much of a difference will that make?  Price might be a factor.  I am going to try and get it under $200 per K.

So what is the terminal difference?  Most reliable yaw, quickest yaw, best fragmentation?  At what velocity does one max out with each of the different bullets?  I know that happens sometimes.  I gather that I will be able to reach 1 MOA with all of these bullets.  I don't know if I will but under 1.5 MOA would be nice.

Experienced reloaders and well read terminal effects persons I call on your knowledge.

IIRC Dr Roberts (who did all the initial research) rated them as follows:
#1 77gr Nosler (best fragmentation)
#2 75gr Hornady
#3 77gr SMK (this one had the longer neck - as do the other SMK rounds, but it had the best penetration)

With only my personal testing and last years hunt to go on, I'll go abit against Forest, or rather Dr. Roberts on this one and state that the 77SMK which the Mk 262 mod is based on is the round ya want.

The OTM fragments too much on live game to meet the required penetration depths I want in my defensive round. The 64grn. PowerPoint by Winchester beats the heck outta it, IMO especially where penetration depth is concerned.

FWIW, due to the different ogive on the Hornady 75 grn. HPBT Match round, I don't/haven't shot more than a few hundred and most of them were long-loaded as they didn't group like the 77SMKs in my rifle, when loaded mag length. Although I think their better "penetration depth wise" than the OTM, so if your rifle likes 'em they may work for ya.

Mike

edited'cus I can't spell, and re-edited cus I could say what I meant properly

Quoted: With only my personal testing and last years hunt to go on, I'll go with Forest on this one and state that the 77SMK which the Mk 262 mod is based on is the round ya want. The OTM fragments too much on live game to meet the required penetration depths I want in my defensive round. The 64grn. PowerPoint by Winchester beats the heck outta it, IMO. FWIW, due to the different ogive on the Hornady 75 grn. HPBT Match round, I don't/haven't shot more than a few hundred and most of them were long-loaded as they didn't group like the 77SMKs in my rifle, when loaded mag length. Although I think their better "penetration depth wise" than the OTM, so if your rifle likes 'em they may work for ya. Mike edited'cus I can't spell

I am not sure that I follow you correctly on this wilson?  Forrest said that the 77 NOSLER was the best bullet and that 77 SIERRA was the worst bullet with the longest neck.  It did have the longest penetration though.  And all three of these bullets are OTM.  Open Tip Match.  So I don't exactly know which bullet you are refering to when you say OTM.

I thought on the 75 Hornady versus the 77 Nosler B&T test, the 77 Nosler appeared to perform slightly better than the 75 Hornady.  However, at the time, the nosler was without a cannelure.  Thus only having a slightly shorter neck and appearing to have only slightly increased fragmentation, B&T recommended to go with the 75 Hornady w/cannelure for reliability purposes.

So the 77 grain Nosler *slightly* outperforms* the 75 grain Hornady?  Is the 75 Hornady as reliable fragmenting as the 77 Nosler?  Do they have comparable velocity floors for fragmenting or is this still undetermined?

So when I have them work up the load, I should have them try both bullets to see if there is a clear accuracy edge and balance that with cost?  I will not look for accuracy down low.  If there is an accuracy point a few tenths of a grain below redline, then that is a different story.  But if it is acceptable, then the load I will have them do will be right at the redline.

Sorry for the confusion, my fault, (corrected my above post) IMO the 77 OTM because of it's excellent fragmentation LACKS the penetration depth for a useful DEFENSIVE round.

In my posts:
The 77 SMK is Sierra's' Matchking bullet, same as used in the current Mk262 round
The 77 OTM is Nosler's' Open-tip-Match bullet
The 75 HPBT Match is Hornady's

Without long drawn out details, I dang near lost a doe last year because of it. The round just flatout exploded and failed to penetrate, luckily for me and the wounded deer I got a second shot and broke her neck although again the OTM did not exit the does hide. Hence my comments on it's usefulness.

I cannot state beyond what I have stated about the Horandy 75 hpbt Match as I have not shot any critters with it, but am relying on the ammo faq and my accuracy testing alone.

My grouping would go like this:
#1 77 SMK
#2 75 HPBTM
#3 77 OTM

Hope this make things clearer.  
Mike

Quoted: Sorry for the confusion, my fault, (corrected my above post) IMO the 77 OTM because of it's excellent fragmentation LACKS the penetration depth for a useful DEFENSIVE round.

Mike,
That is ENTIRELY incorrect.  All 3 of the above rounds meet FBI standards of penetrating a minium of 12" after passing through 4 layers of denim.

123Whisper,
IIRC you can get the Nosler 77gr in a cannalured version now.  As such that would be the optimal round.  Also, not all the 75gr Hornady OTMs are cannalured (for example I know the Black Hills Blue Box I have is not).

If you're loading your own I select either the 77gr Nosler or 75gr Hornady depening on which version I could get that was cannalured.

So when I have them work up the load, I should have them try both bullets to see if there is a clear accuracy edge and balance that with cost?

Given both test rounds are cannalure - that would be a good idea.

Is the 75 Hornady as reliable fragmenting as the 77 Nosler? Do they have comparable velocity floors for fragmenting or is this still undetermined?

The 75gr is a reliable fragmenter, and it fragments way down.  Using the data supplied by Hornady its going to be in the 2200 fps range - give or take.

Quoted: All three rounds meet or exceed the standard 12" penetration minimum.  And I'm presuming that this question isn't about hunting deer... -Troy

No deer hunting with 223.  We use a slug gun.  These loads will be used for playing soldier, and shooting at extended ranges.  Maybe the coyotes too.  Just a hot load to be used when the situation warrants the expense or needs the accuracy at extended ranges.  I have a 1/7 twist and so far the heaviest I have shot through it is 68 Hornady.  My trigger prevents me from getting any decent groups.  I want to have the best I can.

Quoted: Quoted: Sorry for the confusion, my fault, (corrected my above post) IMO the 77 OTM because of it's excellent fragmentation LACKS the penetration depth for a useful DEFENSIVE round. Mike, That is ENTIRELY incorrect.  All 3 of the above rounds meet FBI standards of penetrating a minium of 12" after passing through 4 layers of denim. 123Whisper, IIRC you can get the Nosler 77gr in a cannalured version now.  As such that would be the optimal round.  Also, not all the 75gr Hornady OTMs are cannalured (for example I know the Black Hills Blue Box I have is not). If you're loading your own I select either the 77gr Nosler or 75gr Hornady depening on which version I could get that was cannalured. So when I have them work up the load, I should have them try both bullets to see if there is a clear accuracy edge and balance that with cost? Given both test rounds are cannalure - that would be a good idea. Is the 75 Hornady as reliable fragmenting as the 77 Nosler? Do they have comparable velocity floors for fragmenting or is this still undetermined? The 75gr is a reliable fragmenter, and it fragments way down.  Using the data supplied by Hornady its going to be in the 2200 fps range - give or take.

Ok, that was what I was looking for.  Thank you very much Forrest!

I know we're not talking deer hunting here, and as mentioned above I normally hunt w/ an '06, but as I was testing the OTM last November, I used it in my CR6724 on a stand at the farm where the ranges made pin-point placement a certainty and to see/know EXACTLY how the bullet would perform on a LIVE target.

I know they said it meets the penetration test of 12" I'm just telling you what the 77 OTM did on the doe I took last year and thats why I placed it on the bottom of my list.

Whether I was pushing it too fast outta my 24" AR or whatever, the doe's neck just below the jaw wasn't no 12" thick and the OTM barely made it past the spinal cord.

The first round, fired at 40 yards was aimed dead between her eyes, as she was facing me square on. At the instant the shot flew I'm guessing she raised her head abit and the 77 OTM struck her squarely in the front lower jaw and exploded, taking off her complete lower mandible. I could NOT believe it when she wheeled and ran, after a minute or so she made a loop back and I got off another shot at 110 yards that struck her about 2-3" below the junction of the skull and spinal cord. This round put her down and while it made a mess outta her on the entry side BOTH shots exhibited a decided lack of penetration and an enormous amount of fragmentation, hence my use of the word "exploded".

I chatted w/ brouhaha at "Pre-ban" that week, after this happened and explained the same to him. WHY my real-life results were so far off from the published results I have NO explantion for.

I was using a fairly hot load of H335, one that made one ragged hole outta 3 rounds at 100 yards and both dad and I were quite impressed w/ the accuracy, for all the other loads averaged around a minute that day. I used the same load the next day as I had saved 7 rounds of that particular load.

Somewhere I still have the lower jaw, or rather the multitude of pieces of her lower jaw the OTM blew it into, and I ain't ashamed to say that I dang near threw up, upon close inspection of her. Made a real mess and I would have been quite pissed if she hadn't been so dis-com-bobulated to make a loop and give me another chance to finish her.

Had this been a 77 SMK or even my favorite 64grn. PP rounds, she would have been dead instantly as the 1st round would have struck thru to her medulla, as it was, I prayed for the first time in quite awhile afterward that I didn't have to live longer than about 1-2 minutes with the thought that I'd lost only my second deer in almost 40 years of hunting w/ a rifle. (I've lost 2 others using the bow)

Makes me sick thinking about the suffering she would have went thru and my dad has and will not let me forget that the 223 ain't no deer round, although he knows I've taken a few before w/ the PP rounds, all one shot kills. I won't repeat what he thinks about the 77 OTM round, but I can tell ya this I won't be using it on anything bigger'n a coyote.

Sorry for taking the thread off topic, but it happened and while I'll agree 100% that the 77 OTM is a FRAGMENTING mofo, IMO it don't penetrate worth a damn when BONE and REAL FLESH are involved.

Mike

Quoted: I chatted w/ brouhaha at "Pre-ban" that week, after this happened and explained the same to him. WHY my real-life results were so far off from the published results I have NO explantion for.

My guess is hitting the bone caused the round to break up much earlier.  Bones throw in a whole new dimension.

Had this been a 77 SMK or even my favorite 64grn. PP rounds, she would have been dead instantly

I doubt it.  Maybe with the 64gr, but the SMK would have broken up just as much upon striking bone.

Sorry for taking the thread off topic, but it happened and while I'll agree 100% that the 77 OTM is a FRAGMENTING mofo, IMO it don't penetrate worth a damn when BONE and REAL FLESH are involved.

Mike,
The 77gr Noslers have been used on live flesh with good results (as have the 75gr - which is a common round for LEO use - Honady sells it as the 75gr TAP).  As you pointed out bone makes a big difference (especially with 5.56).  I also wonder about the extra velocity from your 24" barrel and if that made a difference.

Would make a heck of a test with some bone material embeded into 10% gel to show how the rounds react.

Quoted: Whether I was pushing it too fast outta my 24" AR or whatever, the doe's neck just below the jaw wasn't no 12" thick and the OTM barely made it past the spinal cord. I was using a fairly hot load of H335, one that made one ragged hole outta 3 rounds at 100 yards and both dad and I were quite impressed w/ the accuracy, for all the other loads averaged around a minute that day. I used the same load the next day as I had saved 7 rounds of that particular load. Somewhere I still have the lower jaw, or rather the multitude of pieces of her lower jaw the OTM blew it into, and I ain't ashamed to say that I dang near threw up, upon close inspection of her. Made a real mess and I would have been quite pissed if she hadn't been so dis-com-bobulated to make a loop and give me another chance to finish her. Had this been a 77 SMK or even my favorite 64grn. PP rounds, she would have been dead instantly as the 1st round would have struck thru to her medulla, as it was, I prayed for the first time in quite awhile afterward that I didn't have to live longer than about 1-2 minutes with the thought that I'd lost only my second deer in almost 40 years of hunting w/ a rifle. (I've lost 2 others using the bow) Makes me sick thinking about the suffering she would have went thru and my dad has and will not let me forget that the 223 ain't no deer round, although he knows I've taken a few before w/ the PP rounds, all one shot kills. I won't repeat what he thinks about the 77 OTM round, but I can tell ya this I won't be using it on anything bigger'n a coyote. Sorry for taking the thread off topic, but it happened and while I'll agree 100% that the 77 OTM is a FRAGMENTING mofo, IMO it don't penetrate worth a damn when BONE and REAL FLESH are involved. Mike

I don't remember the names, but I do remember reading about this incident.  didn't you say that you were running about 2900 FPS muzzle velocity?  That is about 200 fps or more over what anyone with a standard length AR15 can push them.  I would imagine that would have a lot to do with it.  As well as the teeth and jawbone.  The bullet simply ran into a lot of bone all at once.  I doubt any .224 bullet would have acted much differently other than maybe a 64 PP or a copper solid.

Quoted: Quoted: I chatted w/ brouhaha at "Pre-ban" that week, after this happened and explained the same to him. WHY my real-life results were so far off from the published results I have NO explantion for. My guess is hitting the bone caused the round to break up much earlier.  Bones throw in a whole new dimension.

This is the correct answer.  If you'd hit it in the torso, it would have penetrated much more.  Bone is harder to shoot through than fat and muscle.

Quoted: Somewhere I still have the lower jaw, or rather the multitude of pieces of her lower jaw the OTM blew it into, and I ain't ashamed to say that I dang near threw up, upon close inspection of her. Made a real mess and I would have been quite pissed if she hadn't been so dis-com-bobulated to make a loop and give me another chance to finish her. Had this been a 77 SMK or even my favorite 64grn. PP rounds, she would have been dead instantly as the 1st round would have struck thru to her medulla, as it was, I prayed for the first time in quite awhile afterward that I didn't have to live longer than about 1-2 minutes with the thought that I'd lost only my second deer in almost 40 years of hunting w/ a rifle. (I've lost 2 others using the bow) Makes me sick thinking about the suffering she would have went thru and my dad has and will not let me forget that the 223 ain't no deer round, although he knows I've taken a few before w/ the PP rounds, all one shot kills. I won't repeat what he thinks about the 77 OTM round, but I can tell ya this I won't be using it on anything bigger'n a coyote. Sorry for taking the thread off topic, but it happened and while I'll agree 100% that the 77 OTM is a FRAGMENTING mofo, IMO it don't penetrate worth a damn when BONE and REAL FLESH are involved. Mike

First off, one shouldn't use fragmenting rounds of any kind for medium to large game hunting.  As you may know, hunting deer with ANY .223 is a controversial subject.  Coyotes are about as large as I would go with fragmenting rounds.  Part of that decision is based on what you plan to do with the game after you kill it as well.  More of it has to do with the fact that more penetration is needed in large herbivores than for self-defense rounds.

Bone and muscle structures in larger animals (particular the jaws of a herbivore) are more substantial in almost all cases than those of humans.  This is why hunting bullets are made to mushroom and not fragment and why bonded cores to prevent separation from the jacket are so important in these rounds (and are less interesting in fragmenting rounds).  Fragmentation is a much better wounding mechanism for targets that do not have the thicker and more robust skeletal structures that one finds in four legged creatures.  (Shoulders in particular are problematic since they, unlike human shoulders bear the full weight of the animals front half on a regular basis and are much hardier as a result).

Second, sounds like the velocity of the 77 round you fired was high enough to reduce penetration even more.

There is a velocity point beyond which penetration for a round actually lowers.  This is because the forces on a bullet that yaws in tissue are so extreme and fragmentation so violent that the fragments left are not large enough to have the momentum to penetrate more deeply.  As you bring velocity down penetration depths go up until you hit a certain point (where the total energy still isn't enough to drive fragments to 12" anymore) and then penetration starts to go down again.  Sometimes penetration drops until the fragmentation threshold is dipped under and then penetration goes up again since the bullet remains whole and has more mass behind it to penetrate with.

77 Noslers seem to edge down to the 12" level of penetration in gel upwards of about 2700-2750 fps.  Since those are the speeds we see at the muzzle with a 16" (~2730) I suspect 40 meters out of a 24" is probably higher than 2750.  (As a side note, this suggests that the NATO loading of 77 Nosler is about perfectly tuned for a 16").

The combination of higher velocity and more substantial bone and teeth structures probably didn't help the round hold together enough to keep penetrating.  I do sort of doubt that any fragmenting .223 would have been helpful here.  64 Power Point might have, but it is not designed to fragment much.  M855 might have done the trick as well.

People spend a lot of time comparing hunting experiences with terminal performance in two legged carnivores.  This is a mistake on many levels and results in the sorts of discussions we see here.

To clarify:

From a 16" platform out to 300 meters the 77 grain Nosler NATO loading offered by Black Hills is the best self-defense round I have ever tested or used with one exception: the 100 grain NATO loading we tested last year.  I have also been collecting information from operators who use similar rounds in the field and so far 77 grain rounds (both Nosler and SMK) are proving to be very effective in actual use as well.

77 Nosler starts to yaw faster, penetrates deeper and fragments better than similar rounds (the SMK in particular).  This is critical when dealing with a range of potential adversaries that includes malnourished and under hydrated desert fighters out to overweight and body armor wearing criminal types.

I recommend the 77 Nosler NATO round for self defense highly.  Highly enough that I don't load my "go to" magazines with anything else anymore, and I'm in a spot right now where these actually have the potential to get used.

As a general rule it is important to remember that both the 12" standard and gel testing as we practice it is designed to shed light on performance against two legged carnivores.  The anatomy differences with deer and other game (in particular the stronger and more prominent skeletal structures in herbivores) make this data less useful for predicting performance in game.

For many of the same reasons we don't use performance in game to predict performance against bipedal carnivores.

Finally, please recognize that single shooting incidents never define the typical performance of a round well.  No two shootings are ever alike.  The best we can hope for is a round that performs reasonably well and reliably across a large number of potential situations.  In .223/5.56 this round is, in my view, the 77 Nosler NATO loading.

Quoted: Quoted: Somewhere I still have the lower jaw, or rather the multitude of pieces of her lower jaw the OTM blew it into, and I ain't ashamed to say that I dang near threw up, upon close inspection of her. Made a real mess and I would have been quite pissed if she hadn't been so dis-com-bobulated to make a loop and give me another chance to finish her. Had this been a 77 SMK or even my favorite 64grn. PP rounds, she would have been dead instantly as the 1st round would have struck thru to her medulla, as it was, I prayed for the first time in quite awhile afterward that I didn't have to live longer than about 1-2 minutes with the thought that I'd lost only my second deer in almost 40 years of hunting w/ a rifle. (I've lost 2 others using the bow) Makes me sick thinking about the suffering she would have went thru and my dad has and will not let me forget that the 223 ain't no deer round, although he knows I've taken a few before w/ the PP rounds, all one shot kills. I won't repeat what he thinks about the 77 OTM round, but I can tell ya this I won't be using it on anything bigger'n a coyote. Sorry for taking the thread off topic, but it happened and while I'll agree 100% that the 77 OTM is a FRAGMENTING mofo, IMO it don't penetrate worth a damn when BONE and REAL FLESH are involved. Mike First off, one shouldn't use fragmenting rounds of any kind for medium to large game hunting.  As you may know, hunting deer with ANY .223 is a controversial subject.  Coyotes are about as large as I would go with fragmenting rounds.  Part of that decision is based on what you plan to do with the game after you kill it as well.  More of it has to do with the fact that more penetration is needed in large herbivores than for self-defense rounds. Bone and muscle structures in larger animals (particular the jaws of a herbivore) are more substantial in almost all cases than those of humans.  This is why hunting bullets are made to mushroom and not fragment and why bonded cores to prevent separation from the jacket are so important in these rounds (and are less interesting in fragmenting rounds).  Fragmentation is a much better wounding mechanism for targets that do not have the thicker and more robust skeletal structures that one finds in four legged creatures.  (Shoulders in particular are problematic since they, unlike human shoulders bear the full weight of the animals front half on a regular basis and are much hardier as a result). Second, sounds like the velocity of the 77 round you fired was high enough to reduce penetration even more. There is a velocity point beyond which penetration for a round actually lowers.  This is because the forces on a bullet that yaws in tissue are so extreme and fragmentation so violent that the fragments left are not large enough to have the momentum to penetrate more deeply.  As you bring velocity down penetration depths go up until you hit a certain point (where the total energy still isn't enough to drive fragments to 12" anymore) and then penetration starts to go down again.  Sometimes penetration drops until the fragmentation threshold is dipped under and then penetration goes up again since the bullet remains whole and has more mass behind it to penetrate with. 77 Noslers seem to edge down to the 12" level of penetration in gel upwards of about 2700-2750 fps.  Since those are the speeds we see at the muzzle with a 16" (~2730) I suspect 40 meters out of a 24" is probably higher than 2750.  (As a side note, this suggests that the NATO loading of 77 Nosler is about perfectly tuned for a 16"). The combination of higher velocity and more substantial bone and teeth structures probably didn't help the round hold together enough to keep penetrating.  I do sort of doubt that any fragmenting .223 would have been helpful here.  64 Power Point might have, but it is not designed to fragment much.  M855 might have done the trick as well. People spend a lot of time comparing hunting experiences with terminal performance in two legged carnivores.  This is a mistake on many levels and results in the sorts of discussions we see here. To clarify: From a 16" platform out to 300 meters the 77 grain Nosler NATO loading offered by Black Hills is the best self-defense round I have ever tested or used with one exception: the 100 grain NATO loading we tested last year.  I have also been collecting information from operators who use similar rounds in the field and so far 77 grain rounds (both Nosler and SMK) are proving to be very effective in actual use as well. 77 Nosler starts to yaw faster, penetrates deeper and fragments better than similar rounds (the SMK in particular).  This is critical when dealing with a range of potential adversaries that includes malnourished and under hydrated desert fighters out to overweight and body armor wearing criminal types. I recommend the 77 Nosler NATO round for self defense highly.  Highly enough that I don't load my "go to" magazines with anything else anymore, and I'm in a spot right now where these actually have the potential to get used. As a general rule it is important to remember that both the 12" standard and gel testing as we practice it is designed to shed light on performance against two legged carnivores.  The anatomy differences with deer and other game (in particular the stronger and more prominent skeletal structures in herbivores) make this data less useful for predicting performance in game. For many of the same reasons we don't use performance in game to predict performance against bipedal carnivores. Finally, please recognize that single shooting incidents never define the typical performance of a round well.  No two shootings are ever alike.  The best we can hope for is a round that performs reasonably well and reliably across a large number of potential situations.  In .223/5.56 this round is, in my view, the 77 Nosler NATO loading.

Wow, Tat you need to work on the

Version.

It's good to see you around again.

Didn't Austrian recently detail a shooting in SW Asia where the 77gr. SMKs failed to stop despite good placement precisely because of their long necks?

Quoted: Didn't Austrian recently detail a shooting in SW Asia where the 77gr. SMKs failed to stop despite good placement precisely because of their long necks?

I thought it was some guy with an AK, and two soldiers end up dead because of it?  Something like that.  77 SMKs can have long necks and thus can act like M855 does sometimes.  Knitting Needles.

Are 77 Noslers typically very accurate when seated to mag-length?  In other words, are they sensitive to how far they are to the rifling?  Since everyone uses them that way, I guess the answer is they will shoot fine at mag length.

Tatjana, when will we be getting the "Best of B&T Ammo Tests" thread back?  I noticed that you or one of the other mods tacked the threads that I bumped up.  I don't have anymore saved.  I have the 75-77 but the file is corrupted and won't open.  That was my only way of having the address.  I didn't have them saved to my favorites.  Anyone else?

When you said that the 77 Nosler decreased in penetration at 2700-2750 fps, did this mean that it would be detrimental to have a load that pushed them faster than this?  How much of a decrease in penetration are we talking about at say 2775-2800?  Would a terminal velocity of this result in any decreased lethality?  I would think that the violent fragmentation would still take care of most jobs because of its large permanent cavity.

Does the 77 Nosler have like a 12 inch penetration at 2700 or so fps, then at 2650 fps levels off to 13-14 inches, then as velocity approaches fragmentation floor, the penetration goes up to how much further?

Quoted: Quoted: Didn't Austrian recently detail a shooting in SW Asia where the 77gr. SMKs failed to stop despite good placement precisely because of their long necks? I thought it was some guy with an AK, and two soldiers end up dead because of it?  Something like that.  77 SMKs can have long necks and thus can act like M855 does sometimes.  Knitting Needles. Are 77 Noslers typically very accurate when seated to mag-length?  In other words, are they sensitive to how far they are to the rifling?  Since everyone uses them that way, I guess the answer is they will shoot fine at mag length. Tatjana, when will we be getting the "Best of B&T Ammo Tests" thread back?  I noticed that you or one of the other mods tacked the threads that I bumped up.  I don't have anymore saved.  I have the 75-77 but the file is corrupted and won't open.  That was my only way of having the address.  I didn't have them saved to my favorites.  Anyone else? When you said that the 77 Nosler decreased in penetration at 2700-2750 fps, did this mean that it would be detrimental to have a load that pushed them faster than this?  How much of a decrease in penetration are we talking about at say 2775-2800?  Would a terminal velocity of this result in any decreased lethality?  I would think that the violent fragmentation would still take care of most jobs because of its large permanent cavity. Does the 77 Nosler have like a 12 inch penetration at 2700 or so fps, then at 2650 fps levels off to 13-14 inches, then as velocity approaches fragmentation floor, the penetration goes up to how much further?

Here's my original take on lower velocity penetration from the first 77 grain test we did:

Overall gel penetration at the muzzle is lower in the NATO pressure 77 grain round, probably as a result of increased muzzle velocity and the consequent increase in stress the round experiences when passing through tissue simulant. Accordingly, fragmentation is initially more violent and penetration reduced. The authors expect that penetration of the 77 NATO round from a 16" barrel will increase by 2-3" to match the SAAMI penetration (13-14") after travelling between 50 and 70 meters and as velocities reduce. Penetration should then level off near 12.5" until the fragmentation threshold is reached.

My hard observations on 77 penetration are:

12" (or just under) at 2750-2780 fps (out of longer than a 16" at the muzzle)
12 - 12.5" of penetration at ~2730 fps (the muzzle of a 16").
13-14" of penetration at 2650 fps (at ~50-60 meters from a 16").

I speculate that we'll see:

~13" of penetration at 2550 fps and under (over 75 meters from a 16").



77 looks to slow down on fragmentation around 2100-2200fps (200-250 meters).  I suspect you're still at the 12" mark here though.

The post you refer to made by my brother is here.  In it he says:

That particular incident involved 77 grain Sierra Match King rounds. (This back and forth between Nosler and SMK was a result of SMK's early rounds having no cannelures and then putting them in when Nosler was specified). Sergeant First Class Bennett and Master Sergeant Morehead (may their service never be forgotten) were killed in September by an Iraqi with an AKM who received multiple hits of 5.56 77 grain Sierra Match King. Versus 77 grain Nosler rounds the Sierra Match King rounds are a bit more accurate but have longer (and erratic) necks before yaw and fragmentation. This means that, as with M855, malnourished or skinny aggressors can get lucky.

Someone also asked about the B&T Ammo Labs tests.  They were lost in the site move but will return both here and on the new B&T Ammo Labs site (coming soon).

www.ar15.com/forums/topic.html?b=3&f=16&t=187588

Fixed your link.

Hey Whisper,

Did you see the stuff on the reloading side about loading for a home brewed NATO spec 75-77 gr OTM?

Big Al

Quoted: Hey Whisper, Did you see the stuff on the reloading side about loading for a home brewed NATO spec 75-77 gr OTM? Big Al

Yes, that is originally what I meant to type.  But GSSP and GPSS were just too similar for my tired mind.  It was an unfortunate coincidence that GPSS stood for Georgia Precision Shooters Supply, which was the original NATO spec BH provider.

I have talked to my loader guy at the gunshows before about heavy bulleted ammo.  He did a load for the Illinois state rifle team.  They bot the components and told him exactly what they wanted.  The powder was reloader 15 and on top were 77 sierras.  I don't remember the charge weight, but he said that the one extra round he had chronied 2728 from a RRA 16" barrel.  He said that he prefered TAC powder much better for both metering and clean burning.

Quoted: Quoted: Hey Whisper, Did you see the stuff on the reloading side about loading for a home brewed NATO spec 75-77 gr OTM? Big Al Yes, that is originally what I meant to type.  But GSSP and GPSS were just too similar for my tired mind.  It was an unfortunate coincidence that GPSS stood for Georgia Precision Shooters Supply, which was the original NATO spec BH provider. I have talked to my loader guy at the gunshows before about heavy bulleted ammo.  He did a load for the Illinois state rifle team.  They bot the components and told him exactly what they wanted.  The powder was reloader 15 and on top were 77 sierras.  I don't remember the charge weight, but he said that the one extra round he had chronied 2728 from a RRA 16" barrel.  He said that he prefered TAC powder much better for both metering and clean burning.

Please be careful.  We really don't want reloading data on the Ammunition forum.  You'll see at top that Troy has made this policy here in the forum and there are consequences (thread locking and account locking).

Thank you!

Quoted: Please be careful.  We really don't want reloading data on the Ammunition forum.  You'll see at top that Troy has made this policy here in the forum and there are consequences (thread locking and account locking). Thank you!

No problem, I was more than anything making a reference to what sort of velocity the state rifle team was using.

Tat,

As I understand it, you state that at 2750-2780 fps, penetration is reduced a bit compared with a 2730 fps load.  I understand the dynamics of increased expansion decreasing the penetration of the projectile/fragments.  Here I worked so hard to increase my 75 Hornady velocity (2890 fps from my 16" RRA) beyond the BH NATO spec load and now I'm second guessing myself.  Think I ought to back off a bit?  One increment on my RCBS Uniflow will drop me back down to about 2760 fps.

Big Al

Quoted: Tat, As I understand it, you state that at 2750-2780 fps, penetration is reduced a bit compared with a 2730 fps load.  I understand the dynamics of increased expansion decreasing the penetration of the projectile/fragments.  Here I worked so hard to increase my 75 Hornady velocity (2890 fps from my 16" RRA) beyond the BH NATO spec load and now I'm second guessing myself.  Think I ought to back off a bit?  One increment on my RCBS Uniflow will drop me back down to about 2760 fps. Big Al

This is an interesting question.  I don't know where the breakpoints lie for the 75 Hornady in excess of 2700 fps or so.  If it's like the 77 Nosler (and I think it fragments a bit less than the 77 based on our tests) you probably are ok at least for 12".  I am guessing here though.

This is interesting though:




Top: 77 Nosler @ 2624 fps and 77 Nosler NATO @ 2734 fps

~15" for the slower 77 Nosler. ~13" for the hotter Nosler NATO.

~14" for SAAMI grain 75 Hornady.

Doing some WILD ASS GUESSWORK it looks like we might expect 75 grain Hornady to have better penetration at similar velocity.  If we think 75 grain Hornady behaves basically like the 77 grain Nosler then increasing by 100-120 fps from 2624 (i.e. ~2740) should put 75 Hornady at around 12 - 13"  (Like 77 at the same velocity).  Given that, I suspect your loading is probably ok, or CLOSE to ok.  I don't THINK we'd see 11" or less, but you never really know till you shoot gel.

Also, remember that these gel shots are fired at 15'.  They lose 70 fps at 25 meters.  Probably around 20 fps at 15 meters.

I think you're probably ok.  Hard to tell though.  You are really pushing that round hard.  Sometimes certain threshold velocities cause rounds to behave dramatically different.  (Passing under the fragmentation threshold, for example, immediately reverses a downward penetration trend as the round remains largely intact and suddenly penetrates much better at a given velocity).

Make no mistake.  These rounds at these velocities are quite deadly.  We are doing a little bit of nitpicking here.

What do you want the extra velocity for?  Range?

Quoted: Think I ought to back off a bit?

You need to back off QUITE a bit for your own safety.

I ran some calculations on the numbers you gave me, and you are WAY over spec.  The numbers I got were about 74k PSI...WAY too hot.  And that's why I don't want you to post the numbers here.  

Please be careful and I sure hope you're wearing eye protection and keeping your hands away from the magwell and handguard.

Brou,

I had already planned on backing off a skootch.  Probably to 2750-ish.  I'd rather have a totally reliable hot load than a Hell-Bent-for-Leather load that might someday drop a blown primer in my trigger group or worse.  And no, I'm NOT going to publish my propellant charge weights.

Tat,

Thanks for the insight!

Big Al