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9/22/2017 12:11:25 AM
Posted: 4/6/2006 8:41:16 AM EDT
[Last Edit: 4/6/2006 3:32:08 PM EDT by SC-Texas]
I'm having a discussion with someone that I consider to be a RKI.

He is telling me that this ammo, from a 1:9 barrell, will completely destabilize at 200, 300 or more yards and keyhole into the target if it hits the target at all.

He also claims that he has seen this ammo keyhole into targets at 200
+ yard when shot form a 1:9 barrel.


Since I have 1:7 barrells, this is an academic question for me. But, a KI that I know who shoots long distance with his AR and uses the Black Hills version of htis ammo says he shoots it without problems.

Anyone out there ever used a 1:9 barrel with this 75grn ammo at 200+ yards?
Link Posted: 4/6/2006 8:46:13 AM EDT
[Last Edit: 4/6/2006 3:27:29 PM EDT by JHill]
I am about to go out and shoot my BlackHills 75grn 223 in just a little while.

I have a DPMS 1/9 16"--we will see...I will be able to shoot out to about ~240yds...



ETA:
I just got back from the range and shot 3 rds (trying to conserve) at a target that is about 220-230 yds. No keyholing, no sign of stability issues.

One note: I have shot FC Gold Medal 69SMK at this same range--same target and the stuff shoots about 4-5" lower (point of impact) than 55grn WWB. The Black Hills 75gr tonite shot nearly to POA.

So, I'm set--local shop has the 50rd boxes of this stuff for $21.99. Will have to get a few more to load out mags w/...
Link Posted: 4/6/2006 9:46:03 AM EDT
I have a 1:9 twist 16" bushmaster that will stabilize 75 TAP and 75gr BHBlue box out to 500yards. I will try to take pictures of the 500 yards targets next time I get to the range. I have seen no "keyholing". I have read that button rifling is difficult to get exact twist rates with. This means that some 1:9 are really 1:9.x which could explain why some 1:9s do worse than others with "heavy" loads.

"The exact twist of a buttoned barrel is also unpredictable. The button tends to slip in the barrel so what set out to be a 12 inch twist may end up as a 12.5 inch twist. This is not a problem if the twist is uniform, but if it varies down the barrel - particularly if it slows - then like as not, it will not shoot."
www.border-barrels.com/articles/bmart.htm
Link Posted: 4/6/2006 10:30:41 AM EDT
[Last Edit: 4/6/2006 10:31:27 AM EDT by FMJ]
my range is only 200 yards plus BERM about 220yards

with my bushmaster shorty 1/9 twist I hit tin cans just fine! and 200 yards no key holes?

wich is good enough for me! 77gr and 75gr
Link Posted: 4/6/2006 1:00:24 PM EDT
The person you are conversing with is sadly mistaken on many points.

Perhaps just as sad is that fact that, even when presented with valid factual information, he will still probably not believe you.

The 75gn Hornady OTM (NOT the poly tipped 75gn) was designed with 1/9 twist barrels in mind to compete against the slightly longer bearing surfaced/heavier 77gn Sierra. Hornady recognized that many more barrels are available in 1/9 than the tigher 1/8 or tighter required to RELIABLY stabilize the 77gn SMK, and their solution was the 75gn offering, slightly lighter but with a shape that is conducive to a competative BC and a bearing surface that would be RELIABLY stabilized in a 1/9 twist barrel.

Many report that their 1/9 will stabilize a 77SMK, but just as many report extreme accuracy issues, especially beyond 200yds. NO ONE with a 1/9 or tighter reports any problems stabilizing the 75 OTM, other than the ocasional unhappiness with the fact that in a gun that will stabilize both, the 77s often shoot tighter groups.

Where you see most of the controversy clouding the waters is that the SMK will shoot to a higher potential group wise than the 75s in many guns and they gloss over the fact that the 75 will also shoot in ALL 1/9 guns.

Tom
Link Posted: 4/6/2006 1:14:21 PM EDT
Some people have no problems with 75 grain ammo in 1/9 barels and others have serious stability issues, especially with barrels with heavy copper fouling.
Link Posted: 4/6/2006 2:14:12 PM EDT
I have shot my 75 Hornady reloads to 435 yards with no keyhole in a 1X9" RRA 16". Never tired 77s as I plan to convert to all 1X7" in the near future.

Link Posted: 4/6/2006 2:49:00 PM EDT
I believe that "someone" SC is talking about is me.

I have had problems with bullet weights in excess of 62 gr. in a 1/9 barrel. If Hornady has designed a round that will out perform the lighter rounds, I'd truly like to see it.

Banzai, you have no idea what I would say if presented with valid factual information, obviously you don't know me - no offense taken.

Does anyone have a couple of boxes of this load that they can shoot at 200 and 300 yards our of a 1/9 barrel?

I would be really interested to hear what happens. I would be even more interested to hear how it is that Hornady has been able to overcome the instabilities that similar bullet weights have produced in the past.

I want to make it clear that I have not fired this particular round and I was making observations based on what I have seen in the past with similar bullet weights out of the 1/9 barrel.



Link Posted: 4/6/2006 3:21:39 PM EDT
The performance of a so-called 1:9 ROT barrel performance will depended on where it falls in the tolerance range in the manufacturing of the barrel. If it falls on the faster side (closer to the 1:8), then it will most like work with the 75gr. On the other end of the tolerance, it will most likely not stabilze it.
That is one reason it has been posted, try it. If you want a 100% with the 75+gr loadings, then it is 1:8 or 1:7. Pick your own poison.
Link Posted: 4/6/2006 3:27:45 PM EDT
[Last Edit: 4/6/2006 3:29:41 PM EDT by JJREA]

Originally Posted By Gemeinschaft:
I believe that "someone" SC is talking about is me.

I have had problems with bullet weights in excess of 62 gr. in a 1/9 barrel. If Hornady has designed a round that will out perform the lighter rounds, I'd truly like to see it.

Banzai, you have no idea what I would say if presented with valid factual information, obviously you don't know me - no offense taken.

Does anyone have a couple of boxes of this load that they can shoot at 200 and 300 yards our of a 1/9 barrel?

I would be really interested to hear what happens. I would be even more interested to hear how it is that Hornady has been able to overcome the instabilities that similar bullet weights have produced in the past.

I want to make it clear that I have not fired this particular round and I was making observations based on what I have seen in the past with similar bullet weights out of the 1/9 barrel.






It's been done before many times. But not by me so I have no hard data to back it up. I have a hard time believing you have problems with the heavier than62 grainers. Are you sure your twist is a 1/9? What kind of rifle do you have? Have you tried the 68's and 69's?
Link Posted: 4/6/2006 3:28:53 PM EDT

Originally Posted By Banzai:
NO ONE with a 1/9 or tighter reports any problems stabilizing the 75 OTM, other than the ocasional unhappiness with the fact that in a gun that will stabilize both, the 77s often shoot tighter groups.

Where you see most of the controversy clouding the waters is that the SMK will shoot to a higher potential group wise than the 75s in many guns and they gloss over the fact that the 75 will also shoot in ALL 1/9 guns.

Tom



The 75 does not shoot in all 1/9 barrels and that is from direct personal experience not Internet mythology. Even when it does work with 1/9 barrels, the accuracy is often less than optimal for match ammo.

Some 1/9s will fire it OK, some won't. Based on my experience, the longer, cleaner and newer your 1/9 barrel is, the better it is likely to shoot the 75s.
Link Posted: 4/6/2006 4:27:30 PM EDT
Let me begin by saying that I do NOT have a statistically relevant sample, however, between a buddy and I, we have three 16" 1X9 Colts and one 20" 1X9 Colt. All have shot their best groups ever at 300 yds with 75 gr .223 specification TAP. Temperatures were in the 30's (F) on all range days, and instrumental velocities from the 16" guns were 2550fps, give or take. Group sizes were consistently 1 to 1.5 MOA at 300 yds, with enough sub-MOA groups to be scary. This stuff shoots folks.
POI has been within the margin for error at 300 between 55gr XM193 and the 75 gr TAP. It shoots higher than the 69gr ammo in our guns at that range. The ballistics calculations say the TAP should track within less than an inch between the muzzle and 300 (zero range) with the 55 gr, and hit 50% harder based on kinetic energy.
The Hornady tech rep I spoke to said 1X9 was fine down to a 16" length. I did not believe him, but based on that encouragement began what became a very succesful experiment for me, YMMV.
I have never checked the twist on my Colts, they say 1X9, but tolerances and nominal dimensions may vary among manufacturers. Mine work, I would suggest trying yours so you do not miss out on good ammunition.
That said, new barrels for me have been and will be 1X7 for 5.56/.223 until something better comes along in widespread usage. I started down the heavy bullet path in the 1980's and lost my way for a while. 55 grain bullets make for cheap practice these days.
Link Posted: 4/6/2006 4:35:16 PM EDT
SHooting some heavier loads in my 1-9 has not worked well for me.

I can shoot the 68/69 grain match offerings and not get much accuracy, 2-3 inches at 100yds.

My lighter loads can get well under 1" with alot of regularity.

TXL
Link Posted: 4/6/2006 4:36:03 PM EDT
Hornady 75gr Vmax bullets were 50% keyholes at 50yrds from my 1/9.
Link Posted: 4/6/2006 7:11:59 PM EDT
I have a few rifles that I have shot heavy rounds through with ill results.

My SHTF carbine has a Bushmaster 16" M4 profile upper on it. My other rifles have had similar results.

It has just been my expereince that in order to shoot accurately with a round heavier than 55gr. you need a different twist.

When I get back home, I am determined to get some of these rounds and test them myself.
Link Posted: 4/6/2006 9:06:12 PM EDT
[Last Edit: 4/6/2006 9:09:30 PM EDT by DevL]
A different twist than what? The 1/9 twist is the perfect match to 62 grain ammo, specifically M855. The M855 was desigend to be fired in a 1/9 barreled Minimi. That said individual barrels like different loads. Yours may love some 55 grain loads over 62 grain loads. Also remember the 75 grain Hornady bullet today is different that it was a few years ago. They changed the profile of the bullet and its shorter now. The 75 grain bullet used to be longer than the 77 grain bullet. You cannot compare an early 2000 75 grain bullet's stability to a current one, they are different bullets.
Link Posted: 4/7/2006 7:16:38 AM EDT

Originally Posted By 20iner:
Hornady 75gr Vmax bullets were 50% keyholes at 50yrds from my 1/9.





Thats very hard to belive?
Link Posted: 4/7/2006 7:21:50 AM EDT

Originally Posted By DevL:
A different twist than what? The 1/9 twist is the perfect match to 62 grain ammo, specifically M855. The M855 was desigend to be fired in a 1/9 barreled Minimi. That said individual barrels like different loads. Yours may love some 55 grain loads over 62 grain loads. Also remember the 75 grain Hornady bullet today is different that it was a few years ago. They changed the profile of the bullet and its shorter now. The 75 grain bullet used to be longer than the 77 grain bullet. You cannot compare an early 2000 75 grain bullet's stability to a current one, they are different bullets.





AGREE the 1/9 and the SS109 BULLET!

My Bushmasters 1/9 thinks SANTA BARBRA SS109 IS MATCH GRADE AMMO?

Also I found that my M4 LMT 14.5 1/7 twist

When ZERO with the SS109 BULLET at 50 yards has the same POI as the 77gr Blue box ?

Maybe because its ABOUT the same length?
Link Posted: 4/7/2006 9:02:00 AM EDT

Originally Posted By SC-Texas:
Anyone out there ever used a 1:9 barrel with this 75grn ammo at 200+ yards?



If you go back in the Archives you'll see a thread on some testing I did on this subject.

My 14.5" 1:9 twist Bushmaster M4 barrel would make 8" groups (5-10 shot groups IIRC) at 200y with Black Hills 75gr OTM.

That same carbine could produce 5 shot groups ranging from 2" to 4" at 100y with the same ammo.

I have not tested at 300. But as there isn't much effect on rotational velocity as the bullet goes down range I have no reason to suspect rounds would suddenly start tumbling.
Link Posted: 4/7/2006 9:31:39 AM EDT
So basically, inside the house, you could shoot it suppressed out of a 1:9 10.5" bbl and it wouldn't matter would it?
Link Posted: 4/7/2006 10:54:13 AM EDT

Originally Posted By SC-Texas:
So basically, inside the house, you could shoot it suppressed out of a 1:9 10.5" bbl and it wouldn't matter would it?



Nobody said any such thing. As long as your barrel will stabilize it say at 10y then yes you won't have a problem. If it's keyholing at that range then look for something else.
Link Posted: 4/7/2006 1:45:32 PM EDT
Sorry, I forgot we were in serious ville.
Link Posted: 4/7/2006 1:50:25 PM EDT
Just recived 1k black hills 75gr today. All boxs say on them these rounds are for 1x9 ot tighter barrels.
Link Posted: 4/7/2006 3:28:51 PM EDT
tag
Link Posted: 4/7/2006 3:47:51 PM EDT

Originally Posted By FMJ:

Originally Posted By 20iner:
Hornady 75gr Vmax bullets were 50% keyholes at 50yrds from my 1/9.





Thats very hard to belive?




I don't know, is it?

Link Posted: 4/7/2006 4:01:36 PM EDT
I o find it hard to beleive. But I'll take him at his word since I wasn't there.
Link Posted: 4/7/2006 4:07:39 PM EDT

Originally Posted By SC-Texas:
I o find it hard to beleive. But I'll take him at his word since I wasn't there.



All bbls are different.

Link Posted: 4/7/2006 7:39:08 PM EDT

Originally Posted By FMJ:

Originally Posted By 20iner:
Hornady 75gr Vmax bullets were 50% keyholes at 50yrds from my 1/9.





Thats very hard to belive?



That's because they don't make 75 grain vmax's. I'm not sure what he's talking about. And if they were amaxes, someone had to handload them and they're not supposed to fit in a magazine.
Link Posted: 4/7/2006 7:44:57 PM EDT

Originally Posted By JJREA:

Originally Posted By FMJ:

Originally Posted By 20iner:
Hornady 75gr Vmax bullets were 50% keyholes at 50yrds from my 1/9.





Thats very hard to belive?



That's because they don't make 75 grain vmax's. I'm not sure what he's talking about. And if they were amaxes, someone had to handload them and they're not supposed to fit in a magazine.



Perhaps I'm mistaken, they were Hornady, 75 gr, moly coated. I thought the box said Vmax.

TAP rounds are vmax bullets, no? 75gr tap is 75gr vmax, no?
Link Posted: 4/8/2006 2:29:32 AM EDT

Originally Posted By 20iner:

Originally Posted By JJREA:

Originally Posted By FMJ:

Originally Posted By 20iner:
Hornady 75gr Vmax bullets were 50% keyholes at 50yrds from my 1/9.





Thats very hard to belive?



That's because they don't make 75 grain vmax's. I'm not sure what he's talking about. And if they were amaxes, someone had to handload them and they're not supposed to fit in a magazine.



Perhaps I'm mistaken, they were Hornady, 75 gr, moly coated. I thought the box said Vmax.

TAP rounds are vmax bullets, no? 75gr tap is 75gr vmax, no?





75gn TAP is their BTHP Match bullet. They also make a another 75gn called the A-Max i think. It is the one that can not be loaded to mag length. I think the V-MAx(varmit bullet) only goes to 60gn.


Link Posted: 4/9/2006 5:30:10 AM EDT

Originally Posted By 20iner:

Originally Posted By JJREA:

Originally Posted By FMJ:

Originally Posted By 20iner:
Hornady 75gr Vmax bullets were 50% keyholes at 50yrds from my 1/9.





Thats very hard to belive?



That's because they don't make 75 grain vmax's. I'm not sure what he's talking about. And if they were amaxes, someone had to handload them and they're not supposed to fit in a magazine.



Perhaps I'm mistaken, they were Hornady, 75 gr, moly coated. I thought the box said Vmax.

TAP rounds are vmax bullets, no? 75gr tap is 75gr vmax, no?



Yes, they make 55 and 60 grain vmaxes. And they load them in their TAP line. The 75's are BTHP's.

That said, are you sure of your twist? What kind of a rifle was it?
Link Posted: 4/9/2006 4:36:26 PM EDT
I have shot 77g and 75g with great results out of a 1/9 Wilson 20" non-chrome lined.

Tight groups at 100 and loud whacking sounds on steel at 350 and 400 yards.
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