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Think of the TMK like you would MK262. Except it doesn't need to yaw. And it has a much higher BC. And it's effective down to several hundred FPS slower.
If you use MK262, there is almost literally ZERO downside to switching to the TMK round, and many upsides. If you want barrier-blind performance, this is not even the correct type of round to be considering. |
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I had my first hunting kill with this round, 175 yard shot on a raccoon. Round went in his back as he was climbing a dirt mound, no exit, dead where he was hit.
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FYI..... Sierra is now taking orders for the bullets.... ( for reloading )
https://www.sierrabullets.com/products/new.cfm The link also shows the fantastic BC's of these bullets.... BONUS !! 155gr TMK has a better BC then the 175gr SMK... faster shooting and better BC .... win win. |
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Thanks for link!
G1 BC is now listed for 4 velocity ranges. .420 @ 2400 fps and above .415 between 2400 and 2000 fps .395 between 2000 and 1750 fps .380 @ 1750 fps and below If you dont have a G7 BC, Ive had good luck with JBM software by estimating the time of flight for each velocity threshold and weighting the average BC accordingly. For the 175 grain SMK in a 308 you end up with .490 instead of .505 G1 and that corresponds very close to what I get on the range out to 1000 yards. Using this method for the .420 flight times, the average comes down to 0.410 for muzzle to 600 yards (about 1750 fps). The remaining time of flight from 600 to 1000 is about equal, .837 seconds. Apriximate time of flights are .234 seconds muzzle to 200 yards at .420 BC. .274 seconds at .415 BC 200 to 400 yards. .322 seconds at .395 BC from 400 to 600 yards. (.830 total for average of .410). And .837 seconds from 600 to 1000 yards at .380 BC. That gives you an average BC over 1000 yards of .395. Still dandy. This was calculated for 3200 feet absl and bore 3 inches below scope. It is interesting to note that the bullet spends as much time at .380 BC from 600 to 1000 yards as it does from muzzle to 600. Come ups with a G1 BC of .395 are 36.7 MOA for 1000 yards, about like a 308 match bullet. At .420 it would be 34.8. That is not a big difference on paper but 20 inches at 1000 yards, enough to miss my big 24 inch steel plate. So these calculations do help get on target with first few rounds of ammo. It still crosses finish line supersonic. 1162 fps. (1116 speed of sound at 3200 feet asl). Using this same method the new 175 grain tipped SMK comes down from .545 to a real world .505 average since it spends most of its time of flight at .495 BC. 36 MOA vs 34.5 MOA. (At 2600 fps). Still a worthwhile improvement over the 175 SMK. |
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Hmmm, my 1/12 .308 is really picky with 175gr. loads. That 168 TMK might be the ticket.
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Quoted:
Any new gel tests for this round? View Quote I've seen tests down to 1900 fps, and the results are still quite impressive. I've also sent some to two youtube gel testers. Hopefully something will get posted in the next month. From the gel shots I have seen, it has replaced 75gr 5.56 TAP as my home defense ammo. |
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would it be safe to assume that the 69gr tmk will perform similarly?
Just asking because the extra velocity might be useful for those of us with short barrels, as long as the fragmentation threshold is the same. |
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Quoted:
FYI..... Sierra is now taking orders for the bullets.... ( for reloading ) https://www.sierrabullets.com/products/new.cfm View Quote 150% more expensive than OTM 77 SMK currently available at Powder Valley. |
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Quoted: I am on an extended hunting trip in MS. Have put (3) BHA 5.56MM 77GR. TMKs into whitetail at ranges from 10 ft. to 400 yds. which is really stretching any .223/5.56MM loading. All shots were successful but the shot which best reflects the TMK bullet's potential for SD/HD was a broadside shot at 125 yds. from a 16" 1x7 Colt placed right behind the shoulder and mid-body on a doe. The entrance wound was typical of all .223/5.56MM wounds I have seen, looking like an oversized ice pick puncture. The TMK bullet expanded immediately resulting in a 3" hole INTO the body cavity. The bullet produced a 2.5" exit hole on the opposite side of the body cavity and exited. Internal organs in the bullet's path were reduced to little more than a red soup. Detailed pics will be linked/posted when I get back home around the 29th. View Quote Congrats Leid! In for details and pictures. I'm going back to WV later this month, so hopefully I see something to shoot at. My trip earlier this month was a bust |
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Can't believe I only heard about these for the first time a few days ago.
Now to try and get some shipped over |
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Quoted:
150% more expensive than OTM 77 SMK currently available at Powder Valley. View Quote View All Quotes View All Quotes Quoted:
Quoted:
FYI..... Sierra is now taking orders for the bullets.... ( for reloading ) https://www.sierrabullets.com/products/new.cfm 150% more expensive than OTM 77 SMK currently available at Powder Valley. The .060 increase in BC is a pretty significant difference. |
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Looks like they are doing the same thing with the 69 grain version. Any reason the 69 grainer wouldn't behave similar? Would probably be a better option for the common 1 in 9" barrels.
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Just a note, that a 50 and a 200 zero are really the same in that they cross the sight line twice, while a 100 does not.
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Quoted:
Looks like they are doing the same thing with the 69 grain version. Any reason the 69 grainer wouldn't behave similar? Would probably be a better option for the common 1 in 9" barrels. View Quote It should be a good choice, and with a BC of .375 is comparable to the original 77SMK, but will be capable of a couple of hundred FPS more |
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Jeff,
any plans on a version using the 69 gr TMK? https://www.sierrabullets.com/store/product.cfm/sn/7169/224-dia-69-gr-Tipped-MatchKing-TMK |
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Quoted:
I am on an extended hunting trip in MS. Have put (3) BHA 5.56MM 77GR. TMKs into whitetail at ranges from 10 ft. to 400 yds. which is really stretching any .223/5.56MM loading. All shots were successful but the shot which best reflects the TMK bullet's potential for SD/HD was a broadside shot at 125 yds. from a 16" 1x7 Colt placed at the rear of the shoulder and mid-body on a doe. The entrance wound was typical of all .223/5.56MM wounds I have seen, looking like an oversized ice pick puncture. The TMK bullet expanded immediately resulting in a 3" hole INTO the body cavity. The expanding TMK bullet/bullet fragments/high velocity bone fragments produced a 2.5" hole on the opposite side of the body cavity on exiting. Internal organs in the bullet's path were reduced to little more than a red soup. Detailed pics will be linked/posted when I get back home around the 29th. EDIT to add Pics: Click to Enlarge Pics. If you want to see further detail, click the (+) on the upper right of the enlarged pic. View Quote Nice kill. How did the 400 yd wound look? Did you see any fragmentation at that range? |
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It was a spine shot with instant results on a big 8pt. following a hot doe right past the limp 400yd. flag on my rifle range.
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leid,
Great report. How was expansion at 400 yards? Dead is dead with perfect shot placement. But curious how it did on hard target like spine. Congrats! |
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I don't want to put too many hunting details in the thread and get OFF TOPIC of SD/HD. Both the other (2) TMK shots were on the same big 8 point. The first shot at 400yds. went into the spine which dropped him instantly. By the time I approached him, he was about bled out but managed to weakly raise his head. The second TMK shot at just 10ft. went into the back of the neck just below the head which turned him off like a switch. Here is the interesting part on these TMK shots as it applies to SD/HD: Neither the spine shot nor the neck shot passed thru. I have used 5.56MM 62GR. & 70GR. TSX on several similar shots. The TSXs have always passed thru even on spine shots of whitetail in the 250lb. class. At this point, I am of the opinion that a TMK does not pose near as much danger of a pass-thru for SD/HD as a TSX or bonded bullet. Unfortunately, I did not have time to dig the TMK bullets out before dropping the carcass off at the processor. Had to get to a last minute funeral in Port Gibson.
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mcanto.
We added a 556 69 TMK with our 2015 new products, along with a 556 70 grain GMX, a 308 168 TMK and a 338 250 Accubond. Jeff |
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Jeff, not to derail the thread but I asked this question almost two years ago. I was looking for the one and done round that would be good for SD but also expand reliably at longer ranges. The barrier blind bullets always seem to give up some temporary stretch cavity performance when designed for glass, plywood and steel minimum penetration. I wanted a round that is barrier blind, offers a decent temporary stretch cavity performance and provides the required minimum penetration through all mediums. I also want the extended range of the better, heavy OTM's with their higher ballistic coefficients. It seems like the 62 grain TTSX would fit this bill nicely, since I have been told by Barnes it can reliably expand down to 1700 fps, which with the tipped BC of .294 puts the minimum expansion velocity out past 450 yards. If the barrier performance is on par I think this would actually best the Black Hills 50 gr TSX since its range is limited due to the low BC giving up velocity incredibly fast.
Any plans for some BH 5.56 62gr Tipped TSX? |
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Swat-dude,
No current plans to load the 62 TTSX. I do recognize your points that it would be a good round. Right now we have the 62 TSX which is really good terminally, and absolutely exceptional accuracy wise, and recently introduced. That round actually outshoots the 77 in my MK12.I will keep it in mind though. thanks for the input. Jeff. |
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Swat_dude,
I recognize your points, but right now there are no plans to introduce the 62 TTSX. The 62 we have is great terminally and extremely accurate. It actually outshoots the 77 OTM in my MK12. For long range retained velocity and expansion it will be hard to beat the 77 TMK. I will keep your suggestion in mind. Thanks, jeff |
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Sorry for the double post,I thought first one failed to go through. Jeff
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Has anyone purchased the TMK bullets? I haven't seen the bullets alone for sale yet.
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mcanto,
One thing to keep in mind,is we shoot gel at about 12 feet. Velocity is still pretty high, which tends to decrease penetration. The TMK design also eliminates any neck before the Temp Cavity starts, which tends to limit total penetration. All bullets have a window of optimum performance. One way of looking at it is the window for the TMK is moved down range a bit. It is good to study what each bullet does, and chose the performance that meets your needs. I am not skilled at sharing gel pics, but am willing to share gel pics from our testing or, if we don't have one on file to answer a question, we can do a test and share it as lab time is available. Jeff |
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Quoted:
mcanto. We added a 556 69 TMK with our 2015 new products, along with a 556 70 grain GMX, a 308 168 TMK and a 338 250 Accubond. Jeff View Quote When can we expect to see the 70gr GMX ammo to hit retailers? |
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Jeff, first off, thanks for taking the time.
Why did you guys opt for the GMX, and not the TSX, seeing as how you load TSX's already? Not that it is an issue, as the GMX are great bullets as well. As for the 69 TMK, it may not reach the 12'' mark, but man that wound cavity looks monstrous! Or is it just me not looking at it right? Either way, good job Sierra! |
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Mr. Hoffman, re: 70gr gmx 5.56,
-what velocity should one expect from this load out of a 16" carbine? -what is the velocity "floor" for good expansion (not just a slight nose deformation)? -will it be available in sealed cases (neck/primer)? The reason I ask, is that I have found simple an hour or so in a glass of water clumps powder with tsx and gmx ammo. This is because the monometal bullets have no "give" when crimped, and the case neck to bullet shank seal seems less ideal than with lead core projectiles. This should be a great barrier blind round that follows mk262 mod 1 drop compensators and holds pretty close! Re: 77tmk....I think this is a helluva load for urban home defense!!! Ty for it! |
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Has anyone tried the Black Hills 77 TMK in a 1-8 twist yet?
Any 600 - 1,000 yard come ups available? Thanks! |
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Hatr40 and 12-gauge,
We have great relationships with both Barnes and Hornady, and we make sure we use bullets from both companies. There are number of other companies doing the Barnes TSX (and it is a great bullet). No one else is doing the Hornady. We have tested both and find the bullets are equal performers.We chose to load the Hornady. According to Hornady the floor velocity is around 2100 fps. This compares pretty well to the Barnes TSX bullets. We will be doing testing to confirm the min velocity the bullet expands at. You can expect around 2800-2850 fps from a 16" barrel with the BHA 5.56 70 GMX. Regarding sealing, you make a good point that is is tougher to get a good seal with homogenous copper or guilding metal bullets compared to lead core, for the reason you mention. After your email we put 70 grain GMX (no neck seal) into a cup of water for 16 hours. Our GMX did not take on any water, but that does not mean there is no concern,as it could happen with less neck tension or crimp. We will put some thought into waterproofing the case mouths. We have the capability. It is a separate process and added labor, but may be worth it for the extra value to the user. Fortunately most ammo is not ever exposed to submersion for 16 hours (Time we tested our ammo at) and expected to work. Thanks for your input. Jeff |
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Quoted:
Hatr40 and 12-gauge, We have great relationships with both Barnes and Hornady, and we make sure we use bullets from both companies. There are number of other companies doing the Barnes TSX (and it is a great bullet). No one else is doing the Hornady. We have tested both and find the bullets are equal performers.We chose to load the Hornady. According to Hornady the floor velocity is around 2100 fps. This compares pretty well to the Barnes TSX bullets. We will be doing testing to confirm the min velocity the bullet expands at. You can expect around 2800-2850 fps from a 16" barrel with the BHA 5.56 70 GMX. Regarding sealing, you make a good point that is is tougher to get a good seal with homogenous copper or guilding metal bullets compared to lead core, for the reason you mention. After your email we put 70 grain GMX (no neck seal) into a cup of water for 16 hours. Our GMX did not take on any water, but that does not mean there is no concern,as it could happen with less neck tension or crimp. We will put some thought into waterproofing the case mouths. We have the capability. It is a separate process and added labor, but may be worth it for the extra value to the user. Fortunately most ammo is not ever exposed to submersion for 16 hours (Time we tested our ammo at) and expected to work. Thanks for your input. Jeff View Quote Respectfully, I would pay for it. The ammunition is already "premium" in performance and price. The use of sealed case-necks would make it unique in a good way, in all the kingdom, so to speak. I have searched all over for a TSX/GMX load that is sealed at both ends. NOONE loads it. Also, every single round of Hornady TAP LE 5.56 GMX I have put in a cup of water for 1 hour has had clumped powder when the bullet was pulled. I have not tested the Barnes 50gr TSX I have in just a cup of water, but the Hornady has pretty good neck tension being a 5.56 LE loading, and I can see striations on the bullet left by the case neck when I use my impact puller to take them down. Anyway, I don't have crazy amounts of purchasing power to use to push this agenda, but I'm really hoping that you will pop for the extra cost/labor and seal the case mouths. If it's not offered, you will get at least one phone call from someone asking if you will do a run of 1-2000 with sealed case necks just for him, because...asking can't hurt ! |
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Now they are avaiable for order on Sierrra website
77gr MK Tipped bullets |
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12_gauge,
Respectfully, you are absolutely right. The 5.56 GMX and TSX loads are premium in both price and performance, and the waterproofing is a valuable addition, especially in light of their increased susceptability to moisture intrusion due to their solid metal core bullet design. We will start waterproofing all 5.56mm GMX and TSX loads. No price increase. Thanks for your input. Jeff |
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Quoted:
12_gauge, Respectfully, you are absolutely right. The 5.56 GMX and TSX loads are premium in both price and performance, and the waterproofing is a valuable addition, especially in light of their increased susceptability to moisture intrusion due to their solid metal core bullet design. We will start waterproofing all 5.56mm GMX and TSX loads. No price increase. Thanks for your input. Jeff View Quote Boom! Someone just became a customer for life. |
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Quoted:
12_gauge, Respectfully, you are absolutely right. The 5.56 GMX and TSX loads are premium in both price and performance, and the waterproofing is a valuable addition, especially in light of their increased susceptability to moisture intrusion due to their solid metal core bullet design. We will start waterproofing all 5.56mm GMX and TSX loads. No price increase. Thanks for your input. Jeff View Quote Wow. I am not often taken aback by a company's stellar level of customer service. Consider me taken aback. Well done Black HIlls. |
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Quoted:
Who are you, Jeff? Are you with Black Hills, or Sierra? View Quote View All Quotes View All Quotes Quoted:
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All, We are running 556 77 TMK right now. It might take a week or two to hit dealer shelves. Re min velocity, we have tested as low as 1920 fps and it is still performing well. We will continue testing to see where it stops.. . Jeff Who are you, Jeff? Are you with Black Hills, or Sierra? .. It's Jeff Hoffmann like the owner Link |
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I'm a huge fan of Black Hills and buy it almost exclusively when I can find it. I'd rather support the folks of South Dakota more than some of those communistic states back east. Besides they make a great product for a great price. What more can you ask for?
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Mr. Hoffman, I realize that the sealing of case necks is a "rolling change" going forward. However, I wanted to ask, does this mean that all 70gr GMX that makes it to market will be sealed, or will identifiers be added to boxes that are? How can the consumers who are interested in purchasing the sealed ammunition be assured that that is what is in the box vs. stock the merchant had before the change is implemented?
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Has anyone at Black Hills tried the 77 TMK at 800 or 1000 yards to confirm come ups and if it remains supersonic?
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I wonder if Sierra will make a cannelured version available for reloading???
I'm not really a cannelure would be necessary anyway. |
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Regarding water testing, a cup doesn't exactly simulate real world. Pressure at depth is the enemy of a bullet case. As far as the most likely encountered water resistance needed, I would say submerged the rounds 4 feet under water for 30 minutes. Most folks that would wind up getting their weapon and ammo wet would have at least their head above water and the ammo wouldn't remain submerged for that long as I am guessing the first instinct would be to get your weapon/ammo out of the water and get it dried out. This, of course, doesn't apply to Navy Seals that might be diving with their weapon, in which case the ammo should probably be tested at a depth of 30 to 60 feet for 1.5 hours.
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