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DocGKR
03-09-2013, 04:23 PM
We recently tested some newer supersonic loadings in 6.8 mm and .300 BLK.

http://www.tridentconcepts.org/alumni/Portals/0/NTForums_Attach/139154048171.jpg

6.8 mm Federal 90 gr Gold Dot JSP at 2604 f/s
BG: Pen=12.3", RD=0.62", RL=0.26", RW=83.6gr
AG: Pen=13.0", RD= 0.54", RL=0.22", RW=75.0gr
http://i459.photobucket.com/albums/qq319/DocGKR/Fed6890grGDJSPBGAG_zps8c94883e.jpg
Shot into BG above one through AG

6.8 mm SSA 85 gr TSX OTM at 3024 f/s
BG: Pen=18.5", RD=0.56", RL=0.41", RW=85.3gr
AG: Pen=17.0", RD= 0.58", RL=0.39", RW=65.4gr
http://i459.photobucket.com/albums/qq319/DocGKR/68SSA85TSXBG_zps8476f6b4.jpg
Shot into BG depicted; AG wound profile not shown, but nearly identical

6.8 mm SSA 100 gr Accubond PT at 2680 f/s
BG: Pen=16.0", RD=0.48", RL=0.47", RW=83.5gr
AG: Pen=18.5", RD= 0.48", RL=0.41", RW=78.1gr
http://i459.photobucket.com/albums/qq319/DocGKR/68SSA100grAccubondBGAG_zps0864a520.jpg
Shot into BG above one through AG

.300 BLK Rem 110 gr TTSX at 2250 f/s
BG: Pen=20+", RD=0.54", RL=0.50", RW=107.6gr
AG: Pen=17.0", RD= 0.58", RL=0.22", RW=65.4gr
http://i459.photobucket.com/albums/qq319/DocGKR/300BLKRem125grTTSXBGAG_zpsa45bd717.jpg
Shot into BG above one through AG

.300 BLK Rem 125 gr SMK OTM at 2236 f/s
BG: Pen=20+", projectile not recovered
http://i459.photobucket.com/albums/qq319/DocGKR/300BLKRem125grSMKOTMBG_zps701e47bf.jpg
bilobed yaw cycle with curvature and no hyper-expansion/fragmentation, very much like the 5.45x39mm M74/5N7 FMJ

.300 BLK Rem UMC 115 gr FMJ/CTFB at 2242 f/s
BG: Pen=20+", RD=0.30", RL=1.14", RW=112.6gr
http://i459.photobucket.com/albums/qq319/DocGKR/300BLKRem115grFMJBG_zps5acf9424.jpg
very long, broad single cycle yaw cycle with curvature and no hyper-expansion/fragmentation

Interestingly, the .300 BLK Rem UMC 115 gr FMJ/CTFB offers the longest single yaw cycle that we have ever seen.

Both 6.8 mm and .300 BLK are excellent cartridge choices for individuals and organizations requiring a caliber larger than .223, that functions reliably in an AR15. At this time, the major .300 BLK loadings all penetrate deeper than the 12-18" ideal range for LE use; in contrast there are multiple 6.8 mm loads which currently meet this criteria, along with offering acceptable intermediate barrier capability.

http://i459.photobucket.com/albums/qq319/DocGKR/68vBLKexpanding_zps2bc6082d.jpg
Top row: .300 BLK Rem 110 gr TTSX; below the dime are the 6.8mm SSA 85 gr TSX, Federal 90 gr GD JSP, and SSA 100 gr Accubond PT. Right column in BG, left column through automobile windshields.

While the .300 BLK TTSX is a superb loading for military and hunting purposes, penetration is a bit deeper than ideal for LE use. An LE optimized .300 BLK loading engineered with proper feed profile, 12-18" penetration depth, that is blind to barriers will be a great addition.
http://i459.photobucket.com/albums/qq319/DocGKR/BLKTTSXvFMJ_zps895cdd6b.jpg
.300 BLK Rem 110 gr TTSX vs. .300 BLK Rem UMC 115 gr FMJ/CTFB in BG

MolonLabe416
03-09-2013, 07:27 PM
Great information. Thanks again for keeping us up to date on ammo advances.

Cheers to a great weekend for all.

Odin Bravo One
03-09-2013, 07:57 PM
Doc,

any plans on looking into the various SubSonic offerings? Specifically the big, slow, heavy 200's or 220's?

Thanks for sharing......as always, your expertise is an invaluable resource for the board, and shooting community in general.

DocGKR
03-09-2013, 08:32 PM
The current subsonics using the heavy SMK's just go in, yaw 180 deg, then exit base forward. Nothing very exciting--penetration is very deep; definitely not appropriate for LE use. Once some of the proposed expanding subsonic projectiles reach fruition, then we will appropriately test them.

Odin Bravo One
03-09-2013, 09:58 PM
Thanks Doc.

Looking forward to your findings. Not that the coyotes care........but I find it useful.

LittleLebowski
03-10-2013, 07:58 AM
Since 5.45 was mentioned, any plans of ever testing the Hornady VMax 5.45?

Jay Cunningham
03-10-2013, 08:19 AM
Since 5.45 was mentioned, any plans of ever testing the Hornady VMax 5.45?

I would find this interdasting.

DocGKR
03-10-2013, 10:55 AM
We have a box to test that was graciously donated. The problem has been finding time to do so, since no agencies use this caliber. I suspect it will act like any other .223/5.56 mm projectile of similar weight and construction--for example the .223 Hornady 55 gr TAP.

Chuck Haggard
03-11-2013, 01:19 PM
We have a box to test that was graciously donated. The problem has been finding time to do so, since no agencies use this caliber. I suspect it will act like any other .223/5.56 mm projectile of similar weight and construction--for example the .223 Hornady 55 gr TAP.

While it wasn't a calibrated gel test, I found that the Hornady .223 and 5.45 TAP bullets acted the same in water filled milk jugs, in both fragmentation and penetration.

broberts001
07-09-2013, 04:29 AM
DocGKR,

In regards to the 300 Blackout results, looks like the Rem 115gr and the Rem 125gr SMK did much more tissue damage than the Barnes TTSX. Seem counter to my understanding of those rounds ...

Or am I missing something?

-Bryan

Nightvisionary
07-12-2013, 03:26 AM
DocGKR,

In regards to the 300 Blackout results, looks like the Rem 115gr and the Rem 125gr SMK did much more tissue damage than the Barnes TTSX. Seem counter to my understanding of those rounds ...

Or am I missing something?

-Bryan

Hopefully Doc will have some thoughts as to the terminal effects of the Remington loads. The Barnes TAC TX (30811) bullet penetrates deeply and performs well against barriers. However if you take a look at the 300 Blk gel test performed at Brass fetcher the Tac TX had one of the smallest wound channels of all the bullets tested. The average area in square inches of the expanded Barnes bullet was 0.17 with 20.1 inches of penetration. By comparison the Sierra 125 grain Pro Hunter delivered 0.31 square inches with 18.4 inches of penetration. The Pro Hunter also performed well against barriers.

Rich
10-01-2013, 05:18 AM
How short of a barrel can one go and still have good results using the 300BLK

DocGKR
10-01-2013, 09:52 AM
8" with the .300 BLK 110 TTSX

md8232
10-07-2017, 01:15 AM
Doc
It’s been 4 years since your last post. Has the 300 BO been improved to your standards?

Velo Dog
10-07-2017, 11:50 AM
Has the 300 BO been improved ?

The 300 BO stinks!!!! ;)

DocGKR
10-07-2017, 04:19 PM
The .300 BLK 110 gr TTSX is a very good loading that offer excellent terminal performance for hunting at 300 yds and in. For LE and defensive use, penetration is a bit on the deeper side--be sure to be aware of backstop and potential down range hazards.

Robinson
10-08-2017, 08:59 PM
The 300 BO stinks!!!! ;)

Is this a serious post?

Velo Dog
10-14-2017, 11:00 AM
Is this a serious post?


https://www.youtube.com/watch?v=RCwzdzA-01Q

Velo Dog
10-14-2017, 11:01 AM
;) I take body odor very seriously :cool:

Mike C
10-14-2017, 03:14 PM
The .300 BLK 110 gr TTSX is a very good loading that offer excellent terminal performance for hunting at 300 yds and in. For LE and defensive use, penetration is a bit on the deeper side--be sure to be aware of backstop and potential down range hazards.

Doc did you test the 120gr stuff as well?

Velo Dog
10-14-2017, 08:45 PM
http://www.hornadyle.com/assets/site/files/300-Blackout.pdf

https://www.luckygunner.com/300-blackout-110-grain-gmx-hornady-full-boar-20-rounds

Velo Dog
10-14-2017, 09:22 PM
300 AAC Blackout is abbreviated 300 Blk

http://www.saami.org/specifications_and_information/publications/download/Z299-4_ANSI-SAAMI_CFR.pdf

Mike C
10-15-2017, 04:33 PM
http://www.hornadyle.com/assets/site/files/300-Blackout.pdf

https://www.luckygunner.com/300-blackout-110-grain-gmx-hornady-full-boar-20-rounds

Looks promising. I'd love to see an option that passes all FBI protocols that wasn't tipped. I know it's not the same and I currently rely on the Barnes stuff but I've had a 556 gun tied up by a tipped projectile that came off during the feeding process in the barrel extension which stopped the bolt from locking completely. Still makes me nervous about them even though it has only ever happened once. Thanks for posting that Velo Dog. Always good to have options.


(edited due to the fact I just realized all the intermediate stuff was up there I just scrolled past it too quickly)

El Cid
10-15-2017, 05:51 PM
Looks promising. I'd love to see an option that passes all FBI protocols that wasn't tipped. I know it's not the same and I currently rely on the Barnes stuff but I've had a 556 gun tied up by a tipped projectile that came off during the feeding process in the barrel extension which stopped the bolt from locking completely. Still makes me nervous about them even though it has only ever happened once. Thanks for posting that Velo Dog. Always good to have options.


(edited due to the fact I just realized all the intermediate stuff was up there I just scrolled past it too quickly)

My impression as a non-scientific observer is that LE appears to be moving toward tipped projectiles because they do better with auto glass. We've even seen this with handgun rounds (Feds going with G2 in 9mm and Critical Duty in 40). I love the TSX in rifle and handguns but they can deform and collapse or tear off their petals going through windshields.

Mike C
10-15-2017, 07:50 PM
My impression as a non-scientific observer is that LE appears to be moving toward tipped projectiles because they do better with auto glass. We've even seen this with handgun rounds (Feds going with G2 in 9mm and Critical Duty in 40). I love the TSX in rifle and handguns but they can deform and collapse or tear off their petals going through windshields.

I would agree, near where I am from originally there are quite a few departments that issued TAP ammo. I do believe that the local PD where I live now does as well. But there are some that have moved away from it. Particularly the lighter weight loadings I believe. I do know that my brothers agency switched not too far back after an OIS. If I recall correctly it was a form of TAP ammo from a standard length AR through a side window of a car. Ammo didn't preform as expected and did not incapacitate the aggressor. The projectile fragmented completely after hitting the window. Tempered glass seems to still be a bitch for the most part.

I really like the idea of tipped ammo when looking at ballistic coefficients and soft targets but I still don't have a warm and fuzzy with them with intermediate stuff. I know there is data to the contrary and I should just get over it. I definitely like the TTSX and the like more, even though they see to sheer in instance you've noted they still seem to get adequate penetration with minimal deviation. At least from the non-sciency backyard tests I've done. I would absolutely love to have a 300 BLK option from Federal like their LE308TT2 in 300, or the Speer Gold Dot/Federal MSR like loadings. I really like the 110-123gr range projectiles for the 300 and based on all the charting and actual ballistic data I have it seems to be the most accurate, flat shooting and hard hitting. Having a bonded bullet in that range would be the shit in my uneducated opinion but I do still think the ballistic tip has it's place though, specifically in large urban areas where concerns for over penetration might be an issue. I hope Speer/ATK gets on the 300 BLK train.

DocGKR
10-15-2017, 10:58 PM
The presence or absence of a polymer tip is generally irrelevant to penetration depth. What matters is bullet construction. Something like T-TBBC, T-TSX, T-GMX, Scirocco, Accubond are typically all going to offer adequate penetration compared to a fragile, thin jacketed match or varmint bullet with polymer tip.

Mike C
10-16-2017, 12:41 AM
The presence or absence of a polymer tip is generally irrelevant to penetration depth. What matters is bullet construction. Something like T-TBBC, T-TSX, T-GMX, Scirocco, Accubond are typically all going to offer adequate penetration compared to a fragile, thin jacketed match or varmint bullet with polymer tip.


Doc thank you for clarifying. In all your testing and observation have you ever encountered/observed any issues with feeding or reliability with polymer tipped projectiles? Is my concern about reliability unreasonable? I’ve never observed issues with 300 black but have with Hornady Tap Urban. I think it was a 40 or 55 grain projectile.

Thank you again. For the good info in the above post.

DocGKR
10-16-2017, 10:50 AM
TAP Urban is an extremely fragile varmint type projectile which really has no place in LE duty use. Polymer tip damage is rare, but can happen, especially in poorly built weapons with marginal function.

Mike C
10-16-2017, 03:12 PM
TAP Urban is an extremely fragile varmint type projectile which really has no place in LE duty use. Polymer tip damage is rare, but can happen, especially in poorly built weapons with marginal function.

I confirmed it was Tap urban ammo that I had this issue with, it was in a dept. issued Bushmaster, I believe you are absolutely spot on about the build quality and function. I think I can put my concerns to rest. I also took the time to reread your .308 post on duty loads. Damn was there a ton of amazing information in there. I can't believe that I forgot about that thread, I should have looked it over again when I started to look at .300 BLK projectiles and ammo. The GMX bullet looks very promising for my uses and is much cheaper than the Barnes offering. I wish I hadn't so readily dismissed the load due to poor assumptions on my part about its construction and it being polymer tipped.

Velo Dog thanks again for posting that info.

Doc, if you have a second to answer could you tell us if you already have, or if you have plans to test the 110gr GMX load? Looking at the factory publication Velo Dog posted it looks like it would meet all the requirements for a duty load as the Barnes could with a little less of a risk of over penetration. I believe that your opinion some time ago was the the Barnes offering was the only offering that had acceptable performance, has your opinion since changed with some of the newer ammo or is there insufficient data to formulate an new opinion? Thank you.

DocGKR
10-16-2017, 03:32 PM
The 110 gr GMX works very well and is certainly acceptable for .300 BLK duty use.

PearTree
10-16-2017, 04:10 PM
The 110 gr GMX works very well and is certainly acceptable for .300 BLK duty use.I may have missed it, but do you have a list of doc approved .300 BLK? I didn't see it stickied and last I remember you said no current ammunition was suitable for duty use. I and some of my co-workers are kicking around the idea of a duty .300 BLK sbr.

DocGKR
10-17-2017, 10:16 AM
Right now the best are likely to be 110 gr GMX and 110 gr TTSX.

PearTree
10-17-2017, 10:42 AM
Do you still advocate a proper 5.56 with quality ammunition over .300 BLK? Or is the ammo you mentioned reached a level of performance where the .300 BLK is now a viable option for LE?

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Sensei
10-20-2017, 11:34 AM
Certainly not Doc, but the Barnes TTSX and especially this GMX appear to offer noticeably better gel performance than anything the 5.56 offers when shot from barrels <11.5 inches. That includes the newer all copper 5.56 rounds that do pretty good from sub-11.5” barrels. That GMX load seems to open up beautifully and penetrate just out to 18” after safety glass and metal barriers.

I’m at the point now where the only thing keeping me from always using a 300blk SBR is ammo availability. When traveling far away from home or resupply, I’m using a 5.56 SBR. Otherwise, it’s 300blk for me when within driving distance of my stash.

Oukaapie
10-20-2017, 03:20 PM
Anything new in the land of 6.8 worth mentioning?

Tokarev
11-14-2017, 04:48 PM
I've been playing with an AR wildcat called the 277 Wolverine. It is similar to the 300BLK and 7.62X40 and is based off the 223Rem case but uses 6.8/.277 bullets. It can be loaded to supersonic or subsonic velocities and I've had no problem getting a 150gr bullet to cycle subsonic suppressed.

I've been quite pleased with two bullets when loaded to supersonic speeds. These are the Nosler 90gr bonded and the Speer 90gr Gold Dot. I can push these to about 2,400fps from a 12.5" barrel and am getting 16-18" of penetration in my block of 10% gel from Clear Ballistics. Guys running 16" or 18" barrels have reported muzzle velocities closer to 2,600-2,700fps with the 90gr bullets.

The down side to both the Nosler and the Speer is price. They're expensive and the Gold Dot can be hard to find. But Starline is now making brass for the 277WLV and Speer is supposed to be working with a commercial loader/reloader to provide Gold Dots for "factory" ammo.

Photos of 90gr Gold Dot recovered from gel.

https://uploads.tapatalk-cdn.com/20171114/128775590cd03ae5e09eb3b858c82994.jpg

Tokarev
11-15-2017, 06:44 AM
If for no other reason, the 90gr Gold Dot 277WLV info should be useful for guessing terminal performance of the 6.8 at longer range.

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4gallonbucket
11-15-2017, 11:44 AM
If for no other reason, the 90gr Gold Dot 277WLV info should be useful for guessing terminal performance of the 6.8 at longer range.

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I love the idea of the 277 Wolverine. I happen to have a 7.62x40wt and it’s great, but bullet selection is limited as well — waiting on a 105-120 grain gold dot or Nosler BSB in 30 cal.

Question for you is, when comparing the 6.8spc and the 277W— they’re using the same projectiles— about how many inches of barrel does the 277w “cost” to get same velocities? In other words, if a 12.5” 6.8spc has a muzzle velocity of “x” with a 90gr gold dot, how long would a Wolverine barrel need to be to match that?


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Tokarev
11-15-2017, 02:09 PM
Question for you is, when comparing the 6.8spc and the 277W— they’re using the same projectiles— about how many inches of barrel does the 277w “cost” to get same velocities? In other words, if a 12.5” 6.8spc has a muzzle velocity of “x” with a 90gr gold dot, how long would a Wolverine barrel need to be to match that?



Gosh I don't know. We can assume that the 277 is a "better" choice as barrels get shorter since there's less powder to burn. At what point does the 6.8 peter out? Does it still provide good performance from a 12" barrel?

Anyway, from previous loading experience, it isn't terribly difficult to push a 90gr bullet to about 3,000fps in the 6.8SPC from an 18" barrel.

For comparison, I have seen a few people pushing 2800fps with a 90gr TNT in the Wolverine using Shooters World Blackout powder from an 18" barrel. I haven't used SW Blackout powder nor do I have an 18" barrel so I haven't personally verified. But that's pretty darned impressive if true.


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Tokarev
11-15-2017, 04:42 PM
I found this old thread over on 6.8 Forum with some 12.5" and 16" chrono data.

http://68forums.com/forums/showthread.php?12231-SSA-Ammo-Chrono-Data-16-quot-amp-12.5-quot (http://68forums.com/forums/showthread.php?12231-SSA-Ammo-Chrono-Data-16-quot-amp-12.5-quot)

ranger
11-15-2017, 05:27 PM
I would really enjoy seeing some updated discussion on the 6.8 SPC - it has certainly been "quiet". I frequent the 6.8SPC and the 6.5G forums and you have to sort through a lot to get useful info. I have a 14.5 6.8 with a weld/pinned AAC suppressor mount that I like and a 6.5 Grendel 20 inch set up for longer range. Because I have the 6.8 and 6.5 (and 5.56), I never went down the 300BO path.

DocGKR
11-16-2017, 12:39 AM
6.8 mm works very well from a 12" barrel and decently (better than 5.56mm) from an 8" barrel.

Tokarev
11-16-2017, 05:55 AM
Here are a couple things of interest.

https://www.starlinebrass.com/brass-cases/68-SPC/

https://www.starlinebrass.com/brass-cases/277-Wolverine/

https://www.starlinebrass.com/brass-cases/300--Blackout/

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Tokarev
11-22-2017, 08:46 AM
Another bullet another gel test.

This is Sierra's 90gr varmint hollow point loaded with Hodgdon CFE BLK. Average is right about 2,350fps from my 12.5" barrel.

I fired two bullets. One into bare gel and one through FBI clothing. The bare gel penetrated 17" and had a retained weight of 56.9gr. The bullet fired through clothing penetrated 16" and retained 53.4gr of its weight.

In both cases the bullet started to expand at about 2" into the block and caused the most damage about 4.5" in. The "wound" cavity continued to about 7" then the bullets settled down and continued on into the gel. Both cavities are about 2" wide at the wisest point.

The bullet fired into bar gel had a maximum diameter of nearly .52" while the bullet through clothing came out at just under half an inch.

https://uploads.tapatalk-cdn.com/20171122/e7bdd681fcd0dfd787d574d0fc71c20b.jpghttps://uploads.tapatalk-cdn.com/20171122/00a64815bac6b6f19d9b0217d4191f04.jpghttps://uploads.tapatalk-cdn.com/20171122/65a4366303f558468725c4030317edc2.jpg




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Shawn Dodson
11-23-2017, 12:15 AM
The term "wound cavity" is nebulous and misleading. There are two different types of cavities: 1) permanent and 2) temporary. The temporary cavity may or may not damage tissues - this is why it's necessary to accurately describe the wounding effects you're observing.

5pins
11-23-2017, 07:42 AM
Its my understanding that, as a general rule, the temporary cavity with handgun rounds is not important but with high-velocity rifle rounds, it has some meaning.

Shawn Dodson
11-23-2017, 11:43 AM
The problem with term "wound cavity" is it implies all the disruption visible in ordnance gelatin is destroyed tissue when in many situations, handgun cartridges especially, the large cracks simply record and depict the temporary cavity.

Tokarev
11-23-2017, 11:44 AM
No intention to deceive and I apologize if that's the way it appears.

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Shawn Dodson
11-23-2017, 12:02 PM
Fackler used the term "permanent disruption" to describe tissue permanently damaged by the temporary cavity or the combination of damage produced by both the temporary cavity and bullet fragmentation. He was careful to describe the mechanisms so others wouldn't misinterpret the wounding effects.

Tokarev
01-22-2018, 11:46 AM
Interesting that Hornady is apparently going to offer 277 Wolverine brass soon. This means factory brass will be available from two different sources.

Brian T
01-23-2018, 03:40 PM
DocGKR,

Hornady offers a 110gr Vmax and a 190gr "SUb-X, both load in .300BLK. Any plans to test either?

I ask because I complete my .300BLK pistol, Project: Krush Groove, because who deosnt love the 80's.

Aries144
04-10-2018, 02:59 AM
I'm not the Doc, but just in case you were unaware, here's a test someone else did that included the 110gr hornady Vmax in bare gel, through autoglass, and through a door panel (http://www.silencertalk.com/300AAC/300%20AAC%20Blackout%20test%20results%2006OCT2010. pdf).

My pedestrian takeaway from the above linked test is that the 110 Vmax looks good if you aren't concerned with barrier performance. Kind of like a 75gr OTM in 5.56.

I too await DocGKR's testing of, and comments on, those two rounds.

Tokarev
04-11-2018, 03:44 PM
Hornady offers a 190gr "SUb-X, in .300BLK.


Here's my informal test for the 190gr Sub-X:

https://pistol-forum.com/showthread.php?t=29927


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Rockey
04-11-2018, 03:56 PM
I just posted this in the other thread but a local company offers an all copper subsonic round that will perform much better and doesn't cost much more than the Hornady:

https://moamunitions.com/products/300-blackout-200-grain-subsonic-expanding-round

Aries144
04-16-2018, 01:13 PM
I just posted this in the other thread but a local company offers an all copper subsonic round that will perform much better and doesn't cost much more than the Hornady:

https://moamunitions.com/products/300-blackout-200-grain-subsonic-expanding-round

I've read one example of a slotted monolithic HP round that apparently came apart and destroyed a suppressor. I'd like to see some testing performed with these in some very fast twist barrels, like the 1:5 in SIG's Rattler and sub 16" .300blk MCX barrels.