Gel testing 300 AAC BLACKOUT

[rsilvers]

Just a survey of existing bullets that people may normally wonder about. It is clear that some new bullets should be developed to be optimal for this velocity range.

http://www.silencertalk.com/300AAC/300%20AAC%20Blackout%20test%20results%2006OCT2010. pdf

[alorton]

I can't get the link to work. Just loads a blank page.

As for new bullets, that is the single biggest hope I have for what the 300 BLK can do for me. If it generates enough interest to spur development of bullets for this velocity window I'll be happy as a clam.

ETA: Nevermind on the link, I tried it once I got to work where I have a better connection and it worked fine.

[sharky47]

It worked better for me when I right click - save as.

Thanks for posting the info!

[rsilvers]

Here is a screen grab of the poll pre-gelatin testing. It will be interesting to see if it changes with the gel testing out.

http://img89.imageshack.us/img89/3748/polld.jpg

[buffetdestroyer]

Thanks for the test rsilvers.

I think the Hornady 110 actually surprised me with the results. I may have to look into those for hunting.
________
TOYOTA COROLLA E90 SPECIFICATIONS (http://www.toyota-wiki.com/wiki/Toyota_Corolla_E90)

[alorton]

Some of my beliefs about low velocity .308 bullets were confirmed and some dispelled. I have long thought the 110gr V-Max would make an excellent room entry CQB bullet at lower velocities and this testing seems to confirm that. At .308 speeds it underpenetrates but at the lower velocity it fragments less violently, giving adequate penetration, and did better against barriers than I expected. That is a good home defense or room entry weapon.

The 110gr TSX performed exactly as I expected with one exception, it penetrated less than I thought it would. Regardless, it penetrated plenty and performed well and consistently as they are known to do. This would be a good barrier round to compliment the 110gr V-Max.

The 125gr TNT disappointed me with the long neck length before expansion. The 125gr Nosler BT penetrated alot more than I expected and also had a longer neck length. The Remington 125gr Accupoint faired better than I expected with short neck length, good expansion, and acceptable penetration.

Thanks for posting the results. I look forward to the information this cartridge development will bring us all. I hope to see the subsonic testing soon. Also, you mentioned not using the 110gr Varminter due to the tip. I've used them quite a bit and they feed fine in my AR. I expect similar performance as the V-Max.

[320pf]

Actually, I think that all of the 125 grain bulllets, including the "varmint" type, performed well. The 130 grain bullet also did well. The "neck" of the wound profile would put the bullet right in the middle of the chest cavity of the target... right were you want all of the expansion to occur. The gel test pretty much confirm what I have observed in the world. At the velocities of the 300 Blackout (pick your favorite wildcat name here) the 308 varmint bullets behave like their heavier "Big Game" brothers.

The Barnes TSX bullets behaved as advertised.


320pf


Some of my beliefs about low velocity .308 bullets were confirmed and some dispelled. I have long thought the 110gr V-Max would make an excellent room entry CQB bullet at lower velocities and this testing seems to confirm that. At .308 speeds it underpenetrates but at the lower velocity it fragments less violently, giving adequate penetration, and did better against barriers than I expected. That is a good home defense or room entry weapon.

The 110gr TSX performed exactly as I expected with one exception, it penetrated less than I thought it would. Regardless, it penetrated plenty and performed well and consistently as they are known to do. This would be a good barrier round to compliment the 110gr V-Max.

The 125gr TNT disappointed me with the long neck length before expansion. The 125gr Nosler BT penetrated alot more than I expected and also had a longer neck length. The Remington 125gr Accupoint faired better than I expected with short neck length, good expansion, and acceptable penetration.

Thanks for posting the results. I look forward to the information this cartridge development will bring us all. I hope to see the subsonic testing soon. Also, you mentioned not using the 110gr Varminter due to the tip. I've used them quite a bit and they feed fine in my AR. I expect similar performance as the V-Max.

[alorton]

The average human chest is something like 8-10" thick so the "center" would be 4-5" and the neck length on a few of those gel blocks was that long. I prefer to see neck lengths of under 2" on a tactical rifle, but perhaps we're thinking of terminal effects on different types of "critters".

Actually, I think that all of the 125 grain bulllets, including the "varmint" type, performed well. The 130 grain bullet also did well. The "neck" of the wound profile would put the bullet right in the middle of the chest cavity of the target... right were you want all of the expansion to occur. The gel test pretty much confirm what I have observed in the world. At the velocities of the 300 Blackout (pick your favorite wildcat name here) the 308 varmint bullets behave like their heavier "Big Game" brothers.

The Barnes TSX bullets behaved as advertised.


320pf

[320pf]

You are correct about the average straight on chest thickness. However, I would ask to to stand in front of a mirror and mock-up like you are shooting a rifle at your image. What would be the entry angle to the target? Most likely not straight on but more side-to-side and quartering. The average chest width is about 14-17 inches without considering the thickness of an arm. An arm would add about another 4-5 inches. Hence why I think that the penetration is about right.

Now for four legged critters the average chest thickness is 8-18 inches... Now think of a quartering shot which would add more apparent thickness.

Here is a summary of the gel data.
The Speer TNT
Figure 10&11 max cavitation depth 3.1"-13.6"
Figure 13&14 2029fps max cavitation depth 7.1" – 18.5"
Figure 16&17 2190fps max cavitation depth (7.1 – 18.5 typo??) ~3.1-~12.6 measured from the figure.

Nos125
Figure 19&20 2011fps max cavitation depth 2.7 – 14.8
Figure 22&23 2026fps max cavitation depth 4.3 – 18.1
Figure 22&23 2152fps max cavitation depth 0.8 – 18.1

320pf

[TCCrewchief76]

Why the omission of the 110 Sierra Varminter?

[rsilvers]

Nose cavity too large to reliably feed in an AR15.

[alorton]

I certainly see your point. The 7.1" neck length concerns me, but doesn't disqualify the bullet either. I was just hoping for something a little faster opening. Ideally it would have a very short neck but still show cavitation out to the same depth it did in this test. That said, when working with less energy from the start (this is a 300 BLK, not a .308) you don't have the luxury of excess energy to work with.

While most shots aren't necessarily straight on, I prefer a bullet that will work well in that situation as well as with the full sideways shot. So if you go with an average chest thickness of 9" and width of 20" (including an arm) you would want the largest amount of cavitation to occur between 4.5" and 10" and ideally would run from about 2" to 12". The Barnes TSX performed the best in that regard with cavitation starting essentially immediately but continuing through most of the bullet's travel (shot 1: 0.0"-14.6", shot 2: 0.0"-14.8", shot 3: 0.0"-15.1"). The Barnes didn't have the largest permanent crack diameter, but performed very consistently, which they are known for.

I was surprised that the 125 Nosler penetrated as much as the Barnes. That said, I think it shows some promise in this velocity window. I had high hopes for it as well since it is known for performing well at lower velocities and is a favorite of handgun hunters for that reason.

In the end, I'm grateful that this testing was done and I learned from it.


You are correct about the average straight on chest thickness. However, I would ask to to stand in front of a mirror and mock-up like you are shooting a rifle at your image. What would be the entry angle to the target? Most likely not straight on but more side-to-side and quartering. The average chest width is about 14-17 inches without considering the thickness of an arm. An arm would add about another 4-5 inches. Hence why I think that the penetration is about right.

Now for four legged critters the average chest thickness is 8-18 inches... Now think of a quartering shot which would add more apparent thickness.

Here is a summary of the gel data.
The Speer TNT
Figure 10&11 max cavitation depth 3.1"-13.6"
Figure 13&14 2029fps max cavitation depth 7.1" – 18.5"
Figure 16&17 2190fps max cavitation depth (7.1 – 18.5 typo??) ~3.1-~12.6 measured from the figure.

Nos125
Figure 19&20 2011fps max cavitation depth 2.7 – 14.8
Figure 22&23 2026fps max cavitation depth 4.3 – 18.1
Figure 22&23 2152fps max cavitation depth 0.8 – 18.1

320pf

[alorton]

Nose cavity too large to reliably feed in an AR15.

I saw that you posted this before when asked about the Sierra Varminter and I have to ask, have you tried it and had problems or did you exclude it because of the appearance of the nose?

I have shot quite a few through my 300/221 AR and they feed fine. I've not heard of others having trouble either. I prefer the V-Max, but as far as I know the Varminter will function and would be worth testing IMO.

[rsilvers]

The thing is, if someone had one failure per 90 rounds they probably would not even report it. We really need it good enough for LE or self defense use. I have not tested this exact bullet but did have problems with an open nose on a another bullet, so decided this style of bullet was better for bolt gun use.

[rsilvers]

Photo:

http://media.photobucket.com/image/sierra%20110%20varminter/GuyMiner/hunting%2520photos/equipment/IMG_1027.jpg

[alorton]

The thing is, if someone had one failure per 90 rounds they probably would not even report it. We really need it good enough for LE or self defense use. I have not tested this exact bullet but did have problems with an open nose on a another bullet, so decided this style of bullet was better for bolt gun use.

I can certainly understand wanting to go with the highest level of reliability. I've put about 100 of them through my 300/221 upper, so not a large enough sample size to claim they would be reliable enough for LE work (I'm an LEO, trainer and armorer by the way).

Have you looked into the Speer Hot-Cor or talked with Barnes about bringing back the 100gr .308" bullet? Given the results of the 125gr GameKing and the Hornady 130 SP something of similar construction but a little lighter might perform very well and Barnes' bullets love velocity so the 100gr bullet they used to make for the .30 Carbine would probably be just the ticket. I missed the boat on the .30 Carbine bullets from Barnes, they went out of production before I got into the 300/221 but if this cartridge goes mainstream there might be enough incentive for them to bring it back and maybe even tweak it a bit for the AR platform.

[rsilvers]

The 100 Barnes is a larger nose cavity. Barnes does have a special run of 110 TSX which were manufactured in a way to lower the expansion velocity threshold and I believe those are the best Barnes bullets for this velocity range that are very reliable in an AR15. Call Barnes and order the 110 TSX with the lower expansion threshold. If you can spend that much it would be best to try to get 1000 at a time in case they run out.

[alorton]

The 100 Barnes is a larger nose cavity. Barnes does have a special run of 110 TSX which were manufactured in a way to lower the expansion velocity threshold and I believe those are the best Barnes bullets for this velocity range that are very reliable in an AR15. Call Barnes and order the 110 TSX with the lower expansion threshold. If you can spend that much it would be best to try to get 1000 at a time in case they run out.

Thanks for the tip, I was unaware of the special run.

ETA: In your gel testing, was it the standard TSX or this low velocity version?

[buffetdestroyer]

Rsilvers, is there a chance of a new bullet to be developed due to these results? Something that is compatible for military use, but expands or tumbles well at midrange velocities that would increase lethality without overpenetration?

Maybe something similar to Federal's Expanding Full Metal Jacket bullets?
________
TRIUMPH TRIDENT T150 (http://www.cyclechaos.com/wiki/Triumph_Trident_T150)

[rsilvers]

We feel that no ideal bullet exists for this velocity range and so are designing two new custom bullets. One for military use that is optimal penetration and barrier blind and another that is for hunting, LE, and self defense.

[Expatriot]

Why the omission of the 110 Sierra Varminter?


The very short bullet creates feeding issues. I didn't see any problems related to the large nose cavity. The issues I saw were related to the OAL of the loaded round. The bullet is so short that it is difficult to load to a decent OAL where it will feed reliably.

The jam I found most often was the base of the round diving into the mag and the round ending up jammed vertically between the bolt and the barrel extension.

[Dannix]

OAL influencing feeding I understand, but what are you guys referring to concerning "nose cavity"?

Nose cavity too large to reliably feed in an AR15.

The very short bullet creates feeding issues. I didn't see any problems related to the large nose cavity. The issues I saw were related to the OAL of the loaded round. The bullet is so short that it is difficult to load to a decent OAL where it will feed reliably.

The jam I found most often was the base of the round diving into the mag and the round ending up jammed vertically between the bolt and the barrel extension.
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I'm personally eying the Remington 110gr 30Carbine softpoints.
http://media.midwayusa.com/ProductImages/Medium/10000/1601456621.jpg
(Pic courtesy of MidwayUSA)

Would the OAL with this be too short with this bullet in 300AAC? If so, would it be OK in the 7.62x40? I'd love to get the same performance out of an AR that I can get with my 30-30.

[rsilvers]

That bullet seems worth trying. I am getting the 110 Sierra tested. Some deer were just shot with them and there was complete penetration.

[alorton]

They were talking about the 110gr Sierra Varminter which has a large hollow point compared to most rifle bullets. If loaded to a short OAL it may have some feeding issues in a 300W/300BLK AR. The longer case of the 7.62x40 (by about .2") won't allow it to be loaded short enough to cause problems as far as I know.

The .30 carbine bullet you pictured will most likely work in both but you may have to load long in the 300W/300BLK like the 110gr Sierra or you may not. You would just have to try them.

[alorton]

That bullet seems worth trying. I am getting the 110 Sierra tested. Some deer were just shot with them and there was complete penetration.

More info please. I'd like to know how they perform and at what velocity.

[HUNTER2]

Diamondback Bullets have been working on some 220 gr. rbt bonded and non with with jackets that petal back and polimer ball that work very well on deer size game. Clearwater Custom Bullets are making some soft lead tips rnfb 220's for TC users that get the job done very well. Have not tried in bolt guns. Doesn't mean 100% conclusive test, but all bullets exited with quarter size holes. Longest distance run was 40 yds. with entering front sholder and exiting the stomach cavity. All of these make an impact sound that has to be heard to be believed. 5 deer and counting with youth season coming up again. Lehigh makes some good ones also. Two deer less than 6 feet. Complete penetration and major damage. Work good in single shot and bolt. Don't know about AR.. All have worked better than the 240's that we hope tumble. Hope this info helps. These companies have been working hard to find something that works.

[Dannix]

That bullet seems worth trying. I am getting the 110 Sierra tested. Some deer were just shot with them and there was complete penetration.
What fps?

Why I'm considering the Remington 110gr softpoint 30Carbine bullet:
http://ammo.ar15.com/project/Misc_Images/DocGKR/M1CarbineWP.jpg
http://ammo.ar15.com/project/Self_Defense_Ammo_FAQ/index.htm#.30%20carbine
The fact that it's so much cheaper than other rifle bullets scratched 6mmto7mm-.233 wildcats off my list.

alorton, I'm basically wrapping everything around this bullet. So I'll probably go 7.62x40 if it's too iffy with the 300AAC. I was leaning towards the 7.62x40 anyway...I just don't know if chamber dimensions can be had. Reloading dies are the easy part.

[Dannix]

That bullet seems worth trying. I am getting the 110 Sierra tested. Some deer were just shot with them and there was complete penetration.
What fps?

The Remington 30Carbine 110grn JSPs:
http://ammo.ar15.com/project/Misc_Images/DocGKR/M1CarbineWP.jpg
http://ammo.ar15.com/project/Self_Defense_Ammo_FAQ/index.htm#.30%20carbine


alorton, I'm wrapping everything around this bullet as they are much cheaper than most other rifle bullets. So I'll probably lean towards the 7.62x40 then....if chamber dimensions can still be had.