300 AAC expansion/velocity from 8.2" barrel?

[WS6]

Does the 300AAC fragment, or expand, when using the tipped (non Barnes) bullets at these velocities?

Also, the impact will be, as I understand, well under 2,000fps unless it happens at contact range. Is it going to look like a rifle hit something, or like a .357 magnum from a long-barreled revolver hit something? What I am asking---is TSC a viable mechanism from this cartridge on say, a 75 yard impact from an 8.2" SBR? If so, down to what velocity/distance?

What exactly is the expansion that the 110 Barnes is getting from the 8.2" barrel? I have read that it moves out at about 19XX fps.

Anyway, my main question is, is this a very good pistol, or a mediocre rifle, or what, regarding effect of TSC and other wounding mechanisms associated with a "rifle"? It's kindof "on the line" based on what has been said by Dr. Roberts in the past about velocity.

[DocGKR]

An 8" .300 BLK is an MP5 or MP7 replacement for CQB; not a GP carbine for 0-300 yd use. The TTSX will definitely expand at CQB distances and a ways beyond. As always, use the right tool for the job at hand.

[WS6]

An 8" .300 BLK is an MP5 or MP7 replacement for CQB; not a GP carbine for 0-300 yd use. The TTSX will definitely expand at CQB distances and a ways beyond. As always, use the right tool for the job at hand.

Will the 110 ttsx cause more traumatic wounds at 25 yards from an 8.2" sbr than would a 50gr tsx from a 10.5" sbr in 5.56?

[kenndapp]

i am very interested to hear if a 110gr ttsx at sub 2000fps impact velocities behaves more like a rifle round or a pistol round.

apparently it WILL expand at those low velocities......out to 300 yards from a 9". but my guess is that the bullet is behaving more like .30 pistol round than anything else.




so bullet performance is great. great expansion and at great range from an sbr to boot. but weather or not you get anything more than a .30 pistol type wound is beyond me.

[BigLarge]

Will the 110 ttsx cause more traumatic wounds at 25 yards from an 8.2" sbr than would a 50gr tsx from a 10.5" sbr in 5.56?

Interested in thoughts on this...

[WS6]

i am very interested to hear if a 110gr ttsx at sub 2000fps impact velocities behaves more like a rifle round or a pistol round.

apparently it WILL expand at those low velocities......out to 300 yards from a 9". but my guess is that the bullet is behaving more like .30 pistol round than anything else.
[IMG]http://img861.imageshack.us/img861/9338/300blk300small.jpg[IMG]

[IMG]http://img577.imageshack.us/img577/7161/300aacblkbarriersummary.jpg[IMG]

so bullet performance is great. great expansion and at great range from an sbr to boot. but weather or not you get anything more than a .30 pistol type wound is beyond me.

It looks to me like near IDENTICAL performance nearly to the 110gr TSX from an M1 Carbine. Dr Roberts said of the M1 that it "had a TSC slightly larger than a heavy expanding .357 magnum hunting round". He further states that it MIGHT tear inelastic tissue like brain, liver, etc.

Sounds to me like a quality handgun JHP when it is fired from an 8-9" barrel with some loads.

https://www.m4carbine.net/showthread...6&highlight=M1

Further, all of Dr. Roberts' responses to questions like this

hey guys, i have a custom 10.3" pistol length gas system barrel being made in .300 blackout and im wondering, how does the terminal ballistics out of a SBR compare to that of the 5.56 out of the same barrel length?

result in answers like this:

300BLK is a great MP5SD replacement, with substantially more versatility than a 9mm SMG. In an SBR configuration 300BLK has far better terminal ballistics than 4.6mm and 5.7 mm PDW's. Likewise 300BLK has the potential for better terminal performance and intermediate barrier penetration than 5.56 mm from SBR's. In supersonic form from 16" barrels 300BLK offers terminal ballistics on par with 7.62x39mm or lower weight .30-30's. It should be a very good LE caliber with the right ammunition. The key is getting appropriate .30 cal bullets produced that are designed to work at the lower 300BLK velocities instead of .308/.30-06/.300WM velocities. So far we have not seen any optimized 300BLK loads.

Between his opinion on the M1 Carbine, and his answers when asked about the 300 AAC, a picture begins to form:

It's a great round, but it doesn't behave like a great RIFLE round once it dips below about 1950fps or so. No-matter what type of projectile it is, the velocity just isn't there from the 8.2"-9.2" barrels to perform like a rifle for very far, if at all, depending on the load.

[kenndapp]

It looks to me like near IDENTICAL performance nearly to the 110gr TSX from an M1 Carbine. Dr Roberts said of the M1 that it "had a TSC slightly larger than a heavy expanding .357 magnum hunting round". He further states that it MIGHT tear inelastic tissue like brain, liver, etc.

Sounds to me like a quality handgun JHP when it is fired from an 8-9" barrel with some loads.

https://www.m4carbine.net/showthread...6&highlight=M1

Further, all of MD Roberts' responses to questions like this result in answers like this:


Between his opinion on the M1 Carbine, and his answers when asked about the 300 AAC, a picture begins to form:

It's a great round, but it doesn't behave like a great RIFLE round once it dips below about 1950fps or so. No-matter what type of projectile it is, the velocity just isn't there from the 8.2"-9.2" barrels to perform like a rifle for very far, if at all, depending on the load.

that's what i was thought. but what side of the ballistic scale does 300blk fall in when comparing it to high velocity handgun rounds and low velocity rifle rounds? when it comes down to it......would you say 300 blk while successfully filling sub-gun rolls, is little more than a glorified magnum pistol round? if does truly compare to the m1 type rounds (great info in link, thanks.) i would defiantly think of 300blk closer to a smg type weapon than a true rifle.

[WS6]

that's what i was thought. but what side of the ballistic scale does 300blk fall in when comparing it to high velocity handgun rounds and low velocity rifle rounds? when it comes down to it......would you say 300 blk while successfully filling sub-gun rolls, is little more than a glorified magnum pistol round? if does truly compare to the m1 type rounds (great info in link, thanks.) i would defiantly think of 300blk closer to a smg type weapon than a true rifle.

Reading between the lines, this is exactly what Dr. Roberts seems to be saying.

[S. Galbraith]

It looks to me like near IDENTICAL performance nearly to the 110gr TSX from an M1 Carbine. Dr Roberts said of the M1 that it "had a TSC slightly larger than a heavy expanding .357 magnum hunting round". He further states that it MIGHT tear inelastic tissue like brain, liver, etc.

Sounds to me like a quality handgun JHP when it is fired from an 8-9" barrel with some loads.

https://www.m4carbine.net/showthread...6&highlight=M1

Further, all of Dr Roberts' responses to questions like this result in answers like this:


Between his opinion on the M1 Carbine, and his answers when asked about the 300 AAC, a picture begins to form:

It's a great round, but it doesn't behave like a great RIFLE round once it dips below about 1950fps or so. No-matter what type of projectile it is, the velocity just isn't there from the 8.2"-9.2" barrels to perform like a rifle for very far, if at all, depending on the load.

I used to shoot a lot of M1 carbine a while back. It seems like a nice little carbine, until I decided to do some long range shooting. I could hit the AR 500 silhouette at 300m with no problem.....just needed to compensate for elevation and the mediocre accuracy. However, a 1/4" sheet of plywood at 400m told me just how much that pistol bullet lost velocity. I fired a 5-shot group of some Winchester 110gr FMJ loads into that sheet of plywood and walked out to check the results. I had 5 holes, in a large grouping, but not unreasonable. No keyholing. However, behind the plywood I found 3 of the bullets lying on the ground up against the berm. There was a fresh rain a couple of days before, so that ground was firm and undisturbed. The bullets had lost so much velocity and stability at that range that the bullets didn't have enough momentum and energy do do anything beyond punching through the plywood. Perhaps those old war stories from Korea were correct regarding the .30 Carbine. Now, as a PDW for engagements meant for under 100m, it seems to work pretty well as I have taken a few white tail with SP loads. However, even 100m is pushing it with good broad side shots that are close to the heart and lungs. A couple of white tails that I have shot at over 75yrds have run a considerable distance before dropping. I may have to chrono some .30 Carb loads at 100m just to see how much performance is lost.

[WS6]

I used to shoot a lot of M1 carbine a while back. It seems like a nice little carbine, until I decided to do some long range shooting. I could hit the AR 500 silhouette at 300m with no problem.....just needed to compensate for elevation and the mediocre accuracy. However, a 1/4" sheet of plywood at 400m told me just how much that pistol bullet lost velocity. I fired a 5-shot group of some Winchester 110gr FMJ loads into that sheet of plywood and walked out to check the results. I had 5 holes, in a large grouping, but not unreasonable. No keyholing. However, behind the plywood I found 3 of the bullets lying on the ground up against the berm. There was a fresh rain a couple of days before, so that ground was firm and undisturbed. The bullets had lost so much velocity and stability at that range that the bullets didn't have enough momentum and energy do do anything beyond punching through the plywood. Perhaps those old war stories from Korea were correct regarding the .30 Carbine. Now, as a PDW for engagements meant for under 100m, it seems to work pretty well as I have taken a few white tail with SP loads. However, even 100m is pushing it with good broad side shots that are close to the heart and lungs. A couple of white tails that I have shot at over 75yrds have run a considerable distance before dropping. I may have to chrono some .30 Carb loads at 100m just to see how much performance is lost.

There is no doubt that the 300 BLK has much better projectiles "at distance". However, referencing 0-25 yards, what's the difference? If the M1 .30 performs "like a high velocity pistol, with a TSC only slightly larger than a .357 Magnum", then what makes the 300BLK any better? That is what I am getting at.