300blk - Subsonic in Rattler "outperforms" BCM 9in

[SecondsCount]

Technically the 6.8 SPC, 6.5G, and 6ARC all have more energy than 300 BLK at the muzzle, and they carry that advantage down range.

300 BLK is much closer to 5.56 when measuring ft-lbs of energy. Makes sense considering it uses the same case. The SPC, G, and ARC all use larger cases.

This is for a standard 16" barrel. Once you go short the larger diameter projectiles have an advantage in losing less velocity, but I'd still wager the 6.8 and 6.5 put down impressive numbers from SBRs

I think we are saying the same thing. The shorter the barrel, the better suited for 300 BLK but the other calibers, such as 6.5G, 6ARC, and 6.8 would work well and have better bullet offerings for extended distances.

[Sensei]

Even with the Sig rattler the Barnes 110 should expand out to 250 yrds.

I’ve published chrono results for the Sig Rattler with 110 Barnes at the bottom of the first page here:

https://pistol-forum.com/showthread....Barrel-Lengths

You are getting roughly 1800 fps which is down to 1270 at 250 yards. You’ve also got a 2-foot holdover at that distance. My understanding of the Barnes load is that it expands down to 1400 fps which is going to be closer to 170 yards where the drop is a more manageable 7 inches.

[Baldanders]

If he is really your friend kick him in the nuts.

If not tell him him he is 100% correct.

Nah, he's a big dude like me and in better shape. He'd kick my ass.

[Baldanders]

I don’t know if I’d call it hyper-accurate. I’ve found the Barnes 110 grain black tip to be as accurate as any barrier blind factory 556 load out to 100 meters, and maybe a bit more up close (it creates a ragged hole under 1 inch when fired from the shoulder at 50 yards). Where the Barnes load shines is outstanding terminal performance (as judged by gel, boar, and deer) and reasonable external ballistics out to about 150 meter from a 9” barrel. You might be able to extend that out to 250ish meters with a 12” barrel but all of my 300blk rifles are 9” or less.

The problem with the 300blk is 1) legs beyond 300 meters or so in terms of external ballistics; choose 6.8SPC, 6.5CM, or even a heavy 556 for shots out to 300+ meters as the 300blk coming out the barrel at 2100 fps is dropping like a rock, 2) a bit of over penetration; expect about 20”.

I don't think my boy cares much about terminal ballistics, so .223 is probably better?

[RevolverRob]

I’ve published chrono results for the Sig Rattler with 110 Barnes at the bottom of the first page here:

https://pistol-forum.com/showthread....Barrel-Lengths

You are getting roughly 1800 fps which is down to 1270 at 250 yards. You’ve also got a 2-foot holdover at that distance. My understanding of the Barnes load is that it expands down to 1400 fps which is going to be closer to 170 yards where the drop is a more manageable 7 inches.

1350, per Barnes Ammo Technician - https://pistol-forum.com/showthread....=1#post1075994

So, if you consider ~200y as the max engagement distance with a Rattler and 110 Barnes you should be good to go, might be right on the edge there. Basically, I think of a Rattler shooting supers as equivalent to a 16" .30-30. Yet, I can carry 60-rounds of Barnes and the gun in a backpack with some armor and med kit...It's f'ing ridiculous.

Still, none of it matters if you don't put the bullets on target. Which ultimately means practicing and training with the gun in question, whatever it is.

[RevolverRob]

I don't think my boy cares much about terminal ballistics, so .223 is probably better?

5.56 guns are a lot cheaper to shoot, period.

Even reloading 5.56 is cheaper. I'm cutting down and making .300BO brass and reloading my own. Still, my costs are roughly 0.23/round which is about 40% over what it cost to reload 5.56, and I'm using the cheapest .308" bullets I can (Speer TNT).

When it comes to cost .22LR, 9mm, 7.62x39, and 5.56 are the cheapest solutions out there.

[Corse]

I’ve published chrono results for the Sig Rattler with 110 Barnes at the bottom of the first page here:

https://pistol-forum.com/showthread....Barrel-Lengths

You are getting roughly 1800 fps which is down to 1270 at 250 yards. You’ve also got a 2-foot holdover at that distance. My understanding of the Barnes load is that it expands down to 1400 fps which is going to be closer to 170 yards where the drop is a more manageable 7 inches.

Revolver Rob already passed the info, but this is from another thread:


The minimum IMPACT velocity required for reliable expansion and penetration on these 30 caliber bullets is as follows-
For the-

#30321 110 gr TAC-TX (with the large black colored tip designed for the 300 Blackout) needs 1350 fps.
#30320 120 gr TAC-TX (with the large black colored tip designed for the 300 Blackout) needs 1350 fps.

#30358 110 gr TAC-TX (with blue tip designed for 308 Win velocities and higher) needs 2000 fps.
#30362 110 gr TTSX (with blue tip designed for 308 Win velocities and higher) needs 2000 fps.
FYI- #30358 and #30362 are the same bullet just put into a different box.

#30336 110 gr TAC-X need a minimum of 1900 fps.
#30341 110 gr TSX need a minimum of 1900 fps.
FYI #30336 and #30341 are the bullet just put into a different box.

#30364 130 gr TTSX needs a minimum of 1800 fps.

I've seen some chrono'd speed from a rattler at ~1900 FPS. I'll look later to see what I was getting from my SR30 with factory ammo, with reloads I hit 2300 FPS using barnes data.

[El Cid]

Now to be clear, (‘cause I don’t want people to misunderstand that what I’m saying is testing is junk science and should be ignored), I too once worshipped at the altar of ballistic gel. It has its uses. Mostly good for killing time when you cannot otherwise be shooting, or between wars, whatever. But an inordinate amount of time gets spent wrapped up in concerning oneself in minutiae that you do not need to concern yourself when it comes to shooting for all the marbles. A miss is a miss. Bad guys don’t care what ballistic gel studies showed. They often times don’t give a fuck about marginal hits either. One thing that cannot be argued, is that bad guys respect well placed shots, because they don’t have a choice in the matter.

Even then, there is nothing in the Bible of Ballistics that says an asshole will stop being an asshole with one well placed shot. Pick a round that works in your gun, is reasonably accurate (Sub-MOA/minute of asshole is sufficient), and you can shoot enough of to become proficient. Graveyards have been built for the people killed with supposedly shit ball military ammo. I’m confident that if you brain someone with any high powered rifle, your troubles with that person will be over rather quickly.

Thank you! Always appreciate when a legit end user contributes to technical discussions. Did y’all have a preferred bbl length?

[HCM]

I don't think my boy cares much about terminal ballistics, so .223 is probably better?

Going back to your original question 300 black has done niche uses:

Suppressed .300 BO SBR > suppressed 9mm SMG

Can put Supers in it and get 39-30/7.62x39 rifle like performance out to 200 yards.

Can put it in a 16” AR /AR upper for places you can’t hunt with 5.56 etc but you get the sane effective range as a 30-30 lever gun.

No matter how well it might group at 200 (ok but nothing special) the excessive hold over at distance is a deal breaker.

[Sensei]

Going back to your original question 300 black has done niche uses:

Suppressed .300 BO SBR > suppressed 9mm SMG

Can put Supers in it and get 39-30/7.62x39 rifle like performance out to 200 yards.

Can put it in a 16” AR /AR upper for places you can’t hunt with 5.56 etc but you get the sane effective range as a 30-30 lever gun.

No matter how well it might group at 200 (ok but nothing special) the excessive hold over at distance is a deal breaker.

I think this is pretty much spot on.


What follows is not directed at HCM. Honestly, I get confused by these threads. Perhaps the 110 Barnes will expand out to roughly 175-225 yards. But to what ends? To those encouraged that it expands beyond 175 yards, keep in mind you will have a 110 grain, .30 caliber bullet traveling at 1350-1450 fps. So, what do you expect it to expand to, exactly? Penetrating to what depth? Also, has anyone independently verified these expansion thresholds at sub-rifle velocities?

My suspicion is that it will produce a wound profile that looks something less than what a 115 grain +P 9mm JHP produces - shallow and no temporary cavity to write home about. Most consider that to be less than ideal. So, I stopped trying to make my Rattler be all things. That means I don’t have a LPVO on my 5” rifle to account for the 2 foot drop at 250 yards. Mine is set up to engage 2 legged critters out to about 50 yards max. At that distance, I have no holdovers and still get some temporary cavitation. If I need to engage targets beyond 50 yards, I’m using something that still behaves like a rifle at that distance (9” 300blk, 11.5-14.5” 556, 762x39, 338LM, 50BMG, etc.



Finally, subs in the 300blk. Is there any doubt that loading the Rattler with subs is going to give it something less than 9mm PCC performance? If people accept that premise, is the answer to always make head shots? I ask because that is what I seem to be reading.