PDW length barrels.....300BLK or 5.56?

[ABNAK]

Barrels less than 10.5". Let's say 8" or 9". Let's also establish that we're talking about out to 200 meters max. Now a PDW is obviously intended for CQB-type distances but if need be you could reach out and touch someone at intermediate ranges. Not talking a hill-to-hill shootout in Afghanistan but within 200m.

From chrono data I've seen over the years 5.56 NATO (not talking .223) starts to really fall off terminal performance-wise with barrels < 10.5". However, 300BLK is designed for short-azz barrels, namely in the "PDW" envelope I'm referring to.

So the hypothesis I'm putting forward is that in barrels shorter than 10.5" the 300BLK will surpass 5.56 terminal performance out to 200 meters. You go 10.5" or longer and the 5.56 shines (with good ammo of course).

Fire away.

[Rayrevolver]

So the hypothesis I'm putting forward is that in barrels shorter than 10.5" the 300BLK will surpass 5.56 terminal performance out to 200 meters. You go 10.5" or longer and the 5.56 shines (with good ammo of course).

Fire away.

Lol. I'll bite, although I am not the most versed with 300BLK.

Per R Silvers PDF, find the Max Effective Range slide:
300 BLK (125gr @ 2220fps) from a 9 inch barrel has the same energy at the muzzle as a 14.5 inch M4, and about 5% more energy at 440 meters.


https://www.google.com/url?sa=t&rct=...3PEYqR62ezc0nq

I would put that inside 200 meters, the 9 inch 300 BLK is more effective that any sized 5.56 (based on the "size efficiency" of the package). You can have supersonic mags and subsonic mags.

[Nightvisionary]

Lol. I'll bite, although I am not the most versed with 300BLK.

Per R Silvers PDF, find the Max Effective Range slide:
300 BLK (125gr @ 2220fps) from a 9 inch barrel has the same energy at the muzzle as a 14.5 inch M4, and about 5% more energy at 440 meters.


https://www.google.com/url?sa=t&rct=...3PEYqR62ezc0nq

I would put that inside 200 meters, the 9 inch 300 BLK is more effective that any sized 5.56 (based on the "size efficiency" of the package). You can have supersonic mags and subsonic mags.

I was a big drinker of the R. Silvers 300Blk cool aid for awhile. The velocity you have listed is actually for a 125 grain bullet through a 16 inch barrel. 9 inch velocity is 2050. Silvers/AAC purposefully compared results from a 16 inch 300 blackout barrel to a 14.5 5.56 barrels to cherry pick results but I do think the OP is correct in his assumption. I plan on jumping back into 300 BLK in the near future with an 8.5-9 inch barrel. With hand loads the 110 grain Barnes TAC TX blacktip should achieve 2250-2300 without much problem ( I pushed them to 2500 in a 16 inch no problem)and they will offer some expansion down to 1350-1400 FPS so I think the cartridge with that bullet definitely has an advantage over 5.56 in sub 10.5 barrels.

[darr3239]

Sorry for the quality of this image. I had it saved from several years ago, and don't remember the source. The go to projectile today is still the 110 gr. Barnes TAC TX as NV mentioned.

300-chart.JPG

[ABNAK]

I was a big drinker of the R. Silvers 300Blk cool aid for awhile. The velocity you have listed is actually for a 125 grain bullet through a 16 inch barrel. 9 inch velocity is 2050. Silvers/AAC purposefully compared results from a 16 inch 300 blackout barrel to a 14.5 5.56 barrels to cherry pick results but I do think the OP is correct in his assumption. I plan on jumping back into 300 BLK in the near future with an 8.5-9 inch barrel. With hand loads the 110 grain Barnes TAC TX blacktip should achieve 2250-2300 without much problem ( I pushed them to 2500 in a 16 inch no problem)and they will offer some expansion down to 1350-1400 FPS so I think the cartridge with that bullet definitely has an advantage over 5.56 in sub 10.5 barrels.

Yeah, it's a very narrow niche category but in < 10.5" barrels the 300BLK is in it's element. The 5.56 is designed for "longer" barrels than 8" or 9" and IMHO will overtake the 300 in those categories. But the little PDW scene? I'll take 300BLK.

[turnburglar]

If burning powder is the name of the game- a larger bore will always do better than a smaller one.


338 federal does better than 308

6.5 grendel willl do better in a shorter barrel than 224 valkyrie

300blk will do better than 556 ect

[ABNAK]

If burning powder is the name of the game- a larger bore will always do better than a smaller one.


338 federal does better than 308

6.5 grendel willl do better in a shorter barrel than 224 valkyrie

300blk will do better than 556 ect

Good point.

[1168]

You guys are making me want (need) a 300. Do 300 supers from a 10.5 suppress significantly better than 5.56?

[Buckaroo]

Has anyone made up a Venn diagram that encompasses what we are discussing?
I'm convinced that the 300BLK outshines the 5.56 in short barrel applications but I don't have data to add to the discussion.

Sent from my Pixel using Tapatalk

[tom12.7]

Has anyone made up a Venn diagram that encompasses what we are discussing?
I'm convinced that the 300BLK outshines the 5.56 in short barrel applications but I don't have data to add to the discussion.

Sent from my Pixel using Tapatalk

Variations of Venn's are used all the time. For something like this, you'd be looking at a comparison between some pretty complex diagrams to interpret for either. That is unless you go overly basic and overly basic is your best outcome for that.