7.5" 300BLK Uses?

[Olympus]

I'm trying to decide if a 7.5" 300 has any purpose other than range toy or PDW? I've always wanted a 7.5" AR, but most people say the 5.56 is nothing more than a noise-maker in 7.5" barrel.

I already have a 10.5" AR in 556, so does a 7.5" in 300BLK really do anything else? I know it suppresses very well, but I don't currently have a suppressor for one.

 

[Bartholomew Roberts]

.300 BLK suffers a lot less velocity loss in short barrels than 5.56. Having said that, 7.5" is short even for .300. My 9" .300 will throw 110gr right at 2200fps, so you'd probably be in the same area as .30 carbine with a 7.5" barrel.

 

[Elkins45]

I can't see that the difference is worth the cost unless you want to add a long silencer and keep the length reasonably manageable.

 

[Olympus]

I just realized that I could legally hunt deer in my state with an AR pistol, which would open up a whole new deer season. It would be great if I could do a 300BLK pistol for deer hunting at modest ranges.

 

[Olympus]

From what I'm seeing on other forums, the 300 supers from an 8" barrel seem to be capable of taking deer with 100 yards. Anyone have any personal experiences here?

 

[Bartholomew Roberts]

If you can manage the same accuracy as a traditional hunting rifle, they'll do deer and pigs just fine with an 8" barrel and Barnes TTSX. The Hornady 110gr VMAX can be impressive on deer from the front or side. It varies on pigs from "Wow, that stopped it cold!" to "Well, we will never find him until the buzzards show up."

 

[Olympus]

I would think that I could be more accurate with an AR and a stabilizing brace than I could with a traditional handgun.

 

[yugorpk]

I have a 7.5". Runs great with maybe 25 ft/sec less than mu 8.5". I shoot mostly subs so i couldnt care in the slightest. Supers work fine too. No functioning issues at all.

The ONLY issue I have with it is that the common 7" hand guards put the barrel threads just inside the handguard. Cant use it as is with a QD silencer. Thread on is not an issue but to use QD on a locking ratchet style locking silencer base / flash hider you need a spendy 5.5" rail.

 

[Tirod]

I built a 10.5" AR specifically for hunting during the deer seasons. I used it in rifle season when other firearms are allowed, and Alternate season when rifles are not.

Same as the .300, it's good to about 100m, which is past visibility in the Ozarks in woodlands or dense brush.

It's also a decent HD weapon, short, high capacity, with enough power. There's a lot of discussion about what would be better, etc., but the reality is we use what we have trust and experience in.

Same for a trunk monkey gun - as a pistol in MO it's legal to have up front loaded in a bag concealed. If you were venturing out into private property it's just another choice next to a lever or scout rifle. 5.56 from a 10.5 barrel may not have over 1,000 foot pounds after the first 100m but plenty choose to shoot pistol caliber carbines that don't even start out at the muzzle with that. And 5.56 has a much flatter trajectory for less hold over error.

AR pistols aren't range toys, they are lethal weapons. They are much more powerful than handguns, have longer range than pistol carbines, and with 30 round magazines more capacity. With ten or five round mags, they are often legal for hunting.

I prefer mine to the 16" 6.8 - it's a pound lighter, and 6" shorter. It's noticeably easier to still hunt thru dense brush in a draw or valley, and doesn't have the forward weight leverage that works your off hand as much.

I don't think the OP really has an issue figuring out what the pistol can be used for, it's more his thinking on whether he needs another one that basically duplicates what the previous one offers. He's already sold on them.

 

[justice06rr]

The short answer, No it doesn't do anything more compared to your 10" AR in 5.56.

The only advantage is the 3" length difference. If you don't plan on suppressing the 300BLK, then it may not give many advantages for you. It would make a cool range toy and PDW though!

 

[justin22885]

i personally wouldnt waste my money on 300 blackout at all, if i wanted suppression, 45acp beats it, if i wanted a full on rifle caliber, i prefer 5.56... i wouldnt even call it a jack of all trades because that would suggest performance slightly above mediocre in multiple categories.. more like a joker of all trades, master of none

 

[hq]

At 7.5" I'd look seriously at pistol calibers. Muzzle pressure (blast, noise) with rifle calibers will be a real problem and especially if you're planning to suppress it, pistol calibers are by far the tried and proven prime candidates. There's a certain shock-and-awe -factor in shooting a shorty .223 AR, especially without a birdcage and at full auto, but the sheer noise and blinding muzzle flash will get old very quickly.

 

[Olympus]

At 7.5" I'd look seriously at pistol calibers. Muzzle pressure (blast, noise) with rifle calibers will be a real problem and especially if you're planning to suppress it, pistol calibers are by far the tried and proven prime candidates. There's a certain shock-and-awe -factor in shooting a shorty .223 AR, especially without a birdcage and at full auto, but the sheer noise and blinding muzzle flash will get old very quickly.

Not talking about 223. I'm talking about 300 blackout. Tons of short barrel 300 blackout builds. Most people say it seems to be ideal around the 8.5" barrel length.

 

[Olympus]

i personally wouldnt waste my money on 300 blackout at all, if i wanted suppression, 45acp beats it, if i wanted a full on rifle caliber, i prefer 5.56... i wouldnt even call it a jack of all trades because that would suggest performance slightly above mediocre in multiple categories.. more like a joker of all trades, master of none

Seems to be pretty versatile little round to me.

 

[yugorpk]

There is no comparison. Pistol caliber carbines suck for suppression unless they are locked breach of some sort. The standard AR in 9mm or especially 45 ACP is ridiculously loud out of the ejection port. Might as well be a high point carbine. On target the 300 BLK with 208-220 grain bullets running 1100 FPS or less will easily group in the MOA range out to 150 yards and retain more energy than the 45 ACP. Go for maximum suppression and shoot a 16 inch 45 ACP carbine next to a 16 inch 300 BLK carbine both with top of the line silencers and the difference is night and day with the 300 blowing the 45 away. People do all kinds of silly other stuff with the 300 like try to turn it into a 30-30 or a 7.62X39. It wasnt designed for that. As the 300 Whisper It was designed to be a suppressed round and that it does wonderfully. Out of a 7.5 inch barrel through a good silencer it sounds like a nail gun and still puts a 220 grain round down range with more energy and less drop/drift than a 45 ACP.

 

[Olympus]

There is no comparison. Pistol caliber carbines suck for suppression unless they are locked breach of some sort. The standard AR in 9mm or especially 45 ACP is ridiculously loud out of the ejection port. Might as well be a high point carbine. On target the 300 BLK with 208-220 grain bullets running 1100 FPS or less will easily group in the MOA range out to 150 yards and retain more energy than the 45 ACP. Go for maximum suppression and shoot a 16 inch 45 ACP carbine next to a 16 inch 300 BLK carbine both with top of the line silencers and the difference is night and day with the 300 blowing the 45 away. People do all kinds of silly other stuff with the 300 like try to turn it into a 30-30 or a 7.62X39. It wasnt designed for that. As the 300 Whisper It was designed to be a suppressed round and that it does wonderfully. Out of a 7.5 inch barrel through a good silencer it sounds like a nail gun and still puts a 220 grain round down range with more energy and less drop/drift than a 45 ACP.

Agreed. But plenty of things have been designed for one thing and later discovered to be useful in other ways. I think the 300 blackout can still be beneficial and serve a purpose as a rifle from a 16" barrel. You can go from supers to subs with a simple mag change.

The 300 blackout can get pretty close to 7.62x39 and not too far from the 30-30 as a rifle, but with a wider range of bullet selection? So why try to make the 300 blackout do something the 7.62x39 or 30-30 can do? Because you don't have to buy another gun, optic, and new caliber to load for. The 300 serves a pretty wide range of uses in my opinion.

 

[hq]

Not talking about 223. I'm talking about 300 blackout. Tons of short barrel 300 blackout builds. Most people say it seems to be ideal around the 8.5" barrel length.

And there are far more AK Krinkov builds (and OEM factory guns) than .300BO shorties, which doesn't make them any more ideal for a caliber that's its ballistic twin. Case capacity of 25 grains and barrel volume of just over 0.4in³ calls for a powder with a fast burn rate to have any hope of keeping muzzle pressures at a reasonable level.

 

[hq]

There is no comparison. Pistol caliber carbines suck for suppression unless they are locked breach of some sort. The standard AR in 9mm or especially 45 ACP is ridiculously loud out of the ejection port.

Hardly. Let's not spread rumors here, please. Some carbines like UZI call for a slightly stiffer recoil spring and a heavier bolt (tungsten inserts are a cheap and easy way to mod one) if the breech pressure pulse reflection from the suppressor is an issue when bolt starts to open, but generalization that blowback recoil breech is loud by definition is thick. There are special designs that overcome the need of added inertia like blish lock of the Thompson SMG and roller delayed of MP3, but a gas-type locked breech is by no means a requirement for a very quiet suppressed semi auto.

 

[Olympus]

I'm interested to hear from people who have firsthand experience and what those experiences are.

 

[yugorpk]

Both of these are as accurate as I am capable of being. Both are as reliable as any firearm I own which is 100%.

This one is a 8.5". High pressure 150 grain loads will run about 1900 FPS out the barrel. Subs are whatever speed I load them to. That is a $50 Palmetto barrel and a Silencerco specwar.






This is a 7.5" Anderson Barrel and a SIG 762 silencer. It loses 25-40 FPS under the 8.5 but for subs it doesnt matter. It cycles great with standard 220 subsonic loads and doesnt skip a beat with high pressure rounds either. Silencer or no silencer it works every time. 110 grain Nossler Varmageddon run 2200+ FPS out the tube.

 

[yugorpk]

"Hardly. Let's not spread rumors here, please. Some carbines like UZI call for a slightly stiffer recoil spring and a heavier bolt (tungsten inserts are a cheap and easy way to mod one) if the breech pressure pulse reflection from the suppressor is an issue when bolt starts to open, but generalization that blowback recoil breech is loud by definition is thick. There are special designs that overcome the need of added inertia like blish lock of the Thompson SMG and roller delayed of MP3, but a gas-type locked breech is by no means a requirement for a very quiet suppressed semi auto."


Having owned several of every caliber pistol round carbine I can think of I will disagree. Only non delayed bolt guns that are acceptably quiet are open bolt firing. Simple blowback closed bolt semis with no delay are loud. AR's are loud and from the worst possible place. Sure the HK's and Thompsons ( actual Thompsons, not the semi's ) can be made to be quiet but they are not closed bolt blowback guns.

 

[adcoch1]

The thing I enjoy about the 8.2" 300blk I have is the absence of muzzle flash. There is a little, but not more than a 9mm(used to have a 7.5") and that's with the supers. Accurate enough for a pistol/pdw, and suppressed it would be awesome. Also it is pretty quiet compared to 5.56 even without a suppressor. And a 5.56 this length as previously mentioned, is like your own personal flash bang under rapid fire. I think 300 blk has lots of uses if the ranges are kept down to what it was designed for.

 

[Olympus]

Both of these are as accurate as I am capable of being. Both are as reliable as any firearm I own which is 100%.

This one is a 8.5". High pressure 150 grain loads will run about 1900 FPS out the barrel. Subs are whatever speed I load them to. That is a $50 Palmetto barrel and a Silencerco specwar.






This is a 7.5" Anderson Barrel and a SIG 762 silencer. It loses 25-40 FPS under the 8.5 but for subs it doesnt matter. It cycles great with standard 220 subsonic loads and doesnt skip a beat with high pressure rounds either. Silencer or no silencer it works every time. 110 grain Nossler Varmageddon run 2200+ FPS out the tube.

That's a great deal on the PSA barrel. I was thinking about trying the 7.5" Anderson barrel juat due to cost and assuming accuracy would be sufficient inside 100 yards. I'm glad to hear that both supers and subs cycle without a suppressor. I'd like to add one in the future, but it may be a while.

 

[hq]

Having owned several of every caliber pistol round carbine I can think of I will disagree. Only non delayed bolt guns that are acceptably quiet are open bolt firing. Simple blowback closed bolt semis with no delay are loud. AR's are loud and from the worst possible place. Sure the HK's and Thompsons ( actual Thompsons, not the semi's ) can be made to be quiet but they are not closed bolt blowback guns.

I'd say there might be something you haven't considered thoroughly if you haven't managed to quiet down any of your several pistol caliber carbines to at least A-weighted <125dB level. The predominant noise should consist of the "whoosh" flight noise of the bullet, bolt slamming to the rear of the receiver and the impact on target, of course, or something has gone terribly wrong. But who am I to give advise on this subject, I've only had about a dozen suppressed handgun caliber long guns, thirty suppressed pistols, four suppressed full auto SMG:s and a hundred or so suppressors during last three decades. Just counting suppressed centerfire pistol caliber firearms, that is.

 

[yugorpk]

Well , I remember the first time I shot a colt 9mm carbine with a trident silencer. I thought" That's not going to do at all". Then 9mm and 45 carbine after carbine came and went and they all sounded like crap until I put my first 300 whisper carbine together and I thought "where have you been almost my life". Dramatic difference. I've had pistol caliber smg's too and they all sounded great. Even the macs but the blowback AR's meh. You can have them.