Can someone explain to me what the ballistic difference/deficiency is between .300 supers and 7.62x39? From the charts I see, you can make a case that x39 actually hits harder. If the real appeal of .300 is the fact that they come in super/sub loads and the system can be quickly swapped between them, then isn't it a moot point for a non FFL/SOT in mass? I.e. what does a .300 do that a 7.62x39 can't/doesn't do if you are NOT going to be shooting subs?
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Thoughts on SBR vs no SBR
- Thread starter kingson
- Start date
Basicaly, 7.62x39 just gives you a couple hundred FPS advantage. External and terminal ballistic differences depend on what specific bullet you’re using. Disclaimer, I don’t know a whole lot about 7.62x39 cartridge offerings, but there are some highly effective 300BLK sub and super bullet options now for hunting, LE, or HD. Tipped hollow point bullets, expanding subs, all-copper hunting loads with good expansion, bonded bullets for expansion after barrier penetration etc. It has healthy R&D behind it. I’m not certain the same can be said for 7.62x39. I’ve only seen FMJ, and basic hollow point and soft-point bullets.
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Mesatchornug
NES Member
In addition to what @PappyM3 just said - the whole reason 300AAC exists at all was that folks wanted to put something approximately comparable to x39 in an AR-pattern rifle without a ton of engineering. (Feeding ARs with AK food means piles of effort to get something reliable; I hear it's easier now, but ~20 years ago that was a ball of suck.) With Blackout, all you need is a barrel; the bolt, magazine, etc. are unchanged.
For private citizens, we have the freedom to throw our doll hairs at whatever blows our skirt up - even bougie, brass-cased x39 for a bodged-together, comm-bloc import to have the confidentce to hunt with an AK. Government organizations have less leeway, so selling them on something as straightforward as a barrel swap makes bean counters weak in the knees.
Hooray logistics.
For private citizens, we have the freedom to throw our doll hairs at whatever blows our skirt up - even bougie, brass-cased x39 for a bodged-together, comm-bloc import to have the confidentce to hunt with an AK. Government organizations have less leeway, so selling them on something as straightforward as a barrel swap makes bean counters weak in the knees.
Hooray logistics.
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Gotcha, makes more sense at the government scale, but again the super/sup thing comes into play there as well.
I guess I ask my question from the perspective of the average Joe in MA who wants to build something with a short barrel that retains decent ballistics.
It's not f***ed up/retarded in an AR, because it was explicitly designed to work with it. You retain more stuff that's actually cross compatible with 5.56. (BCG, mags etc)
That said, in defense of your frankengun- the whole thing is sort of moot right now... as if you don't have .300 BLK, you ain't getting any because the price is cosby level rape right now. At least 7.62 x 39 is actually available.
Mesatchornug
NES Member
The answer there is basically always "mission-dependent."
Joe Average has to decide what he cares about. What are "decent ballistics" to him? Punching paper is different than deer. 20 yards presents different problems than 200. Does he care about using a can? How often will he be shooting it? Is this his only rifle/does he care if it has a different manual of arms from the others around him? Does he plan to keep mags loaded for it and another (5.56) rifle such that there's risk of confusing them? Who else will be using it?
Here's a Free Example that you didn't ask for:
I have a 14" blackout barrel waiting for me to build a firearm around it. For me, it'll be a toy of a range-blaster. It's likely not going to host a can any time soon, but the future could do funny things. In this "mission" it's ok if ammo is expensive, and sometimes unavailable because it's only trotting out for the lulz. Here, a fixed mag will serve as an insurance policy against swapping magazines with my 5.56 rifle(s). When I'm tarting it up, I'll probably even go so far as to get one of the super cool 300AAC dust covers to remind me to not shove the wrong ammo in it. In a build like this, an 8" x39 AR would basically be interchangeable because any failure just means I shoot something else for a bit, or go back to my (mom's, who am I kidding) air-conditioned basement for a Sunny D. Hell, the Frankenrifle might even be more fun because the ammo is easy to be had inexpensively.
Meanwhile, if I was looking to rely on something for all of my low-speed, high-drag LARP/HD-fantasies, I'd be making so many other decisions that would influence the cartridge selection. x39 is plentiful and cheap, so building a rifle around it means my training could be too. But here I'd want one that feeds the cartridge reliably because it's no fun clearing stoppages in class. (I've never tried it, but I'm betting it's more exciting in a firefight.) I know the best Fords are Chevy powered, but if I'm planning for life-saving conditions, I don't want to use expensive magazines that are custom engineered to feed a steeply-tapered cartridge just so I can run cheap, steel-cased ammo in an AR. This would lead me to build an AK if I was really drawn in by the battlepack prices on Wolf.
JRT
NES Member
x39 is a short stubby bullet, that makes it difficult to stabilize an optimized subsonic bullet. Subsonic x39 rounds are available, they're really just light loads as opposed to being optimized for subsonic. As far as what you can do in Mass I know you can do SBRs, I would probably start with a 10.5 to 11.5 inch barreled upper 556. From there adding a 300AAC upper is really easy.
They’re really not. M193 might stop reliably fragmenting at 50 yards in a 10.5, but it will still kill things far past that. Bonded LE/defensive loads can reliably expand out to 100 yards or so, but again, will still kill things far past that. And you could even go for something like a 77gr TMK to get reliable fragmentation out to 250 yards from a 10.5” barrel. While 10.5” is generally considered the lower limit for 5.56, it is still good for 300 yard engagements. And any engagements a civilian is likely to face, will be within range of effective fragmentation/expansion in most bullets.
Bullet selection and annoying nuances of trying to get that cartridge working for an AR. E.g. proprietary parts etc
Mesatchornug
NES Member
It really depends how you want to use it.
Even with mediocre external ballistics, you can learn your holds and lob projectiles on target at 300 yards. If you don't care about suppressors, then you can run full power cartridges and you'll get whatever energy down range that it can maintain. 2100 fps is still no slouch.
If you want a long range gun, that's not what pistols are for. If you want a handy fighting rifle, run what you brung and learn from it.
Your biggest risk is unreliability from the proprietary bits that let your capitalist rifle play well with communists. So play with it until you get bored or frustrated, then slap on an upper that speaks 'murican and keep going. That's the best thing about Stoner's design.
For ammo prices right now, the winner is 7.62x39. But that could change rapidly as we are all witnessing changing price and availability on a daily basis.
As far as 300blk and x39. 300blk, being that it uses .308” projectiles, has a huge selection for optimizing ballistics. If you spend a little time looking at reloading components, you begin to see the huge disparity between the .308 selection and .311 selection of bullets. This impacts loaded ammo choices for an end user also.
7.62x39 leaves the muzzle ~200-300fps faster for the same weight projectile and barrel length. 300blk in many cases can catch up at distance because of better projectiles making it a wash ballistics wise overall.
One issue not mentioned here yet is that 7.62x39 in an AR has more stress exerted on the bolt “bolt thrust” which can cause bolt durability issues over the long term. You have less metal on the bolt face because of a larger case head, and you also have more rearward force because of the tapered case profile. Not an issue in an AK as the bolt and lugs are more substantial.
Dennis in MA
NES Member
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How many NES'ers are thinking, "This is my 100yds deer rifle" with a 10.5" .223 in the first place?? Aren't these really INSIDE guns, folks?? Anyone got a 50-yard hallway in their house?
Max range of my short-barrel items is 30 feet. Thirty. In reality, I could tape a 6' dowel to the bbl and if it touches bad-guy, just fire. It's gonna be THAT close. Sights?? Nah. Velocity?? Not really.
The Zompocalypse is not reality. And any civilian engaging targets beyond 50yds, hell, beyond 15 yards, is either in the Zompocalypse or that may be teh last firearm they fire before their jail time.
We can get awful hung up on some minor detail that will derail our original intention. Been there, done that. (Still thinking about sub versus super sonic on my 300BLK ammo. . . . if any was in stock at reasonable prices anywhere in teh first place.)
So here is a couple of SBR that I did so far. I have 3 more to do at the moment, I'm sure I will find others. A PPS43, Suomi M31 and I have a AR-15 receiver that I will build up someday when I have some money.
MP40P
Uzi
MP40P
Uzi
amm5061
NES Member
Well, I wouldn't use .223 for deer, but in a pinch I could sure as shit take a deer at 100 yards with my 10.5. That f***er is dead nuts on, and I wouldn't be using shitty 55gr ammo.
But your point is well taken. The purpose of that gun is engagement inside of 25 yards to be honest. Probably more like 25 feet.
Twigg
NES Member
I'm in a free state the only thing i'd bother forking over another $200 bucks for would be a suppressor or something with at least a giggle switch. Besides, I've got a few as yet unbuilt AR lowers that were 4473'd as "receivers" when I bought them so they could be built as pistol or rifle. I'll roll the dice on a brace. I don't think the ATF IS gonna flip and IF they do I'll address the issue when (if) it ever happens.
gerrycaruso
NES Member
I wouldn't short barrel a rifle caliber. The performance would be awful. If you're thinking that reduced performance doesn't matter because you're only using it inside your house for self defense, consider this. The first time you pull the trigger, the blast and flash will instantly render you deaf and blind. I'd short barrel a pistol caliber because it would increase performance and reduce blast and flash. Two guns that don't look right unless they're short barreled are the Thompson and the Uzi.
allen-1
NES Member
I have two AR pistols. One lives in my office and has a 7.5" barrel with a linear comp on it. Short, maneuverable, and the linear comp makes it feasible to fire a couple rounds indoors with it. I think.
My truck pistol has a 10.5" barrel on it. I have spare ear pro sitting in a bag on the transmission hump in the front of my truck.
So...you think every SOCCOM operator out there with a MK18 or HK416 is...what? Under-gunned? The 10.3” AR platform isn’t something that was dreamed up by Bubba in his basement.
As far as the “deaf and blind” argument, here’s a great vid from someone who did it, not some who simply speculated on it.
allen-1
NES Member
JRT
NES Member
I get his point, you want the psychological advantage and going loud wakes up everybody. I use a kurz silencer on my 10.5 inch home defense AR. Its still loud at the muzzle but its won't deafen me at the ear. You get the benefit of significant muzzle flash reduction as well.
Shark_Cage
NES Member
I’m in Mass without a FFL07 so no can for me. I was talking to Tony Rushmore about what length to go with a 458 SOCOM. He talked me into 10.5. He did say “You know that is going to be fuc-ing loud, right” lol
amm5061
NES Member
Tony from Tromix? I have one of his 16" .458 SOCOM barrels. Great investment, and Tony's the guy who really pioneered the cartridge. It's a thumper, but it's damned fun to shoot.
Anyways, welcome to the club.
Shark_Cage
NES Member
Yup the same. Great guy
dcmdon
NES Member
There are a couple of reasons I can think of.
1) you can have a SBR in MA that would be illegal in pistol with armbrace form.
2) Most training centers that do carbine classes prohibit pistols with arm braces.
Mesatchornug
NES Member
I wonder how long that will remain true when guys like John Lovell are basically saying to go brace if you can because it gets all the benefits of SBR without the stamp...
Here is number 3 and 4 SBR's
First one is a PPS43-C that started life as a pistol. It had a folded stock on it that was permanently fixed in the folded position. Had to buy a parts kit so that I could get the pin and spring to make the folding stock function again. Had to grind and pound out the old fake pin that came with the pistol. Then had to drill out the top rear of the receiver to make the hole bigger where the real pin and spring goes in. The only thing I couldn't do is weld the pin to the cross bar that holds the stock in either the open or closed position. My neighbor did that for me. Bonus use of the parts kit was that I took the full auto bolt and made a post sample registered bolt to fit this gun. Had to cut a grove in the to to match up with the grove in the receiver. Also had to used the parts kit lower so that it would be an open bolt gun again. That was easy to do just had to pound out one pin and the lower fit right on. Now I can use the gun as a Semi SBR or a Post Sample MG. It easy to switch the lower and the bolt out.
Then I just got this abomination in today, It was cheap and looks like it will be fun to shoot. Someone chopped the barrel down to 12.5 in and put the muzzle brake on it. I'm sure the muzzle blast will be fun and a big fireball. The place that I got it from said this was made when the guns where cheap and it was a fun range toy.
First one is a PPS43-C that started life as a pistol. It had a folded stock on it that was permanently fixed in the folded position. Had to buy a parts kit so that I could get the pin and spring to make the folding stock function again. Had to grind and pound out the old fake pin that came with the pistol. Then had to drill out the top rear of the receiver to make the hole bigger where the real pin and spring goes in. The only thing I couldn't do is weld the pin to the cross bar that holds the stock in either the open or closed position. My neighbor did that for me. Bonus use of the parts kit was that I took the full auto bolt and made a post sample registered bolt to fit this gun. Had to cut a grove in the to to match up with the grove in the receiver. Also had to used the parts kit lower so that it would be an open bolt gun again. That was easy to do just had to pound out one pin and the lower fit right on. Now I can use the gun as a Semi SBR or a Post Sample MG. It easy to switch the lower and the bolt out.
Then I just got this abomination in today, It was cheap and looks like it will be fun to shoot. Someone chopped the barrel down to 12.5 in and put the muzzle brake on it. I'm sure the muzzle blast will be fun and a big fireball. The place that I got it from said this was made when the guns where cheap and it was a fun range toy.
Mesatchornug
NES Member
