I'm a noob trying to build a dedicated SBR to eat subsonic 300 with my surpressor. I want to just buy a complete upper but I'm struggling to find what brands are good. I'm looking for:>7 inches>Adjustable gas block>1:5 twistI've found a few random brand but idk if they are any good. What do y'all run? My budget is max 1500 if I had to, but I'd prefer around 1k.
Why do you want 1:5 twist for .300 Blackout? That's retarded. You want 1:5 for heavier rounds, not that. You should be looking for 1:8, 1:7 and maybe 1:6.But in terms of companies, go BCM, Daniel Defense or PWS. If you can't afford that, then Aero Precision. Rannier Arms or PSA if you can't do AP.
>>64387656Is it? I'm not being snarky, trying to learn. From what I've read, shorter barrels should have a faster twist rate
>>64387665The length of the barrel has no effect whatsoever on the twist rate. It's the length of the bullet that matters, and the velocity since a faster bullet going through the same rifling will spin faster. Bullet construction also matters, for example lead bullets will explode if you spin them too fast.
>>64387665Typical .300 BLK twist rates are 1:8, 1:7, 1:6 and occasionally 1:5 from speciality makers. 1:5 is extremely fast and generally used only if you intend to stabilise very heavy bullets. If you’re trying to do both heavy subsonic (~220-240gr) and supersonic loads, a 1:7 or 1:8 is the common sweet spot. If you want 1:5 then you're looking at custom or propriety or expensive stuff.Like it's not 'bad' if you see what I mean, just not really done. Aero Precision, BCM (Bravo Company), Faxon, Rainier Arms, Noveske, Daniel Defense (less likely under $1500), SLR Rifleworks, Primary Weapons Systems, CMMG will likely produce a 1:5 twist rate upper with a 7", gas tube, low‑profile adjustable gas block, handguard, muzzle threads asnd the assembled BCG & CH sometimes included in the cost. It should all be under $1500 (bar DD). Only way you can get cheaper is find a complete upper that includes a quality nitrided BCG and a reputable adjustable gas block.If BCG not included, factor an extra $200 or so.
>>64387615Can somebody explain why people think adjustable gas blocks are necessary? I have a considerable number of ARs and all of them run just fine suppressed and unsuppressed with a wide range of ammo brands and weights. In over ten years I've never had a single malfunction from any of them that could be attributed to improper gassing.
>>64387703Thanks for the clarification man>>64387715Thanks, yeah I'm definitely planning on running heavier grain, so I'll focus on the 1:7. >>64387735From what ive read it's just easier to tune rather than experimenting with various buffers, but I also haven't built one so wtf do I know.All, this is the upper I was looking at originally https://bravocompanyusa.com/bcm-standard-7-300-blackout-upper-receiver-group-w-mcmr-5-handguard/But I started to get confused when I saw the fine print>These barrels were designed to run High Velocity ammo only with a H3 buffer. can I run subsonic with an h3 buffer if they are hotter loads? Or would I need something lighter
>>64387615>>Adjustable gas blockThat is the main problem you're running into. Adjustable gas block makes sense for your build, but they are rarely found on pre-assembled uppers. >>64387703>The length of the barrel has no effect whatsoever on the twist rate. It's the length of the bullet that mattersThis.>>64387735I don't think they are "necessary" per se, but it is by far the easiest way of getting an AR with an oddball barrel length to run optimally. It's also not just about "malfunctions" but also about comfort, as having too much gas in your face when you're shooting suppressed is not fun.
>>64387797>I don't think they are "necessary" per se, but it is by far the easiest way of getting an AR with an oddball barrel length to run optimally. It's also not just about "malfunctions" but also about comfort, as having too much gas in your face when you're shooting suppressed is not fun.That supports my guess that it's just something for people who like to overcomplicate and fiddle with shit unnecessarily.
>>64387615Lmao you pathetic barrellets never fail to make me laugh with your "SBR" threads. Face it, most rifles will be infinitely more effective than your sad pistols will ever be. You are shooting mall ninja 7.62x39, get over it larpers
>>64387615>"pistol">fold-out stock easily visibleShameful.
>>64387823I don't think anyone would argue that 556 is obviously superior lmao. For me however, I want to build one because 30 rounds of 399 will still kill you dead, and it wont give me everlast EEEEEEE if I'm blasting indoors.
>>64387715Also thanks for the brand suggestions
>>64387945>>64387795You're welcome, good luck. Post it when you've built it.
>>64387703Good post overall but>for example lead bullets will explode if you spin them too fastYou're not thinking lead you're thinking FMJ. It's the simple and cheap copper jacket that can't handle over 300k RPM or so. Bonded bullets will do fine, as will monos of course though basically nobody wants to shoot pure lead out of a normal rifle these days.OP: >>64387615When you want to check this stuff just use a stability calculator, tons are available for free online like>https://bergerbullets.com/twist-rate-calculator/You'll see that a 220gr bullet going 1050fps (standard 300bo subsonic) is totally stable (SG>1.5) with a 1:8 twist. No need for anything crazy. Even if you're handloading physically there just isn't much COAL room to go much heavier in that cartridge, so I've never even bothered with 1:7 though maybe some do.Don't forget you can save $400, a very significant chunk vs your $1500 budget, if you wait until after this january.
>>64387615You don't need a chrome lined mil standard steel barrel for a .300. Especially if you going to run subs. I had a PSA 8.5 pistol and the only thing I didn't like about was the rail. It worked, but the attachment method was a little suspect. Get something cheap because you are probably going to end up selling it. If I were you I would just buy a Stribog sp45 PDW instead.
>>64388067I would but my surpressor is for 300 and I don't wanna buy another one desu>>64387810It sounds like it's destined for less fiddling with buffer bullshit. Also what's everyone's opinion on the CMMG Dissent? I'm confused about what it says regarding "include a 1913 Picatinny rail end plate to use in place of the lower receiver buffer tube." What does that actually mean?
>>64387735They're not necessary if you meet one of the following criteria:>you're using supers or subs exclusively>you get everything else perfect with one or two dedicated loads, which usually requires some experimentation>you're okay with running fine on subs but being overgassed as shit with supersFor most people, an adjustable gas block makes the entire process a lot easier, not to mention cheaper.
OP, this might be worth a look. https://www.broadrivertactical.com/products/brt-6612-ab72ebfa-d007-400a-913f-f118f8ce0147>>64387656>>64387665iirc the 1:5 twist rate, at least for the honey badger's development, started as a way to get similar performance out of a 7" barrel as they would with a 1:7 out of a ~9" barrel. Or at least that was one of their marketing pitches. If you are one of those very rare shooters whose rifle doesn't outpreform them, you might notice a slight accuracy improvement for subs, but a 1:7 is fine for supers.>>64388270It means there is an adaptor where the buffer tube usually is that allows you to easily attach a stock or brace.
>>64388270Gotcha. I bought a .45 k can that was rated for .300 so I bought a .300. 30 cal isn't nearly as hard on barrels as .22 cal. You can away with a nitrided barrel. My PSA would shoot super and subs, canned or not. Shooting supers without the can and the gun would jump excessively. Very over gassed. You should tune your pistol to sub suppressed. I don't know much about this company but their products go on sale on gundeals once a monthhttps://overtindustries.com/
>>64387615Pointless meme caliber
>>64388372This, came here to post how fucking stupid 300 blackout is.
>>64388355>shoot super and subs, canned or not.I never really understood why this is something people were looking for. I guess it's great in terms of ultimate reliability with whatever will fit in the pipe, but you're really doing yourself a tremendous disservice by running a gas port large enough for that to work.I have a 10" 300blk with a contract overrun FN barrel (I heard mention it was ordered for some spec ops evaluation trial or some secret squirrel voodoo shit, who fucking knows). It's very interesting, CL, CHF, 10" flat, with a pistol length port reamed for .063 exactly (Picrelated, barrel with pin gauge inserted, before opening up).I don't know who ordered it that way, but I'm assuming it was done specifically because the group using it was expecting to run supers exclusively, always suppressed, maybe with some kind of high back pressure can.I put this project on the back burner for a bit because I started working 70 hours a week and frankly can't be bothered to drum up the motivation at the moment, but I was reaming it out until it functioned with supers unsuppressed.With a standard carbine buffer, 125gr ammo (I was looking to match 7.62x39 specs) and ejecting right, I think I stopped at .078.When I start on that upper again I assume I'll have to step it up again to run subs suppressed, but I don't see the point in running subs unsuppressed. The difference in noise and blast between the two without a can on the end is really kind of negligible (at least out of a 10").I've seen some manufacturers list their port sizes at .092, or even as extreme as .102, and I'm wondering how the fuck anyone runs those without an adjustable gas block and keeps their upper together long term, they must be so over gassed it's got to be genuinely uncomfortable to shoot.
>>64388353Ah ok gotcha. So with that being said, would an adaptor in place of a brace cause more recoil? Is it discernible? I'm pretty new to the world of this shit
>>64389073recoil is pretty light with 300blk in any case, but it shouldn't really make a noticeable difference compared to a standard buffer setup. Recoil's mostly a function of bullet weight times speed, divided by the weight of the gun. Semi-autos spread out the recoil impulse by moving the guts of the gun, vs a manual action. The dissent's recoil assembly looks like it's probably lighter, just from the smaller bolt carrier, so if there's any difference in recoil it'll be mostly from any weight savings.
>>64387656>Aero>2025Are they actually in stock again? Fucking miracle
>>64387870Yeah it will, keep earpro by your rifle
>>64388372You're largely right tbqh.I bought it because I fell for the "whisper quiet," meme. Got a SCAR15P and started loading 200gr stuff going like 1100FPS with a Hybrid 46M.It fucking sucks. The ballistics are garbage, the accuracy is shit, and it's still loud enough to require earpro. 300BLK nibbas are lying through their teeth, honestly.
>>64389148No.
>Don't want to start a new thread:Is there any reason I shouldn't get a 15P in 300 and SBR it into this?Already have a 16/17 so I know what I'm in for, but it's my first 300.
>>64388372Meme as in niche, sure. It's turning into the standard for subsonic shooting. It has all around better ballistics than 147g 9mm and .45 acp. That's really what it should be compared to. It was hard to justify when it was $1-2 a round, but now it is pretty cheap. >>64389073The full buffer system is going to have less recoil compared to the dissent, but the difference isn't a big deal. You'd need to shoot the different systems side by side to notice. .300 blk is relatively light on recoil regardless of the setup. Another argument I've seen is that a buffer system is going to have less wear and tear on internal parts. I haven't seen any real data to back that up, but it is worth considering. Best of both worlds would probably be the buffer system with a folding stock adapter like the one from Law Tactical. At that point, if it is CMMG you're looking at, you could go with the cheap but just as good Banshee instead and put the savings towards the adapter.
Suppressed subsonic guns are still >120db which is a noise level you never want to get hit with, especially indoors. Gun fags are mostly just as retarded as everyone else about their...hobby...so yes there is a lot of stupid shit said about guns.Similar to how a kid might put octane booster and a new air filter on his car and swear up and down he can feel 5 horsepower.A lot of bullshit and wish thinking.>>64389158Remember what I said, and dont let anyone try to tell you otherwise.A sup sub weapon is still >120 decibel.
>1:51:8 and 1:7 are both fine. The former if you will shoot mainly supers, the latter if you will shoot mainly subs. Anything else is retarded. Anyone telling you otherwise is retarded and trying to shill you a meme invented by Kevin Brittingham.
You all bought cheap ass pistol and multi-caliber supressors with traditional baffel designs and wonder why 300 blk is loud.You need to put a closed, dedicated. 300 win mag supressor.No louder than a pneumatic nail gun
>300 Kevin Brittingblack Hamout But we just recently received a technically superior but equally memeful meme round. Why not 338 ARC anon?
>noob falls for the "faster twist means more better" memeMany such cases. Sad!
>>64387615>KAC 1:5 556 10'' barrel If you're going down the high twist rabbit hole—>>64387656>y 1:5Because that's intended by the inventor— and 1:3 to 1:1 would be justifiable IF using exclusively subs (absurd terminal ballistics gains). Without 1:5 the round is even more mid than 8.6 ARC, and the manufacturer's cheating out.>>64387735Wear and tear rate mitigation, reliability with different loads.>>64389158>300BLK nibbas are lying through their teeth, honestly.1:5 is the litmus test. It deserves the vaporware reputation without it.
>>64389398>Because that's intended by the inventorJD Jones, the actual inventor, chose 1:8 for good reason
>>64389398>muh rotational velocidensityI've seen a dozen examples of 8.6, some of them quite high FPS slow motion, and can not find any tangible benefit the spin rate provides.
Damn this thread makes me want to take my 300 out to the range again.I've been out there like 2x a week and I want to try some pistol stuff at my indoor range.Just get a PSA upper with a 1/7Less than 10" if you're man enoughThe blown out gas ports and "sloppiness" of a psa make it chug along better if anything.No, it isnt that accurate past ~250 yardsIt's a fucking AR pistol.Also if your cases are ejecting at 4-6 your AR is UNDER gassed.Mine short strokes Hornady Amax but cycles everything else fine.
>>64387615I don’t care about the cartridge or anything, but what handguard or upper is that? I have a thing for big fat square handguards.
>>64390051Idk, it isn't mine
>>64390051Thats a SIG MCX not an AR at all.The MCX is just SIG's version of their piston ARThe SIG Rattler is actually a SIG MCX chambered in 300 blk
>>64390125Aw, that’s a pity. I don’t tolerate inferior slop like Burger SIG in my collection. Thanks though.
>>64390233I actually like the MCX its a decent piston AR and very handy feeling.Can fire with stock folded as well.If I had an infinite budget I'd probably take their 300 blk offering over the 7.5" PSA I have now.6.75" 1/5 twist, which is almost exactly what OP was asking for btw...6.75 is the shortest you'd realistically want on 300 and the other offering in 9" which is "OK"7-9" is perfect for 300
>>64390233>>64390279Also, its objectively the best and most proven SIG in use with the US military since the P226
>>64387615Grow up and learn to torque a barrel nut.
>>64387615Problem solved
>>64390894Today I will remind them.https://www.xcrforum.com/threads/attention-serfs.9198/
>>64391523A great shitpost
>>64387615All those specs are why I went with the Sugar Weasel upper. Although I would prefer the rifle speed gas block.
