sbr barrel length

[wraith1516]

Was thinking about making an sbr. My question is what is the shortest possible barrel length /w a suppressor wil function properly. I wanted to do a 6 in bbl and a 6 in suppressor all under a 10 or 12" freefloat handguard, is this possible or will it not function reliably.
Question # 2 it is my understanding that unless the suppressor is permanently affixed it will be 2 tax stamps, is this correct.

[lead chucker]

Yes you would need two stamps, one SBR and one for the suppressor. You would have to have is made with a pistol gas system and I would think it would be really touchy getting it to cycle right, the gas port diameter would be tricky. I just got a 12.5" barrel with about a .070" gas port and its still over gassed a adjustable block is a must. With that short of a barrel your velocity will really suffer to I would think. I'm sure one of the other guys here will chime in with some hard facts.

[Variable]

A 6" barrel with a 6" can would still be two stamps even if the can was permanently attached. 6" + 6" is still only 12" inches of barrel. If you had a 10.5" barrel with a permanetly attached 6" suppressor--- then you'd only need one stamp for the suppressor (since the permanently attached can would extend your legal barrel length measurement to 16" plus inches).

That would only work with a suppressor that actually protrudes a full 6" past the muzzle though. Be careful, because a can only six inches long will be back over your muzzle threads and not actually extend your barrel a full 6".....

Either way, I personally wouldn't do a 6" pistol barreled Grendel. As mentioned it'd require a pistol length gas system, and you'd be really far into the weeds about how to get it to actually run well. I'd only do it if you realllllly liked to tinker....

Your velocity would be pretty poor, and I don't know of any normal suppressors that would be warranted for that barrel length in a Grendel anyway. With the Grendels higher case capacity, you'd basicly be sandblasting your baffles (with unburnt powder) under very pressure with each shot. Even a very heavy duty can would likely live a much shortened life. Suppression would be mediocre at best, and you'd probably be surprised at how much flash made it out of the can as well.

It's doable, but (in my opinion at least) not very practical at all.

[wraith1516]

That is the whole point not practical and tinkering , I like to have things that aren't practical.
I was thinking about having suppressor end cap welded to bbl then weld tube to that, so the suppressor core was removable and replacable.
was planing to form1 the can not buy it . What about using a b.r.toth slide over style can

[wraith1516]

I just want something uber short that has more punch than 556 and not super loud mostly for home defense and plinking for the wife she I not 110# soaking wet shot guns arent her cup of tea

[am4966]

I think SD tactical make tubes and other things that can get you going. They even have a titanium tube. If that company isn't right PM me and I'll get the right info to you.

[Variable]

That is the whole point not practical and tinkering , I like to have things that aren't practical.
I was thinking about having suppressor end cap welded to bbl then weld tube to that, so the suppressor core was removable and replacable.
was planing to form1 the can not buy it . What about using a b.r.toth slide over style can

Well, in that case, and knowing what you are up against going into it---- Sounds like fun.

I'm not that knowledgeable about the reflex style suppressors (B.R. Tuote, etc.) as I've never owned or used one. The reflex design should help with back pressure via it's extra volume in comparison to "normal" cans that have the same length forward of the muzzle. There's no substitute for baffles though, so if you want it quiet you'll want a decent length of baffle stack forward of the muzzle.

Having a serviceable can would be highly advisable for a 6" grendel barrel, but there is one extra fly in the ointment. If I remember correctly---- If you form 1 a suppressor: ATF contends that you can't "remake" it later without supposedly paying another tax. Only licensed manufacturers are supposedly allowed to "repair" their suppressors. That's a load of crap, but "the more you know" and all that jazz.LOL My memory is getting fuzzy on some of that stuff though. It's hard to keep up with all of the ATF's regulatory crap.

[Variable]

I just want something uber short that has more punch than 556 and not super loud mostly for home defense and plinking for the wife she I not 110# soaking wet shot guns arent her cup of tea

I'm lazy, so for something like that I'd probably just punt and get an 8" 300Blk upper (if I wanted it that short). Heresy, I know.

Buuuuttt.... Where's the tinkering in that?!?!LOL

If you do a 6" grendel make sure you take lots of notes and post lots of pictures! You'd have a bunch of folks watching your progress!!!

[wraith1516]

Ill post pics when the powers that be figure out how to make it a LUDDITE proof my last computer pissed me off so I literally picked it up and though it out the window (no I didnt open the window first that was a $100 temper tantrum )
but liking the 300 bo idea great another toy wife is going to hide the check book and cc

[wraith1516]

It was my understanding that baffles are non serialized parts and therefore replacable, you just cant have extra ones laying around , has something to do with constructive intent or some such nonsense.

[m796rider]

I'd be a tad worried about baffle strikes unless you're limiting yourself to 90/100gr .264 bullets. It takes a bit of barrel to stabilize the longer VLDs. On a 6" barrel you're not even getting a full twist of the rifling if you're at 1:7 or 1:8.

[wraith1516]

Actually I was thinking about going with 140 or160 grain bullets slow and big like the lapua naturalist

[m796rider]

Actually I was thinking about going with 140 or160 grain bullets slow and big like the lapua naturalist

So you're aiming for a suppressed subsonic Grendel SBR? Yeah, I'd do some checking on bullet stability before mounting that can on that barrel...

[Variable]

The Hornady 160 grain RN bullets are stable out of my 10.5" barrel with a 1 in 7.5" twist, but I have no idea what chopping the barrel back to 6" would do. It might be fine, or it might not. I couldn't say one way or another.

I'd be a little nervous, but that's only because I haven't seen anyone else do it.

[lead chucker]

The only concerns I see with a 6" is functions, velocity, and noise. I think getting a 6" grendel to function would be difficult at best, everything would have to be just right. I dont think the velocity from a 6" barrel would be high enough to expand any bullet. The blast from a 6" muzzle would be so bad, and also coming back though the chamber would be teeth jarring at best. I have a 8" blkout and I get quiet a bit of blast coming back though the chamber so a grendel would be murder.
That said I would love to see one done!