VLTOR A5 on SBR

[JG007]

For a BCM 11.5 that will use a 556 saker part time

1) with the vltor A5 6 position AR10 tube, is the 6.8oz H3 the right choice?

2) after I dial that in, will trying the LMT carrier change anything?

thanks

[Hemoglobin]

1) My Centurion 11.5 runs the A5H3 with and without a Gem-Tech Halo just fine. My BCM 14.5 middy runs the A5H3 100% suppressed and unsuppressed as well. I have only used 5.56 pressure ammo. The lowest pressure ammo I think they have seen is some mid 90's Radway Green and honestly thinking back I'm not even sure that it's under powered, but I seem to recall it being in-between for one reason or another. The A5 is a very forgiving system.

2) No clue - no experience.

[TehLlama]

The A5H3 isn't a bad starting point - the LMT carrier (I'm assuming the enhanced one) WILL change stuff, but I haven't ran that exact combo (and I'm running an oddball dedicated suppressed upper anyway). Between Mark/Pappabear and Grant (C4i) you might have some answers, I'd use the site search to see if any of them have something close to what you're describing.

[Clint]

I'd start with the std A5H2 and go from there.

[Reagans Rascals]

I'm not sure what all the fuss is about... I run an LMT 10.5" MRP CQB upper on a Noveske Chainsaw lower, 95% of the time with an M4-2000 Mod 8. I run it with a standard Carbine Buffer and standard spring and I've never has a single problem with the gun. It even uses the stock semi BCG from LMT that came with the upper....

I've never once had a single Bolt Override, Double Feed, Failure to Extract, Short Stroke or any malfunction whatsoever... and I run a mix of shitty steel Tula ammo all the way up to Lake City M855...

Recoil on my gun is nothing to be scared of and I've put close to 4000 rounds through it with no signs of excess stress or strain on any part of the gun...

so why the need for enhanced carriers and new buffer/spring combos? am I missing something here? or are people chasing a solution for a problem that isn't there?

[markm]

I'm not sure what all the fuss is about... I run an LMT 10.5" MRP CQB upper on a Noveske Chainsaw lower, 95% of the time with an M4-2000 Mod 8. I run it with a standard Carbine Buffer and standard spring and I've never has a single problem with the gun. It even uses the stock semi BCG from LMT that came with the upper....

I've never once had a single Bolt Override, Double Feed, Failure to Extract, Short Stroke or any malfunction whatsoever... and I run a mix of shitty steel Tula ammo all the way up to Lake City M855...

Recoil on my gun is nothing to be scared of and I've put close to 4000 rounds through it with no signs of excess stress or strain on any part of the gun...

so why the need for enhanced carriers and new buffer/spring combos? am I missing something here? or are people chasing a solution for a problem that isn't there?.

You are nuts!!! I just went through this with Pappabear. He got an LMT complete lower and put it under a 10.5.... That sucker WILL RUN... but holy smokes is it a beast.

He put an H3 buffer in and pulled that CAR buffer.... MUCH more enjoyable to shoot. JUST TRY IT OUT!!! You might be surprised.

There are almost NO ARs out there that run optimally on the CAR buffer. Your gun will almost certainly run smoother... I know you're not breaking any parts on your gun, but you'd be enjoying the weapon so much more with an appropriate buffer.

[daddyusmaximus]

so why the need for enhanced carriers and new buffer/spring combos? am I missing something here? or are people chasing a solution for a problem that isn't there?

Some guns don't have the gas system engineered right.

Some times you need to experiment to get a gun running right. I made an AR pistol using a generic 7.5" upper I got at a gun show cheap. Got it running with a Enidine AR-restor hydraulic recoil buffer and a Tactical Springs “RED” extra power buffer spring. Runs absolutely perfect now.

Sometimes you just over think things and make them more complicated than they need to be. I made a SBR out of an Arms Tech Compak 16 upper I took to Iraq. Tried different stupid crap, until I remembered it ran perfect on my issued M4 lower. Put in a standard carbine spring and buffer with an M16 carrier... perfection.

I do love a chrome or nickel boron BCG. So much easier to clean after shooting.

A can adds to the confusion... I have yet to go that route.

[Zuppamon]

From the original post; AR10 tube?

I have an A5 with H3 on a 10.5" switchblock upper with a SF FA556-212 can. It runs smooth, doesn't buck and has never malfunctioned.

[tom12.7]

For a BCM 11.5 that will use a 556 saker part time

1) with the vltor A5 6 position AR10 tube, is the 6.8oz H3 the right choice?

2) after I dial that in, will trying the LMT carrier change anything?

thanks

I have a preference of around .067" for 11.5" 5.56 barrels with mil spec type chambers and comparable rifling for H2 carbine action and A5H2/rifle action systems shooting full power 5.56 with a conventional carrier non suppressed. This also works okay on a 50/50 suppressed rifle, but it's not optimal. Adding the enhanced carrier to the mix, the above carbine action system usually over speeds the action even with a H3 when a suppressor is installed. Adding the enhanced carrier to the same mix with a A5H3 usually performs outstanding.
With larger porting, you will need more mass than the what I listed as my preference. I would not bother with a carbine action system at all on those if shooting full powered ammo only. The A5H3 would be a good starting point with a conventional carrier. With an enhanced carrier, I would start out with an A5H4. Either way, you will still need to test everything out yourself. The A5H4 is heavy and can make a lightweight carbine wobble, this bothers some, others not.
For me, I would've cut down a longer barrel, and port it around .065" specifically for the LMT enhanced carrier/Vltor A5H2 combo with a Colt rifle action spring. Using the larger ports means action mass has to increase to compensate for it. A quality adjustable gas block would not be a bad choice if you can not use smaller porting.

[BufordTJustice]

I have a preference of around .067" for 11.5" 5.56 barrels with mil spec type chambers and comparable rifling for H2 carbine action and A5H2/rifle action systems shooting full power 5.56 with a conventional carrier non suppressed. This also works okay on a 50/50 suppressed rifle, but it's not optimal. Adding the enhanced carrier to the mix, the above carbine action system usually over speeds the action even with a H3 when a suppressor is installed. Adding the enhanced carrier to the same mix with a A5H3 usually performs outstanding.
With larger porting, you will need more mass than the what I listed as my preference. I would not bother with a carbine action system at all on those if shooting full powered ammo only. The A5H3 would be a good starting point with a conventional carrier. With an enhanced carrier, I would start out with an A5H4. Either way, you will still need to test everything out yourself. The A5H4 is heavy and can make a lightweight carbine wobble, this bothers some, others not.
For me, I would've cut down a longer barrel, and port it around .065" specifically for the LMT enhanced carrier/Vltor A5H2 combo with a Colt rifle action spring. Using the larger ports means action mass has to increase to compensate for it. A quality adjustable gas block would not be a bad choice if you can not use smaller porting.

Excellent post.