Building an SBR

[23JAZ]

I'm starting to piece together what will be my first SBR. It is going to start out life as a pistol until I get the stamp. I know I want a 556. I know what I want for parts except for barrel length. It is going to be suppressed. But I am going back and forth on barrel length. 10.5, 11.5, 12.5? Part of me is saying if I'm going to go SBR and I know its going to always be suppressed, go 10.5, I already have a 16" AR. What say you guys for a HD, range toy, SHTF piece?

[rd62]

5.56 is pretty velocity dependent for performance. I have an LMT 10.5 which I am very happy with and has been flawless. If I had to do it over again, I believe I'd go with a BCM 11.5 (which wasn't available when I built mine). I don't think the inch barrel length would be noticed and the ballistic advantages out weight any additional length/weight.

[HCM]

I'm starting to piece together what will be my first SBR. It is going to start out life as a pistol until I get the stamp. I know I want a 556. I know what I want for parts except for barrel length. It is going to be suppressed. But I am going back and forth on barrel length. 10.5, 11.5, 12.5? Part of me is saying if I'm going to go SBR and I know its going to always be suppressed, go 10.5, I already have a 16" AR. What say you guys for a HD, range toy, SHTF piece?

In general, an 11.5' or 12.5" will run better / more reliably. There is a slight ballistic advantage, but for myself, the big advantage is reliability and durability.

The .MIL runs 10.3' barrels in the Mk18 but at the cost of requiring more PM and much shorter bolt life etc. Plus they are running 5.56 ammo.

There is a reason Colt and BCM don't make AR's shorter than 11.5" unless a government customer demands it.

I've had a personal colt 6933 for 8 years and it runs with everything. We are also in the of re-building our 14.5" work guns to 11.5". Our national firearms unit looked at 10.5'/10.3" for suppressed use by our SRT guys and found the juice wasn't worth the squeeze.

[voodoo_man]

An 11 will do everything you need and want.

A 10 will as well with the rights specs but it costs more.

[23JAZ]

In general, an 11.5' or 12.5" will run better / more reliably. There is a slight ballistic advantage, but for myself, the big advantage is reliability and durability.

The .MIL runs 10.3' barrels in the Mk18 but at the cost of requiring more PM and much shorter bolt life etc. Plus they are running 5.56 ammo.

There is a reason Colt and BCM don't make AR's shorter than 11.5" unless a government customer demands it.

I've had a personal colt 6933 for 8 years and it runs with everything. We are also in the of re-building our 14.5" work guns to 11.5". Our national firearms unit looked at 10.5'/10.3" for suppressed use by our SRT guys and found the juice wasn't worth the squeeze.
So 11.5 is the way to go. Are the BCM enhanced barrels worth spending the extra coin?

[donlapalma]

HCM summarized it well. I went with a BCM 11.5" and have been pleased with its performance. I run it suppressed 100% of the time and only shoot factory brass cased M193. Early on, I did have a few failures to lock back on last round so I went with an H2 buffer and all is well.

[23JAZ]

HCM summarized it well. I went with a BCM 11.5" and have been pleased with its performance. I run it suppressed 100% of the time and only shoot factory brass cased M193. Early on, I did have a few failures to lock back on last round so I went with an H2 buffer and all is well.

Thanks for the info.

Rather than buy the complete upper I want to build it from scratch so I was wondering if I should still get the BCM hammer forged or enhanced barrels or just get the standard.

[SeriousStudent]

I'm building an 11.5" suppressed SBR in 5.56 with this barrel:

http://sionicsweaponsystems.com/store2015/5/61-5-chrome-lined-stripped.html

One of the people that helped develop this barrel is a member on this board.

I also have a 11.5" BCM that is not suppressed, and it gobbles down ammo like a fat kid eats cake.

Based on feedback from people I trust, I'm going to use this Sionics barrel. I'm just waiting on the can to get out of NFA jail now.

[23JAZ]

I'm building an 11.5" suppressed SBR in 5.56 with this barrel:

http://sionicsweaponsystems.com/store2015/5/61-5-chrome-lined-stripped.html

One of the people that helped develop this barrel is a member on this board.

I also have a 11.5" BCM that is not suppressed, and it gobbles down ammo like a fat kid eats cake.

Based on feedback from people I trust, I'm going to use this Sionics barrel. I'm just waiting on the can to get out of NFA jail now.
Interesting, however I want to be able to shoot the gun if it's not suppressed also. I think I'm just going to go with the standard BCM lightweight 11.5" and their BCG.

[SeriousStudent]

Interesting, however I want to be able to shoot the gun if it's not suppressed also. I think I'm just going to go with the standard BCM lightweight 11.5" and their BCG.

I have one of those. It works very well.

I am thinking about snagging one of the BCM 12.5" stainless steel barrels, and putting a Bushnell Elite low power variable optic on it.

[HCM]

Thanks for the info.

Rather than buy the complete upper I want to build it from scratch so I was wondering if I should still get the BCM hammer forged or enhanced barrels or just get the standard.

Hammer forged BFH will last longer.

The enhanced barrel has a taper profile like Noveske - heavy at the action tapering to the muzzle. I like it on my 16" Noveske recon - you get the advantages of a heavier barrel with out the nose heaviness of an HBAR or SOCCOM profile. Not sure the difference will be as noticeable on an 11.5".

[HCM]

PF Member Justintime has had good results with his an 11.5" Sionics upper.

[ReverendMeat]

Same boat as the OP, FWIW I'm looking at 11.5, Sionics barrel. I'm 20 min from Tucson for a couple days so gonna drop by them soon

[ReverendMeat]

Interesting, however I want to be able to shoot the gun if it's not suppressed also. I think I'm just going to go with the standard BCM lightweight 11.5" and their BCG.

I went down to see the Sionics guys today and ended up going with the reduced gas port. I asked about reliability unsuppressed and was told that it'll work fine with reasonably hot ammo (testing primarily with M193) but depending on how the rest of your rifle is setup, may have issues with the weaker (Wolf, Tula, PMC 223) stuff. Makes sense to me, and honestly the diameter of the gas port isn't even abnormally small anyway.

Here's a thread with more info: http://www.m4carbine.net/showthread.php?178402-Sionics-11-5-barrel-w-reduced-gas-port-function-report

[23JAZ]

I have my trust, I decided just to turn the rifle I've been upgrading into a SBR rather than build another from scratch. So now I've got some extra cash and of course it needs to be spent. That being said, what is a good suppressor under a grand? I'd prefer a QD type and hearing safe sound reduction.

[HCM]

I have my trust, I decided just to turn the rifle I've been upgrading into a SBR rather than build another from scratch. So now I've got some extra cash and of course it needs to be spent. That being said, what is a good suppressor under a grand? I'd prefer a QD type and hearing safe sound reduction.

Silencerco Omega or SPECWAR. If you are certain you won't have a .30 caliber rifle in the future, the SPECWAR 556K.

[23JAZ]

Silencerco Omega or SPECWAR. If you are certain you won't have a .30 caliber rifle in the future, the SPECWAR 556K.
Nothing is for certain. Will the 30 cal can still reduce the volume to safe levels and keep good accuracy?

[ReverendMeat]

I have the Specwar 762. "Hearing safe" is completely subjective but it sounds just fine to me. At the time I bought it, it was the quietest option on the market.

It's also really long and really damn heavy. I don't have anything .30 cal to suppress and if I could go back and do it again I would've got the specwar 556.

[HCM]

Nothing is for certain. Will the 30 cal can still reduce the volume to safe levels and keep good accuracy?

Yes, and with the Omega you can swap the .30 cal front cap for a 5.56 - that gives you a can which is quieter than a 5.56 can because it has greater volume.

The SPECWAR is a great can, you can swap the rear of the can for different mounting options but only the SAKER and the Omega have the swappable front caps in the Silencerco line.