Not long ago I saw a BCG bearing the SureFire logo. I thought it was a pretty example of laser engraved branding but didn’t realize that it was actually an entirely new product called the Suppressed Optimized Bolt Carrier Group-Long Stroke. It consists of a Bolt Carrier Group, Buffer and Action Spring.
I know that’s quite a name but the new SOB-556-LS from SureFire was designed to improve reliability of suppressed AR-style weapons, particularly during full auto fire.
One major update to this BCG is the spring loaded counterweight visible at the back of the carrier. It helps slow things down a bit with the components all working together to minimize bolt bounce during full auto fire. Ultimately, it all results in more dwell time to the rear for the BCG, giving the magazine 30% more time to load before the weapon has completed cycling.
As you can see, the Black buffer of the SOB-556-LS is .4″ shorter than a Mil-Spec buffer. However, SureFire has developed different buffer weights based in your gas setup.
There is also a new action spring which is slightly longer than the Mil-Spec version and also made from a narrower gauge material. You’ll also note that it features a red marking on the end to denote it is different from the Mil-Spec spring.
Currently undergoing government evaluation, these should be available soonish.
Tags: Surefire
i wonder how much difference the buffer and spring would make in semi auto…. hmmmmmm
Soonish: is that Magpul 2009 soonish, or relative industry soonish? There’s a clear objective difference between types of subjective soonishes.
Well, if it’s anything like the ‘Surefire soon-ish’ they’re famous for it could be another 1-2 years and then it will be immediately discontinued because you suck and they hate you.
Don’t mind me, I’m just bitter about the loss of the tan weapon lights and waiting on the closed-prong WarComp.
They did get that Wrist Light out the door with a quickness, though.
A design so ahead of it’s time I won’t sell it until next year!
I mean, with the advent of adjustable gas blocks (SLR, MicroMOA, Noveske), and piston guns with suppressed/unsuppressed settings, do products like the best way to tackle non-adjusted gas systems?
don’t get me wrong, I fly helicopters and am a day time range clown that spends most weekends in a bay shooting one way on a square range. I have the MicroMOA gas block and some SCARs that I run suppressed.
my question is, do the swoopy dudes not want to run the risk of leaving their gun on the wrong setting and having a malfunction out the gate with the gun not cycling without the can on in the suppressed setting? Ive certainly left my gun in the wrong setting by accident.
apologies if I am off the mark. Maybe everyone is cool with overgassed guns kicking casings off the brass deflector to the 1 o’clock out of the ejection port and I am just a ninny who is particular.
All that being said, either way, looking forward to seeing this as well as the closed tin flash hider that is suppose to be out “soon” as well. I’ll wait…
thanks!
Reading through it again, seems like it’s mainly to prevent bolt bounce, where the bolt bounces off and out of the barrel extension, which can happen when the cyclic rate is high, which is what happens on full-auto AR/M4s; particularly when suppressed.
Jim Sullivan himself has said it’s been a flaw of the AR15 from even when he was working on it. I know he’s worked with Surefire before (60 & 100rd mags) and has designed what he calls improvements to the system, I’d even dare to venture that this might be his handiwork, at least partly. Although that’s just my speculation.
https://youtu.be/gOUKXIrDE0I?t=5m5s
i was wondering if this was Jim Sullivan handy work … and now im speculating it is
I’ve found my new hero, thanks for sharing that video.