FaRKle!

Well the ACC does stand for "Advanced Combat Carbine"...

Welcome from CA! Those Recons are pretty fun guns!

Which LR308 rail height are they? Also, which company's logos (just curious)?

So I pre-empted "the rule" and bought one of Griffin Armament's latest compensators, "The Hammer." I was looking for a lighter weight compensator to put on my LW build (currently sitting at 5lbs, 8.3oz) to replace the Griffin Flash Comp (Gen 2, 2.9oz) I had on there. I saw that Griffin came out with the hammer comp within the past month and tried looking it up. Unfortunately there was little information out there other than this YouTube video. It was difficult to tell if the compensating abilities of this comp were as good as the flash comp, but the video showed that it has very good flash suppressing performance. The hammer comp comes in a smaller package than the flash comp and doesn't include a PVC patch like the flash comp, but does come with shims and over-travel stop washer. I put the comp on the scale and it came out to 2.2oz, less than the 2.4oz on the product page, and .7oz lighter than the gen 2 flash comp, excellent. Like the Gen 2 flash comp, this compensator doesn't require you to put the stop washer on the barrel (Gen 1 did or you would need A LOT of shims to thread properly). At first I expected the compensating performance to be similar to the BCM Gunfighter Mod0 comp since it looks very similar, however, it appears that there's two chambers within the hammer wheras the BCM Mod0 only has one chamber. I asked Griffin Armament what I could expect from the hammer, and Austin replied that both the hammer and flash comp provide flat and neutral muzzle control. If this means that the flash comp and hammer comps' compensating performance is the same I might have a new "go to" muzzle device. One thing I found amusing is that the griffin logo on this compensator is holding a hammer that the logo on the packaging and other muzzle devices doesn't have. I do wonder if the side concussion of this device is worse than the flash comp due to the large open areas. The BCM Mod0 is always touted as a compensator that doesn't beat up those around you, but it's still worse than a standard A2. Unfortunately, I haven't been able to install and shoot the comp yet, but I plan on running it on my LW carbine in a class at the beginning of April. I'll update this thread then.

So I took the new SR-15 upper out today to break it in a bit and see if the system runs as smoothly as everybody claims. I installed my favorite muzzle device (Griffin Armament Flash Comp) and also brought out my BCM middy for comparison. I also wanted to see how well the intermediate gas system of the SR-15 matched with the VLTOR A5 system and what spring/buffer combo felt best. Both the BCM and KAC rifles have 16" barrels, Griffin Flash Comps, URX4 rails, and A5 buffer systems so in addition to seeing which A5 components worked best, I could also compare the difference between the mid and intermediate length gas systems. My default setup with the BCM is a VLTOR A5H3 buffer with Springco Green action spring. When I shot the SR-15 with the default setup of my BCM the gun cycled fine and locked back properly, but felt a bit sluggish. It reminded me of Robo's .308 AR with the CAR-10 XH buffer that drops the brass right at your feet. Sure it'd work and there wasn't much recoil, but it didn't feel optimal. I then tried the A5H2 buffer with Springco Green spring and found that one cycled more smoothly but seemed to have a more noticeable return to battery. The gun moved more from the BCG stopping in the forward position. With these results in mind I decided to skip the A5H1 buffer and instead tried pairing the buffers with the stock VLTOR milspec rifle action spring. Running the VLTOR spring with the A5H2 buffer reduced the movement when going into battery, but the recoil impulse was noticeably sharper than my BCM (though still nowhere near harsh). The last permutation of VLTOR spring with A5H3 buffer proved to be the ticket. The recoil was smooth and there was seemed to be almost no movement of the gun while firing. Everything felt just right. I then swapped the BCM upper onto the lower I'm using with the SR-15 upper and compared the different gas systems. The midlength gas system of the BCM did have a sharper impulse than the SR-15's intermediate system, but I think you'd have to actually be focusing on it to notice. I can't say it was a large difference, although noticeable. One thing I noticed when I picked up the SR-15 was that the gun felt very well balanced. It looks like the SR-15 upper uses a lighter profile barrel than my BCM's gov't profile. I can see why people rave about the SR-15 system, although I was a little surprised that my default BCM setup matched it. Next time I'll have to put the SR-15 upper on a lower with regular milspec receiver extension and CAR buffer to see what an SR-15 complete gun feels like.

I'd just tap it on with a rubber mallet. If you have to remove it you can always re-heat it back up or remove the gas tube and tap it off from the rear. I've had to do that before. If you can get it on without sanding, do it since sanding will only make the sealing of the block to barrel worse.

Isn't the Barrett REC7 supposed to be pretty good?

Got a bunch of little items for sale. Prices include shipping, but if you buy multiple items I'll take a bit off for combined shipping. PayPal (gift or +3%) and USPS MO accepted. 1) Knight's Armament 5.56 QDC Flash Hider - $80 Brand new, take-off from my SR-15 upper. Only rounds it's seen are the ones during test fire at the Knight's factory. KAC P/N: 30555 2) BCM Gunfighter Compensator Mod 0 - $65 Also a brand new, take-off muzzle device from a BCM upper. Only rounds it's seen are the ones during test fire at BCM's factory. 3) Magpul Enhanced Butt-pad 0.70" - $15/each BOTH SOLD I have two lightly used Magpul Enahanced Rubber Butt-Pads. These work on the milspec CTR, milspec MOE, ACS, ACS-L, STR, and UBR stocks. The screws with vibratite are still new and unused. 4) Impact Weapons Components MOUNT-N-SLOT Keymod Handstop - $25/each BOTH SOLD I have two IWC Keymod handstops. Well made and in great condition. 5) SLR Rifleworks Keymod Handstop Mod2 - $23 SOLD Very lightly used SLR Rifleworks keymod handstop. This handstop isn't reversible and the flat side faces forward.

If your dept has already invested in a bunch of equipment for the SR-25s they can also look at the LMT MWS. It has quick change barrels and a proven line of match barrels. Their stainless barrels are made by Rock Creek. Mine shoots sub-MOA. BTW, if your department is looking to get rid of the SR-25's, I'd be happy to buy an ACC upper! ;)

On that note, what do the test targets that shipped with the guns look like?

Sorry, I didn't mean you specifically, rather the department. I agree if the rifles need any correction KAC should do it. I was trying to find ways of partitioning that out. Until you're able to prove that it is the rifles and not the shooters though there will be doubt. If it was just one rifle, I'd be more inclined to say it's the rifle, however if all of your SR-25s are doing it I'm more inclined to say it's the shooters' lack of experience on .308 gas guns (this is without any better knowledge about the shooters). IIRC the USAMU thought the M110s had terrible accuracy when they first received them, but it turned out to be technique and fundamentals which a .308 gas gun requires more of. Hopefully you heal up quickly and show them how it's done :).

Oh wow, the latest and greatest. I'm surprised you went with the ACC and not the APC (non-chrome-lined barrel and heavier barrel profile). I know Knight's designed the rifles so that they could be shot suppressed and unsuppressed without an adjustable gas block, so I don't think the groups are opening up due to overgassing. It sounds like you see the larger groups unsuppressed too so that shouldn't be it. If you want to however, you can try a heavier buffer like an H3 or H4 (IIRC SR-25s ship with an H2 buffer). How much experience do the shooters have with semi-auto .308s? Even going from AR-15s to my .308 gas guns took a good bit of learning. Have you tried putting the rifles in a sled?

Wait, SR-25 or SR-15 (title says one thing and post says another)? What ammo are you guys using? If they are SR-25s, which model SR-25 did you guys get? Shooting a boltgun isn't the same as a semi-auto. I've learned from here that things such as follow-through are much more important.

Looks like there's another Azimuth BCG out there. This one's from Fathom Arms. Price point is closer to the Rangerproof and Sharps (although you can get $20 off with code "AR15News"). I just noticed that only the Sharps' carrier has the lightening cuts in the carrier tail.

Welcome! That certainly is a sweet looking build! I'm interested in that JL Billet rail. Did you have a chance to weigh it and confirm the advertised weight? It's one of the lightest .308 handguards out.

20rnd PMAGs with ranger plates fit and close (barely):

I'll have to double check tonight, but I could've sworn they closed on my 20rnders with ranger plates.

Decided to try the new Griffin Hammer Comp. It'll be interesting to compare to the flash comp. Notice the griffin is holding hammer in the logo lol.

Time to see what all the KAC hype is about! SR-15 E3 Mod2 upper came in!

BTW Tactical Tailor is having a 25% off sale right now on TT-made items.

POF BCM Intermediate Receiver Extension Armalite AR-10 carbine receiver extension

Slash's spring is just the Armalite EA1095 spring. He cuts a few coils off of those for use in LR-308 pattern guns. If you really want to use Springco, use the red spring.

With the AR-15 H3 buffer you'll need AR-10 pattern parts. The UTG receiver extension looks like it'll work (and the VLTOR A5 one definitely will). You'll want an Armalite (Part # EA1095) action spring for this.

AR-10 pattern carbine receiver extensions are different than LR-308 pattern ones. LR-308 pattern ones are the same as an AR-15 carbine receiver extension. AR-10 pattern receiver extensions are longer and are the same length as the VLTOR A5 receiver extension. If you have a LR-308 buffer setup (short buffer) then this UTG receiver extension probably won't work since it looks to be longer (AR-10 pattern). You can put an AR-10 pattern buffer system on a LR-308 pattern receiver set.

That RE looks AR-10 pattern to me. Notice how it has more space between the inner most position and the ramp compared with the AR-15 REs.