Six months. That's how long I'll probably have to wait before the ATF sends my tax stamp for a Griffin Recce 5.56 suppressor. I already have a Surefire Socom 7.62, but I wanted a dedicated 5.56 suppressor that was a bit shorter and lighter for training classes and HD. To help me manage the interminable wait, I decided to get an upper receiver started for my silencer in waiting. The core of the action is of course the upper receiver and the bolt carrier group. I decided to go with Bootleg Inc for this build. They are a division of Primary Weapon Systems that makes their parts for DI rifles. Despite the outward appearance, their upper is forged, not milled, and deletes the forward assist. I've never had to use my forward assist, and it tends to get in the way of my ambi-charging handles. Also, my choice of bolt carrier does not have the teeth for the forward assist anyway. Aside from the light weight and nifty design elements, there are a few small enhancements I appreciate. The dust cover pin is captured at the rear, so you don't have to fumble with a c-clip. The barrel extension mounting area is max spec and a tighter fit than my Aero Precision upper, necessitating a few taps of the barrel with a dead blow hammer to get it seated. The finish is impeccable inside and out, with no tooling marks anywhere to be found.
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| Bootleg Upper - Right |
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| Bootleg Upper - Left |
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| Bootleg Upper - Top Rear |
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| Bootleg Upper - Top Front |
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| Bootleg Upper - Inside Front |
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| Bootleg Upper - Inside Rear |
I already have an SBR'd lower, so I've settled on an 11.5" barrel from Faxon Firearms with a mid-length gas system. The short dwell time is offset by the additional back pressure from the can. The overall length and weight are within an inch and a few ounces of a 16" barrel, but without the pesky noise and fireball. Perfect for training, the indoor range, HD, and the impromptu 3-gun outlaw match. While I don't plan on running this rifle without the suppressor, I still want the ability to "go loud" without having to locate an allen key to adjust a gas block. I already have an 11.5" upper for a Surefire suppressor with an SLR adjustable gas block. It works well, but adjusting it requires taking off the can to access the adjustment nut. The Bootleg carrier only needs a cartridge rim and can be done without removing the carrier, unlike the one from Gemtek. It has four vent settings, though I've only had to use the min and max vent positions. The gas key looks properly staked and everything is finished in Isonite, a form of nitriding. It doesn't have a glossy finish like other nitrided carriers such as my JP Low Mass. I suppose the matte finish is more "tactical" but I prefer the easy cleanup of a slicker finish. It's covered by the dust cover anyway.
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| Bootleg Adjustable Bolt Carrier - Right |
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| Bootleg Adjustable Bolt Carrier - Left |
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| Bootleg Adjustable Bolt Carrier - Top |
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| Bootleg Adjustable Bolt Carrier - Adjustment |
You have to provide your own bolt, firing pin, retainer pin, and cam pin. Faxon Firearms offers matched and head spaced bolts with their barrels, so I went with theirs. The other small parts are from Bravo Company.
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| Faxon Bolt |
Since my upper isn't quite finished, I threw the Bootleg carrier in my current 11.5" upper using its Fail Zero bolt. It uses the same Faxon 11.5" mid-length barrel, but with an SLR Sentry6 adjustable gas block. I turned the gas black to its max setting to get an idea of how well the carrier mitigates excess gas. I use an H3 buffer and standard weight recoil spring. I didn't lube the carrier and the bolt was bone dry. I fired 30 rounds of Federal XM193 unsuppressed with no problems, casings exiting at two o'clock. I attached my Surefire 762 suppressor and fired five rounds to see how the over gassed rifle felt, then turned the gas adjustment to the full suppressed setting, and fired five more. The difference wasn't earth shaking, but very noticeable. The action felt smoother, the gun stayed flatter, and I didn't get any gas directly in my face. However, being at an indoor range, an acrid cloud lingered to my right. I didn't shoot weak-side, but I can't imagine it would be pleasant. It only started burning my eyes after I dumped the remaining 20 rounds in the magazine. For fun, I tried the other two settings and I could feel the increase in gas pressure with each one. I do like the ability to add a little more gas if needed. I then moved the dial back to the suppressed setting, and began to turn down the gas at the gas block. I was able to go from it's max setting (15 from closed) to 9 from closed, before the bolt wouldn't lock back. This tells me that it's still a little over-gassed for a suppressed SBR. For a longer barrel it's probably perfect. I ended up shooting only 120 rounds suppressed. I had to take frequent breaks to let the can cool down, and I had two other guns to sight in. At home, I examined the carrier for abnormal wear and fouling. While I only shot four mags suppressed, the carrier and upper weren't as dirty as I expected, about as bad as shooting Wolf in a 16" unsuppressed rifle. It may have been the lack of lube to attract dirt. In any case, almost all of the fouling wiped off with an old t-shirt.
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| Bootleg on bottom is dirty, JP on top is clean |
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| Bootleg dirty - JP clean |
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| BCG and parts after 120 rounds suppressed |
One range session and 150 rounds aren't enough to make any definitive conclusions about Bootleg Inc's adjustable bolt carrier. I also can't say for certain if I prefer it or the SLR Sentry adjustable gas block. With the Sentry, I can get the gun perfectly gassed, without the eye watering cloud in front of my right shoulder. With the Bootleg, adjustments are easier, though coarser, but it's less likely to fail or come out of adjustment since it's dealing with much lower temperatures and pressures. My gut says to run the SLR on anything that isn't a defensive gun. Since my new upper and Griffin suppressor will take on a primarily defensive role, that's probably where the Bootleg will go.
