To clarify from the beginning, this is NOT a complaint thread. Just observations.
As many of you know, we in Washington state finally had the law changed so that we may actually use our legally owned supressors.
In celebration of this, several large supressor shoots were held in various locations around the state. I attended the one on the Kitsap peninsula with my M4 “frankenabortion”, Gemtech M4-96D, Beretta 92fs and Gemtech G9.
For this shoot, I installed a recently aquited FZ complete BCG, and hadn’t cleaned or lubed the rifle for approx 500 rounds. of non-supressor shooting prior.
During the 2 hours I was there, a friend and I fired approximatly 600 rounds through the rifle, all suppressed, and ended up carbon welding the supressor to the bi-lock. I was unable to remove the supressor at the range, and took it home for cleaning.
Info: The rifle is a Stag/CMT upper, lower, FCG, reciever extension, and buffer, a Bushhamster M4 barrel (1/9) 14.5 inch with permanently attached bi-lock. This rifle has approx 8000 to 10000 rounds down the pipe,most semi, some (somewhere around 1000 to 2000 rounds) FA on the upper receiver only as I loaned it to a local type 7 SOT for some shooting several times(also the reason for the approximation of the round count).
Issues: had 5 failures to lock back on the last round. Three times were with my friend who was there with me and was with his ammunition and magazines. Ammo was Bvac bulk, and the magazines were two FDE Pmags and a single USGI aluminum. I experienced two similar situations with USGI Okay brand magazines. All malfunctions took place near the end of our shooting session, and were followed by several other magazines that locked back the BCG just fine. Other then that, it ran like a top. By this point, the rifle was hot enough that it was too hot to touch even the upper reciever much less the barrel or the can. As it were, the can was putting off so much heat that it was causing visual interferrence in sighting on the targets.
Observations: Gun was filthy as a 3 dollar whore after a three day weekend with no shower. Hand cycling the rifle felt gritty as a gravel road. Was able to remove the M4-96D by hammering it off with a derlin armorers block, a fair amount of solvent, and lots of elbow grease.
After disassembly, I noticed several impacts on the circumference of the buffer that matched up perfectly in shape to the buffer retainer pin. This is brand new wear, never seen before. Doesn’t affect function though. Makes me wonder if the carrier may have been machined just a tad too short and is allowing the buffer to come too far forward and impact the buffer retainer pin. Dissapointing if true.
About the FZ BCG: I had read many review claiming that fouling simply wipes off and cleaning baked on carbon buildup from the rear of the bolt was super easy. I found none of this to be true.
I had to scrub the crap out of the BCG, and it still won’t get completely cleaned. As in it looks like the entire BCG is stained so it’s a kind of gunmetal grey color. Scraping carbon from the end of the bolt required just as much work as before on the non NB BCG that was in it previous.
The rest of the rifle took far longer to clean then normal due to excessinve carbon buildup, but I expected this so it’s no big deal. Some caked on fouling in the upper had to be removed with a brass brush because the plastic mil-issue cleaning kit brush simply wouldn’t touch it. Cleaner used was Lucas feul injector cleaner. I’ve been using this for awhile because it simply eats away carbon as that is what it’s job is on engine valves and it works great on guns and is way less smelly then most gun cleaning solvents. Works best if applied and let sit for a little bit. It will creep and soak into fouling and break it up.
Conclusions: Frankly, I don’t care about the new, non super-silver color of the BCG. It was too shiny in my opinion to begin with. Now it just looks like a heavily worn standard BCG. No big deal especially considering that it still feel just as slick now as it did when new and continued working under those conditions. As advertised, none of the NB flaked off or was worn off, just discolored.
Insofar as the failures to lock back, because the rifle continued to work fine after those incidents and locked back on several more magazines and the brass ejection remained consistent throughout the shooting session, I really have no idea what caused the issues. Could be shitty ammo that my friend supplied ( he supplied all of the ammunition we shot that day) some excessive carbon buildup somewhere, etc. My bet is on the heavy fouling and lack of lube. as the ammo was ejecting very consistently during the shoot whenever observed.
I checked the buffer roll pin to see if it was working it’s way out and binding on the buffer spring and found it to be fine. Carrier key was plenty tight and staked properly. Gas rings were all brand new at the beginning of the shoot.
Weapon was cleaned and lubed with marine wheel bearing grease, and after dealing with a family thing this morning, a return to the range resulted in the following: Rifle function fine unsupressed and supressed through 8 magazines with zero issues. After verifying zero with the can, was hitting an 8 inch steel plate at 150 yards shooting approx 1 round per second and hitting every round out of a complete magazine. Shooting done from the bench.
My prognosis is that the FZ BCG can be run dry under “normal” conditions, even in some difficult conditions, but even it will have minor issues when all lube is burned off, the gun is frikken filthy, and being run with a supressor. To be honest, I believe that with the original BCG in place, the gun would have failed much much earlier considering how dirty it was. As noted earlier, when cleaned, I lubed like I normally do. Just because the FZ BCG can be run dry, doesn’t mean that it should be. All moving metal parts work better with lube no matter what they are made from or coated with.
Final FYI: This rifle is a build of my own. In those 8 to 10K rounds it has down the pipe, I have not had a single failure caused by the gun previous to this. This is a beater rifle and gets used regularly in training where it has been subjected to shitty weather conditions, mud, extreme fouling, etc. and it runs like a typewriter. Truly is my go-to gun and after it proved itself, I would take this over a new Colt any day of the week simply because I know it works no matter what.
post script: The most difficult part to clean was the outside of the supressor and the end of the barrel. After shooting his first few magazines, my friend laid the rifle down on the carpet covered bench without thinking and melted a bunch of the nylon carpeting to the supressor and barrel. Was a fucking bear to remove. I didn’t make him clean it because he supplied the ammo for the days festivities.
