Frag Out! Magazine
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solved with hard-chrome plating on the inside, not the oxidation after chrome plating. d) The gas piston should be made from stainless steel but it is not as stainless steel can't be chrome-plated. During the shooting, the gas piston piston rod with the gas piston hits the gas regulator and this process in- flicts deformation of the piston and the damage of the gas regulator attachment. The problem was solved with chrome plating of gas piston and gas regulator and new gas piston guiding rod from 6AL-4V titanium alloy. The gas piston rod attachment was also changed. This de- creased the return of the gas piston. The improved de- vice does not require lubrication and does not corrode. Now, only the gas piston hits the gas block but due to low mass of this part, no damage is inflicted to the block. e) Main problem, in my opinion, was the design of the gas piston system. The gas piston guiding rod should be removable without barrel detached as this would incre- ase the comfort of cleaning and maintenance. New gas piston guiding rod removed that problem permanently. It can be removed for cleaning without removing the bar- rel. The new mechanism directs the gases from the gas block to the sides to prevent overheating of the barrel and handguard. f) According to the owner's manual, to remove the barrel, the turnbuckle must unscrew with an Allen wrench and then pulled forward. There are two bolts inside the turn- buckle that keep the barrel in place. These parts should be inspected from time to time since they are deforming during the use. The deformation of the bolts may cause one of the nuts to "stick" to the barrel. It happened to me and I was never able to detach the barrel with bare hands. The turnbuckle had to be hit with a hammer. So- lution for this problem was the chrome plating of the bar- rel housing and Tenifer coating of the screw. g) Again, in my opinion, the safety switch and charging handles are uncomfortable. I have decided to replace them with an in-house made steel safety switch and ro- unded charging handles from titanium alloy. The char- ging requires less force now and the switches are easier to operate in gloves. h) Factory trigger was replaced with Geissele Automa- tics SSF but this required a modification of the lower re- ceiver. New axles of the trigger mechanism were made. The bolt carrier was modified to allow charging. The at- tachment points of charging handle and barrel housing were oxidized again. ydowane. i) To decrease traction and allow the bolt carrier to move smoothly, the slides were grinded and oxidized. j) Poor anodizing of the upper receiver and handguard is most probably an effect of use of this particular alu- minium alloy. Instead of anodizing, these parts were MT-Arms plasma coated. The surface of the aluminium was able to cut the glass from that moment. The upper rail does not deform or damage now even with heavier optical sights attached. Finally, the rifle was coated with Cerakote in MAPA camouflage pattern. The coating ma- kes the cleaning way easier and the outer parts do not require lubrication. k) All GROT owners should carefully observe the barrel housing. The barrel is inserted inside and locked with a pin. Because the pin is hard and the barrel housing was hardened, it is possible that some breaking will happen in this area. I have seen couple rifles with this problem. If you notice a break in your gun, contact the manufacturer imiediatly. Geissele Automatics SSF trigger Barrel after tuning Grot Pimp my www.fragoutmag.com