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Joined:
Oct 2024
Posts:
1
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OH, USA
Posted: 2/26/2026 9:02:58 PM EDT
| Just picked up a used upper. Any idea on buffer weight to buy? JP Silent ? Also, it has the old Keymod hand guard. Want to upgrade it to MLok and possibly pull the barrel. I called PWS and they don’t do barrel replacements. So, if it’s shot out , it done? I plan on running this full time with a DeadAir Lazarus. Is everything proprietary on these uppers? Also, I noticed my bolt doesn’t have the spring on it. It seems to run fine though. |
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I have two MK111 MOD1’s that I run Rex Silentium cans on. H2 buffers work fine. I have a H2 JP system in one of them that runs great. I’ve never run them without the bolt spring. PWS Mlok handguards are hit or miss (lots of miss) as far as being in stock. Yeah, once the barrel is gone you’re kind of screwed. But if you can afford that amount of ammo another upper probably is a drop in the bucket. The biggest wear issue I have found is cam pin wear on the upper. Some guys run roller cams to help mitigate this but PWS says not to (or that they’re not needed). Mine wore quick but then stabilized and have not caused any issues. Congrats. They are excellent guns. 
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My MK111 MOD2 SBR uses a Geissele H2 with braided spring. It has a Surefire SOCOM RC2 on it full time and runs well on the suppressed setting. I have an older MK112 MOD1 that also runs fine on either suppressed setting with 5.56 or .223 pressured ammo, same buffer and spring combo. |
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