Issues with Century Arms AP5SD Shooting with Suppressor, Subsonic Ammunition and FRT
Hey all,
I have a Century Arms AP5SD that uses a Warhammer Armaments FRT in a Lee Sporting LS5 Lower. It also uses an HK 90° Locking Piece (down in degree from the factory 120° LP that came on it) and a little printed stop block in the trigger group.
Up to this point, it was run FLAWLESSLY in FRT mode.
However, I recently got a PTR Vent 2 with a SilencerCo 3-Lug Mount and some Freedom Munitions 165gr. Hush Subsonic Ammunition.
Now when I fire with that suppressor and ammo, I CONSTANTLY am having FTFs, FTEs and StovePipes.
It worked flawless for 1 magazine in semi-auto and 1 only. Now it has those issues in semi-auto. And don’t even think about FRT mode. It’s just dead.
Now, I know all about the need for tuning and bolt gap and using different locking pieces and + or - size rollers and check bolt gap with feeler gauges.
When I installed the 90° HK Locking Piece, my bolt gap was at like….25.5mm which is barely in spec. But many of my you said it was fine while others said to add some +1 or +2 rollers.
Originally when I spoke of my plan to FRT and Suppress, many of you said to go with a 90° or even 80° LP. (Hence why I added the HK 90° LP).
I already have some + size rollers in my possession but haven’t installed them yet, as many of you previously recommended just running it as is (with the 120° LP and factory rollers).
I had already swapped to the 90° LP but never installed my rollers.
Thus we are here.
*****I’ve found that it feels like the 165gr. Hush Subsonic ammo is actually the bigger issue….as I can fire in semi with regular, non-subsonic 9mm through that suppressor and have probably 1 issue out of a 30rd. mag. But with the subsonic ammo in, even WITHOUT the suppresssor; just shooting subsonic unsuppressed; it still has the aforementioned issues.
In either case though, running in FRT with either the suppressor or subsonic just straight up doesn’t work period.
So I know both the ammo and suppressor are contributing to the issue.
So…what do I do?
Leave the HK 90° and add my +size rollers to try to get closer to the middle sweet spot between 0.25mm and 0.45mm in my bolt gap?
Or something else entirely.
*PS - Highly doubt this matters at all but figured I’d mention it, I also swapped the factory roller retention spring for one of the HK modern springs (the ones that don’t use the retention plate and just look like a single strand of zig-zagging wire with hooked curls on either end)
Thanks in advance!