[HKAddiction]

Well I tried the RCM 80 Degree LP in my PTR 9KT clone and it would shoot 126 fmj fine, but 147 gr SuperVel Subsonic (900 fps) and 150gr Federal 150 Gr syntech shot once then the bolt wouldn't go back or the next round would jam in the bolt. I switched back to the 100 degree LP and the 147 gr Supervel shot with no problems. The bolt gap with the 100 degree is about .018 to .019; very tight with the .020 gauge feeler and ok with the 45mm guage. Is it ok to use the 100 degree LP or what should I look for as in damage wise on the pistol. There was no marks on the rear buffer.

 

[Twinsen]

From what I've read, 100 degree is for stockless K guns, 80 is for running with a stock and/or silencer.

 

[BulkHead]

Any dimpling/dents in the rails?

 

[djohns11]

Well I tried the RCM 80 Degree LP in my PTR 9KT clone and it would shoot 126 fmj fine, but 147 gr SuperVel Subsonic (900 fps) and 150gr Federal 150 Gr syntech shot once then the bolt wouldn't go back or the next round would jam in the bolt. I switched back to the 100 degree LP and the 147 gr Supervel shot with no problems. The bolt gap with the 100 degree is about .018 to .019; very tight with the .020 gauge feeler and ok with the 45mm guage. Is it ok to use the 100 degree LP or what should I look for as in damage wise on the pistol. There was no marks on the rear buffer.

I had the same experience. The 80 is too unreliable or ammo sensitive. The original LP for the KT I got was 110 degree but I use a 100 which is the same on my CT (I have both models) and works perfect. Over 2000+ rounds (mostly subsonic with a silencer) later no issues. No dimples or roller marks. Don't shoot much now until ammo prices come down.

 

[Goat]

I very briefly had a 9KT. It came with a 100 degree locking piece from the factory. I checked the bolt gap as soon as I got it home and it was .45 mm. I installed a MAD bolt and a RCM 80 degree piece. Checked the bolt gap and it was almost 1 mm.

I sold it straight away.

 

[jontr]

I very briefly had a 9KT. It came with a 100 degree locking piece from the factory. I checked the bolt gap as soon as I got it home and it was .45 mm. I installed a MAD bolt and a RCM 80 degree piece. Checked the bolt gap and it was almost 1 mm.

I sold it straight away.

can you explain more? why do you sell it? thanks. i'm new to this.

 

[Goat]

I sold it because it was barely in spec with the factory locking piece. My intention was to shoot the gun suppressed and stocked. I did not want to mess around with installing under size rollers hoping to get the gap with the 80 degree piece into spec.

 

[jontr]

I sold it because it was barely in spec with the factory locking piece. My intention was to shoot the gun suppressed and stocked. I did not want to mess around with installing under size rollers hoping to get the gap with the 80 degree piece into spec.

thanks for an update.

 

[ottoz355]

thanks for an update.

I’m a little confused- a 0.45mm (0.018”) initial bolt gap is exactly what you’d want on a new gun. It’s near the top of the range, which is fine because as the gun wears out, the bolt gap gets smaller as the rollers get smaller. But it’s a little alarming that the gap would open up to 1mm with the addition of a new bolt and locking piece, assuming both are in spec. A little off, maybe, but doubling is different.

FYI- PTR is finally coming out with their own 80 degree locking piece soon, and supposedly no mods should be needed on the 9KT with it. FWIW, I tried an RCM 80 degree lp with mine, and it fits the PTR bolt fine (have read it will fit or won’t fit from different people), but haven’t shot it since I stuck it in.

Question- when you got failures with the subsonic ammo, was that with or without a can? And which mags- the plastic ones, KCI, German? Just wondering, so I know what to expect when I get to the range next time.

 

[Pilot172000]

I bought an 80 degree for my 9kt. It fit the first PTR I purchased well, but I had to send it back and they sent me a new gun. It will not fit in this one and I just don't have the patience to send it back to them again.