JP SCS in FM9 7" Help

[ShaneO-22]

Hi Everyone, 

 

First post here but i have to admit i've been learning from the forum ever since my first PCC purchase in March of this year, so it has been a long time coming. I have a 7" FM9 that i have only about 150 rds through that I really bought for my wife. The pistol had of course an AR10 spring in it with their factory buffer and the slimmest CH i've ever seen and it was a BEAR to charge. Really impossible for a 125 lb girl. 

 

Did some research and went with the JP SCS enhanced drop in kit and a nice ambi charging handle and she can charge it fine and it made an unbelievable difference in the difficulty to charge the weapon, probably 60% better or more with the smoother SCS and wide handle. Now i am running into some issues tuning it with the spring or system being a little to light (i think???) The bolt will lock back after 1-3 rounds with Winchester 115gr ammo. Recoil feels better of course but I think the system is just too light, but i am a noob. 

 

I can't get anything from JP or Foxtrot Mike because now i have done the dirty and crossed companies parts and neither wants to give any advice because of all the unknowns. If there is anything that i have learned from PCCs its that each is pretty unique in itself and there are tons of unknowns; between springs, bolt weights, ammo, etc. so i understand but also puzzled at the same time. 

 

Outside of the JP SCS its a fully factory FM9, and maybe i just need to try JPs Auxilary Spring Rate kit or some quarters in the back or different ammo or all of that? JP has certainly had the opportunity to make the suggestion to buy their extra springs but they are super tight lipped and don't even want to make a list of suggestions. I've read several places where some FM pro shooters are running similar setups by using the JP SCS but again, hard to pin down details. 

 

Thank everyone out there for what i have already found, I'm sure i can get this working, just hoping to get some experts thoughts out there?

 

Thanks, 

Shane

[egd5]

Since no one else has answered I'll give it a try. I shoot a factory JP and I know nothing about FM products. But, as for the scs system. I'm assuming you have some combination of buffer weights from jp. If you're shooting factory ammo you need more weight in the buffer than for light reloads. I would recommend at least 3 tungston/2 steel or maybe even 5 tungston. I don't know what you have now though.

You are right that there is an almost infinite set of variables involved in getting a pcc set up just right. I hope this may help.

[texasdawg]

You need to supply more info to help diagnose your problems. What mags,  specifically what buffer and weights, which barrel, which spring in use, any spacers in buffer tube,,, the gun shouldnt lock open after three rounds, mag problem or the bolt is cycling too far? Your gun is not even close to a franken gun, so dont fret. 

[ShaneO-22]

Thanks to you both! Sure thing, I have the enhanced gen 2 SCS version that comes with everything available installed on the component, so no extra weights or springs in the box. 

 

I have 3 shiney weights (assume stainless steel) and 2 matte grey weights (assume tungsten) on the system right now. The bumper at the end is the flat style and the spring is the only one i have, looks like it has some red coloring to about half of the spring. No spacers used, although I'm thinking of trying the quarters behind the system next time I'm at the range with different ammo and mags. I wish i knew what strength spring came with this kit to compare it to the 3 that JP offer in their auxiliary spring rate kit that they have 3 stiffness options. It looks like it is the 1 side red, 1 side uncolored which i think from JPs website is the medium strength of the options, so there looks to be just 1 more stiffer strength spring available if that is the case.

 

Mags I've been running are Glock factory 24rd. Barrel is 7" tri-lug from FM, and as you mentioned basically a factory gun minus the JP SCS. I followed the instructions on bolt to SCS fitment so there is no rattling or space between the two.