My first PCC (JP Short Stroke I hope)

[D3w4yne]

Hey everyone. Browsing around on the forum here I've found some great info on the JP 9mm short stroke set up. I used a JP SCS in my first AR build and I absolutely love it. I am hoping to do the same in my latest "AR9" build. Makes sense to use both JP's SCS and BCG but it looks like there's not much info on their latest BCG that has a LRBHO feature (https://www.youtube.com/watch?v=fj6FKup8KIw). My receiver set isn't very main stream but it does have a traditional looking LRBHO feature, I think. I purchased it from Core Rifle Systems specifically because they're local to me and I felt like supporting a local shop as much as possible. The receiver set looks nice and solid, offers ambi bolt catch and mag release (although the bolt catch lever already broke off.... hopefully they'll take care of that).

 

Anyhow my questions are:

 

Does anyone have any experience with JP's latest 9mm bolt?

 

After doing some research on these forums (https://www.jprifles.com/document_pdfs/SCS Selection Guide_758.pdf) and watching the JP media it sounds like the 5 steel version would probably be OK. When/why would I need to go heavier?  I do have some tungsten weights from my other piston AR that I could swap out in case I need to tweak it, before buying more weights ($40/ea is tough).

 

My goals for this build are more in the "PDW" realm of things, but I am very very interested in some of the local PCC stuff that's going on. It looks like a lot of fun and hopefully it's something I can do as more of a recreational thing. I am willing to invest in the meat and potatoes of the gun first and I've had nothing but success with my last JP SCS set up but $440 is almost half the gun though... hah. Just looking for some confirmation before I drop that much on this pistol.

 

Here are few pics of the bolt catch on my receiver in case it helps:

 

https://imgur.com/a/GQLKZsD

 

I hope links are OK. My pics exceeded the max upload size.

 

Thanks!

 

Dewayne

 

 

 

 

[Darqusoull13]

I have been running the new bolt for a while now. It's solid and it works exactly how I expected it to work in my GMR-15 with the LRBHO. 

The Short Stroke SCS improves the recoil cycle more than any other part on the rifle. Right now I'm running the 5 stainless Short Stroke SCS in one of my rifles. Actually I just had 3 guys run the same rifle at our local match Sunday. The words "Witchcraft" and "Dark Magic" came up with regard to that PCC. 
 

[egd5]

My gun has the new bolt (I assume) and it worked every time when I first got it. But now I'd say it locks back probably only 60% of the time. I don't know what has changed. It's not a real big deal to me, although I do like it to lock back. It has a different feel when it locks back and I know I'm empty vs a malfunction. Then I know what to reach for first, the spare mag or the charging handle to try to clear it.

And I know, I should never run empty, but.....stuff happens.

[D3w4yne]

@egd5 are you using a JP lower? If not do you have any pics of your bolt catch you could share? From the best I can tell the new bolt came out around July maybe? Just going by the posting date of the YouTube announcement video.

 

@Darqusoull13 I looked up some pics of the GMR-15 lower receiver and the bolt catch looks pretty similar to mine. Mine has the "lever bar" exposed but I am not sure that would make much of a difference. Thanks for your input. I am super excited about this system. Hopefully it works out.

 

I stopped by Core Rifle Systems today and showed them my broken ambi bolt catch. The guy behind the counter took it and immediately went right to the gunsmith in the back. They replaced it no questions asked. Really made me feel a lot better about my day since that had been stressing me out.

 

Thanks fellas!

 

 

[egd5]

Mine is a GMR-15 from JP. I received it about the middle of June. Before getting it I had called my salesman at JP and asked about it and he said he didn't know if the new bolts were ready yet, but he would see. I didn't want to delay delivery any more to wait on it so I said ok,  put one in if you can. When it came it held open so I was surprised.

I don't have pics and not sure how to post here. Sorry.

[D3w4yne]

Thanks again. I think I will try my luck and see how the system works out with my particular lower receiver. I'll post some pics once it's done and maybe it will help someone in the future.

 

Are there any JP coupon codes out there? I found one on the forum here but it looks like it's invalid or expired.

 

Thanks again for the feedback.

[Darqusoull13]

16 hours ago, D3w4yne said:

Thanks again. I think I will try my luck and see how the system works out with my particular lower receiver. I'll post some pics once it's done and maybe it will help someone in the future.

 

Are there any JP coupon codes out there? I found one on the forum here but it looks like it's invalid or expired.

 

Thanks again for the feedback.

Check your PM's 

[D3w4yne]

Ty sir, you rock!

[D3w4yne]

So far so good! The build is not complete yet (no barrel) but the bolt does hold open if I pull it back on an empty mag. It will pick up a round from my ETS mag as well.

 

I know that may not sound like much but with so little info out there about this new bolt and non-JP lowers I am pretty stoked!

[Hawk21]

5 hours ago, D3w4yne said:

So far so good! The build is not complete yet (no barrel) but the bolt does hold open if I pull it back on an empty mag. It will pick up a round from my ETS mag as well.

 

I know that may not sound like much but with so little info out there about this new bolt and non-JP lowers I am pretty stoked!

What barrel have you decided on?  

[D3w4yne]

I have a Rosco 7.5" barrel on order but it's back ordered. It appears to be out of stock everywhere on the internet... That's either a good sign or a bad sign, not sure which yet.

 

I have a 7" rail and since 9mm barrel lengths include the extension I thought a 7.5" might fit nicely with a 7" rail and have just a touch of my muzzle brake under the rail.

 

This is the brake I ordered (also back ordered): https://venom-defense.com/ar-15-linear-compensator-1-2-28/

 

Not many other 7.5" barrels out there though.

[D3w4yne]

Well... this was unfortunately a complete failure.

 

When I purchased the upper and lower receiver set from Core Rifle Systems they failed to inform me that their lower does not have an ejector, and I failed to notice.... They've designed their own "upgraded" BCG that has the ejector on the bolt face similar to an AR15 bolt. So my new hotness JP SCS and BCG will never work with these receivers. I went by Core to see if we could work something out and the only option I had was to purchase their proprietary BCG.

 

Being that I was supposedly the first person to ever purchase just an upper/lower from them, I advised them that they should not ever sell anyone an upper lower without their BCG since it's worthless without it.

 

I wanted to support a local business but I regret this purchase tremendously. An AR platform that's locked into a proprietary part just baffles me.

[BartCarter]

Did you pay by credit card?

 

Did they inform you that it would only work with their BCG?

[D3w4yne]

I did pay with a credit card. They did not inform me that it would only work with their bolt prior to purchasing. I ended up buying their bolt several weeks later after I discovered that it was the only option.

 

I still have the JP system and probably couldn't return it by now. It has been an expensive lesson to say the least.