JP-5™ Reconfiguration & Tuning video

[Tampa-XD45]

20 minute video by Max L. on the JPRifles YouTube site for you JP-5 owners:   https://www.youtube.com/watch?v=2mfEsvA6260

[Blackstone45]

Thanks for sharing

[jerseyglock]

[Bdh821]

In my opinion, there is 1 key focal point of the entire video.  Specifically at 20:07 of the video

[brian45acp]

Love my 60 degree lock piece with lightest spring. Not sure why people say it wont work and is for hot duty ammo. 

Edited November 15, 2023 by brian45acp

[sharko]

I'll have to try different springs, I tried a 60 and 70 lock piece and couldn't tell any difference except a failure to lock on empty with the 60. Maybe I should try the 90 since one of these days. 

[Dr Mitch]

Interesting, thanks for sharing

[PaleoMan]

23 hours ago, brian45acp said:

Love my 60 degree lock piece with lightest spring. Not sure why people say it wont work and is for hot duty ammo. 

What bullet weight, and power factor do you use?

 

Mine will come with 80 degree piece and I ordered the 70 as well. Will want to see what works best for my setup (125 grain, about 132 PF for 5" barrel pistol).

 

Also, I seen a few videos from JP on this. They all say to do the lock piece first, but one said to do springs next and the other said to do the weights next. I'm wondering which has more effect.

 

I'm hoping to meet up with a friend, when I get my JP-5, as he has an SCS with tungsten weight on his (not sure if he has a lighter spring), and I can swap locking pieces and SCSes to see how things go.

 

 

[brian45acp]

12 hours ago, PaleoMan said:

What bullet weight, and power factor do you use?

 

Mine will come with 80 degree piece and I ordered the 70 as well. Will want to see what works best for my setup (125 grain, about 132 PF for 5" barrel pistol).

 

Also, I seen a few videos from JP on this. They all say to do the lock piece first, but one said to do springs next and the other said to do the weights next. I'm wondering which has more effect.

 

I'm hoping to meet up with a friend, when I get my JP-5, as he has an SCS with tungsten weight on his (not sure if he has a lighter spring), and I can swap locking pieces and SCSes to see how things go.

 

 

I run 124grn going 1150fps and use the lightest spring. Ejection is 7-8 feet and never had a malfunction.

 

I plan to play around some more and see what a 70 lock piece and heavier spring does with a lower power factor load which would be 124grn going 1050fps. Only reason is my back up rifle is my gmr13 and I’m trying out the new Maxim buffer. I want to try and make that rifle feel like jp5 and if I can then I want just one load for pcc not 2.

 

[Eidoss]

I saw a video on JP Rifles YouTube channel that says the higher lock pieces 90, 100+ are for steel challenge, light loads.
They also say the 70 lock piece is ideal for competition (USPSA) because it recoils less.

Isn't that contradictory? I would imagine steel challenge guns have less recoil.

[Darqusoull13]

38 minutes ago, Eidoss said:

I saw a video on JP Rifles YouTube channel that says the higher lock pieces 90, 100+ are for steel challenge, light loads.
They also say the 70 lock piece is ideal for competition (USPSA) because it recoils less.

Isn't that contradictory? I would imagine steel challenge guns have less recoil.

Keep watching where they explain what the lock piece is doing. 

[rpm8300]

I've run my JP5 for a few matches now and the 70 degree seems to be the sweet spot for 124s at 135PF.  Of note, I left everything else pretty much stock to get a good baseline, with the exception of a wave spring at behind the SCS.  The PCC is legit - definitely better than a traditional blowback and 1000% more reliable than the 3 MPXs I ran.

[Sparryttaren]

Exactly which wave spring and does the mechanism work just as well as before?

[Eidoss]

Max mentioned on the SuperVel video of his ammo Video
That he uses the 70locker with the 90%SCS.
The only scs I find with 90% is the one for the AR15 on JPRifle website. (JPSCS-SPRING15-90: 1 side green), is this the one he is using?

[Blackstone45]

8 hours ago, Eidoss said:

Max mentioned on the SuperVel video of his ammo Video
That he uses the 70locker with the 90%SCS.
The only scs I find with 90% is the one for the AR15 on JPRifle website. (JPSCS-SPRING15-90: 1 side green), is this the one he is using?

Yes, in fact if you watch the tuning video in this thread, you'll see that he recommends getting the AR-15 and AR-10 springs packs so you get the full range of springs to try (80 - 110%)

https://www.jprifles.com/buy.php?item=JPSCS-PACK15

https://www.jprifles.com/buy.php?item=JPSCS-PACK10

[telligentgunner]

If anyone's buying any parts, use "MILES" at checkout for 10% off.

[Stefan77]

On 11/14/2023 at 6:43 PM, brian45acp said:

Love my 60 degree lock piece with lightest spring. Not sure why people say it wont work and is for hot duty ammo. 

Same here.  I have ran it with the 70 and 80 and keep going back to the 60* cam.  You have to be aware that running the 60* cam with lighter ammunition can cause problems.  I once canted my PCC with the ejection port facing up using some Eley PCC ammo (shoots really soft but the JP seems like it is running a bit slow with it) and it didn't fully eject inducing a failure.

I do like the Eley PCC ammo but I like the Federal Syntec130grn PCC ammo more. Blazer Brass 115 grn shoot pretty well also with the 60* cam.  

I am debating on playing with the spring rates.  I am really happy where I am at so I'm not sure how much more playing around with it that I want to do?

[cferree]

On 12/1/2023 at 12:04 PM, Stefan77 said:

Same here.  I have ran it with the 70 and 80 and keep going back to the 60* cam.  You have to be aware that running the 60* cam with lighter ammunition can cause problems.  I once canted my PCC with the ejection port facing up using some Eley PCC ammo (shoots really soft but the JP seems like it is running a bit slow with it) and it didn't fully eject inducing a failure.

I do like the Eley PCC ammo but I like the Federal Syntec130grn PCC ammo more. Blazer Brass 115 grn shoot pretty well also with the 60* cam.  

I am debating on playing with the spring rates.  I am really happy where I am at so I'm not sure how much more playing around with it that I want to do?

Did the Blazer 115 lead the comp bad?  I picked up several K on black Friday sales.

[Boomstick303]

My experience has been am FMJ that has exposed lead on the back of the bullet will lead the comp.  Its not anywhere near as fast as coated bullets but it still leads up.  JHP is the way to go if you want to prevent leading.

[cferree]

I usually run MGB or Precision Delta JHP's.  The only factory ammo I've shot is Speer Lawman 115 TMJ's.

I was just curious if the lead in the Blazer's was hard enough that it only lead the barrel a little or is it soft and leads a lot.

[Nolan]

On 12/2/2023 at 11:15 AM, cferree said:

I usually run MGB or Precision Delta JHP's.  The only factory ammo I've shot is Speer Lawman 115 TMJ's.

I was just curious if the lead in the Blazer's was hard enough that it only lead the barrel a little or is it soft and leads a lot.

 

I've run a lot of the cheap Blazer 115gr through my MPX and never had a leading problem.  I don't have anymore on hand,  so I can't check, but I think it's a plated bullet with no exposed lead.

 

Pull one and check.

 

Nolan

[Stefan77]

On 12/2/2023 at 12:41 PM, cferree said:

Did the Blazer 115 lead the comp bad?  I picked up several K on black Friday sales.

I have probably 1K in Blazer Brass on my JP5.  While it is really soft shooting it is dirtier then a lot of other ammo I shoot.  I have leading on the comp from it but it is nothing that really bothers me (little elbow grease and it will clean up).  I prefer to use Federal 130grn PCC Syntec and that is mostly what I feed through it.  The next best ammo that I like shooting through it is Eley PCC ammo.  

[telligentgunner]

I will be testing out the Winchester white box 115 gr with the 60 locker.  I've been shooting Super Vel 115 gr through it and have been having 1 jam (double feed) per match lately.  It cost me a win at a major match recently.

 

I'm suspecting it's the ammo because it ran flawlessly through my JP-5 at USPSA nationals.  But like Max says, it's on the edge.  The Winchester of away from the edge, it's new brass, and I can also shoot it in IPSC and IDPA.

 

Every time I run the Sellier & Bellot ammo, it just runs flawlessly but I want less PF. 

 

FYI, I was disqualified at nationals for shooting the Super Vel 100 gr. PCC Blitz.  I assumed it would be okay since USPSA is affiliated IPSC, but I was wrong.

 

There are some tips about choosing ammo toward the end of this video:

 

 

Edited December 4, 2023 by telligentgunner

[Blackstone45]

yep IPSC PCC requires a minimum 115gr bullet. not sure why - I guess for maximum velocity safety reasons.