Load data needed for mpx and jp5

[jeremy kemlo]

I’m trying to work up a reliable USPSA load for my daughters recently acquired sig mpx 16” barrel gen 2 and  my dad’s recently acquired  JP5 steel challenge version 14 1/2 inch barrel with comp and 70 locker. 
 

I’m trying to keep things simple and use what I have unless someone would recommend a different bullet or powder that would be significantly better.

I have Everglade 115 full metal jacket bullets and Bayou Bullets 145 grain coated bullets. powder is n230. 
 

Anyone have a favorite load for either gun using 115 or 145 and n320?  
Thank

[MCW]

I have used 4.5gn of N320 with 115gn bullets. It has a PF of 128 in my JP5. It is a flat shooting load. 

[Salsantini]

I use 115 FMJ from RMR in my MPX.  4.0 gr of AA2.  1.10 OL.  Soft shooting and reliable.  Most of the poly coated bullets I've tried need to have a really short OL.  The profile is fatter at the tip of the bullet and sticks in the lands of the MPX.  If you have N320 I would start at 3.9gr.  4.5 gr is a max load for N320.   Use the 115 gr Everglade and keep the OL to 1.10.  

[philmadxx]

The 70 degree locker should be fine with most everything as long as don’t want to shoot really soft rounds, like some syntec rounds. An 80 degree shoots everything.

I use 3.9 gr N320 with 124 RMR RN bullets set at 1.118. PF about 125. Accurate, flat, reliable.

Good luck.

[Bdh821]

4.5gr Alliant Sport Pistol under a 115 @ 1.130” is what I run in MPX and JP5

[miller9128]

I just started reloading about the same time I picked up my SIg MPX, 16" barrel for USPSA. I am using 147 Berry RN, 3.8 CFE Pistol, 1.136 OAL. I have had a couple jams and sometimes the trigger seems to lock for 1/2 second. TOday was the first time I had a double feed. THe RO told me today it appeared gases and sparks where coming out the port. I'm looking for any suggestions.

[cferree]

4.5 of N320 under a 115 MGB JHP @ 1.100 OAL, runs great in my JP-5 with the 70 degree locker.  It's a 136 PF.

The recoil impulse make for quick dot recovery.

[jeremy kemlo]

31 minutes ago, cferree said:

4.5 of N320 under a 115 MGB JHP @ 1.100 OAL, runs great in my JP-5 with the 70 degree locker.  It's a 136 PF.

The recoil impulse make for quick dot recovery.

Thanks. I think I will give this a try. 

[rpm8300]

The MPX is a finicky PCC - I ran it off and on for years but couldn't get the consistency I wanted so ended up with a JP5. That being said, I had the most success with 115 or 124 FMJs and a slower powder to get the gas going.

115gn, 1.11 OAL, 4.9 WAC gave me 1140 fps.

 

Good luck with it,

[jeremy kemlo]

28 minutes ago, rpm8300 said:

The MPX is a finicky PCC - I ran it off and on for years but couldn't get the consistency I wanted so ended up with a JP5. That being said, I had the most success with 115 or 124 FMJs and a slower powder to get the gas going.

115gn, 1.11 OAL, 4.9 WAC gave me 1140 fps.

 

Good luck with it,

I have some factory Winchester white box 115 and blazer 124 factory ammo. How would those compare to your reloads? Reliability and recoil impulse?

[rpm8300]

16 hours ago, jeremy kemlo said:

I have some factory Winchester white box 115 and blazer 124 factory ammo. How would those compare to your reloads? Reliability and recoil impulse?

I think that would be fine although you'll be pretty hot on power factor.  Anything 115 or 124 will have more than enough powder to work the piston. You may want to spot check your tappet after a few hundred rounds to see how caked it is.  As far as recoil, it will be hotter for sure but that may not make much of a difference to you.