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JP 15-GMR several buffer systems tested


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Dear all,

 

I am relatively new to PCC please keep this in mind when reading. I started with the new Sig MPX and wanted to love it (and loved it for some time)  but with 1 out of 50 FTF with factory ammo + much more complex to clean then a JP) I sold it... and bought the JP which has been super reliable and gives this proud of ownership feeling (it's a Mercedes amongst cars..)

 

Today I shot some 600 rounds (all 115 GECO factory at 150 PF)  testing 3 buffer set ups for the JP 15-GMR. All shots double tap as fast as sights allowed looking for smallest group / fastest sight recovery at 12 meters (13 yards):

 

* MBX (yellow spring as supplied + blue spring which is softest)

* JP Short stroke 3 steel, 2 Tungsten

* JP Short Stroke 5 Tungsten

 

My judgement:

 

* JP 3 steel/ 2 tungsten : hardest perceived recoil, fast dot recovery, dot going up a bit and to the right, good group (<5 inch)

 

* JP 5 tungsten: softer feel compared to above but somehow a little bit slower feeling.. Group ok, slightly wider then the above

 

* MBX: softest as for recoil by far (really noticeable even if its only 9mm), group was little better then JP 3/2 system. But... Feeling was more ' sluggish', it just didn't feel right to me... Can't explain it better. And you need a lot of locktite to keep all together,  some pieces came loose after only 100 rounds..

 

Overall: the way you grip the gun does more then the buffer system.

 

For now I stay with the 3 steel 2 tungsten JP system for feeling (and reliability).

 

A blitzkrieg system is underway as a new JP from a friend with the standard all steel buffer. So next comparison will come.

 

Kind regards,

Henk

Edited by Fasthenk65
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On 12/15/2019 at 3:09 PM, Fasthenk65 said:

And you need a lot of locktite to keep all together,  some pieces came loose after only 100 rounds..


Something seems off there. I've got way more than 100 rounds with an MBX buffer and haven't had any issues like that.

That said, the Blitzkrieg HD buffer with the spacer weight to short stroke it is currently my favorite setup. About 135 PF is good for me.

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22 hours ago, rowdyb said:

I shoot 140-145pf, 147gr ammo as I pretty much only shoot the pcc in idpa (135pf versus 125pf in uspsa for pcc). I run enhanced bolt, short stroke, 4 tungsten, 1 ss. With the lighter than stock spring.

Rowdy,

 

My pistol load (147 plated RN with 3,4 gn N320) is going down in PF (129 in S2, 125 in JP). Changing bullet and powder (slower) solves it. With 123 gn bullet and a bit slower powder it goes up from 130 in S2 to 139 in PCC (16 inch barrel, like it should). What is your magic recipe?

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Well that's part of the "problem" hahahaha. My pistol load and my pcc loads are different. With using a 147gr bullet and a fast powder I have one powder charge weight for a 130pf pistol load and another for a 140pf pcc load.

 

In my case it is a 147gr Berry's round nose, loaded to 1.145" oal with 3.30 grains of Sport Pistol for my uspsa pistol load and 3.60 grains for my 140pf pcc idpa load.

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I can't decide to leave well enough alone or venture out and try new stuff. I have the GMR-13 and run the JP short stroke kit 1 Tungsten and 4 stainless. I am at a 140pf using 124 grain bullets and the gun runs amazing. I just wonder if its me on distance shots going to slow or if a hydraulic buffer would smooth out the gun and allow me to go faster. 

 

 

Do you guys think between the JP buffers and the Blitz hydraulic there is a big difference? I just scoped their website and now they have a weight spacer that makes the blitz a short stroke. My concern is what is reliable and what is good for the rifle that won't beat it up.With the mass of the JP weights gone that bolt will fly to the rear so that hydraulic buffer better take the energy and soak it up. 

 

Any more thoughts?

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Using 139 PF ammo changed the game.

 

With 3 PCC shooters we shot 20 shots each for each set-up as fast as dot recovered (let's say double taps most).

 

The MBX system had a smal group but 2 out of 3 didn't like the sound of the buffer traveling... it just did not feel good though groups were good.

 

1 liked 5 tungsten better (all said it felt 'softer' then 3 steel/2 tungsten), me and the other guy had best results with 3 steel / 2 tungsten in terms of speed/groupsize.

 

All by all not so many differences (less then expected) and personal taste is a big thing. Grip does it all.

 

I stay with JP buffer system, feels better. Next is 5 steel... coming in in a few weeks..

 

 

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On 12/21/2019 at 9:46 AM, Fasthenk65 said:

Using 139 PF ammo changed the game.

 

With 3 PCC shooters we shot 20 shots each for each set-up as fast as dot recovered (let's say double taps most).

 

The MBX system had a smal group but 2 out of 3 didn't like the sound of the buffer traveling... it just did not feel good though groups were good.

 

1 liked 5 tungsten better (all said it felt 'softer' then 3 steel/2 tungsten), me and the other guy had best results with 3 steel / 2 tungsten in terms of speed/groupsize.

 

All by all not so many differences (less then expected) and personal taste is a big thing. Grip does it all.

 

I stay with JP buffer system, feels better. Next is 5 steel... coming in in a few weeks..

 

 


 

I am at 1 tungsten and 4 steel but for no good reason other than I started with that after my short stroke upgrade and it ran so I kept it. I wonder if adding another might tame it a bit more. I’m also at 140pf using 124grn bullets. 
 

In one sense it’s more weight to slow the impact rearward but I always wonder how much the impact forward causes issues with dot movement. 

Edited by brian45acp
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On 12/19/2019 at 9:16 PM, rowdyb said:

Well that's part of the "problem" hahahaha. My pistol load and my pcc loads are different. With using a 147gr bullet and a fast powder I have one powder charge weight for a 130pf pistol load and another for a 140pf pcc load.

 

In my case it is a 147gr Berry's round nose, loaded to 1.145" oal with 3.30 grains of Sport Pistol for my uspsa pistol load and 3.60 grains for my 140pf pcc idpa load.

So same experience though I always thought longer barrel increases velocity... Going up from pistol load solved the problem!!

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