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LowBoost

Yet Another JP GMR15 or MPX thread.

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First of all, let me clarify that I own a Gen2 MPX K PSB (4.5") which the wife has barely shot, but she likes it in the SBR and suppressed configuration as there is no recoil.

Since it is still under 100 rounds, we have not experienced any of the reported issues by many but I expect I will have to clean and oil soon as suggested with high/early maintenance to avoid issues.

 

This being said, we would like to start shooting IDPA PCC and USPSA and we are looking for a PCC that is reliable and simply runs without issues and of course that has minimal recoil.

I almost ordered a JP MGR15 three times this week, but still not 100% on which way I should go. Should I wait for the new MPX Carbine shown at SHOT Shows 2018 and see if it will be much better and not as frequent maintenance than current Gen2 or simply go with a JP GMR15 and work a load that would possibly provide a similar low recoil as an MPX?

 

Suggestions?

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Before you make a decision, you might look at the new Ruger PCC. 

 

 

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I've been using GMR-15 all summer, it's never failed me and Very, very accurate!

Siverscooby, I don't know of any 9mm that kicks. lol

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Steve: I have a lot of respect for you and your wealth of knowledge, but I think I'll keep my option between these two for now unless a drastic game changer shows up in the next day or two.

 

Based on all the comments I have read, I am sure the JP is among the most (If not the most) reliable there is. Their no BS warranty and customer service is also a great selling point. The low maintenance is a huge selling point for me. Weight is not much of a concern as they both weight less than my 5.56ARs. Price would be about the same unless Sig decides to hi-jack the price on the new model as is industry standard practice with very few exceptions.

 

So, as mentioned earlier this decision boils down to maintenance and soft shooting. Does anyone that has shot both can tell if I can make the GMR15 shoot as (or close to) soft and flat as the MPX? Perhaps the trade-off of reliability is that extra recoil? 

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15 minutes ago, LowBoost said:

Steve: I have a lot of respect for you and your wealth of knowledge, but I think I'll keep my option between these two for now unless a drastic game changer shows up in the next day or two.

 

Based on all the comments I have read, I am sure the JP is among the most (If not the most) reliable there is. Their no BS warranty and customer service is also a great selling point. The low maintenance is a huge selling point for me. Weight is not much of a concern as they both weight less than my 5.56ARs. Price would be about the same unless Sig decides to hi-jack the price on the new model as is industry standard practice with very few exceptions.

 

So, as mentioned earlier this decision boils down to maintenance and soft shooting. Does anyone that has shot both can tell if I can make the GMR15 shoot as (or close to) soft and flat as the MPX? Perhaps the trade-off of reliability is that extra recoil? 

I have both guns you mention now for over a year.  I had to spend a ton on the MPX to get it reliable (Gen2) and the parts and magazines are all very expensive.  Once I got it done the MPX shot well.  The GMR-15 was awesome right out of the box with one exception, weight (personal opinion from  a 160 lb shooter.  So I changed the hand guard out for a carbon fiber one along with the required new barrel nut.  The factory trigger is amazing and my pull is at 2.75 lbs with no take up or over travel. It is my go to gun in all situations.  Easy to clean and maintain and factory support is second to none.  I also tried a lighter weight barrel (BSF carbon fiber tension barrel) and found it made the gun too light in front, so I stayed with the stock JP barrel which is very accurate.  My JP weights in a 6.6lbs as shown but with the stock JP barrel.  Hope this helps.

IMG_1604.JPG

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10cup - The single question that I have not received an answer from yet. How does recoil compare between the two? I am fully aware this is just a simple 9mm round, but there are substantial differences between different systems. Can the GMR15 shoot as soft with a proper load?

 

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Yes easily!  The JP buffer system is tunable the MPX isn’t.  The felt recoil between the two rifles is negligible. (Personal opinion)

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Thanks for the information. I was hoping for someone to mention the tunable buffer system. ;)

One more thing you brought up that I overlooked....The cost of magazines! $80 vs $30!!! 

 

I think I will give the JP a try.

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Glad to help.  Good luck. 

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Hello: The first thing should be do you reload? If you do then the JP can be made to shoot softer than with factory loads. Tune the buffer and make some reloads in the 130PF range with 124's or 147's whichever she likes more. IDPA is going to be 10 round mags if I am correct? Sig 10 round mags go on sale for around $15 and so do Glock 10rd mags. I don't own a JP but have shot quite a few and they shoot well but need upgrades to make them better. I just build my own AR9's and use some JP parts. My Sig works well but it had to go on a diet as well. Carbon fiber handguard and a 16" barrel upgrade. So here we are, if you don't reload get the Sig. If you reload and like to tune get the JP. Thanks, Eric

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1 hour ago, Aircooled6racer said:

.... IDPA is going to be 10 round mags if I am correct? ...

 

Good news, per current IDPA Appendix B:

 

Quote

Division Capacity: Maximum is 30 rounds. Shooters are allowed to load magazines with less than 30 rounds at their choosing. Shooters may use standard size pistol magazines on stages in lieu of 30 round magazines.”

 

Of course you could run into IDPA match directors that hate PCC and find ways to cripple the division. 

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3 minutes ago, BartCarter said:

Of course you could run into IDPA match directors that hate PCC and find ways to cripple the division. 

1

 

Which might be the case in my area. Them boys don't like us with PCCs! LOL

 

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Hello: So for IDPA you can load to 30 rounds for stages that are only 18 rounds max? Why not just use Magpul 21 round mags or Glock 17 round mags with base pads. No need to have that extra mag length sticking out the bottom if you don'y have to. I find reloads are easier with the shorter mags also. Thanks, Eric

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So... which magazines should I get. Glock 17 or 33?

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So... which magazines should I get. Glock 17 or 33?


May also depend on how you reload the gun. Do you reload it like a pistol, bullets forward? Or reload like a rifle, bullets backward and beer can grip. The long mags are easier this way. And is more better IMO. But just like every thing else, what ever you practice and works for you, will be best.


Sent from my iPhone using Tapatalk

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Posted (edited)

Agree. I carry both to my IDPA matches I shoot in. If the stage reflects 12 or more shots to complete I load a 33 rd with 20 rounds.  I ussually load my mags with 6-8 extra rounds.  If it is a short stage with 11rounds or less I load a 17 rd mag. I also carry two extra 17 round mags on my belt in the event I have a 33rd malfunction...

 

Glock has just recently introduced a 24rd mag but their price is higher than a OEM Glock 33rd mag....

 

Brownells currently has the OEM 33rd mag on sale for $28.99. Spend $100 and get 10% off today and free shipping....

Edited by Sigarmsp226

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Posted (edited)

and there are several Glock Mag Bases being made by MBX, Taylor Freelance, etc. that extends the mag capacity for USPS

(and allot easier to get off!)

Edited by zzw26n

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I compete with an MPX gen 2, I have a backup MPX, the JP is light on recoil if you reload and tune the gun.

 

I've been plagued by issues with the mpx.

 

I take delivery of my JP in a few weeks. I promise it is far more expensive to start with the MPX.

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Posted (edited)

I had an AR9 built with all JP stuff, and i reload.. So it shot soft and flat..Now i have a MPX and those same handloads shoot even softer with the Sig.. 

I have since sold my AR9''s and only shoot the MPX.. Some matches when the family comes to shoot it is shared by the 3 shooters and just runs all day.

I do however clean the bolt and piston setup after every match.

                                                                        38782.thumb.jpeg.fd1b3a595534b6ffbabf19cd36c9cb2c.jpeg 

 

Edited by Underwood
edit

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The grass is always greener. 

 

That said, you have the most expensive part already (the MPX). Buy a taccom LW extension, have it pinned and welded, buy a stock for $100 and away you go. IF you reload and you care to experiment with basically limitless load/buffer system options, sure. You can get it to shoot AS soft as an MPX shooting higher PF loads. 

 

I built a few AR-9's, then I built one using a Guard system, then I went to an MPX. There's a thread on here called "To MPX or not" I suggest you read. My take is that the JP is likely the finest AR-9 out there, will generally be reliable, and you pay for that. That said, it is still limited by the physical limitations of the platform it's based around. Sig has the opposite problem. Great platform, occasionally questionable execution. 

 

That said, it flabbergasts me that people take a COMPETITION gun and are talking about cleaning vital components every several thousand rounds, then complaining about reliability. 

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38 minutes ago, Acer2428 said:

 

 

That said, it flabbergasts me that people take a COMPETITION gun and are talking about cleaning vital components every several thousand rounds, then complaining about reliability. 

I know.. I feel the same way.

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Lots of good suggestions in the thread. I am also considering just getting an ILWT barrel and a shroud and call it a day. I already have a stock (It is SBRd) and Timney trigger.

I would just switch between that and the 4.5" + suppressor when just want to have fun at the range, instead of getting a dedicated PCC.

I clean all my "tools" after each use anyway, so I guess I should not have many issues with it?

 

Thank you, everyone, for the comments and suggestions. In a way, you talked me out of spending more money than what I can do away with since I already have the MPX.

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