JP enterprise Gmr13 9mm?

[colbyjack]

Anyone have a gmr13 Rifle? I just got one yesterday. What are you running for sights? I'm thinking 4moa C-more railway.

What are you guys doing for ammo or loading? I haven't shot it yet, I need to load ammo. Do they prefer 147/124/115 any one over the other? Do they like them loaded hot or powder puff steel challenge ammo?

What are you guys zeroing in at? 100 or 50.... I was thinking short, mostly going to use it in pistol Bay type uspsa style matches. What are you shooting for group size? 2 or 3" or more like 5/6 inch groups. I'm new to the pistol caliber carbine rifles. I'm not sure what to expect or what I should be going for. Any info on load data or zero distance for the gmr13 9 mm would be appreciated. I figured if you folks had one maybe you found a good bullet weight and load. Just trying to save a little time and figure out which weight of bullets to buy. Thanks.

[colbyjack]

[kurtm]

Got an EOTECH on mine. Haven't shot it with anything but Federal American Eagle 115 grain ball. It groups right around 1.5" at 100yds with this stuff. Yes I am running a 100 yard zero. The difference between a 50 yard zero and a 100 yard zero is insignificant at bay distances.

This gun is a lot of fun to play with and it has been very reliable so far with very little maintenance. It is FAR better than any other 9mm carbine I have ever played with!!! THANKS JOHN!!!!!

[FlightMurse]

Beautiful rifle. I have been looking into getting a 9mm AR and these are just so much prettier than a CMMG. Does the bolt hold open consistently on the last round?

[wgj3]

Does the comp actually do anything? Doesn't seem like it would have much gas to work with...?

[bmiller]

Beautiful rifle. I have been looking into getting a 9mm AR and these are just so much prettier than a CMMG. Does the bolt hold open consistently on the last round?

Would like to know about the bolt hold open as well.

[Stlhead]

No bolt hold open. Gun runs like a sewing machine. Also run 100 yard zero. I like it for rifle practice more than the 22.

[bmiller]

What is different about the JP than the other 9mm ARs? Is it simply their attention to detail and execution, or is there design differences? I have thought about selling my Uzi and buying one of these. The Uzi is accurate and reliable, but I would like the Ar platform to practice with. I have been looking at the new stag. I wonder how it would compare.

[colbyjack]

I haven't shot it yet, still need to get ammo loaded and buy a sight. I heard the bolt doesn't stay back on last shot. Thanks for all the info so far. The attention to detail is very good. I really like how they used Glock magazines. Does the 147 have a lot of drop at 100?

[FlightMurse]

No bolt hold open. Gun runs like a sewing machine. Also run 100 yard zero. I like it for rifle practice more than the 22.

This is why I was leaning more towards the new Angstandt arms offering. The bolt hold open would be really nice to have working.

[Stlhead]

the JP does not suck. Most 9mm ARs do. closed bolt reloads are fine with me.

[BigBamBoo]

Nice carbine!

I am using a JP GMR-13/PSC-11 upper along with the JP 9mm silent captured spring. I started out with a QC10 Glock pattern lower thinking it would be great to have a carbine that uses the same ammo and mags as my Glock 17.

I could not ever get the last round hold open to function correctly so I ended up by-passing it. And that always bothered me. So I switched overe to a Colt pattern lower and am much happier with it.

But to address your questions:

I am using a Leupold Prismatic scope/sight. My eyes are not what they once were and red dot sights do not work well for me. The prismatic is a actual scope and I can focus it to match my eyes.

I am using a 50 yard zero. I have no problem hitting 6-8" targets out to 100 yards with it.

With good ammo, it will shoot around 1" to 1 1/2" five shot groups at 50 yards. Which I feel is pretty good for a pistol caliber carbine.

Some asked about the muzzle brake...I don't think it does much of anything...looks cool and brings the 14 1/2" barrel to 16.1" for it is not classified as a SBR.

9mm carbines/rifles are great for new shooters, kids, and the girls. Very low muzzle blast. "Different" recoil then a regular .223/5.56 AR.

Many people say it is less recoil then a .223 AR, but that is not correct. The 9mm being blowback opperated just has a slower, longer recoil cycle. More of a push then the sharp, fast recoil of a .223 AR.

Here are some pictures of my JP/QC10 California legal 9mm AR. Yes...the funky stock (Thordsen FRS-15) allows us here in CA to use hi-cap mags, and no maglock.

Enjoy your new JP!

[Stician]

I'm using an Aimpoint PRO

[colbyjack]

Any body have any go to loads for the gmr13 9? Talked to my buddy and he has one. He's having a heck of a time working up a load.

[colbyjack]

Double

Edited July 5, 2015 by colbyjack

[colbyjack]

He emailed me this.... I'm still searching for the best ammo to run in the GMR. Best 147g plated performance with 3.5g titegroup @ 100 yards isn't very impressive, 6-8 MOA.

I tried factory115 FMJ @ 50 yards & it's a little better. I haven't tested 124 or 147 factory FMJs yet.

I had a little issue with ejector coming loose. JP sent a new style ejector with counter sunk holes & iron screws instead of the stainless set screws. They said the stainless won't stay tight.

Sent from BJ's iPhone

[mikeAZ]

A different road?... There are at least 2, maybe 3 options for a 9mm Rifle

1. The Just Right carbine in 9mm, Glock mags. uses some AR parts (also available in 40 S&W, and 45ACP (I have the takedown version, paid $500.00).

2. Palmetto State Armory's, 9mm upper "kit" ($399.99 on sale, Just put together last night), see "Pleasant surprise", www.Arizonashooting.com. . I think this will be the #1..., uses Colt style mags....

3. Mech Tech, uses your Glock lower, I had trouble with mine....Factory blamed it on "High velocity" ammo, not my most favourite weapon...

You should be able to keep the costs near $500/$700 running....Unless you put a $1000.00 scope/red dot on it???....

Edited July 5, 2015 by mike NM

[wgj3]

I never thought much of this concept until I had the chance to run an MP5 the other day. This pistol caliber carbine concept has since become MUCH more appealing to me. I see Buffalo Bore ammo in one post. What ammo are others having good luck with? Sticking with factory stuff or using your reloads? Higher pressure/velocity stuff or standard.

[BigBamBoo]

For accurcy and/or hunting (coyotes) I find the Buffalo Bore a VERY good load for this rig and my last 9mm AR. For plinking and steel shoots, I use WWB 115gr ammo and it works fine for that.

I do not load for pistol, so I can not comment on it.

If your using JP's SCS, they have a heavier spring for hotter loads I am told.

[T.McDevitt]

Any body have any go to loads for the gmr13 9? Talked to my buddy and he has one. He's having a heck of a time working up a load.

I really like 3.5 Solo 1000 with a 135gr Bayou OAL 1.150 (gold or red work better in both don't no why) in the 14" it's 996FPS and in 10.5" its

992FPS Very little dot movement

[72stick]

He emailed me this.... I'm still searching for the best ammo to run in the GMR. Best 147g plated performance with 3.5g titegroup @ 100 yards isn't very impressive, 6-8 MOA.

I tried factory115 FMJ @ 50 yards & it's a little better. I haven't tested 124 or 147 factory FMJs yet.

I had a little issue with ejector coming loose. JP sent a new style ejector with counter sunk holes & iron screws instead of the stainless set screws. They said the stainless won't stay tight.

Sent from BJ's iPhone

Update - After testing several brands of ammo with different bullet weights, I contacted JP. They said I may be the first to have accuracy issues with the GMR-13. They said to send it back. I shipped it back. After testing, JP engineer agreed with my findings. They are replacing the barrel. Should be getting it back next week.

[72stick]

For accurcy and/or hunting (coyotes) I find the Buffalo Bore a VERY good load for this rig and my last 9mm AR. For plinking and steel shoots, I use WWB 115gr ammo and it works fine for that.

I do not load for pistol, so I can not comment on it.

If your using JP's SCS, they have a heavier spring for hotter loads I am told.

Pardon my ignorance, but what's a JP SCS?

[striped1]

JP Silent captured spring (buffer)

[gose]

I never thought much of this concept until I had the chance to run an MP5 the other day. This pistol caliber carbine concept has since become MUCH more appealing to me. I see Buffalo Bore ammo in one post. What ammo are others having good luck with? Sticking with factory stuff or using your reloads? Higher pressure/velocity stuff or standard.

I have an YHM upper on a Stag lower and it runs great, but even with the JP comp and an SCS it bounces quite a bit more than my .223s.

Its a nice plinker and also allows me to run pistol stages and knock down steel, which can be hard with a .22, but for practice I actually prefer my .22 to the 9mm, as the .22 is actually closer to the felt recoil/muzzle movement of my .223s.

With the YHM and Hahn block you get a working BHO as well, if you care about that.

Had the GMR used regular Colt mags, I probably would have bought one, but I just cant get myself to use Glock mags in an AR.

I played around with a few different loads and different bullet weights, but it seems like the one it liked the best was my open minor load (115gr MG in front of 5.something grains of 3N37). That load is ~135pf in my Czechmate and gained another 175fps in the 16" barrels, so I might try and load up something with a little less powder in it.

[T.McDevitt]

I never thought much of this concept until I had the chance to run an MP5 the other day. This pistol caliber carbine concept has since become MUCH more appealing to me. I see Buffalo Bore ammo in one post. What ammo are others having good luck with? Sticking with factory stuff or using your reloads? Higher pressure/velocity stuff or standard.

I have an YHM upper on a Stag lower and it runs great, but even with the JP comp and an SCS it bounces quite a bit more than my .223s.

Its a nice plinker and also allows me to run pistol stages and knock down steel, which can be hard with a .22, but for practice I actually prefer my .22 to the 9mm, as the .22 is actually closer to the felt recoil/muzzle movement of my .223s.

With the YHM and Hahn block you get a working BHO as well, if you care about that.

Had the GMR used regular Colt mags, I probably would have bought one, but I just cant get myself to use Glock mags in an AR.

I played around with a few different loads and different bullet weights, but it seems like the one it liked the best was my open minor load (115gr MG in front of 5.something grains of 3N37). That load is ~135pf in my Czechmate and gained another 175fps in the 16" barrels, so I might try and load up something with a little less powder in it.

I had AR that used Colt mags, that's why I dumped it.. Love the Glock mags never had a problem..and their everywhere