JP GMR-15 questions

[DonVito007]

Hi all,

 

I’d like to ask the JP GMR-15 owners a couple of questions. Preferably the ones who have upgraded their weapons with carbon fiber handguard.

 

I’m in the process of choosing my first PCC a decided to go for JP as I want to shoot and not to worry about anything. Sig MPX was an option as well but since it is basically unavailable in my country (and the same goes for any spare parts should I need some), JP is the only option now. 

I shoot for fun, but pondering to try some competitions in the future.

 

The first question is whether to go for the one from ready rifles or to use JP rifle builder? My JP dealer does have this one in stock:

https://www.jprifles.com/buy.php?item=RR-GMR15APC

If go for a different one, I'll have to wait a couple of months (I live overseas). But I have no problem to do so as I don't want to hurry anything. 

 

Generally, I do like lightweight and low recoil rifles with a light (sport) triggers with a short reset, so I prefer my GMR to be the same. Based on your experiences - is it possible to achieve better recoil or get a lighter trigger by choosing a different components in JP rifle builder? 

 

Speaking of weight:

 

Is it worth to go for a titanium compensator? 

 

I'll definitely go for a non-standard JP handguard as the standard one is heavy for me and its diameter is too big for my small palm & fingers. Since I don't believe thermal dissipator is necessary, I see two options here:

 

1) JP M-Lok - diameter looks much better, but its weight is only slightly lower - it's still sort of new, not even on many pictures...any experiences with that please?

 

2) some carbon fiber - Smoke Composites (12") looks the best to me (did some market check and people on this forum recommend it as well) - its diameter is fine as well and weight is hard to believe (5.37 oz vs 13 oz for the standard JP one), but since my JP dealer is focused on Lancer carbon products, he is somehow reluctant to provide any support related to Smoke Composites handguard, so I'm wondering how complicated is to change the handguard at home (I'm not that skilled in such stuff to be honest), if any non-standard tools are needed (both for removing JP handguard and installing the Smoke ones) and mostly whether is comes with all the stuff necessary for mounting to the weapon?

Is the Smoke Composites handguard sturdy enough, please? Any wobbling when shooting? And how about heat conduction when shooting more rounds in a short time?

 

Any other reasons to go to a rifle builder (except for stuff like different trigger, safety and mag release color) in comparison to a ready rifle, please?

[egd5]

There's a lot of options as I'm sure you know but I'll tell you my choices, a lot of which are just personal preference. I recommend getting it built just the way you want, it's worth the wait.

You don't say what barrel length you want, but I'm guessing the 14.5 with pinned and welded comp. That was my choice also and I got the stainless steel barrel and comp. I also got the stainless bolt too. It looks better and is much easier to clean. The extended mag release is also a must have IMO. Plenty of other minor preference  things to also make ordering it the better way to go also.

I too think the heat dissipator is not needed. It also adds weight, but on that note, now they are selling something to ADD weight to the gun. Although a heavier gun will absorb some recoil, I prefer a reasonably lighter one. As for weight, I have a Smoke composites handguard on mine (12") and I love it. As you noted it is a big weight reduction and that reduction is on the FRONT of the gun. My gun balances much better now. If you go with Smoke they make two diameters that will fit. I don't remember the exact names now but one is a little smaller and if you get the full length rail (I did) it doesn't match up perfectly to the top rail on the gun receiver. I have the smaller one and it's no big deal to me.  ALSO-if you are going to change handguards ask JP for a barrel nut tool when you order. It is free but you have to ask for it. You have to have one to get their barrel nut off.

As for trigger, when I ordered mine I asked about the drop in triggers and what advantage they might have. The person I talked to said basically none, so I ordered the standard competition trigger with yellow springs. His name is Andre and it turns out he is a high level competition shooter. IMO, he is right. It certainly is no hindrance to my shooting. But there's a ton of triggers on the market and a ton of opinions on which is best.

[DonVito007]

Yes, a lot of options. The problem is I almost have no chance to try this rifle before buying (except for getting my hands on one in the store) as JPs are not that popular in my country. The main reason is price – they are simply too expensive for most of the shooters due all the fees to be paid for US goods import. So I basically don´t know what to opt for when building one. And that's why I am happy for any personal preferences and experiences.

 

14.5 barrel for sure. I don´t believe shorter or longer makes much sense to be honest. Stainless steel barrel and compensator is what I'm looking for too. And how about titanium compensator, is it worth extra money, what do you think? It's definitely lighter than stainless steel, but any other (dis)advantages? 

Stainless bolt then, thanks for a recommendation. I was also considering the extended mag release, so thanks for confirmation. Is it ambidextrous by the way? I´m right handed, but my left eye is dominant, so I shoot rifles and shotguns from my left shoulder, using my left hand to pull the trigger etc.

 

Well, ADD weight to the gun…why not…but definitely not to the front of the gun from my point of view. So, I´m with you in this. And, plus 9mm Luger is sort of kicky no matter how heavy the front of the gun is. I believe that if for instance a short stroke system is chosen etc. the GMR-15 recoil can be reduced significantly. Not as much as in case of .223 Rem, but enough to make shooting fun. Any recommendation on what to choose in JP rifle builder to achieve a minimal recoil please?

 

Smoke Composites handguard – yes, checking their webpage I can see it´s either version without top rail (outside diameter 1,69”) or version with top rail (outside diameter not mentioned on the webpage). I´d go for the version without top rail as I don´t think I need it for anything. Do you also use any Magpul M-Lok adapters on your handguard (If they are compatible at all)?

OK, so I´ll ask JP for a barrel nut tool when ordering, thanks for this. And does Smoke Composites handguard come with all the stuff (bolts, screws or what is necessary) necessary for its installation to a rifle upper? And are any non-standard tools needed for this installation, please?

 

Speaking of trigger, I did this preliminary configuration in rifle builder:

 

Trigger Style:  JPFC-M Modular Trigger

Trigger Module w/ Interchangeable Shoe

 

Approximate Weight: 0.2 lbs                                                   $112

 

Trigger Shoe:  Armageddon Gear Revolution Trigger           $0

 

Trigger Weight: Competition/Recreation Trigger JP Modular Trigger with 3 - 3.5 lb. pull     $0

 

Is it the same as yours? And what kind of trigger shore do you have? Curved, flat or that Armageddon one?

[egd5]

I think some of those options were not available when I ordered mine just over a year ago. And some things I just don't remember, but....

 

The Titanium comp wasn't available then i don't think. But I don't think it would be worth spending very much more for, IMO.

I don't think the release  is ambi. but not sure as I'm right handed and shoot that way.

 

I forgot to include, Mine is the scs short stroke with 5 steel weights. I shoot a 130 to 135 PF load so the lighter weights seem better to me. There's a lot of different opinions about that though, but from all I've read the heavier the load you shoot the more weight you need in the buffer. But tuning a pcc for no dot bounce is somewhat of a voodoo science all to itself.

 

I wanted the top rail because I mount my laser there for those hard left lean shots in competitions. That's all I have mounted, no adaptors.

 

The smoke comes with all you need. I went to a gunsmith to mount mine simply because he has the vice to hold the gun so it can be worked on easily. We did have to put a couple of tiny shims just to get the rail to line up just right, but if you don't get a rail I don't know if that would be necessary.

 

I just went with the standard competition trigger (3-3.5) Andre recommended,  No trigger shoe, just the standard curved one that was no extra cost. I don't know what an Armageddon one is.

[MLS2GO]

I have one JP and have ordered a second. I have the one you pictured except with a stainless bolt and barrel. IMHO they both look better and as noted above also clean easier. Mine also has the Radian Raport LT charging handle which is ambidextrous. JP's do not come with a ambidextrous mag release, however in April JP announced a left sided add on Ambi mag release. You should be able to find it with a search. Not sure if it is for standard AR's only? 

[cferree]

I bought a GMR-15 Ready Rifle due mainly to impatience.  The only JP part I've changed is the mag release.  It came with the standard, but I switched it out to the extended.  It gives you more leverage, and it feels easier/lighter.  Mine has the ultra lite barrel.  I wish they offered a lighter hand guard.  With a Tech Well mag well, C-More rail mount, a laser and 5 tungsten weights, it's close to 7 lbs.  I'd love to lose 8-10 ounces of hand guard weight.  I also have the factory comp trigger.  It breaks at 3 1/2 pounds with a very positive reset.  I wish it was closer to 2 1/2.

[SteelCityShooter]

You obviously aren't a US resident so is there a 16" minimum barrel requirement in your country?  You could save significant weight from the barrel and handguard if they could be legally shorter.   JP offers a 10-1/2" barrel in 9 mm and handguards down to 7-1/2" so you may consider these if you can.

[MLS2GO]

I forgot to say I won the trigger lottery apparently my standard trigger came in at  2 3/4 pounds.

[Kokeman]

I have a ready rifle. I primarily shoot UPSA and steel challenge with it. The only thing I've changed is the mag release and a short stroke kit. I am thinking about changing to the new vertical comp. 

[philmadxx]

4 hours ago, cferree said:

 5 tungsten weights

 

5 Tungsten?  JP recommended to me the all steel short stroke version for the 5.5 barrel - why did you order this configuration and does it work well?  Should really tame recoil.  

[FatPanda]

1 hour ago, philmadxx said:

 

5 Tungsten?  JP recommended to me the all steel short stroke version for the 5.5 barrel - why did you order this configuration and does it work well?  Should really tame recoil.  

My short stroke came with a mix of tungesten and steel. I think they changeD the recipe a few times.

[DonVito007]

18 hours ago, egd5 said:

I think some of those options were not available when I ordered mine just over a year ago. And some things I just don't remember, but....

 

The Titanium comp wasn't available then i don't think. But I don't think it would be worth spending very much more for, IMO.

I don't think the release  is ambi. but not sure as I'm right handed and shoot that way.

 

I forgot to include, Mine is the scs short stroke with 5 steel weights. I shoot a 130 to 135 PF load so the lighter weights seem better to me. There's a lot of different opinions about that though, but from all I've read the heavier the load you shoot the more weight you need in the buffer. But tuning a pcc for no dot bounce is somewhat of a voodoo science all to itself.

 

I wanted the top rail because I mount my laser there for those hard left lean shots in competitions. That's all I have mounted, no adaptors.

 

The smoke comes with all you need. I went to a gunsmith to mount mine simply because he has the vice to hold the gun so it can be worked on easily. We did have to put a couple of tiny shims just to get the rail to line up just right, but if you don't get a rail I don't know if that would be necessary.

 

I just went with the standard competition trigger (3-3.5) Andre recommended,  No trigger shoe, just the standard curved one that was no extra cost. I don't know what an Armageddon one is.

 

Yes, seems to me they are changing the options constantly.

 

Hmmm, will check the ambi stuff for sure.

 

Well, I am going to be shooting mostly factory 115 and 124, so I guess I need to talk to my dealer to decide the steel/tungsten ratio is scs short stroke. Will also discuss the trigger with him.

 

OK, great, so if I go for 14,5 barrel, I can order Smoke Composites handguard with no worries.

[DonVito007]

15 hours ago, MLS2GO said:

I have one JP and have ordered a second. I have the one you pictured except with a stainless bolt and barrel. IMHO they both look better and as noted above also clean easier. Mine also has the Radian Raport LT charging handle which is ambidextrous. JP's do not come with a ambidextrous mag release, however in April JP announced a left sided add on Ambi mag release. You should be able to find it with a search. Not sure if it is for standard AR's only? 

 

Agree, stainless bolt and barrel. Will go for the same charging handle. And thanks for that ambi mag release – will double check and try to get it as well.

[DonVito007]

12 hours ago, cferree said:

I bought a GMR-15 Ready Rifle due mainly to impatience.  The only JP part I've changed is the mag release.  It came with the standard, but I switched it out to the extended.  It gives you more leverage, and it feels easier/lighter.  Mine has the ultra lite barrel.  I wish they offered a lighter hand guard.  With a Tech Well mag well, C-More rail mount, a laser and 5 tungsten weights, it's close to 7 lbs.  I'd love to lose 8-10 ounces of hand guard weight.  I also have the factory comp trigger.  It breaks at 3 1/2 pounds with a very positive reset.  I wish it was closer to 2 1/2.

Well, 7 lbs is really heavy for me. I´d prefer 6 lbs max. Is that Tech Well mag well really a must? Speaking of trigger…does the lower accept any AR trigger?

 

[DonVito007]

12 hours ago, SteelCityShooter said:

You obviously aren't a US resident so is there a 16" minimum barrel requirement in your country?  You could save significant weight from the barrel and handguard if they could be legally shorter.   JP offers a 10-1/2" barrel in 9 mm and handguards down to 7-1/2" so you may consider these if you can.

 

Nope, I´m not a US resident and there is no minimum barrel requirement in my country. So, thanks for this comment The point is there is no option of 10,5” barrel in JP rifle builder. It is possible if I try to build upper assembly though. And when I opt for 10,5” barrel and 9,25” M-Lok handguard (7,5” is too short), it means 0.6 lbs less and brings me below 6 lbs in total which would be great! I´d just have to contact JP people and ask how to proceed if I want to build the whole rifle with such barrel length.

Just not sure about the ballistic and especially gun bouncing when shooting with 10,5” versus 14,5”/16” barrel length. Any experiences please?

[DonVito007]

9 hours ago, Kokeman said:

I have a ready rifle. I primarily shoot UPSA and steel challenge with it. The only thing I've changed is the mag release and a short stroke kit. I am thinking about changing to the new vertical comp. 

Vertical comp should do what? Less gun/red dot bouncing?

[Kokeman]

3 hours ago, DonVito007 said:

Vertical comp should do what? Less gun/red dot bouncing?

If I were getting one built I would definitely get the vertical comp. 

 

[Walli]

4 hours ago, DonVito007 said:

 

Nope, I´m not a US resident and there is no minimum barrel requirement in my country. So, thanks for this comment The point is there is no option of 10,5” barrel in JP rifle builder. It is possible if I try to build upper assembly though. And when I opt for 10,5” barrel and 9,25” M-Lok handguard (7,5” is too short), it means 0.6 lbs less and brings me below 6 lbs in total which would be great! I´d just have to contact JP people and ask how to proceed if I want to build the whole rifle with such barrel length.

Just not sure about the ballistic and especially gun bouncing when shooting with 10,5” versus 14,5”/16” barrel length. Any experiences please?

You have to look under JP AR Pistols: JP Pistol / SBR

 

 

[MemphisMechanic]

4 hours ago, DonVito007 said:

 

Nope, I´m not a US resident and there is no minimum barrel requirement in my country. So, thanks for this comment The point is there is no option of 10,5” barrel in JP rifle builder. It is possible if I try to build upper assembly though. And when I opt for 10,5” barrel and 9,25” M-Lok handguard (7,5” is too short)...

When I initially looked into PCC it made all kinds of sense to me to build a gun with an 8-10” barrel. After all, we’re moving around corners and this would let you work your way into and out of ports more quickly...

 

Go shoot a few and figure out what what type of stance lets you really drive the gun and transitikn hard. If you look at all the highest level competitiors, I think you’ll notice what I figured out firsthand: you’ll really want your hand mounted somewhere around 10-13” down the rail, way out in front of the magwell. The increase in control is well worth a few inches of added length.

 

There’s no way I’d build a gun with a barrel shorter than 10 or 11 inches. (My barrel is a turned down ultralight profile CMMG Guard, with the comp pinned and welded onto it so that it’s just past the USA’s minimum of 16” for a rifle.)

 

Edited July 13, 2020 by MemphisMechanic

[ltdmstr]

I started out with a RRA and 16 inch barrel and quickly realized I wanted something much smaller and lighter that also ran Glock mags.  I looked at the stock JPs and there were just too many things I wanted to change.  So I ended up building my own with JP side charge upper/lower/BCG, 10.5" Faxon barrel, SLR linear comp and AP Atlas S-One handguard.  I also modified the receiver for a BAD 45 degree safety (and engraved the receiver to reflect that).  It's compact, lightweight and handles great.  It's also extremely accurate and reliable.  Runs on any type of magazine and mag/extension combo I've tried so far and any ammo I've fed it.  I really couldn't be happier with how it turned out.

Edited July 13, 2020 by ltdmstr

[DonVito007]

7 hours ago, Walli said:

You have to look under JP AR Pistols: JP Pistol / SBR

 

 

Thank you, sir:-)

 

Works fine, the only problem is they don’t offer an option to choose 9.25” M-Lok handguard with 10,5” barrel at all, so it seems to me I need to contact JP anyway:-( 

[Darqusoull13]

17 hours ago, DonVito007 said:

Thank you, sir:-)

 

Works fine, the only problem is they don’t offer an option to choose 9.25” M-Lok handguard with 10,5” barrel at all, so it seems to me I need to contact JP anyway:-( 

Will check that out, thanks for finding that one. 

I have 2 rifles configured with 10.5" barrels as well as a 14.5" barrel and an Ultralight 5.5" barrel. I like them all for various reasons but I will absolutely say the 10.5"s are the most nimble in tight stages. They can all be tuned to more or less the same level of soft recoil with ammo and proper silent captured spring selection so really it comes down to shooting style. I've got a vertical comp coming to test out after having shot one a month back. It's pretty interesting how it changes the dot movement. Having said all that the softest recoil impulse I have tested has been a 10.5" barrel with an Omega 9k suppressor so it might all be perception. 

[DonVito007]

I hope I’ll have time to write JP tomorrow...gonna mention that as well. 

 

Suppressors aren’t legal in my country, so this won’t work for me...unfortunately. 

 

Thanks for your opinion on barrel length. This vertical comp is an interesting stuff for sure...so your initial experience says it helps to control red dot/muzzle bouncing?

[Walli]

There is an interesting discussion about PCC with some JP shooters:

Lessons Learned: PCC Nationals

 

About 18 Min. they are talking about barrel length. I fully agree with them.

[ltdmstr]

Yep.  10.5 with short stroke SCS is prob the best setup.  If you don't want to deal with NFA, 14.5 w/pinned comp is the way to go.  As for the vertical comp and barrel weights, I seriously don't know how recoil is an issue when you're shooting minor pf handgun ammo in a rifle.