Whether as a complete carbine, upper or lower assembly, the GMR-13™ 9mm is a versatile platform that excels in both function and accuracy. The GMR-13™ is available with either our JP-15™ or PSC-11™ upper receiver for a blowback-operated carbine that includes our 9mm Silent Captured Spring standard. The end result is a system that cycles with virtually no recoil, allowing for extremely fast sight recovery with solid 3 MOA accuracy from a pistol cartridge usable out to 100 yards.
With the high-performance ammunition available from many manufacturers, the GMR-13™ makes a solid choice for a competitive match carbine (especially considering the cost savings of 9mm ammo over .223) and is also well-suited to home defense applications given its impressive .357 magnum-comparable ballistics with a carbine-length barrel. The lack of concussion in enclosed spaces and greatly limited over-penetration issues when compared to most rifle cartridges only enhance its suitability in this arena.
Designed from the start with the needs of law enforcement in mind, the GMR-13™ accepts the same G17 pistol magazines as Glock 9mm pistols for carbine/sidearm compatibility and is also available in select-fire configurations. Built on the PSC-11™ upper receiver platform with its dual charging systems, the GMR-13™ readily accommodates those with training backgrounds on either the HK or AR-15 platform. Also available for military and law enforcement, the complete rifle package includes our own JP select-fire trigger setup for precision trigger control in both semi- and full-auto modes. As with all JP rifles, the GMR-13™ comes with parts and service readily available from a trusted US manufacturer.
Base Carbine Specifications:
Machined-from-billet 9mm lower with forged JP-15™ upper or machined PSC-11™ dual-charging upper ($500 upgrade)
JP Supermatch™ air-gauged, button-rifled, cryogenically treated barrel (1/2" x 36)
JP tactical or standard-profile compensator
ACE ARFX or Tactical Intent TI7 collapsible carbine
JP MK III Hand Guard System
Blowback with JP 9mm Silent Captured Spring
JP Enhanced Reliability Fire Control Package with a weight of 3.5-4 lbs.
JP accessory pack including operator's manual, backpack soft case and more
Custom Centerless Ground and Polished Operating Spring Platform: Large-Frame Length: Carbine Length
Does the GMR-13 have any ammo requirements or preferences?
For ammo and loading recommendations, see the current version of John Paul's loading document.
Some newly manufactured 9mm ammo available may have overcrimping issues that can potentially cause catastrophic failure in a blowback 9mm like the GMR-13. It is vital that you recognize the warning signs of such a failure. Please review our Warning for 9mm Carbines.
How will the GMR-13 handle +P ammo?
The GMR-13 action is straight blowback and was calibrated with standard-pressure loads. It has not been tested with Corbon +P ammo. The bolt does not lock during firing, so the primary effect of shooting high-pressure loads is that the bolt will open faster, making your immediate risk that the cases will bulge or rupture because of this. In the long term, you will see a bit more wear and tear from the extra bolt velocity. The 9mm AR is known for being abusive to the hammer pin but we minimize this by using a ramped bolt. Thanks to this and our anti-walk pins, we have not had any hammer pin failures to this point.
Why doesn't my non-JP trigger reset with the JP 9mm bolt assembly?
Like most all of the 9mm bolts on the market, our bolt assembly is ramped in order to reduce hammer wear during the re-cocking point of the firing cycle. The bottom of a 9mm bolt also doesn't come down quite as low as a standard bolt carrier. These two factors together tend to cause the hammer to not be pushed down quite as far as when cycling .223. JP fire control components as well as Mil-spec ones do not experience this problem, but certain other trigger components will not function with 9mm bolts even though they are fine for .223.