We are constantly reevaluating our products from both the safety and reliability standpoint, and it has come to our attention that the thread locker product used to secure the button-head screws in the JP Anti-Walk Pins installed in JP assembled rifles and lowers may not be properly curing. This could allow the retaining screws to vibrate out of the pins during live fire. This applies to any JP-15™, JP-15™/VTAC, CTR-02™ or LRP-07™ assembled—or custom trigger installation performed—with the second-generation anti-walk pins installed with button-head screws.

Loss of a retaining screw due to the effects of live fire could result in the trigger or hammer pins becoming unsecured in the receiver. If the unsecured trigger or hammer pins back out of the receiver and the pin drops one side into the receiver, misalignment of fire control components could cause serious malfunctions such as failure to fire or accidental discharge. Either case can result in injury or death.

It is extremely important to test the screws on your receivers by placing a 1/16" hex driver on both sides and attempting to turn counterclockwise to determine if the screws are properly secured. If either side backs out with little or no force applied, remove the screws and thoroughly degrease the threaded hole and the screw using a solvent such as lacquer thinner. Apply an appropriate thread locker product and allow it to cure as instructed by the manufacturer before further use. Check all screws again after the thread locker sets up. Note that it is only necessary to check to see if the screws will not move with light force applied to the keys. There is no need to apply enough force to actually remove the screws, only to test the retention of the thread locker product.

If you have installed a JPFCP kit or AW pins, also test the screws to ensure that your thread locker has cured and that the screws are secured. In any case, if you are not able to secure the screws properly, please contact us to send in your lower assembly for service in the JP custom shop with a one-week turnaround. Upon request, JP Enterprises will supply new screws pre-coated with a thread locker at no charge to replace these screws.

Email or call us with questions or if you need replacement screws.

Safety@jprifles.com

Left: Anti-Walk Pins in lower reciever
Right: Anti-Walk Pins

This notice pertains to any rifle based on the large-frame AR-10-type platform typically chambered in .308 Winchester, 7.62x51 NATO or other cartridges requiring the longer magazine format. This includes, but is not limited to, the Armalite AR-10, Bushmaster BAR-10, Rock River LAR-8, DPMS LR-308, KA SR-25/M110 series, POF P-308 series, Larue Tactical OSR and JP LRP-07™.

Unlike the AR-15/M16 platform, for which most parts are cross compatible due to the receivers’ standardized design, the AR-10 platform has not been standardized. Before ordering accessories and parts for your AR-10-type rifle, make sure the parts are compatible with your particular rifle platform. The only parts that are universally cross compatible are fire control components. Hand guards and barrels are each slightly different and may not be cross compatible.

Hand Guards: In the JP nomenclature for hand guards, the “D” at the end of the part code refers to rifles using the DPMS LR-308 thread pattern on the upper receiver barrel collar. The “A” refers to rifles using the Armalite thread pattern, which includes the Bushmaster BAR-10 or Rock River LAR-8. JP hand guards using the letter “M” are only compatible with the AR-15/M16 platform and will not fit on any AR-10-type rifle.

Barrels: JP Supermatch™ barrels in .308 Winchester/7.62x51 or .260 Remington are compatible with most AR-10 platforms except the Rock River LAR-8 or Bushmaster BAR-10. Due to the use of an FAL magazine, the extension piece on the barrels used in those rifles must be extensively modified to allow for feeding. Therefore, JP .308 and .260 barrels are not compatible with the RRA or BM rifles.

Fire Control Parts: All the AR-10 variants that we are aware of will accept standard AR-10 fire control components, but the setup may vary significantly between platforms. In the case of JP Fire Control Components, only kits ending in “T” contain the correct spring combination for a .308 rifle. The hammer spring must be of a higher spring rate to ensure both ignition reliability and resistance to finger bounce-off doubling. Release weight on a .308 caliber self-loaders must be at least 4 lbs. With a lighter release than this, you may experience finger-bounce doubling or the firing of more than one round with each pull of the trigger. This is not acceptable for both safety and legal reasons.

Version 1.14.10 9:30

Safety@jprifles.com

JP LRP-07™ rifles chambered in 7.62x51 are designed to function with SAAMI spec. commercial-grade factory .308 Winchester ammunition. We recognize that many avid shooters reload for their rifles, and carefully assembled hand loads should function when appropriate component combinations are used and brass is properly sized and gauged. However, we will not warrantee damage caused by hand-loaded ammunition that is not compatible with the rifle.

We do not recommend the use of surplus military ammunition due to the considerable variation from manufacturer to manufacturer, lot to lot, year to year, and from the components used and the processes in manufacturing. In some cases, surplus ammo has been mass tumbled to clean the years of tarnish off the cases, which actually causes the powder to break down. This drastically changes the burn rate of the propellant and the subsequent internal ballistic characteristics of the load, leading to the potential for extreme pressures.

Much surplus ammunition is not made to exact specifications. We have found that some of this ammunition has caused problems in our rifles due to the use of a tar-like sealant for waterproofing. When this ammunition is used in our rifles, this sealant melts and coats the chamber causing failures to extract and to chamber. Afterwards, any rifle in which this ammunition is used will have the same problem if the chamber and the bore are not cleaned thoroughly. We have found that surplus ammunition from the following countries/manufactures will cause these problems in our rifles:

South African
Venezuela Cavim
Austrian Hirtenberger
Some lots of German
British (underpowered—will not cycle action)
Indian (overpowered)
Winchester white boxes marked 7.62
Wolf steel cased (fouls chamber with coating)

If you have used ammunition that causes chamber fouling leading to extraction failures, you must thoroughly clean the chamber and the bore before using any other ammunition. Then, try commercial .308 like Federal American Eagle 150gr. FMJ or Remington UMC 150gr. FMJ to function test the rifle.

LRP-07™ rifles chambered in .260 Remington

The LRP-07™ chambered in .260 Remington is designed primarily for the skilled hand loader, as there is little available in accurate factory .260 ammunition. Best accuracy is usually achieved at about 10% below recommended maximum load data in recognized loading manuals. Be aware that canister powders can vary significantly in burn rate from one lot to another and if you start a new lot of powder, it may be necessary to work up a new load. Do not assume that a “factory” load for the .260 will perform satisfactorily in your LRP-07™ and assume that there is something wrong with the rifle if a particular ammo fails to function or exhibits high pressure signs. Available factory ammunition is designed for rifles with 1:9 twist barrels. We use a 1:8 twist barrel for improved accuracy with certain high BC-type projectiles. This may not be compatible with some factory loads. You may experience high pressure failures such as dropped primers and excessive bolt velocity resulting in extraction/ejection failures or even possible ruptured cases. If high-pressure signs are evident with any ammunition, discontinue use of that ammunition immediately.

Remember that gas-operated semi-automatic rifles in any caliber are much more ammo sensitive than manually operated rifles. You must find or load ammo that is compatible with the rifle, not expect that the rifle can be made compatible with the particular ammunition that you have chosen.

Safety@jprifles.com

It has come to our attention that certain factory ammunition may not be safe in rifles chambered for 6.5 Grendel®. Because it is an extremely high-performance cartridge, the 6.5 Grendel stretches the performance limitations of the AR-15 platform. As it is also relatively new on the market, manufacturers of ammunition may not have adequate data or rifle samples in their test libraries to make accurate determinations of what constitutes a safe load in all rifles chambered for this cartridge. Do not assume that ammunition is safe in your 6.5 Grendel® rifle just because it comes in a factory box. If you see indications of case expansion in front of the head, extrusion into the ejector pin hole or extrusion into the firing pin hole, this ammunition should be considered unacceptable in your rifle. Stop shooting this ammunition immediately. As a safe and reliable ammo option, we recommend the Alexander Arms factory ammo loaded in Lapua cases.

If you reload for the 6.5 Grendel®, we offer several suggestions. First, buy only Lapua 6.5 Grendel® cases as they have superior metallurgy and will more safely tolerate the chamber pressures associated with this cartridge. Do not try to fabricate your own cases out of another parent case; it is not worth the trouble and is not safe. Second, we recommend loading on a single station press or a press that allows you to feel the primer seating tension. This does not require sophisticated equipment and is a very important indicator of the case’s condition. Most progressive presses tend to isolate the loader from the feel of the primer seating into the case. Lee Precision, Inc. offers a fine hand primer that provides excellent response for the priming operation.

Once you’ve begun reloading ammunition, never start at the top of any load data tables. Work towards a load that delivers the best accuracy, not necessarily the peak velocity. Typically, peak accuracy is obtained 5-10% below peak velocity with any bullet/powder combination. When developing a load, pay close attention to case head expansion and primer retention. If the primer seating force obviously declines, you’re past the acceptable pressure limitations for that combination, and you should reduce the load or change powders. Finally, watch for flattened primers, cratered primers and especially extrusion of the case head into the ejector pin hole in your reloads; these are all indications of unacceptable pressure. You should be able to reload the Lapua cases at least eight to ten times if your pressures are within acceptable limitations. Discard the cases once they show any indications of overpressured loads.

Safety@jprifles.com

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