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:
Some lots of German
British (underpowered—will not cycle action)
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.
© 2021 JP Enterprises. All rights reserved.