MRP Powder

[RHarris]

I have about five pounds of this powder that was given to me about 17 years ago (Started out with about 8#). I use it in my .270 with Nosler bullets. The literature and loads I have found is limited. Have any of you experenced this powder? What rounds have you made up? Its not made anymore but its a great powder and I intend to use it to the last drop.

RHarris

 

[redrabbit]

I was using MRP to launch 140 gr Sierra SPBT out of a 7mm Express(.280 Rem)about the time you got your powder. MRP was unavailable for a while, and I have since sold the rifle. That Rem 700 really liked that load: 1/2" 5-shot groups.

Doug/Red Rabbit

 

[myj]

I have an old Speer #10 manual that I purchased back in 1979. For the .270 Winchester with a 130 gr. Speer bullet, a Max load of 62.0 gr. of MRP is listed as producing 3071 fps muzzle velocity out of a 24" barrel; 60.0 and 58.0 grains are shown as producing 2998 and 2892 fps respectively.

For the 150 gr. bullet, they show 58.0 gr. Max at 2831 fps, 56.0 gr. at 2742 fps, and 54.0 gr. at 2622 fps.

I would suggest starting with the lighter charge and working your way up in half-grain increments while observing all standard safety precautions until you reach your rifle's max load and then backing off a couple of grains for a hunting load. MRP is known as an old magnum cartridge, heavy bullet, slow burning powder. Therefore, you may want to consider a magnum primer for consistent ignition.

Hope this helps.