Norma MRP Shooters

[Idaho Trecker]

I have been working on loads for my 300 Sherman Shortmag and have had the best results with RL 22 which has me curious about MRP since RL 22 is supposed to be MRP seconds. I have bought a LOT of powders to test in this cartridge and am running low on funds at the rate I have been buying so I thought I'd ask some questions to see if it is worth buying MRP.

I did a search here and saw most have said it is not temp sensitive but all the threads are old.

How have you found MRP to be in regards to temp sensitivity?

How does the grain size and density compare to RL22?

How is lot to lot consistency?

Thanks in advance

 

[parshal]

It's been a while since I've used R22 so I can't comment on the grain size difference. I've also only used one lot so can't help there either. However, I've run it over the chronograph with the same lot of reloads at 10 degree differences. Dropping 10 degrees dropped 10 fps. According to my Strelok program it's a .5% difference. I've got nothing to compare that to, though, to say whether that's good or not.

I had a conversation with the head ballistician at Swift bullets a few months ago. He told me that he's tried most all the powders out there to see how they differ in temperature sensitivity. He's conclusion was that they're all temperature sensitive no matter how they're advertised. Take that for whatever it's worth.

 

[Rich Coyle]

I don't know about temperature, but will chime in anyway.

I have a .375 wildcat. When I could get MRP it would fire 100 grains to get 300 grainers to an even 3,000 feet per second. When it disappeared I got some RL22. I heard it was the same so worked up a load with it. It would not get there. I fired enough to know I had to stop at 98.0 grains. The velocity was 2,990 feet per second.

 

[Idaho Trecker]

Parshal I have used plenty of RL22 and have it now. I was asking about Norma MRP.

 

[Idaho Trecker]

Wildcater, That helps alot hearing that. It sounds like MRP may work for me then. Can you tell me how similar the grain size/density of MRP is when compared to RL 22?

 

[parshal]

Parshal I have used plenty of RL22 and have it now. I was asking about Norma MRP.

My mistaken grammer. The loads I was referring to are MRP. I just mentioned R22 since you asked for a comparison and I've not had it in my hands for a while.

 

[Idaho Trecker]

Thanks parshal I was wondering about the RL22 in your comment. That is much more relevant.

 

[Rich Coyle]

Wildcater, That helps alot hearing that. It sounds like MRP may work for me then. Can you tell me how similar the grain size/density of MRP is when compared to RL 22?

They are really close to the same. Although MRP doesn't seem to be as consistent in grain size as RL22.