due to the current primer situation i have only been able to get cci #34 primers for a 308 load.... i am looking at 40 grains of IMR 3031 and a 150 grain fmjbt.....the load calls for a large rifle primer......can i use the 34s for a LRP, or do i need to reduce powder charge and if so by how much?... tia for any responses

That’s was my favorite load until I switched to Varget and RL15 because they meter better. It used to be a common accuracy load. It is not a hot hot load. Try it. It was used in M1 and M14 and didn’t damage op rods. The primer should not take it over the top.  If you are not comfortable doing so, drop it to 38 grains (5% reduction) and go from there.

You'll be just fine with that powder charge and primer with NATO Brass, and you could probably load them a little hotter with commercial brass.  CCI 34's are not any hotter than standard primers, they have a thicker cup, and are more resistant to slam fires.

Pay close attention to the brass for the following reasons:

- NATO brass typically has less case capacity due to it being thicker walled brass. Which means less case capacity.

- Commercial brass tends to have thinner walled cases, and is designed to run at higher pressures than NATO brass.