[Unclenick]

30 cal,

Newberry will have tested in several rifles and taken colaborative data from others testing the load to verify it.

The M14 and standard M1A have the long NATO chamber. It has both a long throat and a 0.004" longer minimum headspace. The exceptions are barrels chambered with the special Clymer match reamer designed just for M852 ammunition loaded with the 168 grain SMK.

Note also what I mentioned earlier, that the Newberry loads are strictly for Winchester brass. Winchester designed special high capacity semi-baloon head cases for ammunition for the U.S. hosted Palma Match in 1992. They later adopted this higher capacity case design as their standard .308 case. I haven't measured the Lapua to see if they've followed suit?

In that Winchester case, Quickload predicts the peak pressure to be about 48,000 PSI for the 155 grain SMK load. In an average NATO chamber it will be 47,000 PSI. If you put the same charge in a Lake City case, with 3.4 grains less water capacity, then fire it in a S.A.M.M.I. minimum chamber, the prediction jumps to over 55,000 PSI. If you then make the mistake of using H4895 in place of IMR4895, it jumps to about 61,000 PSI. Given lot variations on top of that, it is perfectly possible to imagine coming up with a leaky primer even with a lower load. There just isn't any escaping working loads up with the components you will actually use.