I just got through working up a load for a friends SPS 20' barrel rifle.I went with 42gn-44gn of 4064 with a 180gn SMK.The case over all length started at 2.800,but to get 44gn in the case safely I had to go to 2.840.( reason for not going long is that he wanted to be able to mag feed )With his rifle now having 200 plus rounds down the barrel the 44gn and 2.840 load worked great out to 300,the last five rounds came in at 2 1/2".I know this isn't really that good of accuracy,but its just the start,and not the bullet I really wanted to test.I wanted to test with a 175gn or the 178gn BTHP,but buying bullets right now is hard to do.I could have let him used some of mine,but then I would have run out.
As soon as he can buy some 175-8 gn bullets,I'll test all over again for him.I'll too add that this is the first time ever that he has shot from a bench.I have always done the loading and shooting,but he wanted in on the testing so I let him shoot.I think that if was the guy behind the rifle the load would have did better,but hes willing to learn so why not teach him.