I decided to try some MAGPRO today. First I loaded up 1 of each 70,71,72,73,73.5,74grs. Max load according to AA's book is 74.6. I fired all 6 checking for pressure signs and volocity. Every thing looked fine all the way thru. I even thought about going another grain or grain and a half. Anyways I decided that I would load up 10 rounds at 73.5 and check accruacy and speed.
Here's the loadings
Winchester 1x brass slightly bumped and trimmed to 2.100
CCI Mag LR primers
73.5 gr. of MagPro
140 gr Hornady SST seated .004 off the lands best I can tell.
Shot 6 of them they chrono between 3301-3312 and averaged 3 shot groups of .5 ctc.
Here's comes the problem, the bolt is very tough to open on them. I don't just mean snug I mean tight. I pulled 2 of them to recheck the powder. One was dead on 73.5 the other was 73.6. I thought maybe I had missread the scale the first time. The loads seem to be super hot by the way the bolt acts, but they show no other signs of excessive pressure. The AA book shows volocity of 2975 with 74.6 grains out of a 24" barrel. I'm getting about 35fps faster than that with a grain less powder. I can't figure out what is going on with the case. Help. Is this load safe?
Here's the loadings
Winchester 1x brass slightly bumped and trimmed to 2.100
CCI Mag LR primers
73.5 gr. of MagPro
140 gr Hornady SST seated .004 off the lands best I can tell.
Shot 6 of them they chrono between 3301-3312 and averaged 3 shot groups of .5 ctc.
Here's comes the problem, the bolt is very tough to open on them. I don't just mean snug I mean tight. I pulled 2 of them to recheck the powder. One was dead on 73.5 the other was 73.6. I thought maybe I had missread the scale the first time. The loads seem to be super hot by the way the bolt acts, but they show no other signs of excessive pressure. The AA book shows volocity of 2975 with 74.6 grains out of a 24" barrel. I'm getting about 35fps faster than that with a grain less powder. I can't figure out what is going on with the case. Help. Is this load safe?
