So here's the deal. I loaded up some 60 grain Sierra HP's (#1375) the other day with 33 grains of IMR 4064 and got really good results, shooting a 6 shot group of a little over a half inch out of my Ruger M77 with a sporter barrel and a 14 twist. So I decided to try the 60 grain Nosler Partitions with the same load with the exception of the case. I changed from Norma to Hornady but retained the same case length and the same cartridge OAL which put the bullets at 10 thousandths off the lands. The Nosler's shot terrible, 5 shots in a shotgun pattern of about 3 or so inches. The length of the bullets were close, with the Noslers actually being 2 thousandths shorter then the Sierra's. I was really hoping the Partitions would shoot better. Any ideas as to why such a discrepancy in performance? Could it be the weight distribution of the Partition as compared to the Sierra HP? There was no keyholing with the Partitions, just a wide group.
Couple problems I see is Nosler doesn't currently list that powder for that bullet. Not saying it won't work, just something to be concerned about. Nosler is good about giving out info on load data. Its online, so everyone has access to it. That's the first place I'd start if I didn't have their load manuals. The next issue is your seating depth. Run that partition .020" off the lands. I've never had a partition that didn't like that seating depth. That is assuming you know how to find your lands accurately. Also, the length of the bullet is not a good reference when choosing proper OAL. The ogive is different between most manufactures. Again, learn how to find the lands and set your OAL accordingly. If it were me, I'd look at using good ol IMR4350 and start somewhere in the middle and work up from there. The thing I can't stress enough is don't use other bullet manufacture's data for a random bullet you are trying. There are many things to consider there like bearing surface and pressure differences. I see some new loaders trying to take the easy road and that's going to get you hurt. Don't cut corners and try to do chidt half azzed when it comes to hand loading. Its going to bite you in the azz eventually...
