It's the little things, sometimes.

[**oneshot**]

I am new to casting and new to a 41magnum revolver. I have been playing around trying to find the right combo. I changed powder charges, powders, and primers, but wasn't quite happy with the results. I was looking to buy yet another powder and try the tests again. I also thought I'd buy more brass since i was there, they didn't carry the brass I was using so I picked up some Winchester brass instead.

I never had to open the new can of powder. I figured I'd work up a load with the new brass and existing powder (to use it up) to see where it was at. If I had a digital camera I'd post the groups I shot. 4 different powder charges, 1 cylinder of bullets each, All grouped into a nice cluster of bullet holes "one large green SPLAT" on my shootnsee targets. three of the targets looked like only 3-4 bullets were fired at it. I reloaded the same brass and tried it again just to rule out the "new brass" effect and did it all over again. Same result, with one flyer that I think was me. Granted these groups were only shot at 20yards but heck I'm a happy camper after that. I'm loading more to shoot at longer range, just can't seem to figure which charge grouped the best.

Lesson learned, Don't settle for good shooting boolits when you can work to excellent accuracy.

[Bass Ackward]

Case anneal is very important. Maybe just as much as uniformity of anneal, especially when reducing loads from maximum.

Never assume that the charge that grouped best at close range will be the best long range load. You always need to shoot at the range of interest to be sure.

[Pilgrim]

I've never seen a brand of case change result in huge accuracy changes, except for BR shooting that is. So I doubt it was the brass itself, per se. I rather suspect it was crimp uniformity, most likely due to case length uniformity, or perhaps brass hardness (annealing) differences which also will result in crimp differences. Either way, I sure wouldn't part with the original brass until you have figured out what case difference resulted in the accuracy difference. FWIW Pilgrim

[**oneshot**]

I did some longer range shooting (65-70yds) yesterday to verify the accuracy. They all grouped good but one load grouped into 1/4 pie cut of my 5 1/2" shootnc target both times I fired it.
I also tried shooting the "other brass" with the same load and it didn't group at all, more of a scattershot.
I trim all my brass to length to ensure proper crimping. This is when I noticed something interesting. All my "old brand brass" required trimming as usual, while my "new brand brass" were right at my trim length. Not sure of the physics behind this (ie: harder, softer, more springy) but I'll take it.

I'll keep the old brass for my J-bullets since accuracy/grouping wasn't a problem with them.