How do I workout powdercharge&seating depth?

[Chris Burdett]

At last new rifle has arrived Now give me your thoughts on the best/quickest way to arrive at the best charge and seating depth.

[AlanF]

Chris,

This is the general method that Dave Tooley (in case you don't know, one of the best 1000 yd BR shooters in the US) uses :
Use either ladder testing or 5 shot groups at increasing loads to pick a good powder charge. Then experiment with seating depth using that charge. If you can't get good elevation at long range, ditch the bullet and start again with a different bullet. This needs to be done for every individual barrel. It also highlights the importance of having a good selection of suitable bullets in your chosen calibre.

Hope this helps.

Alan

[Chris Burdett]

thanks AlanF it,s that fine line between seating and load that is the goal.So what is the go? Quick answer please before the crows bleeet, swoork, and protest the stock.

[bruce moulds]

hi chris,
this is what i do.
while running in the barrel, max loads can be established with 2-3 powders. these loads might be a bit over max in a fouled barrel, but are a guide. all projectiles 0.020 into the lands for fireforming.
when barrel is run in, load in 0.2 gn increments down from max, up to 3gn.
with a fouled barrel, shoot rounds at 400 or 500, at the same aiming mark,as if for group, having the marker number each shot. 1 target per powder. chrono each shot.
taking note only elevation, select the 3 closest(smallestgrouped) consecutive shots. the middle one is the one to test.
using this load if safe, shoot 3 shot groups reducing jump fro 0.020 jammed to 0.030 jump, in 0.005" increments. the best ones of these can be retested with 10 shot groups.
take the best one and try up to 5 neck tensions in 0.001 bushing sizes.
if this load has low s.d.(15 or better for 20 shots) it should be competitive.
often the 3 closest shots will exhibit quite similar speeds, suggesting that velocity increase is not necessarily linear with powder increase.
good outfits should do better with loads worked up this way.
hope this is helpful,
regards,
bruce moulds.

[bruce moulds]

hi
sorry, omission in previous post.
loads should group less than 0.5"
bruce

[RAVEN]

Adding to Bruce reply find a load then change primer to see if SD is reduced.
I do all my load testing @ 300m if I can in good conditions when you have the right load the results will be very evident
When I was work up a load for the latest barrel I change seating depth from jam to 10thou jump group went from .65mao to .2moa as some other shooter who were sighting in there rifle @ 100 commented at the time
These groups were tighter than theirs.
Personally I think if you can get it grouping average of .5MOA or smaller thats the one you want.
GOOD LUCK anb HAVE FUN
Cheers
RB