expected speed?

B

bruno

CGN Regular
Rating - 100%
3   0   0
Location
selkirk
what would you expect as a max speed for a win 270 using a 140 hornady BTSP, over win 760, or IMR 4350? My manuals say 2900 -3000 fps, but on line i,ve seen as high as 3250. what have you found? it's a 22" BBL savage 110
 
Nothing you read has anything to do with your barrel, and your circumstances. These numbers are what others have observed with their equipment. The only way to know for sure is to fire a few bullets through the screeens, and see exactly what is happening.
 
i did, and with the listed max load, i got 2950. another guy at the range said i could go higher, as we didn't see any signs of pressure, but i'm new and not all that familiar with which signs i shoul be looking for. any suggestions?
 
when your chrony starts to show speeds of 3000+ fps ;)

flattened primers, sticky bolt extraction, etc also can indicate high pressure, but the chronograph is the best way to get an idea as to what your load is doing
 
If you have a micrometer, measure the diameter of the solid part of the case head. Then measure the same area after the round is fired. If there is noticable expansion of the solid head, pressures are high.
 
If you want to get a bit more velocity maybe try moly coating the bullets. Start your load build up all over again with the moly bullets.
 
4350 is not the best powder for a 270 with 140 grain bullet. H4831 is better, and maybe there are other slow powders as good, or better. I think Norma 205 was the best, but now gone.
 
You must log in or register to reply here.
Back
Top Bottom