roysclockgun
Handloader
- Dec 17, 2005
- 736
- 1
As previously reported, I am very happy with the trade that I made for Browning Stalker in 280Rem. with both BOSS attachments. I am sticking with the BOSS that does not reduce recoil, but also, does not create the applified muzzle blast.
My question has to do with the difference that one grain of propellant can make, even when using BOSS. For all these tests I used 140AB. After getting to the OAL that I wanted, I loaded IMR4350 beginning at 52gr. and going up in 1/2 grain increments until I reached 54gr. Keeping the BOSS setting at the Browning recommended setting of "4". My best groups were at 53gr. I loaded up another test batch with only 53 gr. and 54 gr. Making adjustments up and down on the BOSS settings, I got two 4 shot groups at 53gr, that were very, very tight clovers, with two rounds appearing to enter one hole.The sweet spot was at 4.1. Fine so far.
I than began to shoot the rounds loaded to 54 gr. I made adjustments on the BOSS as high as 4.4 and as low as 3.9. The best groups measured right at one inch at the 4.3 setting. I was surprised that one grain would open up the groups like that.
I am satisfied to stick with 53 gr., using the 140AB. On my next outing, I will Chrony my loads.
I am thinking that with my 22 barrel, perhaps too much unburned propellant is blowing out the muzzle, creating the difference in the groups, between the 53gr. load and the 54gr. load. What do you think?
Steven
My question has to do with the difference that one grain of propellant can make, even when using BOSS. For all these tests I used 140AB. After getting to the OAL that I wanted, I loaded IMR4350 beginning at 52gr. and going up in 1/2 grain increments until I reached 54gr. Keeping the BOSS setting at the Browning recommended setting of "4". My best groups were at 53gr. I loaded up another test batch with only 53 gr. and 54 gr. Making adjustments up and down on the BOSS settings, I got two 4 shot groups at 53gr, that were very, very tight clovers, with two rounds appearing to enter one hole.The sweet spot was at 4.1. Fine so far.
I than began to shoot the rounds loaded to 54 gr. I made adjustments on the BOSS as high as 4.4 and as low as 3.9. The best groups measured right at one inch at the 4.3 setting. I was surprised that one grain would open up the groups like that.
I am satisfied to stick with 53 gr., using the 140AB. On my next outing, I will Chrony my loads.
I am thinking that with my 22 barrel, perhaps too much unburned propellant is blowing out the muzzle, creating the difference in the groups, between the 53gr. load and the 54gr. load. What do you think?
Steven
