snowgetter1
09-21-2010, 02:25 PM
Just completed my first barrel swap. Changed to a 25-06 26" varmit from the 22" standard. I became frustrated waiting on Sharp shooter Supply as my wrenches have apparently been on back order for about a month now so I changed the barrel with a pipe wrench. Worked just as described. I would like to thank Lostart for the barrel and the rest of the members for giving me the confidence to complete this.
My question comes from chrono readings that are below what I had in the 22" barrel. It should be noted my 22" firing was first done on a 95 degree then again on about a 90 day then the 26" was about 80. Here are the results.
22" 26"
117gr BTSP 55gr 7828ssc LRM primer (95')=3114 fps; (90)=3070 fps (80)=3004 fps
75gr sierra HP, 57.5gr 760, LR, (95)=3740 fps (80)=3707 fps
85gr Nosler BT, 52gr 760, LRM, (80)=3310 fps
I was expecting a velecity gain not a drop or the same. The 85 gr load is published at 3443 fps. I know from my artillery days powder temp can be important but I would never think it could influence small arms like this. Any ideas?
My question comes from chrono readings that are below what I had in the 22" barrel. It should be noted my 22" firing was first done on a 95 degree then again on about a 90 day then the 26" was about 80. Here are the results.
22" 26"
117gr BTSP 55gr 7828ssc LRM primer (95')=3114 fps; (90)=3070 fps (80)=3004 fps
75gr sierra HP, 57.5gr 760, LR, (95)=3740 fps (80)=3707 fps
85gr Nosler BT, 52gr 760, LRM, (80)=3310 fps
I was expecting a velecity gain not a drop or the same. The 85 gr load is published at 3443 fps. I know from my artillery days powder temp can be important but I would never think it could influence small arms like this. Any ideas?