I broke down and bought 100 Lapua Palma .308 cases and a couple C of the Sierra Palma 155s and tested 25 rounds (5 loads) ranging from 44 to 47.5* gns of Varget in my Mod 70. The results may not impress many here but for me it was the first time I think I've cut so many 1" or smaller ragged holes at 100 yds.
The setup is a post-64 .308 target model 70 with a factory barrel with maybe 1000 rounds through it on a bipod and sandbag and 6.5-20x scope. Factory trigger at 2.5 lbs. The cases were virgin and only trimmed, chamfered and primer pocket reamed. Fed 205M primers. Charges were 44, 45, 46, 47 & 47.5* gns of Varget. I fired through a CED M2 chronograph, round robin, firing the first load, then second, third, etc. coming back to the 1st, 2nd, 3rd, etc until all 25 rounds were fired. After each five rounds I rested a bit to let the barrel cool and reduce any eye strain. Note that to give the same ogive length as my normal 168 gn loads (2.323"), these rounds were only seated 0.057" into the case neck.
The stats were:
44 gn: Avg = 2495 fps, ES 75 fps, SD 29.8
45 gn: Avg = 2579 fps, ES 59 fps, SD 21.6
46 gn: Avg = 2661 fps, ES 45 fps, SD 16.1
47 gn: Avg = 2711 fps, ES 22 fps, SD 9.2
47.5 gn: Avg = 2725 fps, ES 46 fps, SD 17.1
*47.5 gns is the max charge on the Hodgdon website.
I definitely experienced issues with my pulse and hold during the test and my notes indicate that I felt that I threw one shot on target 3 and one on target 4. Next time I'm going to have to use a better target backer. The many layers of staples on the club's target board held the target a bit off the board making the holes more ragged than necessary. At least this time everything worked: no issues with the chronograph, didn't forget anything, etc.
I think that my next upgrade may be a better trigger. It appears that I may be reaching the limit of what can be expected with this gun.
Observations? Suggestions? Criticisms (preferably constructive)? Keep in mind I'm working on a budget, trying to make the most of what I already own. I'm trying to decide between 47 gns and 47.5 gns for the F-Class match on Saturday.
The targets are: center=44 gn, UL=45 gn, UR=46 gn, LR=47 gn, LL=47.5 gn
The setup is a post-64 .308 target model 70 with a factory barrel with maybe 1000 rounds through it on a bipod and sandbag and 6.5-20x scope. Factory trigger at 2.5 lbs. The cases were virgin and only trimmed, chamfered and primer pocket reamed. Fed 205M primers. Charges were 44, 45, 46, 47 & 47.5* gns of Varget. I fired through a CED M2 chronograph, round robin, firing the first load, then second, third, etc. coming back to the 1st, 2nd, 3rd, etc until all 25 rounds were fired. After each five rounds I rested a bit to let the barrel cool and reduce any eye strain. Note that to give the same ogive length as my normal 168 gn loads (2.323"), these rounds were only seated 0.057" into the case neck.
The stats were:
44 gn: Avg = 2495 fps, ES 75 fps, SD 29.8
45 gn: Avg = 2579 fps, ES 59 fps, SD 21.6
46 gn: Avg = 2661 fps, ES 45 fps, SD 16.1
47 gn: Avg = 2711 fps, ES 22 fps, SD 9.2
47.5 gn: Avg = 2725 fps, ES 46 fps, SD 17.1
*47.5 gns is the max charge on the Hodgdon website.
I definitely experienced issues with my pulse and hold during the test and my notes indicate that I felt that I threw one shot on target 3 and one on target 4. Next time I'm going to have to use a better target backer. The many layers of staples on the club's target board held the target a bit off the board making the holes more ragged than necessary. At least this time everything worked: no issues with the chronograph, didn't forget anything, etc.
I think that my next upgrade may be a better trigger. It appears that I may be reaching the limit of what can be expected with this gun.
Observations? Suggestions? Criticisms (preferably constructive)? Keep in mind I'm working on a budget, trying to make the most of what I already own. I'm trying to decide between 47 gns and 47.5 gns for the F-Class match on Saturday.
The targets are: center=44 gn, UL=45 gn, UR=46 gn, LR=47 gn, LL=47.5 gn
