mshelton
Had a new rifle in 6.5x55GWI built a few months back and I've been having some problems getting a working load. The rifle is a Kelbly Atlas action, McMillan Marksman heavy fill stock, 27" fluted HV taper Spencer barrel with break, Jewell trigger and s March 2.5-25 with Kelbly rings and bases.
For load development I'm using or have tried; BR-4, 210m, H4350, H4831SC behind Berger 140 VLD hunting, 130 VLD target and 142 SMKs, Lapua brass turned to .012 and Norma brass turned to .0128, both sets of test cases have at least 3 firings on them, have been annealed, FL sized and trimmed.
Initial fire forming with 100g sierra varminters produced some surprisingly nice groups in the low .2s and high 1s. The good unfortunately groups stopped there. I tried the Berger 130s and 142 SMKs first with both powders/primers, multiple seating depths (+.005 to -.030) and charges. Could never get anything remotely satisfactory. The rifle was sitting high in the stock due to a botched bedding job, appeared functional and fine just high, also had close to 6" of barrel bedded. Decided to mill out the bedding and mill down the pillars to get the action to sit down in the stock, also only rebedded about 1 1/2 inches of the barrel (thinking was, barrel was heating and in the previous 6" of bedding it was starting to get pressure on it). Finished the job and also swapped rings and base.
Restarted load development, this time with some Berger 140 VLD hunting, some early groups showed decent promise but would never replicate results. Best results came from jumping them .030, horizontal was calming down but showing signs of vertical so I went to playing with the powder charge. Here's where the head scratching starts, the past 2 days with 6 out of 10 different loads, different powders and primers combos, I'll get the first 2 shots in the same hole (mid .100s) then the third shot goes between .600 and .800 left or right. Never the second then the third back to the first hole, it's the first 2 in a dot then a slinger left or right.
My first thought is to remove the little bit of bedding under the barrel, thinking that the heat by shot 3 is causing problems but 3 shots shouldn't effect a HV taper barrel that much. Also I have some trued and rebarreled 700s with the Rem varmint taper where the first couple inches of barrel are bedded and it hasn't effected them. I know that's an old argument on here but from what I've seen, that shouldn't be causing my issues.
So now I'm left scratching my head trying to figure out the 3rd shot fling fest.
Any ideas?
For load development I'm using or have tried; BR-4, 210m, H4350, H4831SC behind Berger 140 VLD hunting, 130 VLD target and 142 SMKs, Lapua brass turned to .012 and Norma brass turned to .0128, both sets of test cases have at least 3 firings on them, have been annealed, FL sized and trimmed.
Initial fire forming with 100g sierra varminters produced some surprisingly nice groups in the low .2s and high 1s. The good unfortunately groups stopped there. I tried the Berger 130s and 142 SMKs first with both powders/primers, multiple seating depths (+.005 to -.030) and charges. Could never get anything remotely satisfactory. The rifle was sitting high in the stock due to a botched bedding job, appeared functional and fine just high, also had close to 6" of barrel bedded. Decided to mill out the bedding and mill down the pillars to get the action to sit down in the stock, also only rebedded about 1 1/2 inches of the barrel (thinking was, barrel was heating and in the previous 6" of bedding it was starting to get pressure on it). Finished the job and also swapped rings and base.
Restarted load development, this time with some Berger 140 VLD hunting, some early groups showed decent promise but would never replicate results. Best results came from jumping them .030, horizontal was calming down but showing signs of vertical so I went to playing with the powder charge. Here's where the head scratching starts, the past 2 days with 6 out of 10 different loads, different powders and primers combos, I'll get the first 2 shots in the same hole (mid .100s) then the third shot goes between .600 and .800 left or right. Never the second then the third back to the first hole, it's the first 2 in a dot then a slinger left or right.
My first thought is to remove the little bit of bedding under the barrel, thinking that the heat by shot 3 is causing problems but 3 shots shouldn't effect a HV taper barrel that much. Also I have some trued and rebarreled 700s with the Rem varmint taper where the first couple inches of barrel are bedded and it hasn't effected them. I know that's an old argument on here but from what I've seen, that shouldn't be causing my issues.
So now I'm left scratching my head trying to figure out the 3rd shot fling fest.
Any ideas?
