I have been learning wife's new 6mmBR and am really getting confused as to what is happening.
The story:
1. This gun is a Remington 700 SS SA built by Speedy Gonzales in 6mmBR with a 29" SS fluted barrel with a 1:8 twist barrel. When I purchased it the round count was estimated at 5-600 by the previous owner,appeared to have been shot with moly'd bullets as ammo that came with the gun was loaded with moly'd bullets and the action showed moly residue). I cleaned thoroughly and even used Bore Teck Moly Magic to remove the moly as best I can,pressures picked up AFTER Moly Magic)
2. First loadings were 29.0, 29.3, 29.5, 29.7, and 30 grains of Varget behind a 107 gr. Sierra MatchKing seated .020" off, new unprepped Lapua cases, and Fed 205M primers. Accuracy was excellant,.75"-.5" at 200 yards. Pressures were at the point of being excessive at 30,stiff bolt and ejector marks on the cases) but OK at the lower loadings. Velocities were progressively higher and ES was all under 10 fps. Velocities were - at 29.5 was 2775 fps and at 30 grains was 2810 fps. I reduced the load to 29.5 and wife fired a 1000 yard Match with excellant results and no excess pressure indications.
3. We noted that the case necks were being flattened on one side by the ejector, so I took the spring out and replaced the ejector pin back in the gun to eliminate this flattening and stop the ejected cases from being thrown to the ground.
4. I noted that fired cases were not able to have new bullets hand seat into the case even when the cases appeared to have one side flattened. This along with the high pressure indication at 30 grains of Varget led me to believe that the neck of the chamber needed the cases to be neck turned slightly. So I turned some .002" total and some .001" total. The loads with the necks turned .002" showed a slight decrease in acccuracy, but OK pressures at 29.5 grains of Varget. The cases turned .001" are now getting high pressure indications,stiff bolt and slight ejector marks) at 29.5 grains of Varget - accuracy remains excellant.
The question:
Why the increased pressure signs after the case necks were turned .001" turned smaller? Temps were all the same and powder from the same 8 pound container.
I'm about as confused by this and the little boy that dropped his gun on the floor of the chicken house.
George
The story:
1. This gun is a Remington 700 SS SA built by Speedy Gonzales in 6mmBR with a 29" SS fluted barrel with a 1:8 twist barrel. When I purchased it the round count was estimated at 5-600 by the previous owner,appeared to have been shot with moly'd bullets as ammo that came with the gun was loaded with moly'd bullets and the action showed moly residue). I cleaned thoroughly and even used Bore Teck Moly Magic to remove the moly as best I can,pressures picked up AFTER Moly Magic)
2. First loadings were 29.0, 29.3, 29.5, 29.7, and 30 grains of Varget behind a 107 gr. Sierra MatchKing seated .020" off, new unprepped Lapua cases, and Fed 205M primers. Accuracy was excellant,.75"-.5" at 200 yards. Pressures were at the point of being excessive at 30,stiff bolt and ejector marks on the cases) but OK at the lower loadings. Velocities were progressively higher and ES was all under 10 fps. Velocities were - at 29.5 was 2775 fps and at 30 grains was 2810 fps. I reduced the load to 29.5 and wife fired a 1000 yard Match with excellant results and no excess pressure indications.
3. We noted that the case necks were being flattened on one side by the ejector, so I took the spring out and replaced the ejector pin back in the gun to eliminate this flattening and stop the ejected cases from being thrown to the ground.
4. I noted that fired cases were not able to have new bullets hand seat into the case even when the cases appeared to have one side flattened. This along with the high pressure indication at 30 grains of Varget led me to believe that the neck of the chamber needed the cases to be neck turned slightly. So I turned some .002" total and some .001" total. The loads with the necks turned .002" showed a slight decrease in acccuracy, but OK pressures at 29.5 grains of Varget. The cases turned .001" are now getting high pressure indications,stiff bolt and slight ejector marks) at 29.5 grains of Varget - accuracy remains excellant.
The question:
Why the increased pressure signs after the case necks were turned .001" turned smaller? Temps were all the same and powder from the same 8 pound container.
I'm about as confused by this and the little boy that dropped his gun on the floor of the chicken house.
George