Steven66
06-29-2018, 11:10 AM
I think I made a serious error in excessively firelapping my Ruger 77/357 because I kept feeling roughness in the bore with push through slugs (per Veral Smith's and Marshall Stanton's books). When I made a chamber cast afterwards I found that the rifling did not appear in the cast for almost 0.7" past the mouth of the cartridge case, so the throat is something like a giraffe neck, at least to me. The beginning of the throat measures 0.3615" and shrinks 0.0005" at 0.1" intervals till it gets to the rifling where it is a reasonable 0.3575". I was using up the last of the Beartooth lapping bullets (I think they're about 160 grains with no lapping compound) and got fairly decent groups (around 2" for five shots at 100 yards) using up to 4.9 grains of Titegroup and CCI SPM primers despite a heavy trigger and my newbie bench skills. Velocity was 1123 fps average.
So I thought I would be in good shape when I used unsized Lee 158 grain SWC GC made from water dropped COWW with 4.6 grains of Titegroup (starting over just slightly above the starting load because the bullet was different) after getting an initial three-shot cloverleaf sitting at 50 yards. The SWCs fed nicely from the rotary magazine and I felt like a god. Briefly.
So I cast a lot more, though I used a larger bucket so the quenching might have been different. It all went south from there when I tried to bench them (a pattern rather than a group). I was shooting without gas checks both times because of the fairly low velocity. So I quit the bench and shot five offhand at 25 yards and they went into a 3" circle in the black.
I don't have a hardness tester, so I don't know whether the first batch (I cast them by dipper from the kitchen stove) came out differently than the second batch when I used the Lee 4-20 bottom pour. The boolits come out of the Lee mold at 0.3575" diameter pretty consistently. I pan lubed all of the boolits with LLA mixed with some paraffin and paste wax and have gotten no leading. I will use BLL in the future, but this stuff seems OK for the moment, at least at this velocity.
I have been thinking of putting on gas checks and not sizing them, but the gas check measures 0.360" which may be nice for the chamber but bad for pressure? I can size them with a Lee push-through sizer. I can also anneal the boolits I have in case they're too hard, at least at this velocity.
I'm thinking that I may have too many variable variables, but I'm not sure which ones they are.
Any suggestions? Thanks!
So I thought I would be in good shape when I used unsized Lee 158 grain SWC GC made from water dropped COWW with 4.6 grains of Titegroup (starting over just slightly above the starting load because the bullet was different) after getting an initial three-shot cloverleaf sitting at 50 yards. The SWCs fed nicely from the rotary magazine and I felt like a god. Briefly.
So I cast a lot more, though I used a larger bucket so the quenching might have been different. It all went south from there when I tried to bench them (a pattern rather than a group). I was shooting without gas checks both times because of the fairly low velocity. So I quit the bench and shot five offhand at 25 yards and they went into a 3" circle in the black.
I don't have a hardness tester, so I don't know whether the first batch (I cast them by dipper from the kitchen stove) came out differently than the second batch when I used the Lee 4-20 bottom pour. The boolits come out of the Lee mold at 0.3575" diameter pretty consistently. I pan lubed all of the boolits with LLA mixed with some paraffin and paste wax and have gotten no leading. I will use BLL in the future, but this stuff seems OK for the moment, at least at this velocity.
I have been thinking of putting on gas checks and not sizing them, but the gas check measures 0.360" which may be nice for the chamber but bad for pressure? I can size them with a Lee push-through sizer. I can also anneal the boolits I have in case they're too hard, at least at this velocity.
I'm thinking that I may have too many variable variables, but I'm not sure which ones they are.
Any suggestions? Thanks!