I discovered when shooting one day that the breech area in a Swiss Federal Rile I own is slightly pitted, enough so that I have to make sure the bullet isn't seated below a certain point in the barrel. Below that point and I get flyers. (The rest of the bore is pristine; probably had a load in it for some time.) So, to bump it up without altering my powder charge, I use about 5-10 gr. of COW. Makes sense.
Besides the obvious improvement in accuracy, what I immediately discovered was that the bore was much cleaner between shots, so much so that there is hardly any force needed to run the bullet home.
I also shoot a few single-shot cartridge guns. Same deal there; my .56/56 Ballard shoots a 25gr load of 3f under a Rapine bullet. I need about 5gr. or so to fill the case to the base for a very slightly compressed load. A look through the bore between shots with a COW load shows about 6" of fouling at the breech, then very little to no fouling from there out. Without COW the bore is dirty to the muzzle.
I know from BPCR shooting that Compressed loads are cleaner burning. Cases are cleaner at the mouth and I don't get any gas or fouling back through the action. If I don't use COW in the Skirmish guns, cases are cruddy, the block/interior of the action is cruddy and so is my face.
So, I know compression plays a role,I know COW plays a role, but what's going on during "the burn" that makes this happen?
Tim Lyne
Knap's Batt
#2952V
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