Matt85
06-14-2013, 05:37 AM
im trying to figure out the measurements for my trapdoor rifles bore. im currently having serious issues in that every load I try in the gun seems to shoot VERY high. at 50 yards the POI is 12" above POA and at 100 yards its 16" above POA. im thinking my bullet must be either too large or too small or my seating depth is way off.
so for starters I hammerd a .490 pure lead ball down the barrel to try and get some kinda measurement. this yielded a very nice looking swaged cylinder but ive run into the problem of not knowing how the heck to measure this thing. I have a set of calipers but due to the rifling pattern one side is a land and the other is a groove so you cant really measure land-land and groove-groove. im feeling pretty stupid at the moment so please give me some ideas.
ive also got some chamber casting alloy on the way so some advice on how to take a good chamber cast on a trapdoor rifle and how to properly measure the results would really be appreciated.
thank you
-Matt
so for starters I hammerd a .490 pure lead ball down the barrel to try and get some kinda measurement. this yielded a very nice looking swaged cylinder but ive run into the problem of not knowing how the heck to measure this thing. I have a set of calipers but due to the rifling pattern one side is a land and the other is a groove so you cant really measure land-land and groove-groove. im feeling pretty stupid at the moment so please give me some ideas.
ive also got some chamber casting alloy on the way so some advice on how to take a good chamber cast on a trapdoor rifle and how to properly measure the results would really be appreciated.
thank you
-Matt