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Hello everyone,
I just returned from the range, where I firelapped two guns. The first was a great success, the other we'll call a draw.
The first one alluded to is my Ruger 77MKII .257 Roberts. After a coyote hunting trip this winter I ran a patch through the bore only to see orange - a little rust from the fog and humidity. There was no visible pitting but all of a sudden the rifle started fouling terribly, just after I got it shooting well, too. So I rolled some 115gr BT's in lapping compound, 5 in 220 grit and 10 in 320 grit. After lapping I fired six rounds of regular ammo, and they left very little copper in the bore - EUREKA! I'm going to chronograph some loads soon to see if there was an effect on velocity, since I've read that lapping can decrease velocity in some rifles. We'll see! Accuracy was unchanged BTW.
As for the other gun, I fired fifty lapping rounds through my GP-100 while I was at it. It didn't make any impact at all on my cast bullet loads (still mediocre), I believe I'm going to have to open up the chamber throats a bit to get the proper lapping action. But it still shoots gangbusters with that Speer 158gr JSP. I shot at a prairie dog target at 50 yds and made 4 vital hits out of six. Total group size was about 3.5 inches. That's about the best I've done at 50 yds so far. Now, as soon as I get it shooting that well with cast.... IDShooter
I just returned from the range, where I firelapped two guns. The first was a great success, the other we'll call a draw.
The first one alluded to is my Ruger 77MKII .257 Roberts. After a coyote hunting trip this winter I ran a patch through the bore only to see orange - a little rust from the fog and humidity. There was no visible pitting but all of a sudden the rifle started fouling terribly, just after I got it shooting well, too. So I rolled some 115gr BT's in lapping compound, 5 in 220 grit and 10 in 320 grit. After lapping I fired six rounds of regular ammo, and they left very little copper in the bore - EUREKA! I'm going to chronograph some loads soon to see if there was an effect on velocity, since I've read that lapping can decrease velocity in some rifles. We'll see! Accuracy was unchanged BTW.
As for the other gun, I fired fifty lapping rounds through my GP-100 while I was at it. It didn't make any impact at all on my cast bullet loads (still mediocre), I believe I'm going to have to open up the chamber throats a bit to get the proper lapping action. But it still shoots gangbusters with that Speer 158gr JSP. I shot at a prairie dog target at 50 yds and made 4 vital hits out of six. Total group size was about 3.5 inches. That's about the best I've done at 50 yds so far. Now, as soon as I get it shooting that well with cast.... IDShooter