"redneck gunsmithing" muzzle crown
Posted: Sun Nov 22, 2009 9:52 pm
my mkii starting losing accuracy. so i did just about everything i could to regain the consistancy i once enjoyed, but to no avail.
a couple of weeks ago i figured i'd give the muzzle a deeper more pronouonced crown. i thought that i'd drop it off at the gunsmith but then thought i'd try it myself, projecting the outcomes to be:
1. worse accuracy so i'd send it to the smith anyway to correct my stupidity
2. an improvement in accuraccy
3. a new barrel (refer to #1)
4. no change, no foul
i used a reloading case reamer / chamfer tool, spun it in the muzzle as evenly as i could, and created a crown. i thought that the less than precise manner used would be a problem, but as it turned out, accuraccy improved at 100 and 200 yards.
i was originally getting 1.25" to 1.5" groups at 100, then it started to open up to 2" and seemed to be expanding. after the ream job, i'm back down to a more consistant group.
weather conditions were similar on both occasions
before 100 yards:
after, at 100 yards you can see how the new crown job concentrated the rounds better. if it wasn't for the 3 hits at 5:00, the group would have measured -1.75"
before 200 yards sorry it's sideways ( the top part of the picture got cut off when i posted it there are 4 hits above the grey area):
after, at 200 yards, the signs of vertical tracking is less evident, and the group is more uniform. there were two rounds up top were called blown shots, if it wasn't for them all 30 rnds would have been in the gray. (the gray area is 5" wide by 7" high). (the picture got cut off and can't see the upper portion of the target)
now i'm not suggesting that someone should try this themselves, however that redneck crown job seemed to do the trick for me.
a couple of weeks ago i figured i'd give the muzzle a deeper more pronouonced crown. i thought that i'd drop it off at the gunsmith but then thought i'd try it myself, projecting the outcomes to be:
1. worse accuracy so i'd send it to the smith anyway to correct my stupidity
2. an improvement in accuraccy
3. a new barrel (refer to #1)
4. no change, no foul
i used a reloading case reamer / chamfer tool, spun it in the muzzle as evenly as i could, and created a crown. i thought that the less than precise manner used would be a problem, but as it turned out, accuraccy improved at 100 and 200 yards.
i was originally getting 1.25" to 1.5" groups at 100, then it started to open up to 2" and seemed to be expanding. after the ream job, i'm back down to a more consistant group.
weather conditions were similar on both occasions
before 100 yards:
after, at 100 yards you can see how the new crown job concentrated the rounds better. if it wasn't for the 3 hits at 5:00, the group would have measured -1.75"
before 200 yards sorry it's sideways ( the top part of the picture got cut off when i posted it there are 4 hits above the grey area):
after, at 200 yards, the signs of vertical tracking is less evident, and the group is more uniform. there were two rounds up top were called blown shots, if it wasn't for them all 30 rnds would have been in the gray. (the gray area is 5" wide by 7" high). (the picture got cut off and can't see the upper portion of the target)
now i'm not suggesting that someone should try this themselves, however that redneck crown job seemed to do the trick for me.
Excusse me I mean "double wide" 