eerw Posted February 22, 2009 Share Posted February 22, 2009 borrowed a buddy's open gun...loading 7.0gr of Longshot with 124MG JHP, loaded to 1.140 Looks like its tumbling a bit on paper....I don't see any marks on the comp..any ideas on what to change?? thanks Link to comment Share on other sites More sharing options...
boz1911 Posted February 22, 2009 Share Posted February 22, 2009 Comp or too much crimp are the 2 biggies. But with MG bullets I would look berry, berry carefully at the comp. Link to comment Share on other sites More sharing options...
titandriver Posted February 22, 2009 Share Posted February 22, 2009 What distance? Link to comment Share on other sites More sharing options...
GentlemanJim Posted February 22, 2009 Share Posted February 22, 2009 What barrel is it? I have two guns with KKM barrels...both tumble Jim Link to comment Share on other sites More sharing options...
TMC Posted February 22, 2009 Share Posted February 22, 2009 My new gun with a Schueman 3 port Hybrid has the same issue. The holes look key holed but it shoots about 2.5" at 50. Link to comment Share on other sites More sharing options...
eerw Posted February 22, 2009 Author Share Posted February 22, 2009 What barrel is it?I have two guns with KKM barrels...both tumble Jim KKM .355 bull barrel are you still shooting them..or did you switch out to another brand What distance? at today's match..10 yards to 20 yards..but not all of them did. Link to comment Share on other sites More sharing options...
SLM Posted February 22, 2009 Share Posted February 22, 2009 1.14" seems really short. I load to 1.175" with MG 115's and 121's for my guns. The 124 is a bit longer than the 115 but not much. Just guessing but could it be too short and have to jump too far to engage the rifling and be distorting the bullet from hitting the rifling off center? My KKM is a tack driver... Sorry, had to say it! Link to comment Share on other sites More sharing options...
G-ManBart Posted February 22, 2009 Share Posted February 22, 2009 What barrel is it?I have two guns with KKM barrels...both tumble Jim Jim, Open up the muzzle to .385-.390 and the problem will go away. My gun with the KKM and Ti Bedell comp started doing that at something like 10K and I talked to Dan about it. The streaks on the baffle looked like rifling marks (which they were sorta) and they were at about 1 O'clock when looking at the muzzle. I opened up the second baffle a bit as well (maybe .005-.010) and it has never done it again. I used a hand reamer and it worked like a champ. I shot that gun at 40yds when zeroing it for backup duty before the Nationals and it was grouping perfectly with 115gr MG JHPs. R, Link to comment Share on other sites More sharing options...
HSMITH Posted February 22, 2009 Share Posted February 22, 2009 What barrel is it?I have two guns with KKM barrels...both tumble Jim Jim, Open up the muzzle to .385-.390 and the problem will go away. My gun with the KKM and Ti Bedell comp started doing that at something like 10K and I talked to Dan about it. The streaks on the baffle looked like rifling marks (which they were sorta) and they were at about 1 O'clock when looking at the muzzle. I opened up the second baffle a bit as well (maybe .005-.010) and it has never done it again. I used a hand reamer and it worked like a champ. I shot that gun at 40yds when zeroing it for backup duty before the Nationals and it was grouping perfectly with 115gr MG JHPs. R, +1, my gun with KKM and Bedell TI comp has done it 3 times, the first two times I would go in with a comp alignment reamer and clean it up. It would shoot great for a while. The last time I opened the last two baffles to .385 and it hasn't done it since. The first time was probably 1500-2000 rounds, the second at probably 7-8K rounds, and the last time at 15-18K rounds. I have about 40K rounds on that barrel, it has been WAY too hot several times as in started to turn a bit yellow type of WAY too hot, and it still shoots 3" at 50 yards. KKM barrels have been extremely accurate for me, a beech to fit compared to a Schuemann but they shoot great. Tumbling is probably the comp touching the bullet, if not it is probably overcrimp or crooked seating. The contact with the comp only needs to be TINY to affect the flight of the bullet, I have seen it require a loupe with good light and just the right angle to see it. If in doubt ream the last two baffles on the comp. Link to comment Share on other sites More sharing options...
lcs Posted February 22, 2009 Share Posted February 22, 2009 What barrel is it?I have two guns with KKM barrels...both tumble Jim Jim, Open up the muzzle to .385-.390 and the problem will go away. My gun with the KKM and Ti Bedell comp started doing that at something like 10K and I talked to Dan about it. The streaks on the baffle looked like rifling marks (which they were sorta) and they were at about 1 O'clock when looking at the muzzle. I opened up the second baffle a bit as well (maybe .005-.010) and it has never done it again. I used a hand reamer and it worked like a champ. I shot that gun at 40yds when zeroing it for backup duty before the Nationals and it was grouping perfectly with 115gr MG JHPs. R, +1, my gun with KKM and Bedell TI comp has done it 3 times, the first two times I would go in with a comp alignment reamer and clean it up. It would shoot great for a while. The last time I opened the last two baffles to .385 and it hasn't done it since. The first time was probably 1500-2000 rounds, the second at probably 7-8K rounds, and the last time at 15-18K rounds. I have about 40K rounds on that barrel, it has been WAY too hot several times as in started to turn a bit yellow type of WAY too hot, and it still shoots 3" at 50 yards. KKM barrels have been extremely accurate for me, a beech to fit compared to a Schuemann but they shoot great. Tumbling is probably the comp touching the bullet, if not it is probably overcrimp or crooked seating. The contact with the comp only needs to be TINY to affect the flight of the bullet, I have seen it require a loupe with good light and just the right angle to see it. If in doubt ream the last two baffles on the comp. Exact same combination on my first open (KKM+Bedell) and it started tumbling at 1500-2k. Same fix cured the problem. Link to comment Share on other sites More sharing options...
G-ManBart Posted February 22, 2009 Share Posted February 22, 2009 What barrel is it?I have two guns with KKM barrels...both tumble Jim Jim, Open up the muzzle to .385-.390 and the problem will go away. My gun with the KKM and Ti Bedell comp started doing that at something like 10K and I talked to Dan about it. The streaks on the baffle looked like rifling marks (which they were sorta) and they were at about 1 O'clock when looking at the muzzle. I opened up the second baffle a bit as well (maybe .005-.010) and it has never done it again. I used a hand reamer and it worked like a champ. I shot that gun at 40yds when zeroing it for backup duty before the Nationals and it was grouping perfectly with 115gr MG JHPs. R, +1, my gun with KKM and Bedell TI comp has done it 3 times, the first two times I would go in with a comp alignment reamer and clean it up. It would shoot great for a while. The last time I opened the last two baffles to .385 and it hasn't done it since. The first time was probably 1500-2000 rounds, the second at probably 7-8K rounds, and the last time at 15-18K rounds. I have about 40K rounds on that barrel, it has been WAY too hot several times as in started to turn a bit yellow type of WAY too hot, and it still shoots 3" at 50 yards. KKM barrels have been extremely accurate for me, a beech to fit compared to a Schuemann but they shoot great. Tumbling is probably the comp touching the bullet, if not it is probably overcrimp or crooked seating. The contact with the comp only needs to be TINY to affect the flight of the bullet, I have seen it require a loupe with good light and just the right angle to see it. If in doubt ream the last two baffles on the comp. Exact same combination on my first open (KKM+Bedell) and it started tumbling at 1500-2k. Same fix cured the problem. I'm pretty sure that Bedell is now making the Ti comp with a larger diameter in the last baffle or two to prevent this. I think it's a combination of the material and the length of the comp (since it's on the long side). R, Link to comment Share on other sites More sharing options...
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