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GURU1911 · June 5, 2011, 07:35 PM

Guru1911 here to help with your original question regarding barrel, bushing, & slide tolerances.

The measurement of the slide id, the bushing od, & the barrel od are added together. This is referred to as "total tolerance stack-up". It will give you the potential machine rest 100 yard accuracy if the ammo is up to the task. If your measurements are correct, the total stack-up is .018"---this means that @ 100 yards, the best group would be about 18" in diameter. 50% of the barrel lock up stability is at the bushing end of the slide !!!!!

Stay away from those bushings that have the pivoting inner ring !!!

A properly fitted bushing should yield about .001" clearance in the slide. You should barely be able to turn it with your fingers, but really easy with a plastic wrench. CLEARANCE BETWEEN THE BARREL & THE BUSHING SHOULD BE ABOUT .002"---JUST ENOUGH TO ALLOW PROPER BARREL TILT WITH NO "SPRING" FEEL WHEN DEPRESSING THE BARREL INTO THE SLIDE.

If you have any doubts about your ability to properly fit a "match grade bushing" to the slide & the barrel, let someone who knows what they are doing & pay them.

Any additional questions, please contact me by "pm"

June 5, 2011, 07:35 PM	#5
GURU1911 Senior Member Join Date: December 22, 2010 Location: SEALY, THE REPUBLIC OF TEXAS Posts: 501	SIDEWINDER Guru1911 here to help with your original question regarding barrel, bushing, & slide tolerances. The measurement of the slide id, the bushing od, & the barrel od are added together. This is referred to as "total tolerance stack-up". It will give you the potential machine rest 100 yard accuracy if the ammo is up to the task. If your measurements are correct, the total stack-up is .018"---this means that @ 100 yards, the best group would be about 18" in diameter. 50% of the barrel lock up stability is at the bushing end of the slide !!!!! Stay away from those bushings that have the pivoting inner ring !!! A properly fitted bushing should yield about .001" clearance in the slide. You should barely be able to turn it with your fingers, but really easy with a plastic wrench. CLEARANCE BETWEEN THE BARREL & THE BUSHING SHOULD BE ABOUT .002"---JUST ENOUGH TO ALLOW PROPER BARREL TILT WITH NO "SPRING" FEEL WHEN DEPRESSING THE BARREL INTO THE SLIDE. If you have any doubts about your ability to properly fit a "match grade bushing" to the slide & the barrel, let someone who knows what they are doing & pay them. Any additional questions, please contact me by "pm" __________________ NRA LIFE MEMBER (1984) & PRESIDENT: S.W. LA. R&P CLUB, LAKE CHARLES, LOUISIANA (1994-1999) METALLIC CARTRIDGE RELOADER (1977) & GENTILE CHRISTIAN ZIONIST INFIDEL !!! "THERE AIN'T TOO MANY THINGS THAT YOU CAN'T FIX, WITH $500 DOLLARS OR A .30-06" Last edited by GURU1911; June 5, 2011 at 07:48 PM.