Q:

Barrel set screws, tightening pattern?

I’ve been pulling my hair out over accuracy with my Condor.

All shooting has been done from the same table, using a harris bipod mounted about 4″ from the endcap.

This condor has a custom fitted AR15 grip, which is mounted pretty solidly. I only hold the gun by the grip with the right hand, using my standard benchrest shooting style. Left arm under the pistol grip, holding my right elbow with my left hand. Both elbows on the table.

When I first got the gun, Kodiaks went into a ragged hole at 35 yards.

Since I have had it apart, about 10 times now, I cannot get it to stay within 1.5″ at the same yardage.
I have tried just about every PW setting, and settled @ 10/10 @ 2600 PSI starting pressure. (Anthony was right)
Velocity starts about 920, then runs up towards 960+ for around 20 shots. At this setting, groups average around 1.5″.

I tried CP domed pellets and they grouped about the same, but shot an inch higher. I achieved the exact same result using JSB predators. Velocities ran a bit over 1000 fps for each at PW 10/10. Setting it down to 9/10 brought velocity to the 980’s for both pellets, accuracy and POI did not change at all for either pellet.

I cleaned the bore, using only an oiled patch (breakfree clp) 2 fills ago, no changes in groups.

The only thing I can think of that may have changed is the tightening of the barrel bushing screws.

My Condor has 2 allen set screws that seat into the bushing from the bottom, and another 2 on the laft side of the gun that apply pressure to the sides of the bushing. If I vary pressure on any of these 4, the gap between the barrel and the endcap changes by a barely noticable amount.

Also, I dont know how tight the tolerance is supposed to be between the frame and bushings, but there appears to be a bit of slop in the fit.

I would appreciate feedback on the proper tightening order and pressures needed because I desperately miss the accuracy I once saw with this gun.

Thanks

Airforce Rifles/Pistols

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Viewing 5 replies - 1 through 5 (of 5 total)

quote Bodhisdad:

How much slop are you talking about? Could you use electrical tape around the bushings and still get them in the frame?

And if you cant get them in with electrical tape all way around, just put it on one half, or even a 1/4 if that is too much.

Bear in mind that the tape will likely pull off the bushing eventually if you remove the barrel a few times and leave sticky residue on the inside of your frame or it will wrinkle and jam the barrel in the frame making it difficult to remove.

I used the tape thing for a while with my condor, then I finally had enough and ordered a .25 barrel blank, machined it and some properly sized aluminum bushings and my accuracy improved vastly.

quote :

Anthony, I dont have the gun torn apart right now but I am sure the bushing holes are threaded, at least they appear to be. Maybe they just have grooves worn from the screws.

Your bushing holes should be smooth. They are being marked by the set screws rubbing against them….not good.

Drill them out a little. Hopefully that was the cause of your problems.

My bushings range from 1.006-1.009

Good Luck

How much slop are you talking about? Could you use electrical tape around the bushings and still get them in the frame?

quote Anthony266:

Are any of the barrel set screws binding with the barrel bushings?
If so you can adjust them via the bushing set screw or enlarge the holes.
Binding will cause accuracy problems.

When tightening the set screws, screw them all in half way, making sure all holes are aligned. Then tighten the bottoms first then the sides snug.

Do not over tighten.

Anthony, I dont have the gun torn apart right now but I am sure the bushing holes are threaded, at least they appear to be. Maybe they just have grooves worn from the screws.

Are you saying these should be smooth holes that the set screws will sit into, meaning tight fit but not threaded? If so, I am supposed to bottom the screw out in the hole, pushing the bushing toward the top of the frame tube?

Also, would it be feasable to machine bushings a little bit larger to make them fit in the frame a bit more snug? I ask because it appears to me you make your own bushings, and I was wondering what kind of tolerance you aim for.

Thanks Anthony.

I feel like I owe you a bit of business when funds allow.

Are any of the barrel set screws binding with the barrel bushings?
If so you can adjust them via the bushing set screw or enlarge the holes.
Binding will cause accuracy problems.

When tightening the set screws, screw them all in half way, making sure all holes are aligned. Then tighten the bottoms first then the sides snug.

Do not over tighten.

Viewing 5 replies - 1 through 5 (of 5 total)

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