Can't zero red dot

[nervoustrig]

I am sitting here thinking about the trigonometry of everything. How would shimming the breech up from the tube help, It seems to me as if the problem is in the breech -barrel- red dot mounting. Shimming up the breech would not change that , UNLESS it would make the barrel band push up on the barrel. I tried the same sight on a HW75 and it also showed a poi well below the point of aim, I may slip the sight onto my FWB 300, and see how it performs there.

Odoyle's recommendation is another way of stating what I said earlier...

Also check that the breech is sitting flush to the air tube. If the transfer port isn't fitted correctly and causing the breech to lift at the front, and the barrel band is then pulling the muzzle down, that would explain why your sight and barrel are so divergent.

Likewise, lifting the rear of the receiver may place it on the same axis as the barrel...that is, both of them angled somewhat downward.

 

[jkingrph]

I was wondering about aligning the transfer port. Is there a good way to do this, I seems rather hit or miss on that as you really cannot see what you are doing. I do see with the top barrel band screw snug and the lower backed out, I can slide a sheet of 15lb paper between the breech tube and the action tube. That seems to be no downward tension the barrel though, so with the grub screw holding the barrel in the steel breech it would seem to take a lot of tension to bend or tilt the barrel down,

 

[fivestar45]

The 22xx platform has a major downfall with the breech fastening. If you installed the breech and relied on the small 4/48 screw to pull it against the tube chances are the breech is not seated properly. If you can slide a piece of paper between the bottom front of the breech and the tube you should fix things before you go any further as the POI might not be predictable until you do.

The easiest fix is to use a clamp right over where the T/P is to compress the breech down on the tube, and then take up on the 4/48 screw. Also mount a barrel band right at the front of the breech and lightly tighten the barrel band screws before removing the clamp. Even better results if you add a second barrel band close to the front sight.

 

[Odoyle]

Your problem might be in how you installed the breech. See if you can slide a $ bill between the front bottom of the breech and the air tube.

What will that show?

OH MAN I would loosen up the breech screws and run a shim at the back end of the breech to jack it up a little to fix your problem. A small washer in between the rear breech screw and tube or piece or two of water bottle cut to fit.

I take this back ot won't work since doing this will worsen the problem you need to bend the barrel up. AZ would do it which he does all the tume bend barrels up and he's the best tuner in the world in regards to sheer accuracy and MOUSEFART quiet.

 

[jkingrph]

Today I tried one of the cheapie Westlake red/green dots for ebay and It zeroed without an problem. With my cataracts the green is easier to sight with, not as much flare as the red. Getting ragged ten shot groups at about 40-45 feet.

This sight was designed for the 11mm grove mount, so no adapters needed. I did loosen the barrel grub as well as the little breech screw, and attempted to see if there was any movement to the barrel, none that I could detect, and then held the barrel down tight when retightening the breech screw, don't know if that helped any.