Elevation Knob Question

[XLF30]

Hi,

Got a rack-grade Garand and the little "lug" on the elevation knob that engages the serrations on the receiver is worn almost flat. Can anyone tell me, other than making the "clicking" noise and giving an audible and tactile reference when moving the aperature up and down (clicking is almost absent) does the absence of this lug create any other problems? I thought the aperature might run vertically, but I pull hard on it an it doesn't run. Gun doesn't shoot real well (good cycling, poor accuracy) but it has multiple problems and I'm taking them one at a time. Thanks

[psteinmayer]

Rack-grade are simply placed on the rack after the CMP verifies that they operate properly and are safe. Other than that, they may have barrels like a sewer pipe with a muzzle that swallows a bullet. As for the elevation knob, I believe the serrations are important to holding the elevation in position. You might have a soft spring in the works there... Anyone else know?

[pmclaine]

Its possible your receiver serrations are worn.

There is a fix. A disk with fresh serrations can be epoxied onto the receiver to refresh the "clicks". You will have the choice of keeping it in issue calibration or you can use the 1/4 moa side of the disk for finer adjustments.

I think Creedmoor Sports, Brownells, Sinclair some of the better supply houses carry theses disks.

First check if replacing the knob will solve your problem.

[XLF30]

What is a "soft spring"?

[XLF30]

Thanks everyone. I identified the problem in the first sentence. I'll repeat the question...does a worn elevation knob lug allow the aperature to jump under recoil? Thanks.

[LavaTech]

Thanks everyone. I identified the problem in the first sentence. I'll repeat the question...does a worn elevation knob lug allow the aperature to jump under recoil? Thanks.

Absolutely, it will often permit changes of 1 or more clicks per round fired.

[psteinmayer]

What is a "soft spring"?

Referring to a spring that is weak, and does not hold the proper tension.

[Dean-DGR]

CMP has replaced them in the past. Mail them your old one with a note.

Dean-DGR

[XLF30]

Clarification

Referring to a spring that is weak, and does not hold the proper tension.

Are you referring to the washer-type spring on the screw which holds on the elevation knob?

thanks

[CPC]

I expect pstein meant the rear sight cover or spring. If the cover does not have enough tension the elevation will not hold properly.

[psteinmayer]

Bingo