Elevation changes in a Rem 03-A3

[fa38]

There was a discussion on using shims made from feeler gauges over on the CBA froum and I posted the following.

I have a Rem 03-A3 that has the original rear aperture sight which changes elevation by running the aperture up and down the ramp of the sight. The only way to change elevation is to move the aperture from notch to notch which gives quite a bit of elevation change for each notch.
I was changing the elevation one day and noticed that the ramp has a bit of up and down movement that is spring loaded and pivots a bit at the rear of the ramp. You can change the elevation by sticking a shim from a feeler gauge under the front edge of the ramp. The front of the ramp goes up and the rear goes down. The aperture is at the rear.
I cut shims from the feeler gauge of .012, .010, .008, .006. Set the elevation a bit high and lower the elevation by using the shims. The .012 is the biggest shim I can get under the front edge of the ramp.

[Larry Gibson]

Works with the rear sight on an M1 Carbine also.

I also use shims und the rear sight slide on Mausers and MNs to fine tune the elevation to zero.

[Adam Helmer]

WHY NOT just replace that worn out rear sight? Nothing lasts forever, not even sights.

Adam

[Larry Gibson]

Because the rear sight isn't worn out. The shim just gives finer sight adjustments between the elevation notches.

[Adam Helmer]

Larry,

I have a dozen of 03-A3s and some had worn out rear sights made "Piece Work" production 75 years ago. If using a worn out sight makes your day, I say go for it shimming along the way. I have many new rear sights in case of need.

Adam

[fa38]

My sight is not even close to worn out. Shims are used for elevation changes between the notches on the sight.

[Larry Gibson]

Seems like Adam isn't quite understanding....

[M-Tecs]

I have personally never used this method since I don't have an 03-A3 or an M1 but I have seen it done a vintage CMP matches.

[Tedly]

Excellent idea . I know I've used masking tape on sides of front sights to make windage adjustments

[beltfed]

My question is:
Per the CBA "Issue" Vin Mil rules, I am asking if
such use of shims may be illegal.
Same as "shimming" the action bedding to make it tighter in the stock is illegal??

beltfed/arnie

[beltfed]

OH, not to mention CMP Vin Mil. Garand, 03, etc matches-
"strictly issue" no shimming or glass bedding allowed.
And only allow adjusting the front sight blade height.
beltfed/arnie

[Gewehr-Guy]

this might not be legal in a CMP match, but I used a fine chisel to make notches between the wider spaced notches at 650-800 yds, rather than altering the front sight.

[fa38]

My question is:
Per the CBA "Issue" Vin Mil rules, I am asking if
such use of shims may be illegal.
Same as "shimming" the action bedding to make it tighter in the stock is illegal??

beltfed/arnie

Since the front sight is a Lyman 17 and the rifle is shot in the CBA modified irons category it should be okay.

[Larry Gibson]

It should be perfectly legal in CBA "Issue" Military Rifle category also. The rule prohibits modification to the rifle except the front sight may be raised of lowered. Also blackening of the front sight blade is allowed thus a shim under the rear elevation slide is not a modification to the rifle. In the CBA matches I've shot in it is allowed.

In CBA "Modified Iron" Military Rifle the use of the shim is allowed as any iron sight may be used.

Don't know about CMP matches which allow modern made barrels and other modifications but it would see somewhat hypocritical to not allow the use of the shim.