03A4 Mounting Question

I acquired an 03A4 from a friend a few years ago. The gun is a mix up of parts and amateur restorations.

I'm slowly piecing it back together, and after finding a decent original scant stock this summer, I'm ready to start pushing this thing to completion.

The barrel, bolt, sight base and receiver were all good though. It is a 4.99m with a 1/44 RA barrel.

The mount is parkerized with the small "REDFIELD" mark at the back right of the mount.

Now the bad...

The two sight base mounting screws were a mangled mess. What do I need to buy to mount the base to the rifle? I don't want to use the same ones, they are badly stripped and I am afraid they could never be securely fastened again.

Also, an owner a couple back from me, removed and threw away the one shim under the front of the base, as he thought it was a "bubba thing." I know...just a little info and it could have been avoided.

I know there were different thicknesses of shims, but what could I use?

If anyone knows the size screw I need to purchase, or where I might buy a shim, please let me know.

Thanks,

-Patrick

you can get shim stock at any hobby store,
screws are 8-40 thread, Brownells may carry them as well.

Both screws are filister head
The rear screw is .250" in length
The front Screw is .510 in length.

The shims originally came four to a set: .005, .010, .015 and .020 so they could be mixed and matched as necessary. You might be able to find originals from one of the parts houses but chuck's solution is probably easier - either a hobby shop or auto parts store should have shim stock. The purpose was just to get the scope zeroed and still allow the full range of elevation adjustment on the Weaver scope.

Regards,

Jim

I had the pleasure of mounting a M8 on my A4 about a year ago. The first thing I did was center the crosshairs (same number of turns either direction, windage and elevation). Don't touch them again until you start shooting for fine tuning. I had received some shims from someone on this forum (thanks again) that were absolutely necessary and saved the day.

I put the barreled action in a gun vise before I started all this with the flat of the receiver dead level. Mount the base, mount the scope, center the vertical crosshair will a plumb bob and turning the scope in the rings. Tighten the rings. Bore sight the rifle on a distant object (100 yards if possible). Using the rear mount adjustment screws, align the vertical crosshair on the distant object (after bore sighting). You will see that the horizontal crosshair winds up below the center of the object. Add a shim under the front of the base. You have to remove the scope from the base to do this, but only loosen the right side windage screw and don't move the left windage screw on the base. Remove the base and add the shim(s). Put everything back together and see if the horizontal crosshair has moved closer to the center of the distant object.

If both crosshairs are centered, you are finished. If the horizontal crosshair is still not centered, add or remove shims as needed, repeating the above process. You want those crosshairs as close to centered as possible, as the Weaver scopes of that period don't have a lot of adjustment in them (8 to 10 clicks each way if I remember correctly). You will need that adjustment for fine tuning once you start live firing.

It sounds like a pain, and it is, but once done, they pretty much stay where they should. I click on my scope is 1 MOA. I was so used to 1/4 MOA adjustments, that I blew a lot of shots for nothing.

I also used a bore sighter, which made the job a lot easier. If you can get your hands on one, use it!

I don't like those scopes. 2.5 power sucks in my book, and light gathering is way bad. Still, it shoots where it is pointed and that scope did the job for many years.

Good luck.

Jim

Quote:

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Originally Posted by Jim Tarleton

I had the pleasure of mounting a M8 on my A4 about a year ago. The first thing I did was center the crosshairs (same number of turns either direction, windage and elevation). Don't touch them again until you start shooting for fine tuning. I had received some shims from someone on this forum (thanks again) that were absolutely necessary and saved the day.

I put the barreled action in a gun vise before I started all this with the flat of the receiver dead level. Mount the base, mount the scope, center the vertical crosshair will a plumb bob and turning the scope in the rings. Tighten the rings. Bore sight the rifle on a distant object (100 yards if possible). Using the rear mount adjustment screws, align the vertical crosshair on the distant object (after bore sighting). You will see that the horizontal crosshair winds up below the center of the object. Add a shim under the front of the base. You have to remove the scope from the base to do this, but only loosen the right side windage screw and don't move the left windage screw on the base. Remove the base and add the shim(s). Put everything back together and see if the horizontal crosshair has moved closer to the center of the distant object.

If both crosshairs are centered, you are finished. If the horizontal crosshair is still not centered, add or remove shims as needed, repeating the above process. You want those crosshairs as close to centered as possible, as the Weaver scopes of that period don't have a lot of adjustment in them (8 to 10 clicks each way if I remember correctly). You will need that adjustment for fine tuning once you start live firing.

It sounds like a pain, and it is, but once done, they pretty much stay where they should. I click on my scope is 1 MOA. I was so used to 1/4 MOA adjustments, that I blew a lot of shots for nothing.

I also used a bore sighter, which made the job a lot easier. If you can get your hands on one, use it!

I don't like those scopes. 2.5 power sucks in my book, and light gathering is way bad. Still, it shoots where it is pointed and that scope did the job for many years.

Good luck.

Jim

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Ignore Jim Tarleton's comment about the 2.5 Power Scope. He's at the age where he won't admit he needs a little 'eyesight' help.. :D

Mike,

A little? If you had stopped me in your Trooper days, you probably would have towed my truck when I handed you my AARP card for a driver's license!

Jim

Turn the windage in the direction of the arrow till it bottoms out. Come back to the zero point , then back 4 complete revolutions. That is now centered.
Turn the elevation in the direction of the arrow till it bottoms out. Come back to zero , then give it two more revolutions. This should be close to the 100 yard zero. Adjust the big screws for windage and add/subtract shims to sight in at 100 yds. You must confirm by actual firing.Once sighted in by this , your good for out to a thousand yards ( yah-right) with M2 ball or equal ( 188 clicks up , three revolutions plus 8 clicks ).
The 330 has plenty of adjustment , but due to the crosshairs moving in your field of view , this is how the army set it up to get the most out of it. They recommended sighting it in for a single range ( 200 - 250- 300 yds) depending on your conditions , then just using Kentucky elevation , due to the ease of losing click ( or revolution ) count. Sill , if it was set up this way , you could turn down to bottom and start over and be very close.

HTH , Chris

Wow, I really appreciate all the info!

Thanks to all,

-Patrick

Oh, I nearly forgot.

Were the base mounting screws originally blued or parkerized?

I'm guessing blued.

Thanks again,

-Patrick

they were color case hardened.

By the way , the left screw was staked at the factory after sighting in. You remove the scope by removing the right screw ( bolt handle side) and twisting off. Yours may or may not still be staked , and may or may not still be sighted in if it is due to age , different stocks , etc. Chris

Thanks again!

So all the screws associated with the mounting scope are color case hardened?

-Patrick

Yes.

Jim

actually all the screws were color case hardened.
rifles were shipped without scopes and rings,
the Army installed, and staked the windage screws, and sighted the rifle.
in therory, you could remove the scope, and then reinstall it, it would be back on zero...maybe.

..It was install , sight in , then stake:). But it sounds like you have removed the base , scope , and replaced the stock. Even if still staked , the setting will not be on except by luck. If you decide to set and re-stake the screws , you do the left one ( away from bolt handle). No real reason to do so. It was , as said , to allow the scope to be removed and not have the left screw turn ( loosing adjustment ) and then re-install and tighten the right screw. In theory it still should be sighted in ( really , prob'ly close only ).
I just red-loctited in the left one and a little blue on the right , but I display with a 330 and shoot my two with M84s :super:.
Chris

While the original screws were case colored, most of the A4's out there have been rebuilt. And, rebuilt A4's will often have the base & screws parkerized. So, don't worry about that.

You really need to shim the base at the correct height BEFORE you attempt to mount the scope. The base should not be mounted without shims, as it is the generic Redfield Jr base was selected not because it was an exact fit, but because it was available. I suspect that military armorers made some kind of fixture so that the height of the base was consistent; the 330 series scopes do not have enough adjustment to compensate for being a lot out of alignment.

If you want, I could try to measure the base height for you, either with a micrometer, or maybe my set of spark plug feeler gauges.