Sum of its parts

[klemper]

I have what appears to be a home (or professional) built D that I cannot get to zero. Irons will hold OK, but I just cannot get the scope to zero.
I an thinking of selling it as parts, so what is an m-84 scope, and a Winchester bolt and received worth. other than the Spingfield op rod n trigger assby, the rest looks to be aftermarket. I have $1500 into as it sits, and it is perdy but no zero
Thanks
Jim

[jgaynor]

Jim Do you know if it has a real GI M1 D Barrel? If you remove the gas cylinder and both hand guards the GI drawing number will be stamped at 12 O'clock. The drawing number should read D7312555.

There have been people purporting to offer 'aftermarket' M1D barrels made by turning down a standard M1 barrel and installing a foreign made M1D Scope base. In theory this might work but I have my doubts. The quality of machining expertise required would, I suspect, have to be very high.

On the other hand a real "D" barrel is valuable in its own right.

Regards,
Jim

[Richard H Brown Jr]

Dear Jim:

There's atleast 5 things I can think of offhand.

1. The mount isn't secure enough and is vibrating as a round is fired, moving the zero as established by point of aim. Screw and hole threads are buggered, or not mating tightly.

2. The internals of the scope are messed up, or the adjusments are worn. If it's a true orignal scope.
Try another good scope with the same tube diameter that fits the rings.

3. The alignment of the scope axis to the axis of the barrel is off. I'm assuming you're trying to zero on a prone supported shooting position.
Get a bench mount and shoot for zero on the iron sights at 100yrds, then mount the scope and cheek pad see where the scope cross hairs
align over your iron sights zero holes.
Or try establishing a zero at a shorter distance 25yds or 50yrds with the iron sights and then with the scope.

4. Get a hold of a depot manual for the M1D series and see what it says for aligning the scope mount, scope, cheek pad. There might be
shims involved. (Aberdeen Proving Ground Museum *might* have reference material on assembly and testing of the m1 sniper rifles at Springfield Armory, or the Springfield Armory National Historical Site, or National Archives.)

5. Reproduction parts: You may have repro/fake/non us standard barrel, mount, scope, mounting hardware or if *real* gi issue parts, they failed to pass manufacturing specifications for *true* dimensions and geometery of screw holes, flatness, etc.

6. Mount the scope in a KNOWN real M-1D mount and rifle and see if it zero's on it. And try the Known Real Scope and mount on your rifle. Then your scope on the known m1d with the known m1d mount. Establishes which parts are causing the problem.

If all else fails, somebody here must know a good M-1 Garand smith that works on sniper's, or
can suggest a commercial company like Fulton Armory or Milspec to check out the weapon.

RHB

[Richard H Brown Jr]

Jim

Re my last: do to late night and antibiotics.

1. test your scope and mount on a known true m1d rifle. If it zero's the barrel or stock on your rifle is the problem.
2. test known good scope and mount on your rifle. If it zero's, the problem is your scope and mount
3. test your scope, known gi mount and known m1d rifle. If it zero's, your mount, if it doesn't, it's your scope.

Mount problems include the rings, screws, set screws.

RHB

[Richard H Brown Jr]

Jim:

Did a fast web search for zeroing an M1D scope and found the following threads:

http://www.jouster.com/forums/showthread.php?21881-Sum-of-its-parts&daysprune=7

http://sangamoncorifleassociation.org/phildavis/m1cm1dgarands.html Read the paragraph labeled "The Parallax problem".

References for the M84 state that both the windage and elevation kobs have to be adjusted for any range OTHER than the factory set 300yrd range.

http://forums.thecmp.org/showthread.php?t=40927 refers the reader to http://www.fulton-armory.com/%5Cfaqs%5CM1G-FAQs%5CM1D_M84.htm to extend the zeroing adjustments.

http://forums.thecmp.org/showthread.php?t=32272 the important statement is that the windage knob moves point of impact 1 in at 100yrds.

I'm reading all this as: If the M84 scope is set on the factory collimated preset to 300yrds. And you shoot at a zeroing target set at 300yds, you should adjust windage and elevation to hit point of aim. This sets the scope to the rifle pecularities and the lot of ammo you used, ballistics curve etc. . Any other range you change the windage and elevation to hit point of aim *AND RECORD* the settings for that range *WHEN* you start hitting the point of aim. With a 100yrd zero on the iron sights on a bench rest sled, once you add the scope and set the range for 100yrs on the scope, due to the parallax of the scope being offset 1in to the left of the iron sights, the scope zero grouping with no windage dialed into the scope is going to be around 1 in left of the iron zero grouping at 100yrds. Remember the ballistics curve of m2 ball ammo. Aiming at a 6 o'clock sighting the ballistics curve puts the rounds hitting 1 in higher than point of aim at 100yrds, thus in the bull. With the horizontal grouping point, being the the results of the wind and the sight alignment on the rifle and your eyes. Adding the Scope, shooting at 100yrds on a bench sled with the scope aimed at 6 o'clock, it's grouping should be about 1 in to the left of the iron sights group. That's it's TRUE 100yrd point. You're probably trying to adjust the windage to move it to the same hit point as the iron sights, and wonder why all the other range adjustments are off.
Throwing all this crap I just said away, you need the TM 9-1005-205-12 and TM 9-6131 for the Telescope M84. And the online manual for the M1903a4 at Carlisyle Barracks http://carl.army.mil/wwIItms/TM9_270_1943.pdf to figure out the sighting zero procedures. Or check with the US Army Marksmanship Unit to see if they have any old refences on setting a M1D Zero, Or the Marine Historical Office.

RHB

[klemper]

Thanks for all the information. As far as the barrel goes it is an after market barrel, mfg???. There are no marks of anykind on the barrel and the gas port areas are not chromed. Like I say it iz a partz rifle. though it don't shoot too bad with the irons, 2-3" @ 100 yds, with the catarecs.

[k arga]

i think that your rifle is just fine, i think the problem is in your scope mount. I would say that the block on the barrel is aftermarket and maby the scope mount and they are not matched up for a good tight fit. try putting some layout blue on the surface of the mount or base and see where they make contact. be careful when tighting the mount that you don't pull the threads out some aftermarket blocks are soft

[klemper]

I know the scope mount is an after market, I had to braze the nut back onto the bolt, the chineese weld broke. the block is not marked in any way. I will use some layout blue, on the block. my son has a machine shop, and I have the 300 yd range. All in all it works out quite well