need help mounting scope mounts to 94 winchester.

[mtbugle]

i am installing a scope on a 94 winchester for my father in law and the rear mount appears 3/32 of inch lower than front mount which makes about rifle want to shoot about 70 moa low.  first i thought mismatched scope mounts as bought rifle and mounts from a pawn shop. but same problem with new set of weaver mounts. thought maybe gun, but my older modle 94 also seems to have same height discrepency of the sights when i set them on it.  what am i missing here. I want to fix this fast as he will be here in two days. when i sight down the saddle of each mount they seem to both be directed to the right point of aim, just rear one is about 3/32 inch lower.  thanks in advance , don.

[wtroger]

What number is on the bases you are using sounds like maybe the wrong set of bases or you have a front and rear swapped. I assume this is for an angle eject model 94. They where the only ones drilled and tapped for scopes. If it is not a angel eject then some has done the drilling and tapping and then all bets are off.

[mtbugle]

update.  i bought a new weaver set of mounts and same problem.  I then talked to a gun smith in town and he said its not uncommon on the 94's. as the shim amount is large and didn't have much in the way of metal shims that large and flexible he reccommended paper shims(basicaly cardboard like in ammo boxes.) i did this and achieved the level needed.  but wondered if some of the old time smiths here are comfortable with this for the long run.   i still have barrel pressure cards on some guns that are older than i , but scope mounts are more critical for movement. comments are appreciated. thanks don

[gunnut69]

I would suggest a metallic shim be used, preferably something such as copper or brass. It can be a simple washer around the screw holes.. The rest of the shim is then cast of acra-glass. This provides a stable platform that won't cause corrosion issues. The washers are used to initially set the thickness of the shim.. cardboard would work for this but is not ideal as it is compressible. 

[BoarHunter]

On this Win 94 angle eject, does any one knows for the front base, the nominal specs and tolerances:
-radius of the receiver,
-distance between threaded holes
-and distance from the threaded holes to the chamber edge and receiver edge toward the the barrel.

This in order to machine a low profile front mount.

Thanks

[gunnut69]

If the gun had followed the tolerances there would likely be no problem with the commercial bases. I'd just use a commercial base and lower the higher base to fit the existing receiver contour.

[BoarHunter]

Aluminum is not suitable for my purpose, standard steel base not long and wide enough and to modify them will not save work.
Besides for proper alignment, it is better to mill/drill everything in one go.

Sorry but I should have started an other subject as my question is not really related to the original post. Th original post just made me think twice about tolerances on the Win 94. I plan to make a few bases for my and friends rifles, so my request for nominal specs and tolerances.

[Rangr44]

[On this Win 94 angle eject, does any one knows for the front base, the nominal specs and tolerances:
-radius of the receiver, -distance between threaded holes,-and distance from the threaded holes to the chamber edge and receiver edge toward the the barrel. This in order to machine a low profile front mount.]

JMO - But since you seem to have the said specimen in hand, either measure it yourself, or have the machinist do so. Anyone good enough to machine their own custom bases, ought to be up to measuring for them, too.
You'll then have the exact info you want - and your friend's rifles can give you a basis for comparison of tolerances/variables better then any opinions.

[BoarHunter]

Yes, I could and indeed have measured it but that does not give me the nominal distances and tolerances, just some values applicable to a single gun.
It is not easy to accurately measure to the center point of a threaded hole and the receiver radius ever worse.
For ex. a real nominal value I determined. is the distance between the two 6-48 screw holes. I measured around 9.5 mm-9.6 mm and therefore I assume a nominal value of 9.53 mm because it corresponds to a "round" figure of 3/8 of an inch.

I suppose factories producing mount base designed them from the mfg drawings, it is what I would like to get and as Winchester is gone ?

[gunnut69]

I still don't understand. If you are making custom bases the design specs don't mean much anyway as they are made to measure. If you are going to make mouints using the basic design specs then why?? Just buy the mounts you wish.. Steel mounts are available for the '94. Alter one of them perhaps?  Are you trying to create a new mount design for the '94?  Sorry but I have no specs for the 94 that give what you're asking for..

[BoarHunter]

Indeed I am planning a short run of specific mounts and to eventually have them made by shops like emachineshop.com.

[gunnut69]

Then you will be faced with the same dilemma the makers of the other commercial mounts are, the variability of a 100+ year old design. The problem with reverse engineering a rifle that old is there are minor variations that crop up over time. I don't know how one could cope other than to design in a means of adjusting for variations in the receiver dimensions. Good luck and how about a look at the new mount system??