Home Forums Hunting & Shooting Mausers and Military Rifles 98 mauser scope mount problem

I have a 98 mauser that has been drilled and taped..it has the 2 price blocks that Weaver calls for it .. I've tried 3 different sets of rings and 4 different scopes and can't get one to adjust down to target.thanks for any help

Pics? Have you run a level across the tops of the bases? Which # bases and what 98? Need a wee bit more info before we can provide you any useful input.

45 front and 46 rear... I've been trying to get pictures updated..sorry

Uploaded

As you can see there's not much in the way of markings

So, it's a standard large ring 98. Since the charger hump hasn't been removed, I'd look at the rear base. There is a radius at the back of the charger hump that will interfere with the base, lifting the front. Run a level or flat over the tops of the bases to see if they are on the same plane and/ or level. You might find that the rear base is tilted upward at the front edge where it contacts the charger hump. The base may not be contacting the hump but, it may be higher than the front base simply due to the fact that these actions were not designed with scope mounting in mind. Thus, there tends to be a good deal of variation among the various manufacturers with regards to the rear bridge dimensions. Unaltered front rings tend to be much more consistent in size. Bear in mind too that bases tend to be made to fit commercial Mauser actions. When milsurp actions are altered to a commercial configuration the rear bridge is often not the same height as its commercial counterpart. Many folks address this by shimming the bases until they are level. I like to alter the base(s) or make my own as required.

Thanks... I Just found on Weaver where shimming my be required

Order an EGW picitinny rail(0 MOA) for the military 98 action. Order it without the screw holes. It will be machined to clear the stripper clip hump on the rear bridge:

https://www.egwguns.com/catalogsearch/result/?q=Mauser+98

Order a brownells reamer for 6-48 fillister or tapered screws. Whichever screws you prefer. If you go tapered reamer, you can use the supplied egw screws.

If you know what you're doing, you can center this rail while using the existing holes, which were probably drilled into the receiver by some idiot, without using a jig.

Snug down the front screws. If the rear of the rail floats and doesn't mate to the receiver bridge perfectly, shim it, then cinch down the rear bridge screws.

The one piece EGW rail without holes is your friend. It'll get you on paper if you do it right.

I envy guys with commercial fn receivers, which were drilled and taped properly from the factory with industry standard patterns.

I have fixed three mausers with these rails: a parker hale 243 winchester, a Santa Fe arms 30-06 and a Waffenfabrik Oberndorf Mauser. All with crooked scope base holes. The parker hale needed a shim on the rear bridge.

If you mess up, youre only out $40 for the rail. Try again.

Once you get the rigid rail true to the action, you can do some cutting of the rail and convert it to 2 piece bases If you like an unimpeded action area for loading of cartridges.

The rear mount is definitely lower the the front

Does the scope tube have a kink or bend in it now? I had one of the craptastic Kimber sporterized Swedish Mausers that had miss aligned bases...Kinked a good scope because I assumed the mounts were aligned...

Wouldn't a one piece Redfiled JR base work? If I recall correctly they were designed to fit over the hump.

Pretty sure I have a box with a few it somewhere if you want to try one out. Free plus shipping.

Kent

Then some metal shims under the rear base can get you up to height. Even stock cut from an aluminum can could be a place to start.

if you look at the pics of the front ring and the scope base, you will see it is mounted in a non standard location. Thus, it is unlikely that a one piece base will fit. Due to the non-standard hole spacing (layout) the previous suggestion to drill a blank base to fit the receiver's holes is a more viable option, one I've had to do many times in order to scope a receiver that someone bought thinking they'd save some money buying a receiver that was already drilled and tapped.

Z1r,

Yes the EGW rails are top notch. I fixed another mauser last night. One rear screw hole was off. Height was perfect so no shims.

I ran the base screw from inside the rear bridge. When sufficient thread protruded outward, I tapped on the top of the rail. Pull the rail, and the underside had an imprint of where the screw hole needed to be drilled.

The rigid egw rail affixed to the front receiver ring, is always my "proof check".

First shot out the barrel with a new Redfield 2-7 hit the bullseye at 25 yds, so it's close.

You could also try a 20a on the front, same hole location and lower height than a 46 if I remember right.

Well, maybe. My 1948 FN (FI import) came with a wacky Buhler one-piece base that doesn't line up with any other FN I checked. Only one hole was drilled in the bridge, so I had my smith drill another so I can use any two-piece bases. I suspect that one made the trip over here without holes and was drilled by whoever put the barreled action in the stock. It's a C-ring, so pretty early.

Be sure to get the bore of the rifle level before tinkering with the scope mounts. I machine a piece of aluminum round stock that's a snug slip fit a few inches into the muzzle, long enough to support a torpedo level. Once the bore is level, I move on to attaching and shimming the bases.
Jerry

Try a #55 rear base they are taller. Made for the small ring Mausers.

This may help.
W.R. Weaver Company Mount Base Specifications
DETACHABLE MOUNT BASES
No. of Base Length Hole Spacing Diameter Thickness
11 .812 .504 1.290 .147
12 .812 .504 .925 .155
13 .812 .504 .730 .238
14 .812 .504 Tapered for Savage 99 only
15 .812 .504 .946 .195
16 .812 .504 .840 .205
17 .812 .504 .770 .219
18 .812 .504 1.050 .182
19 .812 .504 1.160 .125
20A 1.168 .860 1.360 .127
21 .812 .504 .710 .273
22 .812 .504 .700 .201
24 .812 .504 .900 .271
25 .812 .504 1.125 .248
27 .812 .504 .930 Tapered .161/.185
28 .812 .504 Flat .239
29 .812 .504 Flat .292
30 .812 .504 .845 Tapered .205/.230
31 .812 .504 Octag. .182
32 .812 .504 Octag. .357
35 1.168 .860 1.290 .147
36 1.401 .604 3.900 .272
39 .812 .504 Flat .165
40A 1.840 .860 1.290 .147
42 .812 .504 .730 .298
43 .812 .504 .840 .265
44 .812 .504 .770 .279
45 .812 .504 1.050 .396
46 1.168 .860 1.290 .222
47 1.168 .860 2.692 .368
48 .812 .504 1.290 .395
49A 1.058 Win. 70 in 375 H&H, 300 H&H only .368
50 4.500 .504 Flat-Tapered .200/.232
53 4.983 Win. 88, 100 1.290 .222
54 .812 .504 1.290 .222
55 .812 .504 1.050 .310
57 2.340 .960 1.220 .250
58 4.624 3.275 Flat .283
59 .812 One hole only Notched .366
60 4.500 Browning .22 Auto, H&R "Topper" .361
61 1.168 .860 Flat .360
62 4.430 Rem. 740, 760 1.290 .222
63A 6.125 Marlin 336 Flat .283
63B 5.450 Marlin 336 Flat .370
65 2.000 None Spec. * .322
66 2.650 None Spec. * .322
67 1.650 None Spec. * .332
68 .812 .504 .916 .399
70 5.900 Rem 600 1.290 .275