Home Forums Hunting & Shooting Hunting Optics Interarms Mark X scope base help?

I picked up an Interarms Mark X and I'm a little puzzled on the scope base. The rear (butt end) is lower than the front (barrel end) of the action. It came with a 2 piece weaver installed. The rear base is taller than the front base as you'd expect. I put a pair of rings on it set the scope in the rings, and noticed that when I began to tighten the rear ring, the scope set above the front ring. I played a bit and put a straight edge on it. It appeared the rear was higher than the front with the straight edge. Looking at the bases they had different screws in them so I thought they might be incorrect. I checked the numbers and they appeared corrected for listed weaver bases for a Mark X. Still, they looked odd with different designs between the front and rear. I decided to order a pair of Warne bases and be done with it.

Warne's arrived, I put them on with no locktite, etc, just to check. Same problem with a straight edge, with rings, and with a scope. It's a noticeable difference where the scope isn't touching the front ring at all when the rear is tightened. It's a difference to big to lap or bed.

I'm not a Mark X junkie and don't have a lot of knowledge on them. Where there versions of the Mark X longer action (this one is in 7x57) produced with different actions that need a specific base? Suggestions?

It's just a Mauser 98. Any Mauser 98 bases should fit.

FN bases should work on a MK X action.

Thanks for the input. So I referenced the Weaver Mounts Chart again with Mauser 98 and FN considerations:

Interarms Mark X: Rear-55, Front-20A - these are what it came with

Mauser 98 : various with action sizes listed - one specific for 98FN is Rear-45, Front-46

Weatherby has one for FN Mauser Style Actions: Rear-45, Front-46

All of the above have a "1" note on them which is: "1. Shimming is probably required for perfect scope alignment"

So according to the chart, the FN/98 uses a different base than an Interarms Mark X and all may require shimming. I could order the 45 & 46 pair to give it a try. I do hate to throw more $ at it if they will be a worse fit. Link to the chart for reference:

https://www.weaveroptics.com/on/dem...les/weaverPdf/2016_WeaverMountsChart.pdf

Pardon the lack of specifics as to numbers, as my tale is about 40 years old.

I bought a Mark X Viscount .270 new about 1980. Mounted a scope using IIRC, bases for an FN and went to the range with it. Couldn’t get it lined up, so went to the premier gun store in the town of Hanover, PA, Sell’s. The younger Mr. Sell told me my bases were wrong. I objected, until he put a straight edge across them and then I felt like an idiot. In no time he had me fixed up and back to the range. Only kept that rifle a short time, as I lucked into a gray rat pre-64 not long after, which is still in the family.

You didn’t say what bases you had, but I suggest you either order a complete set of the alternative numbers, or simply take it to someone that has a good selection and can get it together in one shot. It appears your gun came with a mismatched set and then you ordered the wrong ones from Warne. Get it sorted out and then you can enjoy that very good rifle.

I have three of the Whitworth Mark X 458 and 375's.I put the EGW 47000 Mauser large ring Picatinny rails on all three.

The commercial large ring Mauser should be a Weaver 45 at bridge and 46 on the ring. As I recall, the 55 is for small ring bridge. I'm sure I have both bases around here that I would be happy to send you to try.

Isn't that a Zastava action?

Talley bases and rings

I inherited a Mark x in 308 a few years ago. I put new mounts and optics on it. I used Talley LWs per Talleys specs. No issues with those. There is quite difference in height with the rear being much higher. I know some dont like the LWs but I used them on this setup.
Mine came scoped with the same bases you mention. The Talleys I have on it now are 930709. Box says 1’ Mauser 98 large ring , Remington 798 (low ).

The Viscount shows a different pair on the link above than the regular Mark X. The one I have came with the following that I listed above "Interarms Mark X: Rear-55, Front-20A - these are what it came with"

I'm not aware of any good shop around here that would have all of them to try. I'm fairly certain I'd come out ahead both $-wise and time wise ordering and trying myself. I probably need to get a set for the Viscount and a regular FN with 45/46. I'll end up with 4 pairs of bases....maybe one will work.



If you have a pair of 45/46 that are sitting unused I'd love to try them.

Mr. Sell only charged me for the bases; a different time (maybe different planet), I suppose.

If the 45 & 46 fit, Talleys would too. I’ve used those on several FNs with good results, but if you want irons or a little red dot in reserve, then you want something Weaver-ish.

Please, please, don’t use a rail….

Jay- I pm'd you on the bases.

Why not a rail?

Yep and FN 98 bases work. I've had 6 or 7 and used bases for FN. All worked perfectly.

Early typical Weaver bases allow use of open sights most of the time if the sights aren't flat low.

Typical "mauser-madness" in regards to scope mounting. No biggie, just the nature of the game.

Ive owned an interarms mark x 30-06, a parker hale 243, a golden state arms mauser and an original oberndorrf sporting mauser.

Every SINGLE one of them required different scope base combinations or modifications. The worst, was the golden state arms mauser.

After such madness, the newer, optics-friendly budget guns arent so bad. Even a heavily scratched, rusted ruger 77.......even better.

Gun sellers (especially gunbroker) typically hide the truth about a scope base issue. Whether its an issue with crooked holes, weird base height, bolt clearance etc. Then, the cost gets passed to the buyer. Our fairbanks gunsmith sees it all the time.

My son's first big-game rifle is a sporterized mauser/ 270 winchester. Im grinning........

Because they look like Hell on a sporter, and complicate access to the action, unless they’re cut away on the right side like a one-piece. Partly a matter of personal taste, but also a convenience issue.

I have 4 Mauser action rifles, 30-06, 375 H&H, 416 Remington, and 458 Win mag. I run a rail on all of them, I can't stock crawl and they are easiest way for me to get to scope mounted for proper eye relief for me.

Tell me about it….

Old 98s can come with some wacky issues. My 1948 FN came with a one-piece Buehler base that extends over the receiver ring, and the single rear hole doesn’t line up with other one-piece mounts. Solution: another hole in the bridge and two-piece bases, in this case standard Talleys.

My Heym .308 has three holes, a charger slot, and a thumb cut. Took it to the smith for another hole, but the contour of the bridge doesn’t match standard bases (yes Martha, I ordered the one for rifles with the charger slot!) The hole is drilled just enough too far back to perfectly match a standard bridge mount. Solution: relieve the rear hole in the mount just a hair to permit a screw to line up. Probably an iffy setup for strength, so it got a very light scope to not stress it too much. A proper fix would be a custom base, re-contouring the bridge, or welding up and re-drilling the single hole, all more money than I’m willing to spend. The next guy can pick one.

Once or twice I’ve had to file off the right rear corner of a Weaver base to allow the bolt handle to clear. Can’t recall which rifle(s) required that.

An old Morton custom FN came with bases I was sure were Talleys, but the rings I ordered obviously didn’t match. Turned out to be an old Lyman base. Solution: new bases for something still in existence, and actual Talley bases so I could use the new rings on the 1948.