Home Forums Hunting & Shooting Gunsmithing Interarms Mark x caliber limitations

I posted on here about a year ago that I was buying an Interarms Mark X to convert to 9.3x62. Well, I have the gun, and still have done nothing with it, so before I jump on the 9.3 this time, I wanted to find out what the limitations of the action are. I've heard about opening the bolt up to magnum dimensions. If this is done, what is the longest cartridge that will fit in the mag? The thread I read mentioned opening it up to mag and chambering in 7mmRem mag, but I didn't see if the guy was single feeding because of cartridge length.

300Win mag would be an interest of mine if it'll fit in the mag.

anyone have an easy answer before I start further research?

The mark X was available in .375 H&H from the factory, but was not a "true" magnum length mauser. There were tons, litterally tons of .300 win mag zastavas sold. You should be able to pick up a magnum donor for less than it would cost to modify your current mark X.

The bolt face will need to be altered, you will need a magnum follower and maybe tweak the feed ramp. Other than that, you should be good to go.

.....way too many of the magunm rifles floating about,no need to concert a standard action to a magie....nothing to gain?

I have used them to convert to calibers thay didn't make and a 9.3x62 off a .270/.30-06 would be good, I just finished a 7mag Whitworth that is now a .338 WM,no changes but the barrel....

The 9.3 would be very good.

I see Remington M798s every now and then they seem to be
drying up also.

I'll probably stick with 9.3x62. I like so much of what I see on terminal and exterior ballistics on the caliber.

I just checked my Mark X last night after reading about date of manufacture and it is from April 1973. It's in an older looking Fajen varmint style stock with Redfield mounts.

It's been difficult to decide whether to put a .308 or 30.06 target weight barrel on it, or just go with a standard profile 9.3 barrel. I'm planning in the future to machine a Form 1 suppressor for it, so may just go with a medium weight 21-22" 9.3.

What caliber is it now?

If it's a standard 30-06/270 etc. then it'll be easiest to rebarrel to a 9.3x62.

A 7mm rem mag and 300 winchester mag are what were referred to "short magnums" before the WSM's came out. They don't use a magnum action, they use a standard sized action with a magnum bolt face. If the action will house a 30-06 then it'll take a 7mm rem mag or 300 win mag, they're the same length. You could take a standard 30-06 action and open up the bolt face to make it work with a 7mm rem mag or 300 win mag. Personally I'd rather just start with a factory chambering and avoid the gunsmith work which has a potential to be done incorrectly. The feed rails and magazine would likely have to be adjusted also, all the more reason to start with a factory action in the right caliber.

What's meant by a magnum action is one that'll take a full length magnum like a .375 H&H or .300 weatherby magnum. On an interarms Mark X that meant relieving some of the metal from the front feed ramp which some people claimed was unsafe. I've never heard of one from the factory or one properly done by a gunsmith failing so I personally don't believe they're unsafe.

If you tell us what caliber the rifle is chambered for then someone here can tell you what will need to be done.

"On an interarms Mark X that meant relieving some of the metal from the front feed ramp which some people claimed was unsafe. I've never heard of one from the factory or one properly done by a gunsmith failing so I personally don't believe they're unsafe."

Many years ago, I read of an FN Mauser failing at the feed ramp, where the bottom bolt lug fits.

This rifle was in .300 Weatherby. It is possible that it was loaded to the max, then a few more grains of power added. That is the only one I have ever heard about failing.

It's a 243Win right now. I've already read about removing the block in the mag well to allow for 30.06 length cartridges. I've seen the block and know I need a longer follower to replace the short action length one that's in it.

I'm a machinist and I'm learning some gunsmithing work (rifle building is why I started machining), so it's my first project gun. I'll be doing the work myself, so it's not a matter of difficult, just possible or not.

I've got two notions for the gun. One is a 9.3x62 sporter for hunting and some target shooting (I just like to shoot, so it'll get used when it's not hunting season). The other is a 300WM heavy barrel in a McMillan McHale stock, 1:10 twist for shooting 210 gr bullets. Granted the 300WM would likely get used less since it's be a bear to lug around, but I had a McMillan 300WM from the 80's in a McHale with a 26" tube and regret getting rid of it, so the idea would be making amends with my regret.

Since it's "short",build a 6.5 Creedmoor,it will kill anything in Georgia,long range paper shooting is a hoot and you could still put it in McMillan stock for both uses and have a hell of a rifle and not beat to crap....!

I saw an Interarms Mark X in 25-06 for $389 today, not
bad shape, but I think it had an aftermarket barrel on it.

Well, It's not really short action. Zastava put a mag blcok in and a short follower to allow a short action cartridge to chamber without issues. It's certainly 30.06 lenght action and that was the point of my question- was 300 WM, 7MM Rem mag and 375 H&H an option by just reworking the bolt face.

Since asking, I've sort of come full circle (again) on 9.3x62. If I can work out some data on twist rates, I'm looking at writing a CNC program and machining some solid copper bullets and using it to 1,000 yards. On paper, the 250gr Nosler Accubond matches 175gr SMK's pretty closely.