Is this normal?

[Shootist43]

I have an Interarms Mark X that I'm planning on taking to Africa in about 6 weeks. Although I've owned this rifle for several years, I never shot it till about a month ago. Interarms rifles or at least the actions were made by Zastava in Yugoslavia. I understand that their actions are not as smooth as the Mauser type actions manufactured by others. The last 1 & 1/2 or so of the bolt closing seems "stiffer" than the first 3" or so. Is this normal?

I've tried putting additional oil on the bolt, but that didn't help or change anything. Any suggestions

Some additional background on the rifle. It was "customized" thirty years ago, i.e. new stock, re-barreled, an aftermarket trigger and safety. Sometime later the original owner died, and the gun sat in a closet for over twenty years.

 

[JimP]

Sounds like a area along the bolt rails that needs to be cleaned up to get the roughness out of it.

It is a fairly simple job but it just takes time to do it.

 

[C.W. Richter]

Clean it thoroughly then coat the bolt with valve lapping compound work it a bunch of times then completely clean and lubricate it. Actually I've had several of them and they were amongst the most accurate guns ever had yes some needed work as we say. If my memory serves me correctly not all of the components were made in the same places there was the whitworth from England and the standard inter arms from Virginia but with components from all over. The whitworth European wood was much better and it was cross bolted which the US model was not..

 

[Pheroze]

My Zastava based gun has all the finesse of a farm implement. But it shoots true. I shot it hundreds of times and it started to get better. If it shoots well then it may be normal. Good luck on the safari.

 

[JimP]

When you are using the valve lapping compound don't close the bolt, just work it back and forth.

If you then want to smooth it out even more you can find some automotive polishing compound that is used to remove scratches.

Just work it back and forth, once again, do not close the bolt when doing this.

 

[Ontario Hunter]

The striker sear is catching on the receiver tang as the bolt goes forward to be closed. It is either catching on the tang as the sear enters the track in the sear or it may be catching on the action screw protruding into that tang.

Loosen the action screw and see if that fixes the problem. If it does then all that's needed is for that screw to be shortened a bit. Use a grinding wheel on Dremel tool to take off a small amount at a time and check with action screw retightened until the bolt closes properly.

If it's not the action screw protruding into the track, then it is the sear entering the track slightly off center. I had this problem with my 404 build on 98 Mauser action (Brno vz.24). The previous owner of the action attempted to attach an aftermarket bolt handle. His Bubba welder failed to make sure the bolt didn't get too hot and the back end warped slightly. This required me tuning the striker shaft, bolt shroud, and striker sear. Note how I very slightly beveled the sides of forward face of the sear.

This allows it to slide by the edge of the sear track in the receiver even as it enters off line. You can see the bluing is lightly worn on one side of the sear track because the bolt is warped and tilted ever so slightly in that direction.

It is also possible that the aftermarket trigger was not installed properly and the sears (trigger and striker) are not matching properly. However, I think your bolt is binding up too early for that. I'm almost certain your problem is due to striker sear not entering the sear track properly.

 

[Ontario Hunter]

What safety setup does your rifle use? Striker or trigger block?

It's also possible your bolt shroud is rubbing against the top of the stock as the bolt is closed. You should be able to see the finish rubbed off the top of stock behind the bolt handle and/or behind the bolt release lever. An easy fix. Remove the action from the stock and sand down those two spots and then touch up with oil finish.

 

[Shootist43]

Thanks for all of your "tips." I took a hard look at the bolt. It has a slight witness mark in the back end of the bolt at about 10:30, There is also a corresponding feature in the rifle's guide / bolt alignment area. Suspecting this is the culprit, I will try C.W. Richter's lapping compound idea first. JimP, your caution about not closing the bolt eliminated one of my concerns about using the lapping compound, that being how to really clean the bolt afterwards. Ontario Hunter, the rifle has a trigger safety. When I torqued the action screws to 40-inch pounds, the bolt wouldn't close so I shortened the rear action screw at that time. Pheroze, no doubt due to your legal profession you sir, have a way with words. I'm still chuckling. My last three shots were in two and a third bullet widths.

Being one of Interarm's Virginia models, it has parts from all over.

 

[C.W. Richter]

non-chlorinated brake cleaner (acetone-based in the green can.) can get both the valve lapping compound and it at a Competent auto parts store (NAPA, etc.) The kids at autozone have probably never heard of VL compound lol. *they do sell brownell's and rem action cleaner (it works well-smells identically to carb & choke cleaner). that will do as well. rotate the extractor to expose the grooves in the bolt after the first spray/wipedown to ensure that anything inside the bolt gets flushed out. also work the firing pin similarly once cleaned up and blast that off as well. Good luck! Since you've narrowed down the problem area, the mess will be minimized by focusing on it. I too have had the action screw (and even ever so slightly too long scope base screws) as the culprit at times on new-to-me guns. Could probably do it using the proper dremel buffing wheel and compound or super fine emory/nail file cut to size if especially pronounced.

 

[C.W. Richter]

*and masking tape is your friend for any areas you don't wish to touch

 

[C.W. Richter]

My Zastava based gun has all the finesse of a farm implement. But it shoots true. I shot it hundreds of times and it started to get better. If it shoots well then it may be normal. Good luck on the safari.

I got excited when I saw Rem introduce the model 798 (foreign made on Mauser action by the same Co. that made 'em for Interarms) about 15 yrs ago. 'Saw one at a show and never saw one for sale afterward. Those, with some suggested upgrades, could serve as excellent safari rifles! This is a Very Nice 375 sold on here (i never saw it!) Is this what you have? I did not know until now that the mfr./ exporter is Zastava.

 

[Pheroze]

I got excited when I saw Rem introduce the model 798 (foreign made on Mauser action by the same Co. that made 'em for Interarms) about 15 yrs ago. 'Saw one at a show and never saw one for sale afterward. Those, with some suggested upgrades, could serve as excellent safari rifles! This is a Very Nice 375 sold on here (i never saw it!) Is this what you have? I did not know until now that the mfr./ exporter is Zastava. View attachment 605517

That is exactly what I have. It's a good rifle.

 

[Shootist43]

C. W. Richter, I'm happy to say that the valve grinding compound worked. Thanks again!!

 

[C.W. Richter]

LOL I was such a Motorhead as a teenager working on muscle cars 24/7 so I had the smallest amount of valve lapping compound left from project Buick GSX but it was divine intervention and necessary on an interarms 300 win mag (payment for working on an elders 1956 Chevy panel delivery wagon) which worked and shot phenomenally after the fix! I don't remember all of the titles but do you realize top gunsmiths wrote books called gunsmithing kinks volume 1 2 etc and I bought them up as a kid to fix the factory guns I could afford at that time!

 

[sgt_zim]

I have an Interarms Mark X that I'm planning on taking to Africa in about 6 weeks. Although I've owned this rifle for several years, I never shot it till about a month ago. Interarms rifles or at least the actions were made by Zastava in Yugoslavia. I understand that their actions are not as smooth as the Mauser type actions manufactured by others. The last 1 & 1/2 or so of the bolt closing seems "stiffer" than the first 3" or so. Is this normal?

I've tried putting additional oil on the bolt, but that didn't help or change anything. Any suggestions

Some additional background on the rifle. It was "customized" thirty years ago, i.e. new stock, re-barreled, an aftermarket trigger and safety. Sometime later the original owner died, and the gun sat in a closet for over twenty years.

If you find yourself needing to disassemble the bolt, call me. While it is a Mauser, disassembly/re-assembly isn't quite the same as a conventional 98 or 96.

 

[Ontario Hunter]

non-chlorinated brake cleaner (acetone-based in the green can.) can get both the valve lapping compound and it at a Competent auto parts store (NAPA, etc.) The kids at autozone have probably never heard of VL compound lol. *they do sell brownell's and rem action cleaner (it works well-smells identically to carb & choke cleaner). that will do as well. rotate the extractor to expose the grooves in the bolt after the first spray/wipedown to ensure that anything inside the bolt gets flushed out. also work the firing pin similarly once cleaned up and blast that off as well. Good luck! Since you've narrowed down the problem area, the mess will be minimized by focusing on it. I too have had the action screw (and even ever so slightly too long scope base screws) as the culprit at times on new-to-me guns. Could probably do it using the proper dremel buffing wheel and compound or super fine emory/nail file cut to size if especially pronounced.

Interesting that the threaded screw hole in the tang of similar Springfield 03-A3 is not quite threaded to the top, preventing the action screw from entering the sear track.

 

[C.W. Richter]

Interesting that the threaded screw hole in the tang of similar Springfield 03-A3 is not quite threaded to the top, preventing the action screw from entering the sear track.

Sounds exactly like something John Browning would do (improve upon others' great designs.)