Reader Forum

Marlin Screw Search I’m in need of a magazine-tube stud screw for a Marlin M36, 2nd variation. The Brownells Encyclopedia (13th printing) lists this as part number 36-53 and also lists the thread pitch as a .137 x 42. I was going to make anew screw, but this pitch is new to me and I can find no reference to it anywhere. Could this be a mistake? Any input from you guys would be greatly appreciated. George M.

Burkhart Lancaster, Pennsylvania The book you refer to is usually reliable, but typographical errors do occur even in the most carefully edited manuscripts. You’re advised to call Marlin Firearms at and either request engineering or historical assistance (or both). We are more than reasonably certain the factory records can resolve this problem for you. Rough-Bored Walther I have a Walther P-38 with a bore that’s pitted and rough. What’s the best way to clean it up? Thanks.

First, give the barrel a thorough cleanout. If the pitting is deep and the roughness excessive, you’ll probably have to search for anew barrel. If not, lap the bore repeatedly with JB or a similar cleaning/polishing compound. Butchered MAS Barrels About a year ago, I took in a MAS 49 as part of a trade, figuring to add it to the parts pile because I had been told that it didn’t function properly. Then six months ago, along-time customer bought a MAS 49/56 on-line.

When it came in, I inspected it and advised him not to fire it. When the importers’who shall remain nameless’ converted the rifle from 7.5mm to 7.62, they butchered the breech. It looks like it was done by a one-eyed blacksmith with a dull cold chisel. Then I pulled out the one I had taken in trade and saw the same gouge marks. Yep! Same importer!

As of today, I have three of these little darlin’s laying on my bench, all from the same importer and all showing the same butchery in the breech’ and all blowing the casing out of shape because of crude rework. There should be a law against selling firearms that have been hacked up like this. I’ve tried unsuccessfully to find replacement barrels for MAS 49s from every source I can think of. Do you know of a source for barrels for this rifle? Will the barrel from a MAS 36 assemble in the MAS 49 receiver?

And are they available? I was thinking a 36 barrel could be reworked to accommodate the gas tube. My last thought on creating operational firearms from this pile of scrape is a bit more involved, and I’d like your opinion on the matter. I was thinking that I could bore the breech and then press fit an insert to give me new material to work with. I could then chamber the rifles back to the original 7.5 or to 7.62 like the hamhanded idiots at the importer attempted to do.

I seem to recall you discussing this type of process and having reservations about overall strength and safety of the final product, but I could not find it. I am sure there are other MAS 49s around the country that were re-chambered in the same fine craftsman-like manner, with the same problem of the casing blowing up so badly that they will not extract. Hoping to hear from you soon with salvation. Thank you.

The only parts source for the MAS 49 we know of is Century Arms, with technical operations based in Vermont Though we have done many articles on firearms they’ve supplied, we have never seen one with anything approaching the type of damage you describe. Nevertheless, while we’ve never published an article addressing the specific problem you’re saddled with, we would suggest you take a look at John HInnant’s book, Complete Illustrated Guide to Precision Rifle Barrel Fitting, Third Edition (2003).

The book is available from the author We discussed your case with Mr. Hinnant, and we agreed that a switch to the Model 36 barrel would be problematic because of the gas system. We also agreed that, for strength, any barrel insert you intend to install should be threaded in rather than simply pressed in. Winchester and Browning Questions I have two requests. First, I need information about adjusting the trigger on a Winchester Model 70. I want to retain its crisp let-off, but reduce the pull to about 3 pounds.

My other problem involves a Browning Model 81 BLR (lever-action .243 Win.) A customer dropped off the barreled receiver with forend, buttstock, and a bag full of additional parts. Apparently, he took it apart after dropping it in a mud puddle. All I have to help me visualize the end result of this project is the parts schematic from Browning. The only help I got from the folks in Arnold, Missouri, was the advice that setting the timing on the gear assembly is largely a trial-and-error proposition.

What I need is the step-by-step assembly procedure like you typically include in American Gunsmith articles. Can you help me with these requests? The Model 70 trigger doesn’t have to be removed from the action to adjust it, but with a hunting rifle, we advise against taking the pull down to less than 3-1/2 pounds. Working from a schematic of the rifle, you’ll notice there are three stop nuts on the trigger screw.

Loosen the screw and turn the two upper nuts counter-clockwise simultaneously to lessen tension on the trigger spring and reduce the pull. The same nuts are turned clockwise to increase weight of pull. The lower

(continued from previous page) nut is left alone during these adjustments. Note: If the rifle fires on closing the bolt, the pull must be increased. To adjust trigger travel, loosen the lower nut and turning the trigger screw clockwise until the firing pin fails to release when the trigger is pulled. Maintaining rearward pressure on the trigger, slowly back out the screw until the sear releases the firing pin. Add a quarter turn of back out to the screw and tighten the lower nut.

Of course, if you really want a crisp adjustable trigger, you can replace it with the Timney aftermarket trigger. (See Norman Johnson’s article beginning on page 10 of this issue.) For disassembly and reassembly procedure for the Browning Model 81, pick up a copy of Gun Digest’s book disassembly/reassembly of centerfire rifles. The book also includes details on reinstallation of the gear assembly. Learning Precision Machining I would like to find some good books on gun machine work.

I’ve completed a thorough machine-shop course that was offered at my local tech school. I learned to operate a mill, lathe, surface grinder, etc. I read the synopsis of the course offered by the American Gunsmithing Institute, and it sounds like a repeat of what I have already covered. I have a book by Steve Acker and it is very good, but it covers only a portion of the gun machine work I need to learn. I would appreciate any suggestions on some good books on this type of work.

There’s a two-volume set published back in 1988 by Industrial Press that you might find on-line. While no machining books we know of are "gunspecific," you can acquire the machining skills and then apply them to guns as needed. For example, you don’t have to be told how to mill a flat on a gun barrel if you’ve already mastered the process on a bar of coldrolled steel.

Extend that concept to anything machine tools are used for in the manufacture of firearms, get your tolerances down to a very few thousandths, and you’ll be drilling scope-base holes and cutting dovetails with precision. And when you get really, really good at working to an accuracy of a few tens-thousandths of an inch, you might be sharp enough to join the American Pistolsmiths Guild or the American Custom Gunmakers Guild as a full-fledged member.

There are no shortcuts, however, unless you’re lucky enough to be equipped with computer-guided machine tools from the get-go. CNC equip- Technical Assistance Hotline To access AGA’s Technical-Assistance Hotline, call between 1 and 3 p.m. ET, Monday, Wednesday, and Friday once at all dan email to Chick Blood, Technical Editor, at ment might make achieving accuracy happen a little sooner, but we doubt it would enhance your learning curve any more than a pocket calculator helps in learning basic arithmetic.

Winchester and Ruger Parts I am looking for a forearm shoe for a Winchester Model 37 (.410 gauge) and a magazine throat for a Winchester Model 1400 (20 gauge). I’ve already checked with Jack First and Numrich. Do you have any other ideas on where I might find these parts? Also, I’ve been asked to replace the barrel on a Ruger Mini-14. Having never done this before, I’m wondering if it’s an easy job I should take or a difficult task I should pass up.

Any insight on tools and procedures including headspace problems would be greatly appreciated. For the Winchester parts, call Buckinghams or Nu Line Guns Regarding the Ruger barrel, check the prefix on the rifle (180, 181, 184) There were some engineering changes made after the 180, and we’re not certain if these changes included barrel/receiver threads. If anew barrel fails to conform to the right specs, you won’t be able to mount it without rethreading.

To replace the barrel, you’ll need a good barrel vise, headspace gauges, and a receiver wrench. The wrench may have to be turned with a cheater bar to extend its handle, since Ruger turns in its barrels very firmly. The best source of information on the rebarreling project is a book by John Hinnant, The Complete Illustrated Guide to Precision Rifle Barrel Fitting. It can be ordered directly from the author