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found this http://forums.gunboards.com/showthread.php?80299-Rebarreling-the-M-95-Steyr-straight-pull

"Some and perhaps all are neither any standard metric thread, not the dimensions, I think 1.04in. x 14, which various gunsmithing books copy from one another. The two I have seen are more like 1.04 x 12, which is more like 26.4mm. diameter. I think the pitch is actually the same as the Mauser 98 (2.1mm.?) and not exactly 12 TPI, but as with Mausers, a 12 threaded barrel would be entirely satisfactory. I've seen somebody do a good job by turning down the rear, non pressure-bearing flank on an old Mauser 98 barrel, and the front flank seemed to make perfect contact all along the threads of the Mannlicher action."

"The Steyr is a metric, rendered by some as a 14 TPI, and some as a 12. It is actually a 25.5x2mm metric, same pitch thread and form as the Mauser original, not the commercial."

"Mauser M.93 is a M.25x2 thread. .984" shank diameter.
Mauser M.98 is a M.28x2 thread. 1.1" shank diameter.
M.95 Steyr is a M.25.5 thread. 1.06" shank diameter.

You can whittle down an M.98 shank to fit, but you won't get a M.93 to go unless you can get it to swell some way or other, and that I want to see. Better to start fresh, and go with a new blank. "
" Default

My published source, apart from my own observation, was Harold E. MacFarland's article on barrel thread specifications in "The NRA Gunsmithing Guide Updated", which confirms data given in his "Introduction to Modern Gunsmithing" of 1964. I think he is wrong on the pitch of the M95, but it seems very unlikely that he also is with the Mausers, which are so well documented in such sources as the Brownells catalogue, for their thread cleanup dies. Those for the Mausers are reiterated by Frank de Haas in his "Bolt Action Rifles", thirty years after MacFarland.

It is entirely possible that there were different specifications, over the years, for the M95 Mannlicher. But this could hardly have applied to the much more commonly used Mausers.

MacFarland's diameter figure for the small ring Mauser is .980in. (which makes 25mm., or .984, sound right.) The 1.1in. diameter given for the M98 would be 27.94, so I think it is really 28, or only about .004 larger.

But they don't have a 2mm. pitch. Both are listed by McFarland and other Americans as 1.1in. x 12TPI. It is actually metric, and since 12 would be 2.1167mm., is presumably either 2.1 or 2.125mm.. A true 12 TPI thread, as cut by Americans who don't have a metric equipped lathe, is satisfactory. But in the .625in. length of the Mauser thread, a 2mm. pitch would be more than 0.7mm. out of phase with the action threads, which is unacceptable.

I'm not quite sure what is meant here by "barrel shank". The part inside the action is parallel in all three rifles mentioned, and all threaded. The flange in front of the action in the M95 Mannlicher is given by MacFarland as 1.262in., which looks pretty much like any M95 I know, although you could barrel with a smaller shoulder. Military M98 Mausers had no shoulder, the barrel being close to the thread diameter. For it screwed up tightly against the internal stop-ring at the extreme rear of the barrel, not against its face. The M95 Mannlicher has a stop-ring of sorts, but I don't remember whether it looks adequate for this purpose, and tightening on the front of the action seems better.

One or two odd Mausers had intermediate diameters, but the same pitch as the small-ring and M98 - as indeed did the 71/84 Mauser and the German Commission 88. Most sporting Mausers used the standard threads.

I could well be wrong in remembering the M95 diameter as 1.04in. It could have been the 1.02in. McFarland gives. But I certainly didn't observe a 14TPI thread, but one which interlocked with a Mauser M98 barrel when laid side by side.

An M98 barrel, although of the same thread pitch as I have seen in two M95s, will not enter the action, as I found it, at all. The only real use for one would be if you don't feel confident of cutting a smooth, chatter-free thread. You could reduce it by cutting only the non-load bearing flanks of the thread, leaving the bearing side as you find it. The M95 thread is given as .693in. long, or slightly longer than Mausers, so the barrel flange will need to be cut forward, too. "

"The shank is that threaded portion of the barrel that goes into the receiver. The thread pitch is about 12.7 TPI, by my measurement, which falls close enough to 13 TPI that a man with a metric thread and an inch gauge could be understood if he measured it at 14 TPI.

As you noted, the threads from the M.95 Steyr are the same pitch as the Mauser threads. The metric thread gauge, and the optic comparator show the thread pitch to be 2mm lead, which works out to 12.7 threads per inch. Just for grins and jollies, the 1.5mm lead, commonly used in autoloaders, will measure near as can be and still be off, as a 17 thread per inch, not the 16.9 it actually works out to.

Barrel shank for metric threads are:

25mm x 2mm lead, or .984x12.7 TPI in decimal inch practice. The thread form accounts for the difference in actual practice, because the metric thread, often referred to as a Whitworth, but actually even taller and skinnier, is narrower at the base. The 60 degree thread of common SAE practice is shorter and wider than the taller, skinnier thread, which is a 47 and a half degree thread. That's where the extra .004", .002" per side, goes to. The Germans and most of Europe used the 55 degree Whitworth in a deviation from the earlier thin threads, and a 60 degree thread is today ISO standard. Unlike some others, I generally mark my editing.

Same goes for the 28x2 mm thread of the Mauser shank. Same thread pitch, same thread form, different diameter. The threads between a M.93 shank and a M.98 shank will definitely mesh, but the shanks most emphatically are not the same. The M.95 will mesh, also. It is intermediate in diameter between the M.93 and M.98 barrel shanks, and works out as a diameter between 25.5 and 26 mm. I have one of these barrels, a takeoff with a bore that resembles a Pyongyang sewer pipe, but clean threads and shanks (and it was an 8x51R too, for a shame....), and mine mikes 1.042" which would allow me to clean up a M.98 barrel shank for use in the M.95 action. The dial caliper gives me a shank length of .697" to the shoulder."

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