Some questions have been running around in my head, so I thought I would ask them. Especially since I have had three custom rifles made on M98s!

1. How are the threads on a M98 barrel cut? Do you use a outside die and cut them by hand? or turn them on a lathe? or use a die and a lathe together?

2. Are the threads cut like pipe threads, that is, they taper down and self tighten? or are they more like machine screw threads where they are parallel and tighten up due to compression or stress?

3. How to you measure the threads? Clearly, they is quite a bit of differences between the various Mausers.

Thanks in advance.........

RobertD

Straight thread, cut on a lathe. Measure just like any other thread.
Tighten until bottomed on the inner ring, also touching the outer ring of the receiver is a option (gap at the outer is allowed, inner ring contact is mandatory).
There are only 2 standard thread sizes for Mausers (large and small), the only exceptions are those receivers that have had the their threads recut during a "truing/bluprinting" process.

Some of the Turks have 11 1/2 tpi. All other Mausers have 12 tpi.

Straight thread!

Now that is interesting. This is what brought up the question. Since the thread is straight, what holds the barrel in place year after year of shooting? It would seem to me that the barrel would want to loosen up.

Some use loc-tite, maybe some use bubble gum? Some 'smiths actually use a ramp thread which requires neither. Some folk use nothing at all. Try www.benchrestcentral.com and search the archives for "ramp thread" or read "Rifle Accuracy Facts" by Harold Vaughn who devotes a chapter to the subject.

Dan

Pres., TYGC
www.TonsOfTrivial.Info

Dan, I've found that the best way is simply to have a friction fit. The reason barrels don't come loose is that the direction of twist is generally the same as the thread. What this means is that shooting the gun applies torque to the barrel which causes it to tighten. You have to be careful when rebarreling things like the norwegian krags because they have left hand threads and can loosen if using a right hand twist. This is the theory I've always heard. BTW, Remington uses locktite on the 700's

Toolmaker

Just like putting a nut on a bolt. When the nut is torqued properly it stretches the threads and that is what keeps it tight. If it's properly torqued you never have to worry about it comming loose. Loctite fills any gaps in the threads. The absence of air makes it harden and keeps the threads from loosening. If the threads are torqued and locktited you may need heat to remove the threads depending what type of locktite is used. All locktites liquify at 300 degrees F.