Commercial Mauser

[B R Shooter]

A friend has a commercial mauser that he has owned for many years, Shilen put a barrel on it in 220 Swift. He shot out the throat and asked me to set it back. I have the barrel, not the action, and I'm duplicating what he had. Straight forward, 12TPI thread, flat breach. I cut the entire chamber off the end and rethreaded from there, so I have the old chamber/threads in hand.

Rented a reamer and gauges, they arrived yesterday. I dropped the go gauge in the chamber and surprised to only protrudes out of the barrel by .120" or so. I measured this quickly using a dial caliper, I have the properly measured dimensions written down. This just seems a small amount for the brass to stick out, hardly exposes the full extraction groove of the gauge.

Anyone do one of these actions, and see the same? I repeat, I have the original entire chamber end that has been used for years, so there is no mistaking how it was chambered before.

[Sailormilan2]

You're in the ballpark. I just checked using a spare .257 Roberts barrel I have, and using some dummies made of converted 7mm brass, mine are sticking out .112" & .115". I have mounted that barrel and tested these dummies, and bolt meets resistance when camming down. So, head space is still a bit short.
When I dropped a factory loaded round in, it measured .098". But, I have not tested that one with the barrel mounted. So, there is a good chance my dummies were not sized properly.
Don't forget that there will be about a .003" crush factor when tightening up the barrel in the receiver.

[MostlyLeverGuns]

Check the amount the extractor extends from the bolt face. As long as the extractor does not hit the barrel, the fit should work. Less exposed brass is a good thing.

[PTCSmith]

I do Mausers regularly, and I would advise that you get the receiver and bolt to work with. You can measure the distance from the primary torque shoulder to the bolt face to see how much the gauge should protrude. Also, you can measure what the tenon length needs to be to seat on that primary torque shoulder.

Bill Jacobs

[B R Shooter]

I have the original chamber and tenon intact. I have already measured it all and even timed the threads so the barrel markings will line back up. I am confident in the tenon/threads/lengths. Now that I have the go gauge and measure the existing chamber, I will chamber it to match it exactly. I was just surprised about how little the gauge is exposed, when compared to other push feed actions that I've done.

[Texas by God]

I'm not a pro by any means but I mount the barrel and finish chambering the last little bit by hand on a Mauser. YMMV.

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[PaulG67]

I have done a couple of Mausers of my own and agree with post #4, having the receiver and bolt will give all the needed dimensions.

[B R Shooter]

Guys, clambering a barrel using an existing barrel, or by the dimensions you have from a previous barrel/chamber for that action, is commonplace. Having the ability and tools to measure all the critical areas is not hard. Including aligning the lettering on the barrel. It is done every day. There are actions that are made to such close tolerances a barrel will fit any of them. A Mauser isn't one of them, but having the old barrel that has been fired a few thousands of rounds without incident pretty much proves it is within proper tolerances. At least for this owner.

[DCM]

I would not trust that the last person who did it, did it to My OCD specifications Ever. YMMV
Agree with post #4.
I have seen way too many folks AssUme that the last guy did it right only to find they are wrong.

[B R Shooter]

The majority of benchrest actions are glued in the stock. They are not intended to be removed easily. There are ways to check an existing chamber for proper headspace, then duplicate the barrel. It ain't rocket science.

[Texas by God]

Why cut the entire chamber off to set the barrel back? Was the toasted throat that long? The cartridge head should protrude enough from the chamber for the bolt to close tight against it while the extractor just kisses the barrel face. Shilen did it right, copy them and put it together.

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[B R Shooter]

Why cut the entire chamber off to set the barrel back? Was the toasted throat that long? The cartridge head should protrude enough from the chamber for the bolt to close tight against it while the extractor just kisses the barrel face. Shilen did it right, copy them and put it together.

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Two reasons, yes the throat and forward was pretty bad. Had a full 26" to work with, so I cut it through the neck portion of the old chamber. This preserved the entire works to measure.

Second, I rented the reamer, so I had the tenon and threads to duplicate ahead of renting the reamer. Typically, most actions measure off the shoulder, but not the Mauser. And I wanted to time it back so the lettering Shilen did would be in the right place. And most actions I work on are 1-1/16 and this was bigger, so I had to make new measuring holders and thread gauge. So by having the old chamber in hand I got all this done before needing the reamer. Once I had it delivered it was just a matter of measuring headspace and chambering. All finished this morning.

[Texas by God]

Despite their odd case design, .220 Swifts have always been accurate IMO. Let us know how it does and pics, please.

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[Gaseous Maximus]

A friend has a commercial mauser that he has owned for many years, Shilen put a barrel on it in 220 Swift. He shot out the throat and asked me to set it back. I have the barrel, not the action, and I'm duplicating what he had. Straight forward, 12TPI thread, flat breach. I cut the entire chamber off the end and rethreaded from there, so I have the old chamber/threads in hand.

Rented a reamer and gauges, they arrived yesterday. I dropped the go gauge in the chamber and surprised to only protrudes out of the barrel by .120" or so. I measured this quickly using a dial caliper, I have the properly measured dimensions written down. This just seems a small amount for the brass to stick out, hardly exposes the full extraction groove of the gauge.

Anyone do one of these actions, and see the same? I repeat, I have the original entire chamber end that has been used for years, so there is no mistaking how it was chambered before.

I've rebarreled probably a couple hundred Mausers and that .120 is actually a little on the long side. For what its worth I like to face the front of the receiver on a mandrel, and use that for the primary bearing surface, cutting the shank about .0005 shorter than the depth of the inner ring. But that wasn't the question. just info no one asked for.

[B R Shooter]

"I've rebarreled probably a couple hundred Mausers and that .120 is actually a little on the long side"

Yep, it is, I just grabbed the calipers and did a quick depth measurement. My proper measurement is .109".

[Larry Gibson]

B R Shooter

I understand what you're doing, no problem. Only suggestion I have is, since the owner obviously reloads, is to get 3 - 5 fire formed cases from the owner. Measuring how much those cases protrude from the barrel breach face. That will give you a much truer measurement of the actual dimension from barrel face to the bolt face than will gauges.