I have just about saved enough money to have a custom gunmaker get started on a custom rifle based on a 1909 argentine action. I understand that, in general, DWM 1909's are very well made. I want to start out with an action with the best bolt fit possible. What should I look for (i.e. measure, and how to do so) when I examine a candidate action. Is there a specific serial number range to look for? Are standard models or cavalry carbines best? The action will be annealed, opened up substantially for the intended cartridge, and then re-carburized. Will carburizing leave a couple of thousands of an inch finish on the lug raceway surfaces, thus titening up tolerance? I am thinking that I should use a cavalry carbine in order to retain the bent down bolt handle, as the old rifle that I would like to reproduce has a military style bent down bolt.

I have owned several. I don't think serial number would make a big differnce as I have had them with early serial numbers and later serial numbers (as designated by the letter code preceding the numbers).

This is just my opinion, worth 2 cents adjusted for inflation, that 1909s are inherently smooth because of their relative softness. I have had them hardened up to where they weren't as smooth feeling. Not a great difference, but one that could be noticed.

If you are going to use a scope, you are going to have to use a new bolt handle, and I would highly recommend having somebody that knows what they are doing weld a new one on for you. Otherwise you are going to have to use super high scope rings.

I would recomend that you you look for one that has no setback, and that you lap it half in before heat treating, and do the rest after it has been heat treated, just to take into account any minute but very possible warpage.

Really nice ones aren't so cheap anymore. I do have one that has been annealed and needs a few parts (but doesn't have any bottom metal) that I would sell for $175.00. Otherwise , good luck on your project.

Bolt fit has less to do with the bolt than with the way the bolt bore was bored. The bolts rarely vary more than a thou or two in diameter. The rear bore, for lack of better words, is the one that usually varies. The larger it is the sloppier the bolt fit.

For best fit you could cut off the rear bridge, weld up the bore surfaces, weld on another bridge or the original and then rebore.

Generally though they are fine as-is. If you have a mis-matched bolt and access to many, then look for the one with the largest diameter. That will reduce some of the play.

But you really need to define what you mean by fit? Bore fit is probably the biggest governor of play but the size of the guide cut in the bridge has some effect too.

As to soft or hard actions producing smooth or no so smooth operation, I found the opposite is true. After polishing and the hardening they were much slicker than before.

There is not much to anneal on a 1909. Those that I tested were about Rockwell B80 which is around RC20 and off scale in the C range. This is easily machinable. It also a bit too soft for high pressure and hard use in my opinion.
When heat treated the receivers tend to bend upward at the thumb cut notch.
The smoothest 98 I have ever messed with was a really worn VZ-24. Reducing the strength of the follower spring reduces the upward force the follower puts on the bottom of the bolt. This permits the bolt to operate much more easily.
You can test this by operating your bolt in the receiver with out the follower.

quote:

Originally posted by ireload2:
When heat treated the receivers tend to bend upward at the thumb cut notch.
....

Not when done properly. I've never had one warp yet. Not that it can't happen but when you quench properly you can reduce warpage to practically non-existenet.

Ireload2

How did you test them? From what I have been told the reason to anneal is not becasue they are too hard to machine, but rather that if you don't you set up stresses that will casue warpage if you reheat treat them.

22WRF,
I worked at a company that had the Wilson Rockwell tester. It used the 1/16" ball indenter for the Rockwell B scale and the Brale diamond penetrator for the C scale. I only tested on the flat bottom of the receiver behind the recoil lug -not the correct way to test. The correct way to test is to cut a slice out of the receiver ring so you can test the locking surface directly.
The others that I tested - 2 FN military, a BNZ and a VZ-24 tested in the low 30s Rockwell C as best I remember. I have some complete rifles but I can't sneak them into work.