Action Screws on Milsurps

[daboone]

What I've learned thus far is:

As a rule of thumb "V" threaded barrels on round bottom actions can benefit from a free floated barrel and accuracy isn't much affected/effected by the screw's torque. That's good news for
Savage 110 & Remington 700.

Most of my milsurps are flat bottom actions and square threads and are a different animal when it come to torquing down the screws. These rifles seem to shoot better with some amount of up pressure from the fore end of the stock. But there seem to be a big difference in the torque pressures between Mauser K98, 91/30, 03A3, T38 and the K31 as well as to the shimming of the fore end of their stocks.

So if there are any rules for figuring how to torque action screws and amount of shimming on these ladies? I would love to be enlightened.

Information

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[Patrick Chadwick]

I don't know the answer - but it's a very good question!

Up to now I have used the principle that if the action is bedding down on wood, then wood is elastic and should therefore be placed under a certain amount of compression to keep the position stable under load, temperature and humidity changes etc. But compressed, not crushed !

Which is one reason why...
1) Soaking a stock to clean it or remove dings, after it has had a century or so to slowly shrink into a stable configuration, is not a clever thing to do if you want an accurate shooter. Unless, of course, you don't mind waiting another century for the wood to stabilize again. The wood expands, and may well warp. Not necessarily so much that you can see it, but quite possibly enough to spoil the stability and thus grouping accuracy and consistency.

2) And trying to accelerate the drying of that soaked piece of ancient wood by putting it in the oven, the blazing sun, or whatever you choose to speed it up, is just going to make matters worse. How do you think bentwood chairs are made? By methods rather similar to those proposed by the "stick it in the washing machine and then dry it in the oven" fans.

3) A stock should be oiled on the INSIDE as well as the outside. Again, this is to preserve the balance of the wood, not for reasons of prettiness.

3) Since wood shrinks over time, if you want a good shooter, do not let yourself be impressed by "never been out of the stock" staked screws. They were tightened up way back when, to a torque that they no longer have - because the wood has aged. They need to be removed, cleaned, lightly greased, and retightened.

4) If the stock has been oiled (inside and out!) then you will need to check the torque after the first shoot, and then again a couple of weeks later.

How tight? It requires some feeling. The screws must be cleaned and lightly greased on the threads, otherwise you will mistake thread friction for torque. If you use a screwdriver blade in a holder* with a tommy bar, then about "2 thumbs" tight is what you need. "2 hands" tight will be excessive. I do not advise using an ordinary screwdriver in the single-hand grip - the force is asymmetrical, so it is too likely to slip and spoil the screw slot, the wood, and you! If you only have a normal screwdriver, then secure the rifle in a clamp, place the handle against your chest, and hold it with both hands, using it rather like an old-fashioned drill brace.

And remember - you are compressing a piece of wood, not changing a wheel on an automobile.

---------- Post added at 09:16 PM ---------- Previous post was at 09:14 PM ----------

round bottom actions can benefit from a free floated barrel and accuracy isn't much affected/effected by the screw's torque.

Probably because the round bottom action is spreading the wood, and the natural "springiness" of the wood is holding the action firmly enough over a wide range of torque.

*A drill-press setup is ideal.

[Rumpelhardt]

As one who habitually over tightens fasteners I have taken to torquing all the screws on my firearms. I use a Wheeler FAT Wrench. Not overly expensive and it works. Generally I torque action screws to 45 inch pounds. Tight enough to hold but not enough to overly compress the wood. Sight screws/scope screws to 15 inch pounds. NOTE I SAID INCH POUNDS NOT FOOT POUNDS. You Newton Meter people are on your own
.Screws on permanently mounted scopes and sights get a dab of blue LockTite. It's very easy to check screws for proper tension with this before a shooting session though using the above method I have never had a properly fitting fastener come loose.
I'm not saying this is the only or even the best way but it does keep me from stripping or even worse breaking the screws in my guns.
My Winchester Model 70 which as you know is a flat bottom action responded very favorable to being free floated.