Oviedo Model '93 Mauser, Caliber 7mm, Mfg. 1927

[Patrick Chadwick]

Top of action ring to trigger guard housing bottom near front screw is 1.363" in AND out of the stock! No wood compression going on up front... Tang to trigger guard measures 1.905" in the stock and roughly 1.869" free state out of the stock. Recoil lug depth ~0.248" but the recess in the stock is only 0.220". No surprise that the bottom of the lug is the only contact at the front of the receiver.

The front end is not tight enough.

The ideal setup for the system is if the wood is slightly pinched when the trigger guard assembly is screwed up until metal meets metal. I do not have a definition of "slightly pinched", it's a matter of feeling. My feeling goes: doing it all up "One-hand" tight at first should mean that the wood is being pinched, but triggerguard metal is not yet meeting receiver metal. But "two-hands" or "tommy bar" tightness with the rifle held upside down in a cradle should just get metal to metal. Do not go to "wheelbrace" tight, as that will be FUBARing the screw and/or crushing the wood.

OK, I know that is not an exact science, and it depends on the strength of your hands and wrists. Still, I reckon you have the hands-on experience to interpret what I am trying to say. My feeling is that the rear trigger guard screw will be OK is it is, but at the front end you need about 0.020" of pinch. Either pack out the recess below the trigger guard plate at the front (in effect bedding the floorplate - ideal, but tricky) or insert a 20 thou washer between the floorplate and the wood (a cheat, but easy) or file the 20 thou off the screw boss on the system, to allow the parts to come closer together. This last option is mechanically good, because it preserves the fit of the floorplate in the cutout. It is, however, an irreversible alteration. So whichever method you choose, experiment with washers under the floorplate first, to determine the right amount of pinch.

But first of all - check that the trigger guard screw is not bottoming in the boss on the system, as this will prevent any wood pinch from being achieved. It is conceivable (I once had one with a non-original screw that was a tad too long!) that simply filing 20 thou off the end of the screw will enable the whole assembly to be tightened up just that little bit more to pinch the wood.

The whole idea behind pinching (and not crushing!) the wood is that as long as it remains in elastic compression, the pinched wood will in effect act as a spring washer to keep the system firmly held in the stock.

Patrick

[jmoore]

Essentially, your post is a detailed description of the "fix" done in the Kydex shim posting, except I'm only at about 0.010" pinch.

I'll leave it be until test time and add a little if things are worse than before.

ETA: Clearance around the front band is about non-existant! Maybe only 0.003-4". Lots of metal removal would be required to do the fabric tape trick mentioned by Patrick Chadwick a couple of posts ago.

[jmoore]

Ran a whole six rounds through the rifle yesterday on two different targets, one of which is displayed in the Milsurps Rifle Competition. But here's a repeat:



Stupidly enough, the action STILL moved back about 0.010"- enough to be hard against the wood at the rear of the action again. Going to do a teardown directly. Odd to see the POI wasn't affected much!

Madness inducing rifle! Poor workmanship, "basic sights", random discontinued (I think) cheap ammo, tired bore, weak crown, cobbled repairs in progress, no stability in the stock, no support except the back of my hand on a chunk of wood whilst firing off the bench, and it shoots- amazingly well!

Why do I feel that once I sort the dramas on this rifle it'll never shoot a decent group again?

[Patrick Chadwick]

Essentially, your post is a detailed description of the "fix" done in the Kydex shim posting

Kydex shim posting??? Wossat? Did I just waste a lot of time and non-sustainable brainpower in reinventing the wheel?

Patrick

[jmoore]

The front end is not tight enough. The ideal setup for the system is if the wood is slightly pinched

Well, it's not wood to metal, but wood, kydex, to metal to get the "slight pinch". But it looks like I need a little more forward shimming to minimize tang splits. So, temporary is good. Have been too busy today to do a pull apart. Plus, I left my camera at the house!

[vintage hunter]

JM, have you added the liner in the rear action screw hole? Doing so will solve a lot of your promlems, it will pretty much rule out the chances of a tang split and reduce if not eliminate action shift.

[jmoore]

JM, have you added the liner in the rear action screw hole?

Not yet! Mostly because the length and location fore and aft have yet to be established. As I understand it, the liner prevents vertical crushing of the wood via overtightening of the rear action screw. It does not help much (or should not be required to help at all) in locating the action fore and aft. That's the function of the recoil lug. Ideally, the rear tang bushing/liner/pillar should NOT contact the rear action screw itself!

[Patrick Chadwick]

And I still don't know what kydex is...

[Dad]

Kydex is a thermoplastic (acrylic-polyvinyl chloride).

Kydex - Wikipedia, the free encyclopedia

D.

[jmoore]

Finally! Got the 0.060" kydex shim. Bent it to both raise the action so that it doesn't sit on the bottom of the recoil lug and forward enough that it isn't trying to split the rear of the inletting with every round.

Of course, now I can't get good groups with no effort like before...

Today's final target:


100yds, Using the cool but in short supply S&B 175gr ammo as detailed above.

Can't ever be easy...