OK Guys,

My "practical build" .458 AR Mauser is in the process of being bedded. Is going into a Fajen's synthetic stock that appears to be a really tough fiber filled plastic. Have only done one other rifle in the past so I am a real newbie at this.

The center section is done. Came out of the stock nicely, so the Johnson's floor wax worked well as a release agent. Only a couple of small bubbles ... at the front upper corners of the front of the action ring. Need to fill them for visual pleasantness, but the fit is good and the floor under the action and shank of the barrel is great.

Now ... the next questions are:

1) Given the tough nature of the stock, it is necessary to do the back tang of the action? If the purpose of the bedding is to assure a fitted height for the back end of the action, the stock itself should perform that well as it is non-compressable and very tough.

2) Is it necessary/desirable to bed the front and rear extensions of the bottom metal? Looks to me like the primary value of this is to assure that the action goes back into the stock in exactly the same place every time (while allowing the bolt through the rear to remain untouched by the stock).

Sure do appreciate your guidance here.

Thanks again Fellas ... your input so far has been priceless.

Mike,
for "belt and suspenders" you can spot bedded the rear tang and the "shoulders" of the action, right behind the mag well...

then, relieve the VERTICAL portion of the tang, just a bir, so the action doesn't touch the plastic along the rear of the tang ONLY

jeffe

quote:

1) Given the tough nature of the stock, it is necessary to do the back tang of the action? If the purpose of the bedding is to assure a fitted height for the back end of the action, the stock itself should perform that well as it is non-compressable and very tough.

Mike
it's not necessary as long as you have a good bedding of the front portion and the recoil lug.

However I'd say that it is desirable.

That said, it'd have been preferable that you'd bedded the entire action all at once and as a matter of fact, I'd recommend removing enough of the bedding material you have already done to allow you to do the entire action at once.....and this to include an inch or so of the barrel.

quote:

2) Is it necessary/desirable to bed the front and rear extensions of the bottom metal? Looks to me like the primary value of this is to assure that the action goes back into the stock in exactly the same place every time (while allowing the bolt through the rear to remain untouched by the stock).

It's not at all necessary to bed the bottom metal except that I do it if I need to make it "fit" the stock better. Or a filler is needed somewhere.

Bedding the bottom metal has nothing to little to do with the reason for glass bedding the action.

Have a great rifle!

When I glass a Mauser, if the stock has been inletted with the flat section from behind the recoil lug all the way to the tang looks truly flat, then I accept it as flat.
1) I remove material for 1/2" behind the recoil lug and glass that. This sets the height of the front of the receiver equal to the flat section of bedding, gives something for the front screw to pull against, and bears the recoil.
2) Glass is under the first inch of barrel. This gives the front action screw something to pull against and damps barrel vibration.
3) A single glassed in pillar on the tang sets the hight of the receiver in the rear equal to the flat section of inletting.
4) A single glassed in pillar at the rear of the bottom metal sets the depth of the bottom metal in the rear and gives the rear action screw something to pull against.
5) Glass under the bottom metal at the front sets the depth of the bottom metal in front and gives the front action screw head something to pull against.

I glass the tang pillar in compression with a screw in tension that has been modified to have a head the same size as the OD of the pillar. There is no bottom metal when I glass the recoil lug, barrel, and tang pillar.

The flat inletting of wood, fiber glass, or injection molded plastic will deflect less than .0001" if compressed at 10 psi during the glassing. This would be about 10 pounds of rubber band force holding the rifled action to the stock.

The flat inletting does not need to be .0001" flat, as the high spots will carry the load. I use fine sandpaper to knock down the worst high spots.

The steel pillar compressed at 1000 psi will deflect less than .0001" during glassing if the ends of the pillar have been trued and polished. I use 3/8" tubing.

If the inletting is not flat, or the height of the flat section of inletting is not what I want, then everything is much more work.


Mausers converted to .223 with acceptable inletting get no glass as they have almost no recoil.

Injection molded stocks may flex the flat section of inletting when the action screws are tightened. Fixing the flexing to keep the stock flat between the first inch of barrel and tang with glass makes the stock too heavy. Fixing with Aluminum machined drop in is too much work. I give up on improving injection molded stocks. They seem to work on 10/22s without modification.


What does all that mean?
If it looks flat and stiff, then the flat section of inletting is the reference to which everything is glassed and put almost no glass on the long flat section.