Why not use action screws or action screw/washer for holding action for bedding?

[bsumoba]

I am planning to bed my McMillan stock this week. I have MarineTex, Johnson's past wax, modeling clay, electrical tape, blue painters tape, lots of q-tips and stirring sticks.

My question is that I see most sites advocating for using electrical tape, rubber tubes, etc and wrapping this around the action and stock to hold them together while curing; why not use a counterbore screw or a threaded rod, washer and nut to hold the action in?

My stock already has aluminum pillars in them. The action is sitting fairly well in the stock when McMillan inletted it. There are a few things I need to relieve, but that is minor dremel work.

 

[Larryh128]

No reason not to. Make sure to get lots of release agent/wax on the threads.

 

[Dgd6mm]

I have used the action screws, since have moved on to 1/4-28 studs for centering the action in the stock.

 

[carlsbad]

If instead of action screws you use longer studs (1/4 28) you can screw them into the action and then use them to guide the process of mating the action with the stock. Makes it easier to smoothly accomplish this critical step. --Jerry

 

[bsumoba]

Great!

This is exactly what I will do. I was thinking 3-4", 1/4-28" studs screwed into the action for guides, then using either a nut/washer to secure it from the bottom side to secure it.

 

[amlevin]

The idea behind not securing the action with the action screws is to eliminate internal stresses that tightening these screws will create. Most will use the action screws or a couple of cut off bolts with the same size and thread pitch to locate the action and bottom metal but then use the elastic bands, tubing, etc to "squeeze" the action into the bedding with all forces spread equally from front to rear of the action.

If you were to tighten an action screw to it's full torque value you now have localized internal stresses that can be as much as 1200 PSI at each point.

Once the bedding has cured it won't matter but if you want a "stress free bedding job" then it's a good idea to not tighten the action screws at all.

Everyone has their own take on this and in reality it's whatever works best for them. Just remember, some people dont' even worry about whether the action is ever removed from the stock, they just glue it in place and then shoot. Need a new barrel? Clamp the action wrench in a vise, clamp on the barrel wrench, and change. The stock is just along for the ride (and often in the way too :).

 

[bsumoba]

I have 3 action screws and what I will do is use 3" studs to locate the action in the pillars and then use a washer and nut and tighten to just past hand tight. I feel like with the 3 screws it will spread the pressure across the whole of the action as long as I don't go crazy tightening them.

 

[jr600yd]

I put vasoline on the screws. Bedding material will not stick to it.

 

[Preacher]

It also helps to tape the headless action screws so they fit snug into the pillars, and provide a good center

 

[Patch700]

I have 3 action screws and what I will do is use 3" studs to locate the action in the pillars and then use a washer and nut and tighten to just past hand tight. I feel like with the 3 screws it will spread the pressure across the whole of the action as long as I don't go crazy tightening them.

Resist the overwhelming urge to tighten the screws too much lol....This is where most people mess up and actually force the action to conform to the reference points of the stock when it is the bedding you want conforming to the action... This is why most folks have good luck getting it rite the first time by not inducing stress and using the tape method.

One way to check your finished product is when you set the action back into the stock and have all the screws lightly snugged up , from that point no matter if the torque you apply is 15 inch pounds or 50 inch pounds the screws barely move. This tells you the action is not compressing or being contorted while torqueing the screws. If you notice that the screws do indeed move a good amount when going from say 15 inch pounds to 50 then you will probably have to do a skim coat to tighten things up.

Good luck and let us know how it turns out.

 

[bsumoba]

I have 3 action screws and what I will do is use 3" studs to locate the action in the pillars and then use a washer and nut and tighten to just past hand tight. I feel like with the 3 screws it will spread the pressure across the whole of the action as long as I don't go crazy tightening them.

Resist the overwhelming urge to tighten the screws too much lol....This is where most people mess up and actually force the action to conform to the reference points of the stock when it is the bedding you want conforming to the action... This is why most folks have good luck getting it rite the first time by not inducing stress and using the tape method.

One way to check your finished product is when you set the action back into the stock and have all the screws lightly snugged up , from that point no matter if the torque you apply is 15 inch pounds or 50 inch pounds the screws barely move. This tells you the action is not compressing or being contorted while torqueing the screws. If you notice that the screws do indeed move a good amount when going from say 15 inch pounds to 50 then you will probably have to do a skim coat to tighten things up.

Good luck and let us know how it turns out.

I will be dremelling the inletted portion just a tad bit more so I can get more bedding compound in there. Right now, the ejection port, bolt release, rear tang and sides of the action are near perfect if I did not bed it.

I completely understand the reason to not torque down the screws too much.

Shouldn't be too hard of a job. ???

 

[Alex Wheeler]

Anything you do induces stress. Using screw, tape, tubing exc. It will show up on the dial indicator. I have used every method, and measured the results. The only way I do it now is stress free, meaning nothing holds the action in. Push it down in the stock, use studs to help with alignment, and let it cure. No screws, tape, exc. It takes almost no force to move a wood or glass stock. JMO.

 

[Patch700]

You are rite Bryan it shouldn't be lol.... As others have mentioned it is the details in the mock up that differentiate between an OK bedding job (one that is better than it originally was) and a very good one that as Alex mentioned has no stress points.

Key things such as having good clearance between the action studs (by wrapping layers of tape around studs to ensure they are perfectly centered) and the pillars , as well as having 2 points of reference that will set the height of the action ( one at the tang and the other where the barrel is nearest the fore end)

The tang area is going to give you the rear height and by wrapping tape around the barrel where it is nearest the fore end this will give you your front reference height... At this point as Alex mentioned the barreled action should sit where you want it and you do not need screws to hold it into the stock.

A simple dry run will confirm that the barreled action will stay put with no mechanical force required.

 

[Alex Wheeler]

A couple more tips, if you make your pillars fit your action screws tight, then they will center the action for you. Then ream them for clearance later. Its ok to use a c-clamp to get the action down into the stock. Sometimes if the inlet is tight it can be hard to get that mud to flow out. I like Marinetex grey as its thinner and easier to get to flow. Once the action is down it the stock take your clamp off. I take a measurement before from the bottom of the stock to the top of the action before and after I put the mud in so you know your all the way down

 

[bsumoba]

A couple more tips, if you make your pillars fit your action screws tight, then they will center the action for you. Then ream them for clearance later. Its ok to use a c-clamp to get the action down into the stock. Sometimes if the inlet is tight it can be hard to get that mud to flow out. I like Marinetex grey as its thinner and easier to get to flow. Once the action is down it the stock take your clamp off. I take a measurement before from the bottom of the stock to the top of the action before and after I put the mud in so you know your all the way down

Excellent Tips! Thank you sir. I am considering doing this way, but I can't help but think I am going to want to put light tension on the action screw stud using a nut.

I chose MarineTex for that reason that it is a little less viscous than Devcon and it matches my stock color ;D

Here is the rifle I am bedding by the way...338 edge. Action and scope is shared with my F-Open rifle. Just swap out the barrel and stock and its like a new rifle. I have another Bat M multiflat on order so I will have 3 stocks and 2 actions to do any combination I want.

 

[hpshooter]

I use 1/4-28 studs and to center the studs in the pillars I use sleeves made of 1/4" ID brass tubing that you can obtain form hobby shops. The tubing is very thin wall and it comes in telescoping sizes so you can set the clearance you want. In my case I use another piece of tubing and solder it 90 degrees to one end of the sleeve and use it as a "T" handle for removing the sleeves after cure. I find the tubing more precise than tape. Coat everything with release and you are good to go.

The tubing also makes a great sleeve to line the pillars up with the action screws if you install the pillars in a separate step. In my case I secure the action in the bedding with rubber tubing or Scotch 33 electrical tape as opposed to any thing that can exert force on the action or screws while curing.

This has worked well for 15 rifles using Devcon Steel and Kiwi neutral shoe polish for release, non have stuck.

As a side vinegar will clean up epoxy without resorting to Acetone or MEK and won't hurt stock finishes or synthetic stocks.

T W Hudson

 

['Freak]

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