Recoil Bedding; Attempt on HMR

[Rflshootr]

The compressive failure strength of most epoxy resins is 10,000 psi. A common .25X28 screw/bolt (common to most actions), lightly lubricated, will exert slightly under 4,000 pounds of compressive/tensile force when about 150-inch pounds of torque is applied. This indicates that any good epoxy can handle compressive forces generated with tightening actions with hand tools applied to 1/4 X 28 action screws, provided adequate/uniform support under the epoxy. The problem then is soft plastic or wood stocks under the epoxy. The solution being using a non-compressible support, like aluminum tube (pillar) or column of epoxy.

If you torque to 150 inch pounds, you've already screwed up. No pun intended.

 

[ntsqd]

I think that the point being made was that at normal action screw torque the compressive force exerted is extremely low as compared with the compressive strength of the bedding material.

 

[nealm66]

Just don't give up. It's very rewarding when you get it right. Some good suggestions here and you'll eventually get it right. I think the biggest thing is when you get all that old stuff dug out is to sit the action in and see if you can tell where it might be having issues. I like to wrap some tape around the barrel to center in the channel and make sure it has clearance like was suggested I don't bed in front of the lug. It should be a tight and flat fit when you're done. Enjoy the journey

 

[General RE LEE]

Just don't give up. It's very rewarding when you get it right. Some good suggestions here and you'll eventually get it right. I think the biggest thing is when you get all that old stuff dug out is to sit the action in and see if you can tell where it might be having issues. I like to wrap some tape around the barrel to center in the channel and make sure it has clearance like was suggested I don't bed in front of the lug. It should be a tight and flat fit when you're done. Enjoy the journey

Thank you sir! I'll get it right. I've got 235 rounds down the bore of this 6.5 PRC. Hopefully I'll get it right before I hit 300 rounds lol

 

[nealm66]

That's a perfect cartridge to learn with. Just enough recoil to find the weak spots but not so much it could easily be shooting technique. It will be fun to follow your journey and extremely helpful for all of us including those that believe they have everything figured out as we can all learn new things.

 

[PopNFresh]

I use devcon. Can't remember which one

 

[nealm66]

Another good thing to learn with devcon being so expensive is how much to mix up to avoid a lot of waste. First couple I did I mixed enough for 3 rifles

 

[ntsqd]

All but one of the important numbers for Devcon Aluminum Putty are better for this application than the Devcon Steel Putty, and that exception is a tie. I've posted them in the past.

 

[PopNFresh]

but also make more than you need, running out 4/5 the through a job sucks significantly. throwing away extra is usually less wasteful than doing it twice.

 

[nealm66]

All but one of the important numbers for Devcon Aluminum Putty are better for this application than the Devcon Steel Putty, and that exception is a tie. I've posted them in the past.

Would you mind explaining a bit? This is a really good thread

 

[ntsqd]

Would you mind explaining a bit? This is a really good thread

Rather than distract this thread and open a whole new can-o-worms I'll quote myself quoting myself: https://www.longrangehunting.com/threads/best-bedding-material.285456/post-2347255 That thread is a good deep dive into the discussion of bedding material options.

 

[nealm66]

I remember reading that thread. I think I used the steel but I'd ordered it before that post. Will definitely try the aluminum in the future.

 

[cjl2010]

I'm in the minority I believe. We pay gunsmiths to perfect everything down to as small as we can measure and pay by the $1000's yet people decide they want to save $300 and marry that product to the stock. I'd rather pay for bedding and ignition than I would for gunsmithing.

 

[codyadams]

I believe some pictures of your taping job before installing the bedding material would help explain how you got your desired results if you have any ?

Pretty much all mine are done like this, unless the stock doesn't have pillars yet, then I usually drill the holes for the pillars, attach them with the action screws to the action with very light torque, and drop the whole thing in. Sometimes I put just the pillars in first, then the action bedding, just depends. This was just the most recent one. I carefully clean up the overflow with a wet Q tip while the bedding is wet. Let it cure for a few days. Final clean up is with a dremmel, cutter bit, and a steady hand.

For the Devcon, I go by weight, using an accurate scale. 1:9 ratio steel putty and harder.