Bedding material left in a rifle reciever blind hole. Happens far too often.

[AZShooter]

While it doesn't happen every time someone beds a rifle, it happens enough for me to remind others of this issue. Thought I'd post it.

Recently a veterinarian friend of mine who is very busy asked me to put a scope on his recently rebarreled and rebedded mauser. It shot groups that were large with some almost touching then others jumping to form another group. It screamed bedding issue to me. I tore it apart and with a bright light and magnification found epoxy in the bottom of the hole! (one of my friends who has also encountered this issue calls it the dreaded booger)

Ruger M77s and Mausers front action screw holes are blind. If bedding material gets into the hole the action screw will bottom out before the action fully sits in the bedding. Seems so simple yet I have experienced it enough to check a poor shooting rifle for this issue right away.

A similar situation can occur if the action screw is too long due to altered bedding so rifle sits lower in stock. Some grinding on the end of action screw is all that is necessary to solve issue. Been there a few times as well.

To date four gunsmiths have done this to some of the rifles I have had the unfortunate luck to own or shoot for friends. Two of these gunsmiths sell some of their customs for well over $10,000. It is amazing that is should happen at all, BUT IT DOES. Perhaps they are used to bedding receivers without blind holes more often they forget to check. Who knows.

Add this to your accuracy checklist

 

[Azrael]

Cure: take a hand drill with a 1/8" bit and carefully dimple the epoxy plug in as many places as you can. Chances are the remaining honeycomb will fail before you're done and the remainder can be picked apart with a dental pick.Run a bottoming tap through if you have one. Done. If they had any sense at all there would be grease on the threads.

Prevention: Use inletting pins screwed into the action when lowering the action into the bedding compound. Story writes itself from there.

 

[Canhunter35]

Prevention: Use inletting pins screwed into the action when lowering the action into the bedding compound. Story writes itself from there.

Does an inletting pin work on the angled screw of a m77 action?

 

[Azrael]

Never tried, but I don't see why not.

 

[J E Custom]

When I bed a rifle I take a screw with the same thread and grind the head the same diameter as the threads so it will pass through the stock action screw hole. Then I use one or two tubes of wire shrink rap on the screw that will just fit in the action screw hole in the stock (Longer so the end of the shrink rap ends up smaller when heated).

I also apply wax/release agent to the shrink wrap to make it come out easy after bedding.

The main purpose of doing it this way, It to align and locate the barreled action the stock radially and axially and to prevent bedding compound from getting in the action holes. I do this on both ends of the action and on every action whether or not it has blind holes because it also keeps the compound from getting into places that you don,t want with some actions.

It also helps guide the action down in the stock, helping distribute the bedding compound and removing any bubbles and also minimizes cleaning/reaming the action screw holes in the stock.

Just the way I like to bed actions.

J E CUSTOM

 

[AZShooter]

Agree on how to prevent it. Agree it is easy to remove if found. Too bad those "gunsmiths" that left the material in the blind holes are oblivious.

I would venture to guess there are a few rifle owners who never knew of this possibility who were driven crazy trying to solve the cause of their rifle's poor accuracy.

 

[codyadams]

Never tried, but I don't see why not.

I have tried it, and you can't just drop it in, the angle doesn't allow it to happen easilly. I have pillar bedded 4 rugers and bedded 3 others that already had pillars in the stock.

My best solution so far, is I put a small amount of plumbers putty in the action screw hole, just to plug it, not fill it. The rear has the pillar installed with a tapered head screw to center it, just snug, not tight. I have another tapered head screw with matching threads for the front action screw, that I used kiwi polish on for realease. I gently set the action in the stock with bedding material with the pillar not yet screwed to the action. Some bedding material sometimes gets around the screw hole, that is ok because of the putty. I ensure the pillar oriented properly, and screw in the tapered head screw until just snug, to hold the pillar against the action. I have my screw ground to a length that only requires one turn or so to snug up. I use electrical tape to tape the action into the stock, with wraps of electrical tape around the barrel at the forend to center and float it.

Once the bedding compound cures, I take the screws out, pop the action out, and clearing out the small amount of bedding compound from the front action screw hole is quick and easy, any that may have gotten in was not squeezed all the way to the bottom, as my screw hardly engages, and the compound is only setting on soft plumbers putty, and comes right out. Clean out the hole with a q tip and acetone, and it's still like new. For any bedding material inside the front pillar, I simply drill it out with a fitting drill bit. You don't want that contact on your front action screw.

Has worked well for me.

 

[Azrael]

Add pinched mag boxes to your list of things to check.

 

[AZShooter]

I have a long list Azrael which I keep in my documents. Some are sneaky, like front scope base screw bottoming out on barrel threads, another false tightness. Plus many more.

Thanks everyone for contributing.

 

[Azrael]

I have a long list Azrael which I keep in my documents. Some are sneaky, like front scope base screw bottoming out on barrel threads, another false tightness. Plus many more.

Thanks everyone for contributing.

If you've gone that far, why not post your trouble shooting check-list? You're bound to help someone.

 

[AZShooter]

Okay Azrael I'll list them.

First of all I am not a gunsmith but do much of my own work. I have many friends that come to me for help with their rifle's loads or a problem.

This list is probably incomplete but checking these items has helped fix some inaccuracy issues.

Often I encounter the obvious, the action screws are loose.
Action screws should be torqued to an inch pound value.

Check front action screw hole for bedding material or bottoming out

Leupold windage style rear base windage screws not tight

Ruger rings not seated properly in bases

Front scope ring base screw touching threads of barrel.

Imperfection in crown

Screw holes in wood stock too small, drill larger so sides of action screw won't touch

Bolt handle touching stock

Mag box must not bind

Recoil lug making contact in bottom of bedded slot
causing the action to sit off bedding

Front of trigger group must not touch stock

Trigger guard must not touch trigger

Uneven bedding--- tightening one action screw to see if the action pulls up at other end.

Barrel should not make contact with barrel channel. Due to some flexing some rifles required additional material be removed from stock.

 

[Azrael]

Much of this hobby/obsession is fueled by knowledgeable enthusiasts. Joe average has a guru or two who sorts his stuff out for him and even the gurus have their go-to-guys. By the time it gets to the gunsmiths the line between leading and being pushed is a little blurry. Heck some of them need to be dragged.