Bedding the M1A

Bedding the M1A was not as bad as it seemed.  Using Scott Duff's excellent M14 Owner's Guide as a reference (buy it here), I spent some time looking at how the parts fit together, where the barrel hit the stock and where the critical points of support were.  I mostly followed the directions in Duff's book, with some minor and one notable exception, detailed below.  I strongly recommend reading Duff's writing on bedding before starting: he goes into much greater and superior detail than I ever will.  Primary benefit of this page are the pictures, something sorely lacking in the book.

I've had the opportunity to shoot the rifle several times since finishing this project and am very gratified by the results.  Prior to starting, the action was loose in the stock, a by-product of being stored for a long time with the trigger guard latched.   The gun, being an NM, shot well, but there was the occasional WTFDTSG, as well as a wandering zero and variation in POI as the barrel heated.  I was happy keeping them all in the black.  Since the bedding job, flyers are gone and I'm able to see a noticiable improvement in groups.  Zero and first/cold shot is dead-on and the shot doesn't walk as the barrel heats.  Granted, much of this is subjective as I'm shooting the gun with open sights and 40+ year old eyes, but I consider this time well spent.

Since first posting this page, there have been several very helpful comments and suggestions made.  Some I integrated into the text, but others I can't.  I strongly urge you to read the discussion of this page on BattleRifles.com before beginning.  If you have a comment or question, please send me a PM from BattleRifles.com or TheHighRoad.org; my username is larryw.  You can also send email to "larry" at this domain (dimark.com).   There have been many kind words and requests to link.  I am honored by these, and links to this page are always welcome.

Onward!

Before doing anything, taped up the stock and replaced the receiver and trigger group into the stock. Using these as templates, I carefully trimmed the tape so I could peel away the excess, revealing the area to be trimmed and protecting the rest of the stock from errant Dremel bits and dribbles of bedding material. Duff recommended using the receiver to scribe the stock for trimming, I took one step further.  Also, tape or protect every inch of wood that you don't want to get bedding material on; trust me, bedding goop will find the exposed wood.

Next I cleaned the liner assembly and roughened up the wood so I could permanently glue it into the stock.  Make sure to fill the gap in the front and clean out any bedding material between and under the tangs.  I used Brownells Acraglass Gel to glue this in as well as for all bedding tasks.  I chose not to glue the front ferrule in at this time.

 

Click on the pictures to see larger versions.

Working ever so slowly and carefully with my Dremel and a steel routing bit, I cut back the stock along the vertical areas where the receiver meets the wood, as well as the front and rear "horseshoe" at the top of the stock.  You do not want to remove all the material along the top of the stock as you need some wood to support the receiver as the bedding sets.  If you remove the material from the horseshoe forward, the receiver will sink into the bedding and you'll have a poorly bedded gun and a helluva mess to clean up. 

 

 

Top view of the stock showing areas that support the bottom of the receiver.

Using a sharp chisel, I trimmed the cut lines so they were nice and straight.  Key word here is sharp!

Note how I drilled holes into the wood to create small posts that will be filled with bedding compound.  It is critical that you work the bedding into these holes to make sure you have a good, solid foundation.  When ready to bed, lay a little compound down and work into the holes with sharpened Popsicle stick before you fill the rest of the area.

Scott Duff's book calls for a "Bedding Collar" to support the barrel while the compound sets.  Well, I didn't have a bedding collar, but 30Cal at BattleRifles.com had a great suggestion: use a coathanger instead.  Works like a charm!

Please read the comments by m14dan regarding this technique and fore-end pressure.  Other common items may apply the desired forend pressure: try clothesline or heavy gauge welding rod.  Keep after it until you find something that works for you.

You did buy a pound of non-hardening modeling clay, right?  In a bright color so its easy to see and clean up when you're done?  Don't do as I did and get the stuff that is impervious to any solvent known to man: picking this out of the smallest nooks and crannies is a pain in the ass.  Instead, you want to be able to squirt the steel with brake cleaner and have the clay wash away.

When applying clay, keep one thing in mind: if bedding compound (epoxy resin) can find a small crack or crevice to lock your stock and receiver together, it will.  As you can see, I filled the receiver, the area between the lugs, the recess for the locking lugs, the connector lock, anywhere goop can run.  Yeah, I know, more than I needed, but then I've never accidentally glued a receiver to a stock either and don't intend to start now.

Here's another shot of the clayed receiver.  Use a sharp craft knife to trim the clay to remove excess and give you clean edges.  Filling the receiver, between the legs, and generally going a bit overboard with the clay helps keep it where it belongs and is fine as long as it doesn't get in the way of the receiver properly seating into the stock

Note the shiny appearance of the barrel: that's release agent.  Apply a thin even coat of release agent on all steel parts that will even be near the bedding compound.  Let dry and apply a second coat.

Release agent is like ammo; you can never have too much.

This is one area I depart from Duff's book.  Duff suggests using the trigger group to clamp the receiver into the stock as the bedding compound sets.   Only problem is that means you have to leave the clay out of the locking lug recesses, greatly increasing the chance that you'll glue your receiver into the stock, turning your rifle into an overpriced club.  There is a way around this...

Some have reported deep (DEEP!) grinding marks on the outside of the receiver legs.   If your receiver is like this, make sure to remove the marks with a file or similar method before you bed the action.  Failure to do so greatly increases the chance you'll lock the action and stock together.

Note shiny appearance of the steel meaning there's release agent applied.  Release agent is good!

Clayed the bottom of the bolt catch.  Large blob on top of receiver was just to provide support and keep everything glued together.

You did apply at least two thin coats of release agent, right?

Clay the horseshoe to create a dam that will be filled with bedding compound.  Easier to add more clay than needed, than it's to clean up the overflow of bedding after its hardened.

That's if you're not cleaning up the wood chips that result from gluing everything together and having to forcefully separate the receiver from the firewood that once was your stock  You can always buy a new stock from Fred's.  Or do it right.

And the front of the stock.  As the Op Rod, guide and spring are removed from the barreled action, we can build this area up to control the flow. 

If you need a smoke or pit stop, now's the time to do it because you're about to get real busy. 

Mix up a good sized batch of bedding compound.  In the Brownell's kit, I made one that was 3/4 a "blue scoop" of epoxy and 3/4 a scoop of hardener.  Add a little coloring to match color of stock and mix well.  Don't whip air into bedding as you don't want voids.

Some like to bed in stages, first doing the vertical areas and letting everything set, then going back and doing the horizontal areas.  I chose to do it all at once.

Turn the receiver over and butter along the angled top rails of the receiver; fill this area in.  Next fill all horizontal wood areas that you prepared, starting with the drilled pillars.  Fill so there's about 1/8" of bedding material over the top.  Next, do the vertical areas: same drill.  Air bubbles are a bad thing.

When that's done, carefully insert the receiver into the stock and press down to seat into the stock.  Using masking tape firmly secure the stock and receiver together.  Don't wrap too tight, you don't want to crush the receiver into the bedding.  Just firm.

One reason I like the Brownells bedding material is it cleans up with alcohol.  Carefully go around the receiver wiping away any excess that has squeezed out.  Make sure you don't wiggle the receiver in the stock. 

Go grab a beer or three, because you're done until the compound is fully set.

When set (you know because the excess material in the mixing tub is rock hard), turn the gun over, support the stock wrist and barrel near the front band and using a hammer and wood dowel or brass punch, beat on the bottom of the receiver.  It will take some effort to separate the parts, so work slow.

Trim all the excess bedding from the stock using a Dremel, steel router bit and plenty of patience.  Pay attention to the mag well, rear of the receiver near the horseshoe and the front near the barrel.

Next we bed the trigger group.

Picture shows areas that were Dremeled and will be filled with bedding compound

Trigger group from the rear, already clayed and painted with release agent.  This is really the only area that will see direct contact with the bedding compound.

Make sure to apply release agent to the front ears of the trigger group.

From the right. 

More clay than needed, and in areas that probably won't see any bedding compound, but better safe...

And from the left using clay in areas that probably won't need it.  Note that the hammer is cocked and the safety is engaged (back).

Using another section of coathanger, make a U shaped section, about 1" long that is about 1/4" between the legs, as seen to the left edge of the picture

Butter the wood and insert the trigger group.  Swing the trigger guard until its about 3/8" from closed.  Do not lock it down, you want to have it sit a tad high to apply clamping pressure once everything is set.

In this picture, the tape was peeled away for clarity, and only after I used an alcohol soaked rag to wipe up all of the excess goop that had squeezed out.  To cut the amount of grinding, use a sharp craft knife to trim away any compound that squeezes out, especially in the mag well.

Insert the coathanger U into the hole in the safety and trigger guard to keep this 3/8" gap.  This will allow the trigger group to properly clamp down once the compound is set.
Picture of the top of the stock once done.  I may go back and skim bed to clean up the minor voids, such as the one you see at the end of the horseshoe, but only if I get real fussy about this as it won't affect performance.

One comment that was made on BattleRifles.com was with regards to bedding the front of the receiver, where you see the tangs.  I didn't do that, but may at a later date.  As of the writing of this, I have 250 rounds through the gun since bedding and the improvement is noticable: I don't think I need to bed the front, but if I were to do it all over again, I probably would.  I'll add pictures and details if this new knowledge forces me back into the shop to do it right.

(Note: it did, see below).

From the right.
From the left.
Bedded trigger group.  Note the channel that was cut in the middle of the rear section of the bedding.  If you don't have this, the trigger won't have room to move when you pull: no click, no bang, no joy.

Trim excess bedding with Dremel and steel router bit, clean clay and release agent (isopropyl alcohol works pretty well) from steel and lube.

Let everything set at least 24 hours before you clamp the trigger group down solid.

tn-DCP_0295.jpg (26907 bytes) The finished product. 

Before you shoot the gun, you need to make sure the hammer doesn't follow the bolt.

Verify the gun is unloaded.  Cock the bolt, pull trigger and while keeping the trigger back, recock.  Release trigger and dry fire again.   Do this three or four times, making sure the hammer falls each time.  If the hammer follows the bolt down (the hammer already dropped before the trigger was pulled), you'll need to redo the bedding for the trigger assembly to ensure complete engagement of the sear.

tn-DCP_0317.jpg (51381 bytes) The Second Round

"Interesting you didn't bed the front of the receiver."  Words that ate at me: if you're going to do a job, do it right. 

So, back off comes everything and out come the pins that hold the Op-Rod guide.  I found gently grabbing the roll-pin with some dykes and levering it out was the easiest way to remove the pin without damage. 

Same drill as before, fill every nook and crevice with clay.  I decided to skim bed the previous bedding job to remove any small voids at the same time, thus the clay on the receiver legs and around the bolt catch.

I don't think bedding the front is something I'd want to do at the same time as bedding the rear and top rails; FWIW, doing this as a second (or third) step is my recommendation.

tn-DCP_0318.jpg (49860 bytes) Front of stock showing clay dam.  You want to make this dam so that the very front of the receiver butts up against it: you do not want to have the bedding agent supporting the barrel. If you do, don't worry, you'll just have some extra work grinding this out so the barrel is floated.

Clay at rear will mate with the clay in the receiver to create a pocket that will be filled with bedding compound.  Work slow until you get these two areas to mate up and seal properly.

You did apply at least two thin coats of release agent to all steel surfaces, right?

Fill area to top of rear dam with bedding compound.  If you're going to skim bed, now's the time to apply a thin coat to the areas you want to hit.

I clamped everything together this time with bungee cords instead of masking tape.   Worked well, but now there's a ding in the stock that I need to steam out.

tn-DCP_0320.jpg (49104 bytes) This is what it looks like fresh from separation.  You will need to spend a good amount of time with a Dremel relieving certain areas.  I reassembled the receiver, applied a thin layer of clay to the front of the stock and inserted the barreled action as far as it would go.  The indents in the clay told me where to remove material.

Work slowly, only removing a minimum of material.  Reapply clay, insert action and repeat process until everything fits together properly.  Once that's done, put a thin coat of clay around the channel for the Op-Rod guide and spring, work the action several times and verify clearance.

Latch trigger group and confirm hammer doesn't follow bolt.  If good to go, carefully tear apart and clean. 

From here on out, you'll robably need to use a long punch/wood dowel and hammer to get the action out of the stock every time you strip the gun for cleaning/tweaking: this is a good thing.  :)