Home Forums Hunting & Shooting Gunsmithing Whats your preferred bedding compound? Any tips for a first timer?

I picked up a new to me Montana 270 from the 24hr classifieds, on my first quick range trip it shot just under 1” for the first 3 rounds, now I taken it a few times my 5 shot groups are closer to 1.75” to 2' with the same rounds.

When I torque the action to 45 lbs it did not feel like the action was tight. I also could not move the magazine box, after removing the stock and trying again the mag box is now free. I am thinking of bedding the recoil lug, should I also bed the entire action?

How far do you up the barrel do you go?

Whats your preferred bedding compound, release agent?

Do you at a pressure point at the end?

Any tips for a first timer?

Here is what my before is..

I use an engraver, the vibrating type, to spall up the existing bedding.

This is a Kimber Mountain Ascent. I used Foredom carbide carving burrs to carefully remove the factory bedding, which was painted and partially hydro dipped.

great write up, thanks

Are you dissatisfied with that accuracy? Seems "minute of deer" to me.

It is minute of deer but I think the action could fit better which would make it shoot even better. Besides it is time I learned to do my own bedding.

Marine Tex grey and Kiwi neutral shoe polish for release agent.

Brownells Acraglas gel and paste wax. I bed the front action ring and about an inch and a half of the barrel, free float the rest of the way. Be sure the magazine box is free and there is clearance around the action screws. Invest in some long bedding guide screws to keep the action straight as you set it into the stock. I then use clamps to seat the action into the stock and bedding compound.
There are many other methods that work but this works for me. I normally do 20 to 30 bedding jobs a year.

Devcon 10110, and kiwi paste wax.

Devcon 10110 and Johnson's paste wax...

And have wd40 with q-tips handy for clean up.

An outstanding product, but overkill for bedding due to cost and high viscosity. It is often difficult to get perfectly complete bedding jobs with it in shops that run to the cool side because it is stiffer than most epoxies.

I apply it on the action and the stock before assembling to avoid the issue, which makes estimating the required amount a bit tougher... far from a bad choice though.

Very ordinary epoxy at a premium price...

Marine Tex is my current favorite. And gray is the only one to use as the white is actually for gel coat repair and significantly more brittle than the gray.

Heresy! Complete heresy!

Have used JB Weld, not the five minute kind, and Johnson paste wax. Worked fine. Tried the Miles Gilbert kit from Midway. It does not get rock hard. Thought it was ratio, but several attemps gave the same results. Maybe I got a bad batch, but why try again when there are many good choices.

I've had the same experience with the Miles Gilbert kit and I was very careful with the measurements. Thought it might be the micro-balloons. Nice kit as far as the accessories go, but the epoxy itself is sub-par.

Really like the Pro-Bed 2000 kit from Score High Gunsmithing.

Acraglas Gel and Brownell's release agent.

Hornady one shot case lube for realease agent.

Devcon aluminum and Brownells release spray

I'm using the last bit of Micro Bed that I have on hand. As far as epoxy kits specifically marketed to rifle loonies and smiths, it was the best IMO. I have some Hobby Poxy 2 I can fall back on, and some powdered aluminum to add to the mix. I've used it before and the stuff is a bit runny, but it'll harden nicely.

Score high Pro Bed 2000 , I live in Albuquerque and go pick it up at his shop, it is the best product I've used period . I Bed 30 a year at least. You can even mill it!

I have used acraglass gel on numerous rifles with good results but on the last rifle i bedded i was out of acraglass and used regular JB weld with Hornady One Shot case lube as a release agent. It worked well and I would use it again.

I used to use steel bed from Brownells. Now I use standard JB Weld on the last 15-20 and it works very well for a good price.

Please name an epoxy you cannot mill...

I always run a wrap of masking tape around the barrel at the forend of the stock to make sure the barrel stays centered in the channel. Keeps it free floated too.

I would go with the one that has the most amount of working time and lets you bed your action at your leisure. So far Probed has the most amount of working time and it is not even close , not to mention that it is noncritical when mixing. Great Stuff

:

You could not give me Acraglass or Acraglass Gel

That stuff worked great. Too bad it's no longer available

Yes


Not necessary, but if you do, no farther than an inch or so.


Acraglas GEL (green box). Lots of work time, sets up slowly, can be dyed brown or black. I use Johnson's Paste Wax because it works great and I had a can when I did my first job. Kiwi Neutral Shoe Polish also works and is cheaper.


No. IMO pressure points are a factory kludge around poor bedding.



Use at least two light coats of release agent to be sure it gets everywhere. Be on the lookout for areas where epoxy can make a "hook" to lock the action in. Bed the REAR of the recoil lug, not the front, sides or bottom. It makes the action much easier to remove and you don't want any chance of the action teetering on the lug. Let is rest on the bottom of the action.

Acraglass jel is forgiving and if you follow the instructions pretty fool proof. I've tried several and am going to use Marine Tex on my next one.

Marine Tex is favored by most pro's including McMillan and the military units that build the upper end tactical and competition rifles they use. Kiwi or a good paste wax makes a great release agent. Devcon works in a pinch but it doesn't have the compressive strength of Marine Tex gray. I think they like it mostly because it has a high tech sounding name. Avoid any release agents that leave anything visible on the surface or it will show up in the bedding. For precise results with Marine Tex we use a gram scale and mix it by weight. When mixing by weight, the ratio is 6.3 parts resin to 1 part hardener. I'm a stickler for precision in everything I do.

Old Willys, The bedding shown in your picture looks pretty good. I would test it with a dial indicator to see if it's stress free. Place the complete rifle horizontal in a padded vise by the barrel upside down. Stick your indicator base on the barrel and your indicator tip on the stock near the swivel stud and zero it.



Loosen the front action screw and it moves less than 1/2 a thousandths (.0005) then I would leave it alone. Bedding done correctly will not move at all. We check ours with a 1/10 indicator and they rarely move more than a 10th (.0001") if at all.

To answer your other questions I prefer the barrel fully free floated from the lug forward.

Devcon markets dozens of epoxy mixes... some have quite a bit higher compressive strength than MarineTex.

Here are some of the particulars for the common Devcons.

Aluminum 10610 (8,420#), Cured Shrinkage .0008 in./in. -- $61
Steel 10110 (8,260#) Cured Shrinkage 0.0006 in./in. -- $44
FasMetal 10780 (12,700#) Cured Shrinkage .0093 in./in. -- $85
Wear Resistant Putty (WR-2) 11410 (9,800#) Cured Shrinkage 0.0005 in./in. -- $62
Ceramic Repair 11700 (12,700#) Cured Shrinkage 0.0022 in./in.-- 3 pound pack is $169
Bronze 10260 (8,540#) Cured Shrinkage 0.0010 in./in. -- $95
Stainless 10270 (8,400#) Cured Shrinkage 0.0010 in./in.-- $83
Titanium 10760 (15,200#) Cured Shrinkage 0.0010 in./in. -- $120

MarineTex Gray (13,000#) Cured Shrinkage reported to be 0.0001 in./in -- 12 ounce can $35

Most of the comparable strength epoxies are not suitable due to shrinkage, chemical susceptibility or cost. The only one of those that exceed Marine Tex (13,000#) is the Titanium mix at (15.200#) but still shrinks a bit more than MarineTex. Applied thin it really isn't an issue. It is a pain to use and spoils in the can in just a couple months. The working time is very short and it's really stiff. It is $120 a can.

I've used different bedding kits. Only a couple of times I've had issues. Both were with Brownells release agent. Though many times it's been ok too. Now I use car wax. The issue I've had with Brownells release agent was that it didn't release everywhere. Maybe they just had a bad batch, I don't know. I use acetone to clean the barreled action before I add a release agent (after it is thoroughly dry).
I like gel best because it's easy.

Other beginner tips if there's any bedding material oozing out because you've used too much clean it up before it hardens.
If you're bedding to a plastic or man made material be sure that the surface is clean and rough.
If you're bedding to wood, be sure the wood is clean and nothing but bare clean wood, unless you want to add steel screws (I've never)
I like to 'gouge' out behind the recoil lug so that much of the recoil area is bedding material. Rough is your friend.
I will sometimes put electrician's tape on the barrel from about 2" or 3" in front of the recoil lug to the end of the forearm. Then bed the entire fire arm. The electrician tape is removed and the barrel is free floating. This will seal the stock and make it stiffer. - depending on the application. Otherwise per advice on 24, I will coat the barrel channel with spar varnish.

Several points should be addressed here...

Acetone is used to clean surfaces you want to stick to the matrix agent whether it be epoxy or whatever... Why degrease something to apply an agent to keep it from sticking? It reminds me of nurses waking up patients to administer a sleeping pill???

NEVER use car wax as a release agent!!!!!!!!!!! It has a ton of silicone in it and it is very difficult to get rid of if you ever do any finishing/refinishing. Fisheyes are a major pain.

Barrel channels should be sealed EXACTLY the same as the finish on the rest of the stock.Spar varnish is a wonderful finish but if it is different from the rest of the stock it can and will cause issues. It has been addressed repeatedly here...

You work in measurements of ten thousandths?

You listed the commercial quick-cure formula details, why not use the industrial formula numbers? Hint, they are very similar to MarineTex and all are serious overkill.

Lot of respect for you Sitka, BUT I'll disagree with you.

1. I'm bedding a Mauser98 barreled action. The rceiver had dirt, grease and gunk in the areas of crevices- behind the recoil lug etc.

This 'material' need d to be removed or there could have been other areas that would take the brunt of the recoil.

2. I use a lot of 'release' agents. The only release agent I've ever had trouble with is Brownells blue release agent that comes in their kit.
Talk about fish eyes....

3. I used to finish my stocks with boiled linseed oil. The barrel channel got the same treatment. I put on many many coats.

There's been a lot of poo hooing regarding oil finishes. I stopped using linseed oil, Tru-oil etc. due to this critique.

I'm not sure that I'm right on this one, but I've followed advice from several people on the campfire that recommended Spar Varnish in the barrel channel.

Question: "If you were bedding a 700 stock or other factory stock with an opened up barrel channel, what would you use?"

I'm bedding this Mauser action in a fiberglass stock. I'll paint the stock. Would you be ok with Spar Varnish in the barrel with this?"

On the next wood stock (last one a couple of months ago too) I'll do I plan on sealing the stock with Spar Varnish and finishing with a rubbed oil finish. I think that Spar Varnish without the oil would work fine. Ok with you?

Finally, it's difficult to address every scenario in a short reply.

BTW, I used Hornady's case spray 'One Shot' for a release agent this last time. It worked well.

I appreciate your reply and I don't mean to be condescending or critical. I've been bedding stocks since the early 60's, but I do not know as much as many on the fire, probably that includes you Sitka Deer.

I understand removing chunks of dirt and hard grease before bedding, but I would not characterize that as "degreasing" so much as cleaning it.

I have seen fisheyes many times and have used Accraglass release agent quite a bit, especially a number of years ago, but I do not recall ever seeing them when using Accraglass. I do know car wax is horrible for them.

Oil finishes are just fine when used where and when they make sense and are applied properly and treated appropriately.

Spar varnish is another very good finish type... but the key to the barrel channel is getting the channel sealed just like the rest of the stock. If the stock is sealed poorly, (for example with an oil finish and the channel has a different but good coat of spar varnish) atmospheric water will move in and out of the stock more readily than the barrel channel. Most foreends are cut with rising grain and with added water can and will bend into the barrel as the outside swells. The problem is differential absorption and you can seal the barrel channel too well.

Try to keep the finish as close to the same as possible.

Sealing a fiberglass stock is best done with epoxy if the gel coat has been cut through.

I did not bed my first stock until 1965.


ETA: No insult taken nor intended.