Improving Accuracy with Bedding

PJ

Thanks for sharing your experience.
I believe the kids playing clay is called Play-Doh which is what I also used.
I agree this is one operation you can’t rush and you must be detail orientated.
I too felt satisfaction when my bedding turned out quite good actually and no physical lock between receiver and stock occurred.
Well if a physical lock did occur I still had one out. My research found an article of using the freezer. Glad I didn’t have to go this route.
One thought I did have while the epoxy was hardening is that if I did something incorrectly what was to stop me from redoing the bedding? Nothing and only some additional prep work would be again required.
Just happy to have done it correctly the first time as I hate doing anything over twice.


Ed

GWS

I have no experience with an AR but free floating a barrel in a bolt rifle is a must in most cases for accuracy. I believe by free floating the barrel the harmonics are not then affected from unwanted dampening.

Bedding actually accomplishes a few things.

It creates an exact fit of receiver to stock basically eliminating any loose play.
This should also help’s produce the same directional path reaction from recoil.

One thing not commonly considered is the affect of receiver flexing. Though some consider it minor it still can have an effect. Here you can also add a third pillar to help secure the receiver even more and reduce the flexing more.

Another area of focus should be the recoil lug if your rifle has one. Improper or uneven contact with the stop point on the stock can also have an undesired effect. Still yet is the attention to the tip of the recoil lug that has room to rock sideways. This can be eliminated by bedding the tip of the recoil lug to keep it absolutely stationary in relation to the stock. Another good point about bedding the tip of the recoil lug is that it allows removal and installation of the stock to the same location. This eliminates any settling shots required.

My first bedding job was done with my 10ML-II and what a difference it made when proper attention was give to all areas being bedded.



Ed

All I can say is:

Bedding the action is a must! Also, most 'factory' rifles cannot be properly bedded. This is because of tolerance stack mismatches between the various components. Now, the Ruger American has some very nice design features that greatly enhances the accuracy on a stock factory rifle. The Remington Model 700 rifle has some models that also have similar features.

Anyhow; I did a photo-essay on my 1st Custom 1022 build. In it, I describe how I made a pillar for the rear part of the receiver. I used JB Weld for the pillar. The JB Weld works great! I also used the Miles Gilbert Bedrock Glassing Kit. To tell you the truth ... I think the Miles Gilbert kit is a bit much for the glassing. It has all the stuff you need, but it can be done cheaper and more efficiently using stuff you can readily purchase at TAP Plastics.

I used to go to TAP Plastics a lot in my previous hobby of High Power Rocketry. There, you can purchase everything you need to do any kind of polymer or layup work.

For the mold release, some folks use neutral shoe polish. The oil that comes in the Miles Gilbert kit is junk in my opinion. It is basically oil. The best mold release is a high-end car wax. Just about anything that has carnuba wax in it will work. However, I have found that the Megiuar M8 Mold release wax really does fit the bill. Also, an 11 oz tub is pretty much a lifetime supply ... that is unless you do 100's of firearms per year.

For the clay, (this is also very important), I use the Blick Van Aken Plastalina Modeling Clay. This stuff works great. It keeps its plasticity under a wide range of temperatures. I have heard that play-doh works pretty well. The problem with modeling clay is that it is pretty difficult to scrape off. The best way to remove the modeling clay is to use plenty of acetone. Acetone will really remove the modeling clay!

As with most things, the most important part of doing this process is the prep. You need to properly inlet everything. Also, you will need to use plenty of that Scotch Blue Painter's Tape. You will need the tape to keep the epoxy away from all of the places you do not want it to stick too!

As when to peel that painter's tape? All epoxy-based systems have three (3) times associated with it. They have the following times:
1. Setup time, (this is the time where you can work the epoxy)
2. Hardening time, (this is the time where the system gets way too hard to work)
3. Curing time, (this is a long time. This is the time when the epoxy system is FULLY cured ... usually days)

You need to wait for the setup time, (usually 5-10 minutes for 1-to-1 epoxy, and about 1 hour for 4-to-1 epoxy) to peel away the tape.

The general rule is: The longer the time, the harder and stronger the result will be. Also, 4-to-1 epoxies are generally harder and stronger but take a lot more time to harden and cure than the 1-to-1 epoxy. Both JB Weld and the Miles Gilbert bedrock are 1-to-1 epoxy based systems. I have found that if you want the very best in dimensional and thermal stability, a 4-to-1 system is the best. However ... I believe the 4-to-1 is probably way overkill for firearms and firearm work. If you, for some reason, decide that you want to make a high performance / high stress aircraft, or missile systems ... then the 4-to-1 with kevlar or carbon is the ONLY way to go!

One of the better tutorials I have seen is the Glass Bedding a Remington 700 by the Brownells Corporation. Also, 6mmBR has a pretty decent tutorial on Stress Free Pillar Bedding. Now, one of the things these tutorials do not tell you is how to use that Blue painters tape to make sure all your lines are clean and to keep the epoxy resin away from the stock. Keeping the epoxy away from the stock is very important. First of all, the tape will give you clean lines, and second, having any epoxy flow into places where you do not will cause the stock to permanently bond to the receiver!!!

The other thing I have found is to use any of the following to thicken the epoxy, (I have used all of these ... for High Power Rocketry):
1. Glass micro-spheres (comes in the Miles Gilbert kit)
2. Cabosil, (pretty commonly used to thicken the resin)
3. Colloidal silica, (also commonly used)
4. Finely chopped Fiberglass, (yields a very strong polymer)
5. Zoltek finely chopped Carbon Fiber, (extremely strong and light weight)

Now, be very careful if you use any of the thickening agents. It is highly recommended that you wear one of those dust masks when using this stuff. However, using the glass micro-spheres pose the least health hazard risk. I have used the micro-spheres without wearing the mask. Just be sure to turn off any fans or anything that will lift the thickening agent into the air!

For the applicators, I use the tongue depressors, popsicle sticks and definitely chop sticks. They usually have a counter full of them over at your local Panda Express. The price is very good too... They are basically free! I usually grab a handful whenever I am there. I use chop sticks and bamboo skewers for a lot of my firearms work. Chop sticks work extremely well along, with those disposable cotton makeup pads your wife uses ... This combo works exceptionally well for cleaning the chamber of your bolt gun!

Also, it is very important to wear latex or nitrile gloves when handling any epoxy! The resin, and especially the hardener is hazardous to your health! Plus, the stuff does not come off the hands very well either.

To clean up... you need to do this immediately. Acetone is perhaps the best solvent to use to clean up any spillage of the resin or hardener. PJ mentions using keton as a solvent. This keton is called Methyl-Ethyl-Ketone here in the USA. You can get MEK here at Lowe's. MEK is a great solvent. It really dissolves resin and hardener like nothing else! Personally, however, I like acetone better.

If any of you have any questions, please let me know through this forum. You can also PM or email me.

Ken

Ok I will have to play devils advocate here for just a moment. I do agree with free floating and bedding an action makes SOME rifles more accurate. I have owned a few non floated rifles that would drive nails out to 400 yds. I had a Savage mod 110 in 7-08 bought in the mid 80's that was extremely accurate, I currently have both a Howa and Weatherby Vangard SII that are very accurate. The one common point on all of these rifles besides be factory rigs are they are not free floated. I had both the WBY and Howa floated and accuracy actually dropped off till I shimmed the fore end tip to put some upward pressure on the barrels. These three example are the exceptions to the rule for me but all three (no longer have the Savage) were outstanding before and after the jobs were done. Do I agree that most of the time floating a barrel and bedding an action make the more accurate sure but their are always exceptions to the rule.

I'm going to chase the devil around. I too have several rifles,model 70s,that shoot well without bedding or floating, they have a forend screw that has to be snugged up just right. I also have several that did considerably better when they were bedded and floated,these included model 70s. and Ruger 77s. so I guess it is some what rifle specific like load development.

Dan : Fisrst off those rifles in the video are just too heavy for hunting! What you say regarding the bedding floating issue is right on. With my pre '64 M70s I have found a very low tollerance for changing torque values applied to the three screws with the midle one being "looser" than the trigger gaurd or forend screws, the .220 Swift doesn't like the forend screw at all, it's not floated though. My Ruger M77s and my Win.M70 Featherweights have bennifited from bedding and floating. Since all have wood stocks the non-floated rifles are my fair weather rifles, I've not tried them in wet weather yet.   Another thing you mentioned,  is watching "hunters" sighting in their often expensive rigs with the barrel resting on the bags or rest instead of the forend the difference is quite noticable with an optical  bore sighting tool and unfortunately they haven't a clue, though some are willing to learn.

Ed your point is well taken. In my case I don't do one without the other,now I will have to give consideration to just bedding the reciever.

Ed: I'm sorry you had to let a rifle go under those circumstances.  I also believe in the 1 shot and drop philosophy and won't hunt with a rifle which I can't get to sub-moa. The only rifles which I will not alter are my Super Grade model 70s which fortunately with some careful torquing of screws and tweakingt loads I have achieved the needed result also I place a personal limit on range dependent on the rifle.