How much bedding compound do you leave in front of the recoil lug?

[Bart B]

Anyone thinking any stock fore end with a pressure point somewhere between it and the barrel will always have the same force and direction against the barrel needs to do the following.

Measure how much the bore axis moves relative to the line of sight in different shooting positions and different holding parameters. Easy to do and an eye-opener to most. No ammo required and can be done in your shop, front room or bathroom.

With plenty of clearance from the barrel to the fore end, the force against the barrel will always be zero.

 

[7magcreedmoor]

I bedded my savages with the barrel nut and barrel both taped for free float of everything in front of the lug. Also float everything behind the rear action screw, and both sides of the action (these are sporter actions, not the heavy target type).

 

[Canadian Bushman]

Anyone thinking any stock fore end with a pressure point somewhere between it and the barrel will always have the same force and direction against the barrel needs to do the following.

Measure how much the bore axis moves relative to the line of sight in different shooting positions and different holding parameters. Easy to do and an eye-opener to most. No ammo required and can be done in your shop, front room or bathroom.

With plenty of clearance from the barrel to the fore end, the force against the barrel will always be zero.

I guess this applies to those bedding in front of the lug?

Can you describe how you would measure the movement of the bore axis in relation to the line of sight in varying shooting positions?

 

[Bart B]

No bedding touching the barrel at all. Otherwise, it's not "free floating."

Yes, I can describe how to measure the movement of the bore axis in relation to the line of sight in varying shooting positions. But I'm waiting a little bit to see if someone else figures out how to do it. Gunsmiths and others often figure out how to measure all sorts of things on rifles. I've never read/heard of anyone else explaining how to do this. It's really quite simple if one thinks through what's happening and a procedure to measure it.

7magcreedmoor, on that Savage receiver, how much of its sides do you keep the bedding off of? I've never heard of anyone not bedding the complete sides of the receiver from the stock edge one one side all the way around its bottom to the other side.

 

[Canadian Bushman]

No bedding touching the barrel at all. Otherwise, it's not "free floating."

Yes, I can describe how to measure the movement of the bore axis in relation to the line of sight in varying shooting positions. But I'm waiting a little bit to see if someone else figures out how to do it. Gunsmiths and others often figure out how to measure all sorts of things on rifles. I've never read/heard of anyone else explaining how to do this. It's really quite simple if one thinks through what's happening and a procedure to measure it.

7magcreedmoor, on that Savage receiver, how much of its sides do you keep the bedding off of? I've never heard of anyone not bedding the complete sides of the receiver from the stock edge one one side all the way around its bottom to the other side.

I could think of a few ways but none that i would value over firing bullets at range.

Ive also seen many shoot from multiple positions and not match their drops up with their prone position drops. Heavier recoiling rifles makes this very obvious.

However, when you let me in on a procedure that you consider to yeild valuable results, ill promptly test my rifle thats bedded an easy 2" in front of the recoil lug, and my other thats bedded only behind the lug, and report my findings. Im never against gaining some more understanding.

 

[Bart B]

Shooting groups to see how pressure on the fore end that's contacting the barrel requires a human, rifle and ammo that shoots no worse than 1/10th MOA if you want to see a 2/10th MOA bore axis change from that external pressure.

Here's my method for fore end to barrel contact at the fore end tip......

1. install an optical collimator in the muzzle.

2. Zero the scope (at least 10X, more is better) reticule with its lower left hand corner barely touching the collimator reticule center so the smallest change can easily be seen.

3. Go into a normal bench rest position most folks use with the rifle's fore end and stock toe resting on something, then move around and notice how the scope reticule moves relative to the collimator reticule.

4. Do the same thing with normal field or range shooting positions and notice how much the barrel bends moving the collimator axis relative to the line of sight.

If the reticules don't move relative to each other, then the barrel's totally free floated. It's obvious to most that this method is better than any group shooting way.

To see the effects of a bedding pad under the barrel chamber area, first get a rifle so made and ammo that you can shoot into no worse than 1 MOA through 600 yards with 20 or more shots per group. Then shoot such groups at 600 starting with all the bedding in place, then after removing 1/2 inch of its front part and shoot another group. Such tests typically show vertical shot stringing shrink as more bedding's removed.

Barrels expand as they heat up. As they get larger in diameter in the chamber area across several shots, they bear harder on the bedding under them. That changes the barrels' whip parameter in the vertical plane. Not much, but very accurate rifles and ammo will show it if the shooter's up to the task. The chances of seeing it with most sporter rifles and people shooting them revealing what that bedding pad does is very small.

 

[7magcreedmoor]

No bedding touching the barrel at all. Otherwise, it's not "free floating."

Yes, I can describe how to measure the movement of the bore axis in relation to the line of sight in varying shooting positions. But I'm waiting a little bit to see if someone else figures out how to do it. Gunsmiths and others often figure out how to measure all sorts of things on rifles. I've never read/heard of anyone else explaining how to do this. It's really quite simple if one thinks through what's happening and a procedure to measure it.

7magcreedmoor, on that Savage receiver, how much of its sides do you keep the bedding off of? I've never heard of anyone not bedding the complete sides of the receiver from the stock edge one one side all the way around its bottom to the other side.

I tape the side rails adjacent to the magazine. Full contact on the receiver ring at front and as much of the back as can be had given the savage sear placement. I will take some pictures and post when I get home later.

 

[7magcreedmoor]

I tape the side rails adjacent to the magazine. Full contact on the receiver ring at front and as much of the back as can be had given the savage sear placement. I will take some pictures and post when I get home later.

The card just fits, tight at front and back ends. I read somewhere or other that you should guard against any "bridging" under the receiver when doing a bedding job. I taped the sides of the receiver for clearance just like you should make sure the magazine box in a Remington isn't pinched tight between the bottom-metal and the action rails. Can't say it definitely improves accuracy, but it sure hasn't hurt it any. Both these rifles shoot very well.

 

[engineer40]

The card just fits, tight at front and back ends. I read somewhere or other that you should guard against any "bridging" under the receiver when doing a bedding job. I taped the sides of the receiver for clearance just like you should make sure the magazine box in a Remington isn't pinched tight between the bottom-metal and the action rails. Can't say it definitely improves accuracy, but it sure hasn't hurt it any. Both these rifles shoot very well.

That's interesting. Did you shoot Before and After groupings?

Sometimes I get impatient. But most of the time I only change 1 thing, then do Before and After groupings... then label the target so I know what changed. This works good for even simple things, like torquing the receiver bolts, changing muzzle brakes, uniforming primer flash holes, different rifle holding styles, etc...

I'm always so curious what is affecting what. It's cool to see proof; even when the proof isn't want to expected or wanted it to be.

 

[Clay Target Guy]

I am not a gunsmith (nor do I claim to be) but this is how I bed my rifles.
I pillar bed (with pour in pillars) and skim bed the action. I bed the rear of the action and like someone else said leave the center section free floated. I bed under the front ring of the action. I tape off the bottom of the recoil lug (to keep from bottoming out after screws are torqued down). I bed in front of the recoil lug for about 1-1.5", if the rifle shoots like I want, great. If it does not, I can cut the bedding in front of the lug until it does shoot. To date, I have only had to cut 1 rifle in front of the lug.
I bed all my sporter weight rifles as well as my heavy barrels the same way (most of my rifles are sporter weight).
Here is a picture of a wood stock off of a Remington 700 I bedded.

 

[Canadian Bushman]

I tried to perform the test with a collimator in the barrel today but could not get it to sit still enough in the bore to trust and measurments of the test. Ill have to try to get another or come up with something else entirely.

 

[engineer40]

Is there an accuracy advantage of not bedding the entire action and leaving the middle free floated? Or is this a case of the law of diminishing returns? (Where you can most of the accuracy improvements from just doing the front and back?


I personally leave the last 1/8 inch of the rear tang area of the stock for the action to rest on. Then I wrap the barrel in tape a few times near the end of the forearm (to free float and center the barrel in the forearm). I then remove a bit of material in the stock all the way through. The only metal parts of the rifle that are touching the stock are the tiny bit of rear tang and the taped wrapped barrel.

I bed it all the way through; from 1/4 inch in front of the recoil lug to the end of the rear tang. The actions are very tight and so far have proven to shoot exceptionally well afterwards. But I'm always looking to learn more and maybe the extra effort I am putting in isn't worth it?

I build a small putty dam about 1/4 inch in front of the recoil lug to stop any compound from going further forward.

The rifles that do not have metal pillars I will also drill the receiver bolt holes larger on purpose and make sure those are filled with the bedding compound as well.

 

[7magcreedmoor]

That's interesting. Did you shoot Before and After groupings?

Sometimes I get impatient. But most of the time I only change 1 thing, then do Before and After groupings... then label the target so I know what changed. This works good for even simple things, like torquing the receiver bolts, changing muzzle brakes, uniforming primer flash holes, different rifle holding styles, etc...

I'm always so curious what is affecting what. It's cool to see proof; even when the proof isn't want to expected or wanted it to be.

I've never done a before/after test. This is just the way I bed them. Before doing my own I trolled the web for tips and keeping the middle clear came up somewhere or other. Having heard of folks having issues with remingtons if the mag box was tight it made sense to me to avoid any chance of pressure anywhere except the screw areas themselves. One of the videos I saw dealt with the Savage heavy target action with solid bottom, small ejection port and three bedding screws. On that one, the fella did bed full length from recoil lug to rear screw and left the tang floating, but said he does the standard sporter actions with their skinny flexy side rails as I have done. If I had a dud shooter, I might try bedding the sides to see if it helped, but so far they shoot just fine. I have three and parts are collecting for number four as I write this.

 

[Bart B]

A little history of epoxy bedding round receivers when it was first done decades ago.....

Remington 7XX receivers were popular in benchrest matches. They were cheap and did very well with 22 and 24 caliber cartridges shooting bullets under 100 grains of weight. Full contact epoxy bedding them with the barrels totally free floating was great for best accuracy.

Some of the high power match rifle shooters tried epoxy bedding their .30-06 chambered rifles built on the Remington 7XX receivers. Again, best thing for accuracy to date. For a couple hundred rounds.

Then fliers were noticed; not too bad but 1/4 to 1/2 MOA away from aiming point that top ranged competitors easily noticed. So they rebedded the receiver all over again. Same thing happened a few hundred rounds later. Those using Remington actions on their 30 caliber magnums rarely got 200 rounds down range before they started throwing fliers.

Some of the military teams tried a 2" thick recoil lug on their Remington action based 30 caliber magnums to resist the torque 200 grain bullets put on their barreled actions leaving at 2800 to 2900 fps. That helped for an extra hundred or so shots.

Then someone decided to copy what some benchresters had started doing with their Remington receivers; epoxy them in a flat side/bottom aluminum sleeve with cutouts for bolt and loading. That fixed the problem and the same epoxy bedding job on that sleeve lasted for a few barrels.

In the 1980's when really good bullets were available in 28 caliber, people shooting 7-08's with 140 grain bullets from barrels fit to round Remington receivers, the receiver stayed in place and accuracy stayed good. Same thing when people started shooting 155's from their .308 Win's in round receivers; all things held together.

All of which sort of ended up with the old rule of thumb that bullets heavier than about 160 grains not be used with round receivers if best accuracy is the objective. Mid Tompkins has championed that for decades; as have others.