Bedding checker results

[DShortt]

So I recently bought the bedding checker mentioned in other threads. Using it, I've noticed significant movement when loosening the front action screws, but next to nothing when loosening the rear action screw.

Curious to see what others are seeing.

Thanks for looking.

 

[Justintime]

What position is your gun in when you are checking? My understanding is that your gun should be in a vertical position that doesn’t allow the weight of the barrel or stock to influence checker when you loosen each screw. Movement shouldn’t be over .002. Of course less is better. When I check my bedding jobs, I clamp the barrel to a high top table with the butt of the stock flat on the floor.

 

[DShortt]

I've been clamping the barrel in cushioned vice jaws near vertical with the stock up.

Just confuses me because every rifle checks the same. They're shooting well, so I didn't anticipate this result.

I didn't put the butt on the floor. Perhaps that's the reason. (?)
Come to think of it, that would put the recoil force away from the lug.

Well, crap.

 

[Justintime]

How much movement are you seeing?

 

[DShortt]

How much movement are you seeing?

Oh, it's unnerving. .035" to .040" on the front screw. .001" or less when loosening the rear.

I'll be re-checking things later now that it's occurred to me that I think I'm doing the test with the rifles in the wrong position.

 

[Justintime]

Good luck!

 

[DShortt]

Yeah. Just re-checked 2. I've got problems.

(SIGH.)

 

[BuffaloBill]

Before I bedded this one, it showed lots (about 40 thousandths) movement. After bedding with Marine Tex it showed less than one.

 

[LVLAaron]

40 thou is crazy. If it were truly that far out I would think you'd notice binding somewhere. BAT actions more or less need perfect bedding; with only 1 thou of clearance it doesn't take much to bind the bolt.

 

[AlNyhus]

Oh, it's unnerving. .035" to .040" on the front screw. .001" or less when loosening the rear.

I'll be re-checking things later now that it's occurred to me that I think I'm doing the test with the rifles in the wrong position.

Wirh that much movement, the problem area(s) will be pretty obvious.

 

[DShortt]

So, the stocks are bedded. No binding. Rifles actually shoot pretty good. Consistent? Well, consistently 1/2" or under? No. But that's probably me to be honest. They're rebarreled off-shelf actions with factory triggers and an owner who struggles with wind, mirage and form. I know that.
The stocks I see this in are not pillar bedded. I *think* I'm actually seeing compression but that's just theory at this point.
The fact that the screws don't seat and tighten up quickly tend to make me think that.

 

[DShortt]

Before I bedded this one, it showed lots (about 40 thousandths) movement. After bedding with Marine Tex it showed less than one.
View attachment 1684832

Wouldn't that position push the stock away from the recoil lug?

 

[AlNyhus]

One thing to mention when checking movement.

If it's a repeater, check it w/o the magazine spring. The upward pressure from the follower spring can cause quite a bit of movement.

Also, the direction of the indicator needle will tell you what's going on...high spotted, bottomed out recoil lug, etc.

 

[BuffaloBill]

Wouldn't that position push the stock away from the recoil lug?

Gravity would be acting on the chassis, pressing it against the lug, correct? Do you mean the force that the dial indicator exerts, pushing the forend towards the barrel? That creates a small error term I suppose.

 

[DShortt]

One thing to mention when checking movement.

If it's a repeater, check it w/o the magazine spring. The upward pressure from the follower spring can cause quite a bit of movement.

Also, the direction of the indicator needle will tell you what's going on...high spotted, bottomed out recoil lug, etc.

I suspect this is what is happening. It would definitely explain what I'm seeing. I was sure I was missing something but couldn't put my finger on it. I'll re-check this evening.

 

[SKWERLZ]

I suspect this is what is happening. It would definitely explain what I'm seeing. I was sure I was missing something but couldn't put my finger on it. I'll re-check this evening.

This is something I’ve wanted to check.
I think I have something I rig up to get an indicator on the barrel.

 

[DShortt]

This is something I’ve wanted to check.
I think I have something I rig up to get an indicator on the barrel.

There's a thread on the site about a 3D printed bedding tester available off EBay. IIRC AINyhus started it. I just got one last week, so I'm on the learning curve.

 

[LVLAaron]

FWIW: If you're bending the action, even a little, you should be able to feel it. Things should "bottom out" quickly. I have a rifle that's not perfect, but it's only out like 2 thou and you can tell when tightening the rear screw. It feels like you're crushing or compressing something, vs a hard lock up.

A comparison would be a good barrel tenon on a good action. The barrel snaps into place because things are straight, vs a clapped out factory remington that needs 200ft lbs because things aren't straight.

 

[DShortt]

So, just re-checked for movement without the magazine spring installed. And unfortunately for me, it's still there. I suspect it's the recoil lug bottoming out, or 'wedging' into the bedding is more accurate, but not sure.

I'm going to spend some time reviewing the bedding tutorials before doing anything else.

Maybe my 'bad days' aren't as much me as I thought.

 

[DShortt]

Curiosity question :

Has anyone checked a bedded Savage action with one of these testers?

If yes, what did you see?