Bedding a chassis gun

[audiopro74]

[Bullets&Whitewalls]

I always thought the idea behind the MDT stuff was not having to do that. Don’t they claim that on the site?

[longrange1]

this raises a lot of questions for me...

first what make/caliber of gun/chassis are we talking about? custom? factory?
have you reached the point that YOU can shoot better than your gun can?
do you hand load? if yes where are ESs or SDs at on your hand loads?

theres more but these 3 should be more than enough to answer your question.

[audiopro74]

this raises a lot of questions for me...

first what make/caliber of gun/chassis are we talking about? custom? factory?
have you reached the point that YOU can shoot better than your gun can?
do you hand load? if yes where are ESs or SDs at on your hand loads?

theres more but these 3 should be more than enough to answer your question.

[baih777]

Make one trip.
shoot it first with match ammo.
Which savage model did you buy ?
I have a few savage rifles. Only my Stealth will shoot factory Hornaday 140 match in a .05 moa group at 100yds.
I have to reload for the others. Or it's 2 inch group at 100 yds.

[ar15barrels]

Put an indicator on the chassis so that the indicator is reading deflection of the barrel.
Stand the gun up so the butt is on the table and the muzzle points to the ceiling.
Loosen and tighten the rear action screw and watch the indicator.
If the indicator is moving more than a couple thousandths, the chassis should be bedded.

I have yet to find ANY chassis that can pass this test.
My bedded stocks move less than a thousandth.
Unbedded chassis usually move between 50 and 150 thousandths.
I have seen chassis that bend the reciever so much that the bolt binds in the receiver.

This video shows the gun horizontal but I get better test results with the gun vertical.

[ar15barrels]

People like to believe that, but actual testing of receiver deflection shows otherwise.

[ar15barrels]

Competition shooters normally bed their chassis because they want them to shoot as good as possible.

[Mike402]

I've got an FN SPR that used to sit in the original A1 stock that was bedded and a reliable .5 moa gun. I switched over to an XLR Evolution and groups went to 1 moa consistently. I called XLR and they said doesn't need to be bedded, need to redo load development, work on my technique with chassis, blah blah blah. Could never get it to group like before. I ended up bedding it myself with JB Weld at the two action screw contact points. Doesn't look like a professional bedding job, but restored accuracy to its former state. I would just do it regardless for ease of mind.

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[ar15barrels]

I've got an FN SPR that used to sit in the original A1 stock that was bedded and a reliable .5 moa gun. I switched over to an XLR Evolution and groups went to 1 moa consistently. I called XLR and they said doesn't need to be bedded, need to redo load development, work on my technique with chassis, blah blah blah. Could never get it to group like before. I ended up bedding it myself with JB Weld at the two action screw contact points. Doesn't look like a professional bedding job, but restored accuracy to its former state. I would just do it regardless for ease of mind.

Your empirical data must be wrong because the manufacturer said it does not need bedding...

[MissiontoMars]

Very interesting! I never would have thought to bed a chassis.

[smoothy8500]

People like to believe that, but actual testing of receiver deflection shows otherwise.

Is the deflection due to the inconsistency of the receiver machining dimensions more than the chassis machining issues?

[ar15barrels]

Is the deflection due to the inconsistency of the receiver machining dimensions more than the chassis machining issues?

Most common reason is for the uneven support of the reciever due to the V-block design implemented in most chassis.
It's simply not possible to get support behind the rear action screw when you have no contact in the middle of the bottom of the receiver.
So with the tang unsupported and hanging about 1/2" to 3/4" behind the V block contact points, the rear of the reciever gets bent down as the rear action screw is torqued into place.
On trued receivers with a snugly fitted bolt, it's common for the bolt to bind after the rear action screw is tightened.
The solution is to bed the reciever so that the bedding is supporting the reciever as the action screw is tightened.

Even without an indicator, you can wrap your hand around the forend and over the barrel and feel the barrel moving when you loosen and tighten the rear action screw.
This is the result of the receiver being distorted.
It's upwards of 1/8" of barrel deflection on some chassis.

[longrange1]

personally id shoot the gun as is and not worry about it until you feel you have out grown the rifle...ive owned 6 chassis'd rifles none are/were bedded and all did/will shoot in the 2s and 3s.

the big problem bedding it is if you decide you dont like the chassis or want to up grade it will be hard sell...if you decide you love the chassis after shooting it for awhile then bed it.

[audiopro74]

..ive owned 6 chassis'd rifles none are/were bedded and all did/will shoot in the 2s and 3s.