I’m building a rifle using a B&C M40 stock. I have a medium Palma barrel, and there is a bit of contact where the barrel begins to taper down in front of the chamber. I’ve heard of people sanding in this area to relieve this contact, are their any tips/best practices I should keep in mind before I get started?

I’m currently doing this with a stock as well.

I taped the barrel. Installed action screws. Rear fully tight. Front lose. Emery cloth under the barrel. Using barrel as a guide, emery until it floats.

The more to remove, the slower the process.

I've did a couple , I used deepwell sockets [mechanic tools] - sandpaper wrapped around them .

Main thing is take you time easing the barreled action in and out for test fits often . It's easy to get going too deep in the barrel channel [under the barrel] so keep that in mind .

Start at the chamber area and work your way up .

Blue tape the edge of the stock where the barrel channel starts give it a lite coat of flat black paint the length of the barrel channel - that gives it a nice factory look .

I do as ol_mike, use deep sockets, adjust the socket size, and sometimes two layers of paper to get the fit right. Just stroke it up and down the barrel channel.

Go to the hardware store and pick up a few peices of dowelrod a couple of sizes larger and smaller than what your Barrel is. Wrap with sandpaper and it is done perfectly in no time. Have done dozens like this and works everytime.

I'm another that uses deep sockets. Go slow and careful and stop and check pretty often.

Do what outdoorag said. Keep going full length so as to stay with the barrel contour. Should have at least a business card thickness between barrel and stock. Even a little more won't hurt .

I also have used the deep socket method. Works well.

Another vote for the deep socket method.

You can even do the deep socket method to take off most of the cut, then tape the barrel with wide vinyl tape and do the sandpaper strip method with loose action screws to get a uniform gap.

Yep, one more.

I got that 30-06 in 1982 and I put a Bartlein barrel it to to convert to 280AI in 2018.

Clark, you lapped the channel smaller?

He must have run the lap backwards....

Yes, I made the mating radius smaller, so the action screws could secure it from rolling in reaction to barrel twist in recoil.

This is like when I make pillars, I make the mating radius undersized so they act as V block [force multipliers as my gun designer father called them].

Thanks, makes sense.

You tape the barrel , put rear action screw in tight - loose front screw - start at the barrel lug using strips of sand paper [how wide?] and move forward as barrel falls into place ?

Thoughts on bedding a small amount in front of recoil lug ? Anybody do it ?
I bedded my M. Coleman 22-250 with 1/2'' bed in front - shoots great .

Yep...sell it while you can and get something good instead.

Hint..............

Bedding in front of the lug...you are creating a tuner that changes harmonics. You may get lucky, may not. Barrel heat may change things a bit.

If you want a tuner that works, look at Harrells:

http://harrellsprec.com/index.php/products/tuner-brakes

These tuner brakes are dumb butt simple to tune a barrel in when you are wanting groups below .250.

Tuners are no where near rocket science, not even close.

Mike Ezel of Gunsandgunsmithing makes one hell of a tuner with no brake.

Tuners take a guy from shooting 3/8" groups to groups in the zero's and ones in hurry from hunting rifles.