Make it loose.. the new xlr's are loose with the mag tube being loose also.. they shoot great..

I have no clue on the silicone ..

 

M. L. McPherson in his book Accurizing the Factory Rifle discusses using RTV silicone as a bedding material between the forend and the barrel. He also recommends relieving the forend wood where it contacts the receiver and the barrel band or cap and fitting with glass bedding material in those areas. After the glass bedding dries, he beds the barrel in the barrel channel using RTV silicone and plenty of release agent. You should relieve the barrel channel substantially prior to bedding the barrel in RTV to allow the cured silicone room to provide a supple and soft gasket.

I have used this method on three 336s and it always has improved accuracy, sometimes substantially.

 

Thanks for the input - I don't understand bedding the foreend to the cap and receiver. The cap doesn't seem to be a strong enough mount to offer a stable platform to a bedded foreend. As for the rtv, do you just cut a groove down each barrel channel and seal, then rtv w/release agent. Any more info is greatly appreciated - thanks!

 

This is interesting since I have a 336c. Ive not got to shoot paper yet but would like to get it as accurate as I can without gunsmith assistance.
Daryl P.

 

The reason for the bedding material at the cap and the receiver is that it gives a perfect fit without applying pressure to wood/metal interface.  The whole procedure goes something like this:

1 Disassemble the forend/ mag tube assembly. It is a good idea to disassemble the receiver and butstock as well in case the epoxy bedding materials flows in unexpected ways. (Always use the gel type bedding materia to prevent unnecessary flow)

2. Apply masking tape to the receiver where the forend attaches.  The idea here is to protect the receiver from bedding material.  Apply masking tape to the outside of the forend cap for the same reason.

3. With a fine toothed file, remove a small amount of wood from the forend where it connects to the receiver and cap.  Remove just enough so that if you reassemble the rifle, it will move slightly back and forth.

4. Spray the receiver, barrel  and cap with as much form release as is reasonable.  (I use a ton)

5. Apply the gel type bedding material to the wood at the receiver and cap end. (Use the coloring aditives to make this look good) Before doing so, make sure to mask the stock so that any epoxy that extrudes from the fittings will not get on the wood.

6.  Install the forend into the receiver,fit the cap and loosely tighten the cap screws.

7.  Allow to dry for a couple of hours with the barrel and receiver supported.  Do not allow the rife to rest on the forend while the epoxy hardens. The rilfle should be right side up and horizontal during this process.

8.  After a couple of hours, cut off any extruded epoxy which  should have hardened enough to allow carefull trimming.

9.  Allow epoxy to dry overnight.

10.Remove the forend assembly and with a dowel that closely matches the barrel diameter, sand enough wood from the channel so that it will allow the passage of several pieces of paper once assembled. I use 80 grit paper.  The idea here is to remove enough material so that you can bed the barrel in enough RTV silicone in the barrel channel to provide a soft, supple gasket.

11.  At this point, I seal the barrel channel and any other parts of the forend that may still be unsealed.  I've used 5 minute epoxy to do this by mixing a small amount, smearing in the barrel channel with a finger, and then allowing the epoxy to dry for an hour. You should mask the outside of the forend before applying the epoxy or the silicone to prevent damage to the finish.

12  Place the barreled action upside down and horizontal so that you can access the portion of the barrel that lays under the forend without encumbering  this area.  I made a few wooden fixtures to securely hold the rifle in this position.

13.  Smear a thin layer of RTV silicone ( I use black heat rated silicone) into the channels.  By smearing this into the channel rather than just applying it straight from the tube, you will provide a better initial bond.  Then apply some large beads of silicone into the barrel channel.  You want to put enough material in so that it will extrude out of the forend when the forend is set in place.  (Oh, make sure to mask off the magazine tube channel)

14.  Spray the barrel and receiver with a lot of release agent.  There is no such thing as too much.

15 Set the forend in place and attach the forend tube and screw snugly in place.

16 After a couple of hours cut any silicone that has visibly extrued from  the barrel, forend juncture.  I use a sharp razor blade, taking care not to scratch the barrel.

17 Pull off the masking tape from the forend but do not disassemble.

18 Allow to cure for at least 24 hours.  You may need more time than this depending upon the temperature.

19.  Disassemble the forend and cut off any silicone that extruded into the mag tube channel.

20.  Reassemble the rifle.

Note:  I have reapplied silicone when I found that I had not put enough in the barrel channel and left gaps.  If you  do this, clean the cured silicone with alcohol and reapply the release agent before rebedding.

McPherson's book gives a much better description.  He also recommends bedding the mag tube at the same time in silicone but I've not had very good luck with doing this.  I use a neoprene washer at the mag tube retaining stud and call it good.

 

OK, related question. Have a 336, no following letter, 20" bbl with band behind the front sight. Had it 'apart' today. During reassembly I noticed that the front band applies cosiderable pressure to the bbl. Actually draws the mag tube toward the bbl about an 1/8th of an inch.

How do I relieve this what I consider 'excessive' downward pressure from the bbl? Is there a different band available or some other majic?

 

It sounds to me as though you need to remove some metal from the outer surface of the mag tube where in joins the receiver. To check this, disassemble the rifle put the mag tube in the receiver and press the tube towards the barrel. If you encounter resistance before the tube reaches its normal position, it is probably restricted by the receiver. I took a 1/4" wood dowel and wrapped one end of it with tape until I could press fit it into the front end of the mag tube. I put the other end of the dowel in a drill and spun the magazine while holding a bit of sand paper to the outside of the tube where in enters the receiver to remove metal and smooth the surface. Check the fit with the receiver often so you do not take off to much material.