TomG
posted this
21 January 2016
I built a long range Varmint match rifle similar to the one you are building. I used a Tooley MBR stock and had Mc Millan make it with heavy resin all the way through for rigidity. It's really heavy and the finished rifle runs around 19 lbs.
I chose the MBR for the wide forend and the extra length forend. It allows me to put my bipod way out which increases the length between the rear bag and forend.
I used a Remington mid length action and sleeved it with a 10 inch Davidson sleeve. The sleeve is flat on the bottom and has a 5 deg. draft angle on the sides so it goes in and out of the bedding without shaving any bedding material. I completely trued the action and bushed the bolt before glueing it in. I call it my poor man's Stolle action. It's got a 40 X trigger on it set at 4 oz.. The top has a dovetail that takes Kelbly rings.
I've shot full length bull barrels on it and others that tapered to .75” at the muzzle and never saw any difference in accuracy. In my opinion, the weight of the barrel has little to do with the inherent accuracy. I've worn out maybe 5 barrels on it and most were Hart, Lilja, Shilen and H&S brands. Chambered in 6 MM Rem. Ackley Improved it shoots the 215 gr. Tubbs into 1 inch at 300 yds. That's the average of 4 five shot groups and all shots counted.
I think that a heavy barrel taper shoots just as well as a straight cylindrical barrel and is a lot easier to handle. You will get less droop with a tapered barrel. When I had a straight inch and three eights barrel on it I built a support about 4 inches in front of the sleeve and bedded it into the stock. It was like a big scope ring spit horizontally to clamp on the barrel. It never shot any better with it as when fully floated. It's the quality of the barrel not the weight. I use a separate throater to cut the throat and the freebore dia. is .0003” ( three tenths) larger than bullet dia..
I never bed any of the barrel. I want it to always vibrate the same from shot to shot with minimum influence from the stock. I don't like to bed the reinforce end of the barrel because that is the part that heats up and expands in diameter. This can create tension when it does and can cause the action to raise up ( unseat in the bedding) slightly as it get hot. Never let the bolt touch the stock as well as the trigger. It will influence the vibrations. I once had a CB benchrest rifle that was acting up a little and found the Jewell trigger touching the stock. When I relieved it the rifle went back to shooting again. When a gun is properly bedded with a floated barrel it should vibrate like a tuning fork if you hold it by the wrist of the stock and then strike the forendl. If it sounds dull and doesn't hum, it's not bedded properly.
I occasionally switch barrels on this gun to fireform brass, etc.. I've found that I can remover the scope, remove the action and change the barrel back to the original and the gun will still be sighted in within one quarter minute click. That's tearing it down and reinstalling the good barrel and scope and it will not change point of aim more than a quarter inch at 100 yds. When you can do that, you know all the surfaces are true and the bedding is correct.
When I bed, use Devcon F1 or F2 aluminum Epoxy, I forgot which. I'm wintering in Tucson so I'm not near my shop. It has a low shrink rate and if you wan't to really get it close, you can do a second thin skim coat to take up for the initial shrinkage. I use alum. pillars under all action screws of 5/8” diameter stock. This makes the rifle not sensitive to screw torque as it's compressing an alum. pillar and not the stock material.
This is getting kind of long but I thought I'd throw out a few ideas on what I did that worked well for me.
Your mileage may vary.
Tom Gray