Monday, 21 March 2011

New Rifle Build Part 1

I have finally got round to starting my latest rifle project, a light weight stalking rifle in .308. My last two projects were supposed to be light weight stalkers but turned out considerably heavier than I expected so this time it's definitely going to be light weight!

My donor rifle (pictured below) is an old Rem 700 (short action) which I picked up cheap from my local dealer. I would have preferred a short action Savage but trying to find a cheap second hand one is nearly impossible. The other advantage of the remy is availability or parts, although savage parts are rapidly catching up.

I've had the action for ages but I finally got the stock this weekend, a McMillan Lazzeroni Thumbhole in a green, black and grey marble finish. It's a very nice looking stock and feels, as you would expect from McMillan, very well made.

As you can see from the pic I've already tried the action in the stock. It fits nicely but I think I'm still going to epoxy bed it once I have the barrel fitted. I'm also going to have to relieve the barrel channel a little too I think.

The donor rifle itself as you can see was an old classic hunter style and looks as though it has very little use. When I had a look with a borescope the barrel looked almost new. I was tempted to leave it as it is for a while but then I though just because it looks new doesn't mean it's going to be accurate so I've ordered a Pac-Nor #5 contour 1in10 twist polygonal blank which hopefully should be here in the next couple on months. 

I've gone for polygonal because my last project was fitted with a polygonal barrel and whilst I haven't had it long enough to make any firm conclusions on first impressions I'm impressed. I am getting slightly increased velocities compared to what I should be getting according to the reloading manuals (taking barrel length into consideration too), accuracy is very good and fouling is minimal.The claimed advantages are as follows but as I said I haven't come to my own conclusions on some of them yet:

  • Not compromising the barrel's thickness in the area of each groove as with traditional rifling.

  • Providing a better gas seal around the projectile as polygonal bores tend to have a slightly smaller bore area, which translates into more efficient use of the combustion gases trapped behind the bullet, slightly greater (consistency in) muzzle velocities and slightly increased accuracy.

  • Less bullet deformation, resulting in reduced drag on the bullet when traveling through the barrel which helps to increase muzzle velocity.

  • Reduced buildup of copper or lead within the barrel which results in easier maintenance characteristics.

  • Prolonged barrel life.

  • As for the #5 contour, I could go lighter but then it would be getting close to the limit for cutting a 5/8 thread so I can fit my moderator.

    Anyway, that's it for now. More to follow on the build when I get the new barrel.

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