rufous
Well-Known Member
I will eventually need to rebarrel my 300 Win Mag big game rifle. I have had great success with the present Lothar Walther barrel but am considering options. I am thinking about possibly going with one of the polygonal 5R rifling types produced by Schneider, Border, Boots Obermeyer or 5C produced by Broughton. Supposedly they are easier to clean and may give higher velocities. I am not really looking for higher velocities (I just need to get the Barnes 180 TSX to go 3080 fps or the Nosler 200 Accubond to go 2930 to match up with my Leupold Boone and Crockett reticle) and premium hand lapped barrels clean up pretty easily in general anyway so I do not really see a great need for these polygonal rifled barrels but may go that route just to try it out.
I am also considering a Lilja 3 groove (supposed longer barrel life). Lilja lists as a regularly stocked item an 11 twist 3 groove in a #2 contour. I think an 11 twist would be adequate (according to the Greenhill Formula as downloaded from the Z Hat website if the bullet starts out faster than 2800 fps then it can be 1.55" long and still be stabilized by an 11 twist). The Nosler 200 Accubond is 1.495" long and the Sierra 220 Matchking is 1.49" long so both of those bullets should be stabilized by an 11 twist. In practice would an 11 twist suffice?
Then there is the question of contour. My current barrel is I guess about a #4.5 contour based off of Lilja charts. It measures 0.675" at the muzzle. I would like to reduce the weight of my rifle somewhat. It weighs 9.3# with the scope. The stock is a Rimrock synthetic. I am guessing that if I went with a Lilja #2 I would lose about 0.75# in barrel weight. But accuracy is very important to me and I wonder if I go with a lighter barrel whether or not I will sacrifice accuracy. With my current barrel I routinely am able to shoot sub 2" groups at 250 yards (today I put 6 shots into 1.8" at that distance). So should I stick with a #4 contour or can I get away with a #2 or 3 and still get similar accuracy?
I also wonder if any of you have had cera-kote applied to the bore of your barrel. If so how has that worked for you? Thanks for any advice you can provide, Rufous.
I am also considering a Lilja 3 groove (supposed longer barrel life). Lilja lists as a regularly stocked item an 11 twist 3 groove in a #2 contour. I think an 11 twist would be adequate (according to the Greenhill Formula as downloaded from the Z Hat website if the bullet starts out faster than 2800 fps then it can be 1.55" long and still be stabilized by an 11 twist). The Nosler 200 Accubond is 1.495" long and the Sierra 220 Matchking is 1.49" long so both of those bullets should be stabilized by an 11 twist. In practice would an 11 twist suffice?
Then there is the question of contour. My current barrel is I guess about a #4.5 contour based off of Lilja charts. It measures 0.675" at the muzzle. I would like to reduce the weight of my rifle somewhat. It weighs 9.3# with the scope. The stock is a Rimrock synthetic. I am guessing that if I went with a Lilja #2 I would lose about 0.75# in barrel weight. But accuracy is very important to me and I wonder if I go with a lighter barrel whether or not I will sacrifice accuracy. With my current barrel I routinely am able to shoot sub 2" groups at 250 yards (today I put 6 shots into 1.8" at that distance). So should I stick with a #4 contour or can I get away with a #2 or 3 and still get similar accuracy?
I also wonder if any of you have had cera-kote applied to the bore of your barrel. If so how has that worked for you? Thanks for any advice you can provide, Rufous.