260 rem + custom chamber, help with oal ??

[HighGround260]

I dropped my barrel and action off at the smiths today to be fitted up for 260 rem and He asked if I wanted him to cut the chamber for a certain bullet and oal. I said sure since I'm using a rem 700 long action I might as well use up as much mag room as I can. I was going to have him cut it for 140 berger vld as I have some and that's what I was planning on using but then I got to thinking what if I want to run say 140 Amax or 123 scenar. Am I better off to chamber for the 123 and seat the 140vld deeper? Any advice is appericated this is my first build.

 

[Blank]

I just had the throat lengthened in my .260 Rem barrel, the 139gr Scenar touches the lands at 2.950" (AIAW), the 123gr Scenar jumps about .060" and still shoots lights out (1/4 to 1/2 moa). The nice thing is that sinse the 139 is one of the longer match bullets (base to ogive) I can seat any other 6.5mm bullet as long in the mag as possible and the bullet will take up as lite case capacity as possible. Do not worry about bullet jump, most all will handle it just fine including the VLDs, see Berger bullets recommendations for example: Berger Bullets Seating Method for VLD Bullets - A "Sweet Spot" with a Long Bullet Jump will give the best accuracy.

The 140gr Amax is similar in shape to the 139 scenar, seat a bullet .020" up from the neck shoulder junction and have your smith cut the throat so that it touches the lands at that length. With the availability being what it is these days you never know what bullet you end up shooting.

http://www.bergerbullets.com/effect...coal-and-cartridge-base-to-ogive-cbto-part-1/