3 groove Barrels

[FEENIX]

I know a long dead thread but while researching my "situation" I came across this and figured I'd ask here.

Had a 30.06 rebored to .35 Whelen, 3 groove, factory Rem ammo is fine but factory Federal caused serious pressure problems. It was suggested to me it might be a tight bore so I slugged it.

Also, Rem bullets measured .356, Federals, .358.

Lands and grooves are equal width, the reborer stated .349 bore and .359 groove diameter, meaning .005 groove depth.

When slugging the bore the measurement I got across from one groove to the opposite land is .349. Add .005 for the missing groove depth and I come up with a groove diameter of .35.

Am I correct or have I missed something?

Here's a sketch I made.

I have a 30" SS Lilja 3G 1:8" #6 contour barrel on my 270 AI and don't have any problem with both factory ammo and handloads. My current accuracy load 1s 2993 FPS suing 175 Matrix VLD. Extremely please and very easy to clean as it hardly fouls.

I have 27" SS Lilja 3G 1:9" Sendero contour on my .30 Lara and have fired 40 factory ammo thus far without any issues. No handloads yet.

 

[RevJim]

I had a Lilja 3 groove, .224, 8" twist made up into the 224 TTH. This was several years back. it shot extremely well, was not a fouler and preferred the 75gr Swift Scirocco. I shot a big hog up close ( neck shot) and it chilled his doo-doo post haste! I didn't shoot it enough to hurt it and later traded it off. It was my first and only 3 groove and I was impressed. Good luck.