Chamber differences

[RonS]

What is the difference between the 308 Palma and 308 Win chambers?

 

[Dans40X]

What is the difference between the 308 Palma,7.62X51 NATO & 308 Winchester chambers?

basically-
a couple thousands larger body diameter & a 1/2 degree difference in leade angle & length.

 

[Rustystud]

There is a .0035" difference between SAAMI a go and a no go gauge. There also are variables in the web area, shoulder area, neck diameter, and throat diameter and length. Pacific Tool and Gauge list 5 different 308/Palma Prints in the book of prints. 1. Winchester 308 (SAAMI), 2. Match 308, 3. Obermyer 308, 4. 95 Palma 308, 5. Bisley 150 (150 rule) 308.

Since FTR has started there are hundreds of custom 308 reamers throated to accomodate the 185, 200, 210, 215 Bergers all that have a .473" or greater bearing surface. and Non of which will fit into a short action 2.808" magazine box.

For those who reload a fat/loose chamber makes for additional working of the brass which is not a good thing. The oposite occures with to tight of chambers.
Nat Lambeth

 

[RonS]

Hey Rustystud, thanks for the explanation. I have a Savage Target action sitting around and I've been thinking of trying either F-Class and/or Palma shooting and figured I could use the same barreled action for both disciplines but switch stocks. So which of the 308 chambers do you think would suit both disciplines. Unfortunately I'm privileged to be able to shoot 600 yards on occasion but limited to 200 yards on a typical day. I would like some feed back on barrel length and twist with a heavy palma contour using up to a 155gr bullet.

 

[Rustystud]

Your Savage do the job on either dicipline. I prefer a heavy palma contour for FRT and a medium palma contour for shooting with a sling. International palma requires a 155 grain bullet. It works best in a 1:13 twist, tight bore (.297"-.298") A 1:12 twist can be used as a compromise. FTR has moved toward longer, heavier, higher BC bullets and they work better in a .299"-.300" bore. The tight bore and long bearing surface bullets cause pressure issues. With palma you will be using irons and 30+ inch barrel for a longer sight radius and added velocity. There are several FTR and Palma shooters who use the McMillian long range prone stock for both disciplines. The stock on Jeff Rorers FTR rifle once belonged to Kent Reeve one of the best palma shooters ever.
Nat Lambeth

 

[RonS]

Rustystud, again thanks for your input. I was thinking of getting the Savage Palma stock, I already have the Savage F-class stock but I will look into the McMillan stock.

 

[Rustystud]

You might look at the McMillian, Stockade, Whidden, Bernowsky, and Russo Socks.
Nat Lambeth