.308 or .307 ???

BC · Post by BC » Mon Mar 04, 2013 5:01 pm

Pretty soon I need to have the .308 barrel on my rifle changed. There are quite a few barrels with a .307 calibre on the market. Does anyone know what the pros and cons are of these barrels.

Thanks

BC

Brad Y · Post by **Brad Y** » Mon Mar 04, 2013 8:40 pm

My barrel is a 0.298" x .3065" krieger. Im not a big fan of it- it produced alot of copper to start with and has been finicky with loads. One minute it seems brilliant, the next I scratch my head a little. Its going to be relegated to hunting and varmint duties soon. Next one will be .300"x.308"- supposed to be a winner.

johnk · Post by **johnk** » Mon Mar 04, 2013 9:18 pm

If you're talking about the .308 W calibre, I've got my best results from the larger diameters - a .300/.308 Kreiger & a Maddco, similarly generous. I was looking at the Kreiger only a week or so ago. I pulled it out after 5½ thousand rounds before I did Bendigo for the first F class teams. It still looks sharp & clean and was shooting perfectly before I retired it.

aaronraad · Post by **aaronraad** » Mon Mar 04, 2013 10:45 pm

BC wrote:Pretty soon I need to have the .308 barrel on my rifle changed. There are quite a few barrels with a .307 calibre on the market. Does anyone know what the pros and cons are of these barrels.

Thanks

BC

Great for swaging down projectiles and stressing thin jackets. I think it had a role to play when shooting FMJ military projectiles? If you're keen I think there is still merit in the German squeeze bore concept.

Triplejim · Post by **Triplejim** » Tue Mar 05, 2013 4:42 pm

Brad Y wrote:My barrel is a 0.298" x .3065" krieger.

The .3065" groove size worked well when we used ADI 144 which often measured .3072".

BC · Post by BC » Tue Mar 05, 2013 7:31 pm

My current barrel is a True Flite .308 and I am using the Sierra 155gr projectiles. I like this barrel but I was wondering if I can improve my scores with a .307 barrel and still using the Sierra 155gr.

Triplejim · Post by **Triplejim** » Tue Mar 05, 2013 7:44 pm

BC wrote:My current barrel is a True Flite .308

As a general rule for 30 cal 155g, we order our barrels in 307 4G, 3075 5R and 308 6G. (Lapping adds ~.0002")
The idea is to keep the length displacement of the bullet to within certain parameters.

jcinsa · Post by **jcinsa** » Tue Mar 05, 2013 7:50 pm

Jim,

what do your barrel codes 4G, 5R, and 6G denote ?

Thanks

John

Triplejim · Post by **Triplejim** » Tue Mar 05, 2013 8:01 pm

4 Groove, 5 R-form, 6 Groove have a read of
http://obermeyerbarrels.com/faq.html

.308 or .307 ???

.308 or .307 ???

Re: .308 or .307 ???