The Down Range Forum

Member Section => Down Range Cafe => Topic started by: Hazcat on December 20, 2007, 07:35:48 AM

Title: Need MilSurp Chamber Pressure help.
Post by: Hazcat on December 20, 2007, 07:35:48 AM

Hey guys and girls,

I would like to by an old Ishapore .308 (Enfield .303 re-chambered).  I like BIG old clunky stuff and boy does the Ishy fit that category! ;D

I really only want it if it will fire .308 Win as well as 7.62.

My problem is I have read that "YES it will fire .308 Win" and I have read "NO 7.82 NATO only."

Here is an article on it but I don't know how true this is.

http://www.surplusrifle.com/shooting2006/308vs762nato/index.asp

Does any one have a definitive answer? ???

Thanks!

Title: Re: Need MilSurp Chamber Pressure help.
Post by: Hazcat on December 20, 2007, 09:27:34 PM

I'm sorry.  Did I interrupt the coffee klatch with an honest GUN question?

Title: Re: Need MilSurp Chamber Pressure help.
Post by: gunman1911 on December 20, 2007, 09:44:37 PM

This may take a little research but I like a challaange let me see what I can come up with.

Title: Re: Need MilSurp Chamber Pressure help.
Post by: gunman1911 on December 20, 2007, 10:50:53 PM

Ok here we go as for .308 I would not do it as the . 308 has more chamber pressure than the 7.62 as they may have the same case dimensions but are loaded differently .Example: a load for 7.62 topped with  155gn bullet under 37.6 gr of VHT N 140  and a c.o.l of 2.800 is different from the .308 with the same components but 39.3 gr of the same powder. and a c.o.l. of  2.800 so it would raise thee chamber pressures well above that of the 7.62, but if the firearm in question is chambered in  .308 shoot all the 7.62 you can get you hands on. This information was not difficult to find in a reloading manual. But at 11:45pm it to cold to go out and reload I figured that if I can help you  why not you seem like a decent guy. Hope I helped :D

Title: Re: Need MilSurp Chamber Pressure help.
Post by: Hazcat on December 21, 2007, 07:00:47 AM

Thanks Gunman1911. 

I have looked up the pressures and have read both pro and con articles on the net.

The Con is as you state due to chamber pressure.  The pro side says that "Yes, NATO ammo runs around 50,000 and .308 runs around 60,000 but the chambers were proofed at those (higher) levels when manufactured." 

So you see where I am on this.  I was hoping some one here had proof of the chamber being proofed originally at higher levels or some definitive answer.

Title: Re: Need MilSurp Chamber Pressure help.
Post by: jaybet on December 21, 2007, 12:10:01 PM

Quote from: Hazcat on December 21, 2007, 07:00:47 AM

The Con is as you state due to chamber pressure.  The pro side says that "Yes, NATO ammo runs around 50,000 and .308 runs around 60,000 but the chambers were proofed at those (higher) levels when manufactured." 

Haz, I'm no expert but I work with engineers. If it's designed for ammo that generates 50,000 of anything, it will probably handle almost twice that without compromise.