[No.4Mk1]

I am currently looking at wildcatting one of my .303 rifles. Its called the 303Epps. anyways there are three different action strengths for the .303.

smle 45,000CUP
No.4 48,000CUP
P14 52,000CUP

With this .303Epps you should only use the p14 action. There is lots of proper loading Data for this cartridge. The thing is if I shoot a proper size bullet to bore diameter will that increase pressure? If it does that could become an unsafe thing. How can you measure pressure generated by a cartridge? Is it a formula to do with muzzle velocity?
Is it some fancy equipment ?

madgunsmith seems to know abit about surplus rifles but any info would be great

Thanks guys
Geoff

 

[No.4Mk1]

I guess I left one thing out. On a .308 that measurement is from groove to groove. The .303 on the other hand is from land to land and the grooves are suppose to be .005 to .0055. So if you work it out the correct bullet size should be .313 or .314 depending on what size the barrel made it to. The normal .303 bullet is .311. So what I guess I'm gettin at is having a tighter fitting bullet in the bore will that seal better and raise combustion pressure? Or do you think that the .311 bullet grows enough to seal properly?

 

[madgunsmith]

A copper jacketed bullet will usually not expand to completely fill the bore.

Any time you increase the bullet diameter, pressure will increase. So be careful!!

For the .303 Lee Enfield, try the 180 grain Hornady .312" bullet. I've used this bullet in the 7.65x53mm. It shoots well for me.

The Oehler chronograph folks offer a piezoelectric transducer system. The thing works with the Model 43 chronograph. The transducer is glued to the chamber of the rifle and you can use this system to measure pressure accurately. But I know of no other way that the average guy can measure pressure accurately.

If I remember correctly, Ross Seyfried tested this system for Guns & Ammo magazine back in 1990.

Check this out:

http://www.oehler-research.com/model43.html

Mad

 

[No.4Mk1]

That was what I was affraid of ohh well we can all dream cant we..

Thanks Mad. u da man