what would it be? 243x57?

[biff's reloading]

if you had a 243win chambered rifle, and made it .200 longer, then necked down 7x57 brass and fireformed them, what would u have? dont know why i thot of it, and was wondering....

 

[Mountainsheep]

Biff's,

A 7x57 necked down to 6mm with a 26 deg. neck is the 6mm Rem.
If you fireformed it to have the 20 deg. neck of the .243 Win, that would roughly be thw 6mm Swift.
Dave

 

[Wild_Bill]

Hi just measure your reamer .200 down from the place where it cuts the base of the 243 chamber where the new base of the case will be. get the cases you want to use and also measure them i would get the reamer reground so the base is the correct dimention as it will be to big. Most of the 7X57 cases i have used are smaler in the base than the 243 cases so you have a size diference before you make the chamber larger at the base. David Kiff would regrind your reamer to suit your needs if you go that way. another option would be go with a 6mm Rem improved it will have a slightly longer neck and a 40 degree shoulder so the case capacity should be very close because a 6X57 is a 6mm Remington.

Cheers Bill
Australia

 

[biff's reloading]

the 6mm has a 26 deg shoulder, but the 7x57 has a 20 deg.... with the same OAL, but the 6mm loses .2cc to the 7x57 case??? 3.48cc for the 6mm and 3.68 for the 7x57. the 243 has the same 20 deg shoulder, and is wider at the base of the shoulder.... guess if i had a reamer cut, id probably be better off going with the 6-284. i was just trying to cheat the system /ubbthreads/images/graemlins/smirk.gif so the 243 stretched out .200 would be a 6mmAI without the 40 deg shoulder, since the body would be wider than the 6mm or 7x57....... dang, i thought i really had something big there!! /ubbthreads/images/graemlins/smile.gif

 

[Wild_Bill]

Hi if you already had a 243 reamer Dave Kiff will re grind it for around $60

I did know about the diferences but i was just giving you a basic comparison I believe it would be a great case you could also choose your neck length and mabe get between the 243 and 6mmRem i would look at a 30 degree shoulder and a neck length the same as a 6mmBR then you could use 6mmBR neck dies and seating dies like are used for the wildcat 6mm6.5X47 Lapua tou couls use RWS 6.5X47 Brass as RWS makes the best brass available and would get the performance of the 6mm284 as the cases would hold more pressure and not loosen the pockets as fast as LApua. The 30 degree shoulder will also fed very well in a long action you would have an awsome case on your hands you may require a body die but if you worked the case taper out you could use a 30-06AI or 280AI body die to resize the base of the case and bump the shoulder with a 6mmBR Type s bushing neck die then just use the 6mmBR seating die adjusted up to do that operation.

CHeers Bill

 

[Guest]

Hi,

According to P. O. Ackley, that would be a 243 Rockchucker.

C'ya, John.