Submitted for comments, the 5.7x45 CZ (5.7 CZ). This cartridge is based on a necked down and blown out 7.62x45mm Czech. The cartridge is designed to fit in micro-actions like the CZ-527 and Remington 799, as well as the AR-15. Ballistics should closely approximate the 22-250. Bolt face is the same as the 7.62x39mm Russian.

Comments are welcome

http://guntech.com/ammo/5.7cz.jpg


Cartridge : 5.7x45 Czech
Bullet : .224, 60, Sierra HP 1375
Cartridge O.A.L. L6: 2.260 inch or 57.40 mm
Barrel Length : 24.0 inch or 610.0 mm
Powder : IMR 4895

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.124% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-11.2 83 29.38 3090 1272 36715 8915 95.8 1.203
-10.1 84 29.75 3126 1302 37960 9029 96.3 1.185
-09.0 85 30.12 3163 1333 39247 9139 96.7 1.167
-07.9 86 30.50 3199 1363 40575 9245 97.2 1.149
-06.7 87 30.87 3235 1394 41948 9347 97.6 1.132
-05.6 88 31.24 3271 1425 43365 9444 98.0 1.114
-04.5 89 31.61 3307 1457 44830 9536 98.3 1.097
-03.4 90 31.98 3343 1488 46344 9624 98.6 1.081
-02.2 91 32.36 3378 1520 47909 9706 98.9 1.065
-01.1 92 32.73 3414 1552 49527 9784 99.2 1.049
+00.0 93 33.10 3449 1585 51185 9856 99.4 1.034 ! Near Maximum !
+01.1 94 33.47 3484 1617 52928 9924 99.6 1.018 ! Near Maximum !
+02.2 95 33.84 3519 1650 54717 9986 99.7 1.003 ! Near Maximum !
+03.4 96 34.22 3554 1682 56566 10042 99.8 0.989 ! Near Maximum !
+04.5 97 34.59 3588 1715 58481 10093 99.9 0.974 !DANGEROUS LOAD-DO NOT USE!
+05.6 99 34.96 3623 1748 60460 10137 100.0 0.960 !DANGEROUS LOAD-DO NOT USE!

Here's a size comparison:

http://guntech.com/ammo/3-22s.jpg

Sorry, what is the 7.62x 45? I am familiar with the 7.62x39 (AK 47).
Thanks.

A post WW II development that the Russians didn't want.

http://ammoguide.com/?catid=320

Bye
Jack

Used by the Czech VZ-52 rifle

http://mauser98.com/vz52.html

Brass can be formed from 6.5x54 Mannlicher-Schoenauer and is now available from Buffalo Arms.

Looks like a "go-getter" to me! :D

I'm hoping that a 223 can be rechambered without requiring a barrel setback, but in any case, it should be possible to rechamber 223 to 5.7 Cz

What will you use for the base case? I wasn't aware the the 7.62x45 available with a Boxer primer.

I think the 6.5 Carcano case would provide about the same size base caseand i know they are available with Boxer primers.

CA Dude

What will you use for the base case? I wasn't aware the the 7.62x45 available with a Boxer primer.

I think the 6.5 Carcano case would provide about the same size base caseand i know they are available with Boxer primers.

CA Dude


Buffalo arms is selling boxer primed brass cases for 7.62x45. The case could also be formed from 6.5x54 MS

http://www.buffaloarms.com/browse.cfm/4,770.htm

Looks very interesting...but brass ain't cheap.