new wildcat -43 Express-

i did a few drawings (well shamelessly stole from the internet and changed the numbers on them) of the 43 express case

the 43 Express can be chambered into a 43 mauser chamber with only cutting a small (0.020" bigger diameter) shallow (about 0.130" deep) counter bore, i plan on working with this load still and getting some solid numbers for the cartridge and some load data with estimate pressures, im looking at getting quick load



here are some pics of the 43 mauser and 43 express case drawings (they both use factory 43 mauser chambers)

48862050637_e9730ab37b_z.jpg
 
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Evanguy.
.284 Win is within .013" in the web with a rebated rim that you won't have to enlarge the bolt face.

284-Win-ACFD04.gif


Depending on how much length you gain from expanding the neck and shoulder, you might make up most the 0.27" of the shorter .284 Win case.
 
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Thanks, dead meat.

In my case using the 300 weatherby winchester brass and the 300 win mag RP brass they are the same thickness.

Im sure different brands have different thicknesses though. But they should be pretty close as both are made from a 375 h&h case. The 43 express has lots of clearence in the neck area to allow for thick or thin necks. Its not what one would call a match chamber.


And Diopter, i already opened up the bolt face for a 375 h&h case. Also there is such a small shoulder to have to try and get it to head space off it. I liked like ease of using a belt. Easy to make feed from mag and easy to set head space with no reamer.
 
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i have some loaded ammo now, 20 rounds i also have another 80 brass ready to go i just need a .447 sizer
quick load estimate is pretty close with the charge vs velocity. my 53gr charge of h4895 gave me 1800fps QL says 55.5gr for 1809fps


49410422873_a3fbc6bb53_k.jpg
 
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That would be an interesting build. I looked into doing that before one day standing there thinking the 71/84 barrel looks like it will fit the large ring small shank long tenon ( oddball mauser receicer(more on it below)) mauser 98 receiver. And it did with threads cut 0.010" deeper and clocked correctly.

If the corrrect size barrel falls into my lap id build a 10.75x68. I would also build it with a .430 barrel if thats what i had.

This in metric is 11x62

Receiver used;
"Type VI, Oberndorf intermediate action
Action OAL: 8.750
Recvr screws, center to center: 7.835
Bolt body length: 6.165
Magazine length: 3.115
Receiver ring dia: 1.410, large ring
Barrel shank dia: .980, small shank
This type has a longer than normal receiver ring

I call this the Oberndorf intermediate action, as they are the only ones who produced it. Commonly encountered models include:
1903 Turk
1909 Peruvian
1935 Argentine
Oberndorf Commercial"

The Curio and Relic Firearms Forum July 14, 2003
 
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so i have gotten the ole Mauser out of the safe to play around with this a bit more.

i have 50 cases prepped and primed ready to load.

i got a lee sizer for .447" bullets
bullets are now all sized to .447 fixing the issue i was having with the .449 bullets and tight necks.

i took the best measurements i could for QL and got some predictions. i plan to witch to IMR 3031 from H4895

CQ is showing me i can possibly get 3000 lbs ME with a pressure of 26k using 55gr charge of imr 3031, it says id need 57.5 of h4895 and it would be 28k for the same ME

id like the max PSI to be 28kpsi ( this is saami spec for the trap door 45-70) this barrel is a 71/84 so its old and made for black powder might as well keep it low pressure. (the receiver is a large ring Mauser)

so the IMR seems to give me a little more wiggle room. i plan to load 5 cases of 51gr, 52gr, 53gr, 54gr, 55gr ,56gr and send them over a crony to see what im working with. i want to see 1940-1950FPS to give me the 3K ME
(QL says max load for imr is 56.7 that's 28k psi and 2000fps)


so the plan for this round is a medium game cartridge with 3000 ft-lb ME and low pressure for brass life and safety due to using a 134 year old barrel with smokeless. make brass super easy out of countless different brass head stamps

it came to be because i bought a unknown large ring for very cheap, and i noticed a 71/84 barrel i had sitting there would thread on. the huge rim wouldn't fit the mag and the bolt face so i went with a rimless version and the 375h&H case had all the correct measurements and a belt to help with shoulderless/rimless head space.. then before I knew it was i making up arbitrary numbers on ME ,FPS and pressure lol

ill get pics soon on the loaded ammo. i hope to get it loaded tonight.

also many thanks to JamesHarrison for helping me out
 
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