Quiz!!

[Brians356]

Can anyone identify these two cases? They are both once-fired in standard sporters (SAAMI chambers) and un-sized. The case on the right's neck slips into the case on the left's mouth with maybe a couple ten thousandths clearance, and seats snugly near the neck/shoulder radius without undue pressure.


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[Texas10]

I gonna guess 30-06 on the left, 6.5 Cm on the right. Any money in this?

 

[Wingnut00]

270 on the Left. 260 on the right. Just a guess.

 

[luckeeshot]

30.06 and .243 win biased on shoulder

 

[Prose]

30-06 and 7mm-08 is my guess

 

[LitLBoy]

30-06 and 7-08

 

[TIMO]

My guess is 30-06 and 284 Winchester.

 

[paperpuncher]

243 and 270

 

[Ringostar]

Trying to compare case length I would guess guess 270 or 280 on left, and 6mm Rem on right.

 

[Rsadams]

270 and 6mm rem...

 

[ShootDots]

I am going to guess, an 8mm Mauser and a 6.5 x 284.

 

[Brians356]

Ringostar was close, but Rsadams nailed it: 270 and 6mm Rem. Good show, Rsadams, kudos! (Honorable mention to Ringostar.)

Almost certainly 243 or 6 Creed etc would also fit snug in the 270, but the bodies would look different.

Fun, huh?
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[Dusty Stevens]

The body taper gave the 6mm away for me but i figured you threw a curveball on the bigger case. The 6mm rem is one of the all time greats

 

[Brians356]

Ignoring the bodies, you can eliminate combos where the fired necks couldn't slide snugly together. The difference between 6mm and .277 bullet diameters is .034". Assuming like neck clearances in chambers, the fired neck IDs will also differ by about .034" if the neck walls are the same thickness. Dividing that by 2 suggests neck wall thickness of slightly less than .017" would allow the smaller neck to just fit inside the larger. So assuming most OEM neck walls are close to .016" thick, any candidate caliber pair's bullet diameters need to differ by about .034". Can anyone think of any other two common bullet diameters that differ by about .034"?
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[Ringostar]

That’s why I threw out 270 or 280. Only .007 difference and not knowing actual neck thickness of your 6mm brass. I wasn’t positive that it would slide in. I’ve never owned or loaded any of the 3. Yes, it was a fun challenge. Edit: I guess that it also could have been a 244.