How big of a mistake did I make???

[nefarmboy]

Ok...started loading my first 10 round batch. Using Winchester 7.62x39 new brass, S&B LR primers, Lee 3 die set on an "O" single stage press, .311 dia decapper, Lee case lube, and Lee Auto Prime. I lubed the case necks (inside) and cases (outside, careful not to get any on the shoulder). Ran them through the full length sizer, then primed them. After all were primed, I (should have done this before priming, I know now) decided to check the measurements against my Hornady Loading book for a standard case. This is what I found:

Out of 10 cases, 7 were 1.211", 2 were 1.212", 1 was 1.215". For comparison, I checked a once fired case from my mini30. It measured 1.219". The Hornady comparator case measures 1.216" (btw measuring my chamber using the Hornady LNL measuring tool and the 123 gr FMJ bullet I'll be using with this comparator said to insert the bullet just shy of the cannelure). To top it off, none of these measurments correspond to any in the book (1.198" to the shoulder and 1.289" to the neck, SAAMI says 1.252" Min 1.262" Max to the Datum).

I set the Lee die as per the instructions that came with it. That is, I screwed it in 'til the ram, fully extended, touched the die, backed the ram off, and screwed down 1/4 to 1/3 turn then tightened the lock nut. Did I screw it in too far? I can understand the .001" offset on 2 of 'em but .004"??? Not enough lube??

Do I have 9 good and one tosser or 1 good and 9 tossers??? I know experts can deprime a live primer but I'd rather not, yet.

Finally, the Hornady book says that the Mini 30 has a .308 bore. I thought it could take both .308 and .310.

 

[bobotech]

Older mini-30s had the 308 bore as far as I know but they switched to the 311 bore soon after because people were upset that they weren't able to shoot cheap commie ammo.

Slug your bore for the definite answer.

 

[Marlin 45 carbine]

beginning with the 189 series the M30 has a .310 bore and the new ones have a .308 bore (581 and newer)
I think you are OK to load those cases and it sounds to me as if you had the die set right. that chamber is fairly loose tolerance-wise so load 'em up and try a couple placed into magazine one at a time. if they shoot and eject well then you're good to go IMO.

should have added that if you are useing the correct powder then there is not enough case capacity to get you into any trouble - just make certain that the level of powder in the case doesn't come up past the mid-way level of the neck.
set OAL so you have some room in the magazine for reliable functioning and the case length is OK, I use a Lee trimmer about every 3rd sizeing. I haven't had much luck with Win brass myself. I use a light crimp with the Lee FCD.

 

[Remo-99]

7.62x39mm ammo specifcations have some pretty wide tolerances, and so do some chambers in cheap commie made ak's, sks's etc.
It's like that so that cheaply made ammo from china will fit a cheaply made russian rifle and vise-versa.
Just taylor make your ammo to suit your particular rifle, all should be fine.

 

[nefarmboy]

I'll be using Hogdon H322 powder and crimp to the cannelure using a Lee FCD. I knew it had to be short enough to load into the magazine. My biggest concern was excessive headspace. Didn't want to blow my new gun up!

I guess I'll finish the longest one first and see how it works then the 7 shortest and see how it goes.