I saw the article that mentioned Reloading for autoloading rifles, and some comments that seemed to not completely answer questions people may have.
It is important to note that reloading any caliber is a delicate undertaking for any gun you are about to trust your life with. The use of case gauges is an important one, but for the part-time reloader they are an expensive investment (~$30-50 each!). A much easier method is to test the cartridge in the firearm, to accomplish this, if you are working on either a progressive or single stage press, reload a few rounds as dummies. This means no powder, no primer, just case and bullet, and test them in the gun for fit and feed. Do not test fit live ammunition unless you are in a place where a discharge is allowed. (For most of us [that live inside city limits] this means a firing range). Numerous negligent discharges have resulted from people not following proper safety precautions, and even if you do this is never a guarantee that a mechanical problem won’t develop causing an accidental discharge.
If you have issues with reloading bottle-neck rifle cartridges, a likely fix is to use small base dies, these will size the brass down to a smaller size, and will size more of the case than a standard full-length sizer. However, the added working of the brass will result in earlier failure of the brass.
When it comes to [reloading] dies, I recommend against buying those made by Lee Precision, I have had far too many cases that were mangled, scratched, or had other defects resulting from the poor quality of Lee [brand] dies. One thing to be especially careful of when using Lee dies is the decapping pin will sometimes stick in the flash-hole, if you are working on automated loading equipment this will likely detonate the [fresh] primer when you go to seat it. (Most other manufacturers have switched to a headed [de-capping] pin, making this an extremely rare problem.). RCBS, Redding, and Lyman all make very good and sturdy dies from hardened tool steel, Dillon offers tungsten-carbide sizing dies for bottle neck rifle cartridges, if you have money to spend, the Dillon dies
will likely outlast your grandchildren, provided they have an adequate supply of decapping pins (RCBS, Lyman, and a few others offer free replacement parts, Dillon believes these to be a consumable item, and charges for them).
Regarding the differences between Military and Commercial cartridge specifications
You are absolutely correct, 5.56 and .223 have the same external case dimensions, but for the most part the similarities stop there. 5.56 has a SAAMI maximum working-pressure of 55,000 PSI, where as the .223 [Remington] maxes out at 50,000. If a 5.56 round is fired in a .223 firearm, then pressures are likely to be extreme, another key difference is the 5.56 chamber and throat dimensions are different, the engraving force will be reduced, and there is the potential for some gas leakage to the rear, a cumulative effect of this will be lower over-all pressures.
However, with .308 [Winchester] and 7.62mm NATO [the specification difference] is slightly the other way, but for different reasons. The .308 and 7.62mm NATO rounds are functionally identical, while there was some disagreement about the chamber pressures generated by some commercial ammo (SAAMI maximum some say is 62,000 PSI) and some military ammo (maximum pressure at 50,000), there seems to be a larger issue with the military chamber being longer, and thus being harder on the brass. If you are reloading, you can account for these differences with your selection of load and powder. That is one of the true advantages of reloading your own ammunition.
In all likelihood, anyone using a good quality military semi-auto in 7.62mm NATO isn’t going to notice any difficulty using commercial .308 ammo. But keep it in mind if you ever do encounter problems.
I hope all is well Jim, glad to see you are getting some more public exposure. It seems that the population at large is waking up, I had a co-worker hand me your book “Patriots” the other day. I giggled a bit to myself and told him I already had the book. Even my mom started asking me questions about the SurvivalBlog site, after hearing about it on the news. Lets hope all the people who are waking up to the unpleasantness we are all facing are able to head it off and clean up this mess before a lot of people have to get hurt. Sincerely, – Drew
JWR Adds: Part of the problem in discussions regarding commercial versus military cartridge specifications is that some of the specs are written in terms of pounds per square inch (PSI), while others are written using Copper Units of Pressure (C.U.P.) They are not the same scales!