reloading 30 30win and using gauges

[Slamfire]

Slam fire,

Instead of using lube, I seat the bullets so they lightly contact the lands and hold the cases against the bolt face. The case expands to fit the chamber correctly. After that, the comparator works great to set the shoulder with the sizing die.

That would not have worked for my Marlin. Marlin reamed the chamber such that the rifling for the throat is way down the tube. To have the bullet touch the lands, the cartridge OAL is a half inch longer than loading port ejection length, which is 2.5". Might have been able to single load the round, but if it no go bang, I would have had to remove the lever and bolt to eject the unfired round.

It is just easier to grease the case. I also don't have to consider drive in, where the firing pin actually pushes the case forward, seats the bullet deeper. If the friction between case and chamber is high, that will fix the cartridge forward of the bolt face, till internal pressures stretch the sidewalls.

By the way, it does not take much lubricant to make my system work. Just leave the sizing lube on the case, don't tumble it off, I have done that lots of times.

A drop of oil will work. Trillions of rounds were fired in delayed blowback machine guns that used a drop of oil on each round, so the case would be as friction less as possible.



this had an oiler on top




These rounds were manually greased. This mechanism was used by everyone in WW2. The British, the Germans, the Japanese (maybe the Russians) all had versions of this machine cannon on planes, trains, trucks, ships, etc. The Oerlikon was the most produced machine cannon of WW2. And yet, the principles of operation have been totally forgotten in the shooting community.




The Pedersen delayed blowback rifle used wax.



I fired tens of thousands of 308Win and 30-06 rounds with Johnson Paste wax rubbed on the outside of the case. I preferred Paste Wax to oil or grease when shooting my Garand or M1a in competition. Wax dries hard and if I dropped the round or clip, all I had to do is shake, blow, the dirt off. I highly suspect most, if not all, shiny factory brass case ammunition is coated in a wax. To keep the round pretty and bright for the customer. We all love shiney things, don't we? I have read in several sources aluminum cases are coated with a wax, so the case won't stick in the chamber. Under the temperatures and pressures of combustion wax turns to a liquid, and becomes a lubricant.

 

[Varminterror]

No need to waste time boring on the lathe to make your own comparators - Hornady and PTG make these readily available on the market for $30-50, and frankly, an hour of my time is worth a lot more than that to bother making my own. Frankly, a wrench socket can be used, or a washer and a nut if a guy is too cheap to spend less than the cost of a box of bullets for a proper tool - it’s a reference length, getting all worked up about the leading edge isn’t pertinent. But if a guy really cares enough about the ammo to be measuring their shoulder bump, just buy the tool and go to work.

To the OP’s question - personally, I have no use for case gauges, and despite loading now for 30yrs, loading for hundreds of cartridges, literally millions of rounds, and actively loading over 40 different cartridges regularly each year; I just don’t use them any more. I used them extensively when I was manufacturing ammo for sale, since it needed to meet minimum SAAMI dimensional spec to fit all chambers, so gauging was a QA step, but I load ammo for personal consumption now, and I load specifically for the corresponding rifle chambers which will consume the ammo. I don’t even use comparators for most of my ammo - I use bolt close method and rely upon tactile feel of the bolt dragging at the kiss length. Whether it ends up 1 thou or 3 thou bump, it’s kind of irrelevant, whatever the rifle says it wants is what I bump. I record a reference headspace length when I get the feel I want, but I try to avoid adding complication and cost where none belongs.