# Progressive vs Case Trimming



## ScottChapin (Jul 7, 2010)

I'm finally going to get serious about reloading and will get a progressive press. Although I will eventually reload rifle cartridges, my focus is on feeding my 45 auto habit. I am trying to figure out how case trimming comes into play with a progressive press.

My understanding is that you should trim a case after it is resized, since it will lengthen during that process. You should probably clean the primer pocket at that point too...right? How does that fit into a progressive operation? Certainly, you don't remove the shell after the depriming/resizing operation, so what do you do?

Also, how should I set the crimp? Should I just set the die to seat on a factory loaded round? I don't even see that a factory round is crimped. Is the crimp that slight?


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## Steve M1911A1 (Feb 6, 2008)

Cases that have been through a .45 ACP chamber will not normally need to be trimmed.
There's not enough pressure involved, to stretch the case or make its metal flow.

Check your cleaned, once-fired and range-pick-up cases for proper length, trim them only if it's required, and then don't think about it again.
Your .45 cases will split long before they'll ever need re-trimming.

Rifle cases are another matter.
They should be checked right after cleaning and re-sizing, every time they're fired.
But most of them won't need trimming anyway.

It's easy enough to keep a length gauge right by your press, and to measure rifle cases quickly between steps.
It's a pass/fail operation.
Trim only the ones that fail.

Your crimp depends upon your caliber, and upon the bullet you're using.
All .45 ACP cases should be _taper_-crimped, not roll crimped.
Do that with a separate, dedicated, taper-crimp die, at the last station of your press.
The .45 headspaces on its case mouth, so a roll crimp will not do the job properly.

Many rifle cartridges should also be taper-crimped.
For instance, I use jacketed bullets in my .30-'06 loads, and they are all taper-crimped.
Since the .30-'06 cartridge headspaces on its shoulder, its _lead_-bullet loads should be roll-crimped into a cannelure or a lubricant groove (that is, a circumfrential groove in the bullet). Certainly, loads for tubular-magazine rifles, for instance the .30-30, should all be strongly roll-crimped, to keep the bullet from being shoved back into its case from recoil.

Does all that help?


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## ScottChapin (Jul 7, 2010)

Thanks Steve. yes, that helps a lot. It confirms what I guessed was the way it works. When you check for case length, do you use the nominal dimension for that case, or is there a plus tolerance?


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## Steve M1911A1 (Feb 6, 2008)

I don't worry about tolerances, when gauging cases.
But I admit to trimming rifle cases just a little short, so I don't have to trim them again for a few iterations.

I like the resized case to be easy to slip into the (flat-plate) gauge, leaving, ever so slightly, a tiny gap between case mouth and gauge edge.


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## rex (Jan 27, 2012)

Steve is right,there's no big fuss for straightwalled pistol rounds.I do crimp separate from seating,it just makes more sense to me.

Expand the mouth only enough to start the bullet without shaving lead or jacket,then crimp a 45 to an outer case mouth diameter or .470/.469,you're done.You really aren't crimping the case,you're ironing out the flare to start the bullet.If you use mixed brass,set your crimp on mid spec brass like Winchester,then the thicker brass like Federal or Starline will slightly crimp the bullet,but the thinner brass like Remington will still be cool.If you run into bullet setback consistantly,your sizing die is too large and need a tighter one.You can see where the bullet is in cases I run through my RCBS dies,the case is slightly wider at the bullet than the rest of the case.The case tension is what needs to hold the bullet,not the crimp for auto pistols.

If you're seating and crimping at the same time,back out the die and screw the seat plug in to seat a bullet long,and screw it in slowly until the bullet is seated to it's recommended OAL.Then back out the plug or remove it and screw the die in until it touches the case.Give it 1/4 turn and crimp,then measure.Sneak the die down until you get .470 mouth diameter.Set the lockring,reinstall the seater plug and run it down to the top of the bullet.Load the next at this setting and doublecheck the diameter and OAL.The OAL may come out a thou or so long,so just tweak the seater in a touch,but I've never had the diameter change.Same principle doing both in seperate dies,sneak down where you want and lock the setting.

I forgot Steve mentioned the case gage.If you don't want to buy one do the plunk test in the barrel(s) they will be used in.I have one thats made out of a cylender of aluminum,mimicks the barrel's chamber.If it isn't min spec,there's no guarrantee it will chamber in yours.Most chambers are reamed to handle any ammo you buy but some are on the tighter side.Good replacement barrels can come on the tight side and require finish reaming,but factory guns usually only use tight chambers on their match versions.If it drops in and slides back out,you'tr good,and the case head should be flush or slightly shy of flush for length.


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## Steve M1911A1 (Feb 6, 2008)

Yeah. I never used a case gauge for .45 ACP reloading. I used only that "plunk test."
(However, rifle reloads need a little more care.)

That "plunk test" was especially important for reloads used in competition. If the cartridge didn't slide right in, sit flush with the chamber mouth, and then slide right out again, it was rejected to the practice-only pile.

BTW: Weird as it seems, .45ACP cartridges used in a properly-set-up 1911 do not need to headspace at all—not on the chamber mouth, anyway. They really "headspace" on the extractor groove. They are trapped between the chamber wall and the extractor hook, and that holds them in place quite sufficiently for the firing-pin's strike.


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## rex (Jan 27, 2012)

I was going to mention headspacing on the extractor but didn't want to throw too much at once.

Assuming you have good headspace without measuring it,this is how I judge OAL on the plunk test.With the barrel locked full foward in the slide,look for a gap at the breechface and rear of barrel hood when held to a light,this is they're relationship when the round ignites.If there's basically no gap,the hood is the longest the round can be.If there is a gap,that is your max headspace,so anything flush with the hood has room for crud.I always stay a little short because of that.

I find some truth to Will Shuemann's idea of barrel cleaning belief,alot of barrels are ruined by overcleaning.Unless the gun is going to be put up,my bore doesn't get cleaned every time I shoot it,and sometimes the gun just gets a quick outside wipedown afterwards.All depends on the load you're shooting really,Bullseye and light loads of 231 always trashed my guns but other loads can take twice as long to get there.All my guns are in at least great shape,with some being like brand new out of the box even after a few thousand rounds.


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## ScottChapin (Jul 7, 2010)

Checking the case OD at the mouth makes great sense for crimping. Thanks for that tip!.

When I was in scouts, many moons ago...LOL, some NRA competition shooters (.22 rifles) said they cleaned their barrels once each year. They claimed modern lubricants negated the need for cleaning and that cleaning threw of the point of aim.

As long as the powders in 45 ACP rounds is not corrosive, I wonder about cleaning too frequently as well. I am thinking of cleaning with an ultrasonic cleaner to avoid barrel wear.


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## rex (Jan 27, 2012)

The ultrasonic is a good idea and I've heard good about the Outers FoulOut.Watch anything with amonia like strong copper solvents,you can only leave them in so long or they will attack the surface of the bore.

I wouldn't say the NRA shooters were completely right but close.Modern lubes do cut down on the work required to clean,but they don't negate it.They were correct about the first shot after a cleaning being different,that's how it became known as a fouling shot.No matter what,there is residue left behind after patching the bore dry to shoot so that first shot burns it off.After that you're shooting to the potential of the barrel,and successive shots slowly dirty the bore causing accuracy to slowly diminish.The bore's material,finish,dimentions and ammo's material and dimentions all factor in if the bore gets trashed fast or not.I still believe in breaking in a new bore,but I don't obsess about it since I don't have a $400 barrel to shoot benchrest matches.If I do break in a barrel that doesn't instruct you how to,I shoot a few rounds of jacketed and swab it out,repeat a few times and then run 10 and clean.When a box of 50 is gone I just let it rip.If I intend on shooting lead I run 100 or so first to hopefully burnish down any flaws.

A good bore and properly fit bullet won't foul out fast,but things aren't always ideal.Some of these shooting schools have you go 1K rounds without being able to clean it,that is what it should be able to handle easily for a combat weapon.


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## Steve M1911A1 (Feb 6, 2008)

I always used lead bullets, even in competition, so I did have to "get the lead out" every once in a while.
But my pistols were cleaned only just before actually participating in the match itself.
All my practice, thousands of rounds, was fired from an uncleaned gun.

I used six grains of 231, behind either a 230-grain RN, or a 200-grain SWC. (In practice, it's good to be able to see where your first shot went.)
Using bullets produced from Hensley & Gibbs molds, both shapes worked perfectly at the same RN-seater setting. No readjustment was necessary.

Six grains of 231 is a pretty strong load, and dirty, but it always worked, was sufficiently accurate, and it always moved the pendulum far enough to make "major caliber."


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