Case trimming before or after resizing

[mikld]

As an aside, and FWIW; I read an interesting article on 45 ACP reloading and the theory came up that some semi-auto cases shrink in length due to the case head pressure/banging against the bolt actually compressing the extractor groove, shortening the case. In theory that sounds right (from a life long machinist/mechanic's standpoint), but in real life, I cannot verify nor have I experienced this phenomenon...

[hounddawg]

[quote]As an aside, and FWIW; I read an interesting article on 45 ACP reloading and the theory came up that some semi-auto cases shrink in length due to the case head pressure/banging against the bolt actually compressing the extractor groove, shortening the case. In theory that sounds right (from a life long machinist/mechanic's standpoint), but in real life, I cannot verify nor have I experienced this phenomenon...[quote]

brass is pretty malleable. 16 to 18 pound recoil springs, if I were to give a seat of the pants guess I would say it's possible

[cw308]

When looking at the Unclenick diagrams on sizing and reading posts from F.G on it's not possible to set back the shoulder . You can see how the fired case lenghtens and when the case is pressed up into the sizing die how it squeeze's the case shoulder back into a specific length . Answering both questions on trimming and shoulder setback . How and when do you trim when using a turret press , I'm only a single stage reloader .

[F. Guffey]

When looking at the Unclenick diagrams on sizing and reading posts from F.G on it's not possible to set back the shoulder . You can see how the fired case lenghtens and when the case is pressed up into the sizing die how it squeeze's the case shoulder back into a specific length . Answering both questions on trimming and shoulder setback . How and when do you trim when using a turret press , I'm only a single stage reloader .

There is no way I can compete with reloaders that make this stuff up. I have moved the shoulder back on cases when sizing. Problem for reloaders: There is a criteria. The shoulder does not move back because someone says it does.

And then there are those that claim it does move back. They claim they can move the shoulder back, none of them can explain how it happens; I hope they are not claiming they can move the shoulder back for my benefit.

F. Guffey

[F. Guffey]

Answering both questions on trimming and shoulder setback . How and when do you trim when using a turret press , I'm only a single stage reloader .

I have more than one turret press and at least 15 single stage presses. I do not have to look up at the press I am using to determine case trimming. I have forming dies, my forming dies are multi taskers, they are trim and forming dies. When I form a case with a forming die I finish it by trimming the case before I lower the ram with a hack saw and finish with a file. There are times I trim with aircraft countersinks; the counter sink give me that smooth bevel on the inside of the neck.

And then there is the Wilson case gage; reloaders can not accept the Wilson case gage as a multi tasking tool; I am beginning to believe reloaders can not multi task.

F. Guffey

[Rimfire5]

I don't use a turret press for rifle cases, so I can't say I have ever tried to size necked brass on a turret press.

I have never seen a carbide die for a rifle caliber. I would really like to see someone use a turret press to resize necked rifle ammo with a standard rifle case sizing die without using case lube. Without lube, the die would lock a round in the sizing die within a couple of strokes, if not the first.
With lube, without being able to clean the lube off, it probably would mess up some of the primers resulting in misfires.

Not so with straight-sided brass with a carbide sizing die, since you don't need lube.
The videos the OP watched were probably showing straight-sided handgun brass loading.

[gwpercle]

I have a Pacific case trimmer , old school rotary type trimmer .
The "Book" says to size then trim...only problem with that is the sized neck wont fit over the 30 cal. pilot . Bought a new one ...same problem ! Fired cases fit right over both pilots...sooooo I trim them first then size...been doing that for 50 years and doing just fine. In theory sizing and then trimming may be best/correct/proper way to do it...
But you know what they say about theory...it's all theoretical .
Gary

[cw308]

F.G.
So to use a turret press and turn out properly sized brass the case has to be sized , trimmed and chamfered first . Why would someone go with a turret press , it doesn't seem to me to save time .

[hounddawg]

I have a progressive under the bench that I used to crank out pistol and .223/5.56 in bulk with. Cases that could be trimmed every few firings in the case of the rifle stuff and never trimmed as far as pistol. I never did any but for bottle neck cases I trimmed to minimum then neck sized

bulk .223 and 9 mm and even .45 is so cheap and available now I just stock up on the plinking stuff when it is on sale. It's not precision ammo but it goes bang. I do like to do my 38's and .357's myself still but that is about it for me with straight walled cases.

[F. Guffey]

So to use a turret press and turn out properly sized brass the case has to be sized , trimmed and chamfered first . Why would someone go with a turret press , it doesn't seem to me to save time

It depends on the skill level of the user. I use the turret with 6 positions; one position for the forming die, the next position for the sizing die, AND THEN another forming die and another sizing die. It is not likely I am going to seat bullets but there is a chance I will be forming cases that requires more than one forming die. To understanding the saving of time a reloaders would have to understand installing dies and adjusting dies requires time.

And then there is one press that is never considered when sizing and forming; that would be the two ram press. I form on one ram and size on the other.

F. Guffey

[cw308]

When I tried the bushing dies they did recommend sizing down the brass in two stages if the OD was greater hen a certain amount . I always size then trim and chamfer for every reloading session , even if it's more of a lite shaving . Just became part of my routine . Wouldn't chamfering make seating smoother .

[F. Guffey]

Wouldn't chamfering make seating smoother .

I have the RCBS case prep center; I understand that means nothing to most but for me it means there is no excuse for not putting a bevel on the outside and inside of the neck. And the countersink is designed to bevel the edge of the hole while it is trimming. And then there is the file' the file can put a nice finish on the end of the neck.

F. Guffey

[cw308]

I never skip a step in reloading but never used a file , would seem very time consuming .

[F. Guffey]

I never skip a step in reloading but never used a file , would seem very time consuming .

To use a file the reloader must first own one, then there is that thing about knowing how it is used. Then comes that part about deciding the rationale for using the man tool 'the hack saw and the file'. If a reloader does not have a trim die they become one of the reloaders that talk about it.

For the reloader that has a forming die (AKA) also known as a trim die there is no way the reloader can trim the end of the case more accurately than with a file across the top of the trim die.

Unlike most reloaders I can not find an excuse like 'very time consuming' as a good reason not to do it.

Again, I find the aircraft countersink works when trimming. It helps to support the outside of the neck; when forming cases the neck protrudes through the top of the forming die. That is the reason the hack saw for me is the preferred tool and then there is the aircraft countersink. And then it gets complicated but in my madness because of the things that seem time consuming.

F. Guffey

[hounddawg]

I personally do not see trimming as a arduous task. I use Wilsons, have a trimmer set up for each cartridge I load for and use a B&D screwdriver to power the cutter. 2 taps to get the case into the holder snug, 10 seconds trimming, 2 taps to get the case out and a half turn each way to break the edge using a manual chamfer/deburr and it's done. I get a exact trim on each case and a perfect chamfer and deburr in less than 20 seconds.

No file, adze, sandpaper, brick or disk grinder needed.

[valleyforge.1777]

I went through this same dilemma when getting set up to load 7.7x58 Japanese rifle rounds. Had a bunch of once-fired brass, needed to be trimmed, loaded, etc. Using a Dillon XL650 progressive press. Was used to using the Dillon RT-1200 trimmer when reloading 223, with one tool head set up with a Dillon trimming/sizing die in station 4 with the motor attached. Would load up the case feeder with lubed 223 cases, run them through the press to get trimmed, then sit down to chamfer and debur my pile of "trimmed and sized" cases on the Lyman case prep center. Then using a different toolhead, I would run the lubed cases through the FL re-sizing/decapping die in station 1, then powder loading in station 2, bullet seating in station 4 and crimping in station 5. Works well and have done tens of thousands of 223 cases that way, but it does take 2 tool heads and two runs through the press with an intermediate step off the press to chamfer and debur.

So, with the 7.7x58 Japanese rounds, I did not have a Dillon trimmer die, so I bought the RCBS trimmer with the motor. Wanted to just run the 7.7x58 brass through that trimmer, then chamfer and debur, and then run through the press using the re-sizing/decapping die in station 1, etc. Asked online and half the people said "do whatever you want, many people trim first" and half the people said, "oh my gosh, the world will end if you trim first". Some politely pointed out that you can sort of "over trim a bit" and then re-size and that should even things out OK if you are not aiming for match-grade ammo anyway. Well, I tried the trim first, and guess what? The cases did not fit on the pilot for the trimmer motor and I found out that I definitely HAVE to size first and then trim. Oh well.

So, fast forward to this week/weekend. I was setting up to get started loading 30 WCF (30-30 WIN). Had a disastrous time using the Dillon trimmer die and motor for the 30 WCF cases, I'll tell that story some other time. So it is back to the RCBS trimmer motor and guess what? The re-sized cases are too tight on the trimmer pilot, but the unsized cases do fit over the pilot OK. So this time it WILL BE trim first, then chamfer/debur then run through the press including re-size/decapping in station 1, etc. I think. Got to try that out because I am afraid that even though I seem to need to do it that way due to the pilot, I am afraid that trimmed brass will get messed up when subsequently going through the re-sizing die. That was what happened with the brass done with the Dillon trimmer motor. The sizing die then belled (more like rolled" a lip) onto the case mouth and I've got to throw out a whole lot of brass I processed. So, hoping this trim first, then size thing works OK and will report back tomorrow.

[F. Guffey]

The re-sized cases are too tight on the trimmer pilot,

I have a set of pilots that came with a trimmer I purchased before the invention of the Internet. Because I did not have any bad advise I did not have a problem but after the Internet reloadrs went into mortal combat with the small neck cases and 'too large' pilots. They could not get the case heck onto the pilot and of they did that had fits pulling the cases off the pilots.

F. Guffey

[cw308]

F.G
Why are your answers always in some kind of code . All I asked was why would you use a file in making a nice finish on the end of the case neck . Seems pretty time consuming . Anyway , I just follow all the steps in reloading , makes things pretty simple , less problems in the long run .

[hounddawg]

All I asked was why would you use a file in making a nice finish on the end of the case neck

the real question is why anyone would be concerned over the finish on the end of the neck. Wilson has a carbide cutter and leaves a perfect finish, much smoother than any file is capable of. The outer rims are knife edges, and need deburring and chamfering to get rid of the sharp edge it leaves. Otherwise the edge could shave the jackets during the seating, you want the inner and outer edges slightly angled or rounded

[cw308]

Hi dawg
I guess some guys ( F.G.) have a!ot of time on their hands to clean up case necks with a file . I get ragged for turning out nice shinny brass by wet tumbling . I don't think I'll let him off so easy after hearing that one . Using a file to clean up case necks . I have that one listed in my log book , thanks F.Guffey .

[old roper]

cw308, I may be dating myself. I remember having trim die and used file and I got Wilson when they didn't make stand for it or something to hold case holder down. I got pretty nice Wilson and use it. I still have those trim dies and I'm no fan of FG but I think I could trim case faster using trim die and I really hate to say that. The both square case

[zeke]

"As an aside, and FWIW; I read an interesting article on 45 ACP reloading and the theory came up that some semi-auto cases shrink in length due to the case head pressure/banging against the bolt actually compressing the extractor groove, shortening the case"

45 acp cases get shorter in length over time from being resized alot of times. The brass flows downward, and slightly outward at bottom of the body below where the die reaches. This can cause feeding problems with tighter chambered pistols, and is not a theory.

Easy to fix/verify with the Lee push through die, which resizes the entire case body and returns the case close to original length.

[sparkyv]

Originally Posted by DukeConnor

Size then trim. Don't get caught up in speed.

I agree. My turret press is speedy for pistol rounds, not so much for rifle rounds, because of the multiple times I handle the brass; I resize, then trim rifle brass. No need to trim for most pistol brass, magnum brass can be an exception. The convenience of the turret press is that I leave all the dies in a turret for each caliber. No need to readjust the die setting each time.

[valleyforge.1777]

In terms of the brass being too tight for the pilots on the RCBS Trim Pro2 (with motor), it looks like that is mostly an issue with brass from pulled bullets. I pulled the bullets and dumped the powder from 400 rounds of 7.7x58 Japanese from PCI cartridge because their quality control was horrible and the rounds were squibbing in my rifle when fired. I ultimately discarded their undersized (for 7.7x58) bullets and their powder and I used their primed brass to load my own. I had to trim the brass, it was over the trim-to-length, and the brass was too tight for the pilot on the trimmer, so I had to neck re-size first, then trim.

Fast forward to yesterday: Doing trimming for once-fired 30 WCF brass (30-30). Turns out it fits over the pilot without issue if I trim first, which means one less run through the press, and it means I only need one tool head set up for the press because I can re-size as station 1 on the Dillon XL650 after trimming. The final length of all of the brass is close enough to each other that I was able to set the trimmer length so that the longer brass after re-sizing is pretty much just exactly perfect, piece after piece.

There were some big thunderstorms yesterday afternoon, but the world, apparently, did not end. Did visit my parents for dinner and found a cat and a dog living together, so who knows? Maybe that's the first sign and the world IS going to end after all since I trimmed before sizing...

[Unclenick]

Valleyforge.1777,

Folks who outside-turn necks have the same issues. Some cases have thicker necks than others and some folks size them down differently and yet, they all have to fit over the pilot mandrel without being so loose the turning operation chatters and makes the wall uneven. The general solution is to use a slighter wider diameter expanding mandrel to set the neck ID. You size the case without an expander and let the expanding mandrel set its ID for the pilot. It's an extra step, but since outside neck turning is something only done once, most folks don't object. Sinclair sells the expanding mandrels and a special die body to hold them. As a method of expanding necks, it is less prone to tilting a neck off-axis than the standard pull-through expander in a sizing die is. This could certainly set a case up for your trimmer pilot, too.


cw308,

I think Mr. Guffey is talking about forming brass in the context of the Japanese round. It is pretty standard that forming a longer or wider case down gets you more excess neck than you would want to remove with a trimmer. That's where hacksaws come in. They, in turn, leave a pretty rough edge that can catch on a trimmer cutter, so draw filing the case mouth flat and square while it's still in the trim die (or whatever die you are using) is pretty standard practice for that. But once the newly formed case has been done that way initially, using a standard trimmer becomes practical thereafter. Some folks, since they have the trim die already, just stick with filing. I've done both, and it's not clear to me that filing is always slower than a manual trimmer once you've developed the routine and feel for it.

Nothing touches power trimmers for speed, though.