Can I trim rifle cases BEFORE re-sizing

[valleyforge.1777]

Two questions: do cases lengthen more from neck sizing or full length sizing?
Do Dillon presses meter I-4064 more consistently when one is not resizing in station 1?

[jmorris]

If you are just neck sizing the base of the case remains “blown out”, so there would naturally be less “growth”.

The Dillon measure is independent of the other stations, vibrations aside. There are folks out there that add vibrators to the measure and say it makes them more consistent.

I have some to test some day but stick (pun intended) with powders that meter better than extruded when using progressives.

[valleyforge.1777]

Thanks, that makes sense. I've got a bunch of cases I need to process and load, (including trimming) but after each gets shot once in my rifle, I will have fireformed cases and will only neck size for subsequent reloads.

I was thinking maybe you guys had me convinced to do a separate press run just to resize/deprime and then trim, but not for consistency of the length but so I can get somewhat smoother and more consistent powder drops by removing resizing from the press run for loading powder and bullets. I "could" do that, I have an RCBS Rock Chucker in addition to the Dillon XL650.

The cases that I trim first and then resize are coming out to be different lengths by about +/- .003 inches. Not enough for me to worry about it. I'm shooting for my own enjoyment and my own practice, not competing with the rifle.

[Sure Shot Mc Gee]

With my Pacific trimmer? Its easier to trim prior to Resizing than after due to the cartridge base with seated spent primmer squarely pinching too trimmer ram. (keeps cartridge brass from rotating)
Being I trim my brass to Minimum tolerance the brass growing_ during FL resizing_is so minimal it doesn't concern me.

[cw308]

I use to pitch for my High School and other leagues , Guff , you sure do throw more curve balls them I ever did . Who's confused Vinnie ? Stop with the breaking balls .

[F. Guffey]

Who's confused Vinnie ?

Forgive, reloaders remind me of Vinnie, One of his best lines went something like; "I AM SOOO CONFUSED", he got that way ever time he was crowded and or had to think.

F. Guffey

[D Michalak]

I think he's talking about Vinnie Barbarino from Welcome Back Kotter. Lol

[Unclenick]

Originally Posted by valleyforg.1777

The cases that I trim first and then resize are coming out to be different lengths by about +/- .003 inches.

That's pretty normal, I think. The 0.010" I mentioned was the worst case I happen to recall measuring. I usually only check after resizing, so there may have been more I am unaware of, and it is still something to keep an eye on, especially if you don't intend to retrim for the next load cycle.

I suggest you stop and measure the next 30 cases after resizing and then calculate the mean and standard deviation of the resulting 30 data points. If you are going to load again without retrimming, do this with cases that have been through the maximum number of loads you intend to try to get without retrimming. Divide the difference between your maximum allowed length and the mean by the standard deviation. If the result is 3, you have a 1:740 chance of getting a case that is over the limit, which is still probable enough that you'd better use a cartridge gauge to check each loaded round's neck for going over. But if you get 4, you have only about 1:32,000 chance of getting one case that is outside the limit on the long side. If it is 5, the chance drops to a huge 1:3,5000,000. With anything over 4, the chances are the barrel will be shot out before you get an over-length case. If you replace the barrel, you will probably get a different amount of case growth during resizing, and so will have to make the test over again. For that matter, even with your current barrel, it is a good idea to repeat the test when you adjust the trim length or get a different lot of brass or change your load. Those factors can all affect growth after resizing.

[F. Guffey]

Can I trim rifle cases BEFORE re-sizing

Again, I have trim systems that trim the neck before the case is sized and I have trim systems that do not involve a pilot and then there is a variation; I have one system that has case holders for fired and sized cases.
I also have a very unique case trimmer from RCBS, none of the pilots will fit the neck of the case after the case is sized. that one is older than the Internet.

And then there is the Lee case trimmer system, I do not use it but I have it just in case. And I have another trimmer, it does not have threads even though it has the appearance of being a sizing die.

And then there is the trim system that sets up on the shoulder of the case; again with no pilot, I believe there are two of those systems.

And then there is the fear of wadding up the end of the neck at the end of the chamber.

I have one 30/06 chamber that will allow the case to chamber with a case that is 2.508" long, with that chamber I have no fear the neck will lock the bullet up at the end of the chamber because the chamber had an additional length of .016" from the datum to the bolt face.

To avoid loss of bullet hold I add the additional length of the chamber to the length of the case instead of mindlessly 'looking up case length' with disregard to chamber length.

F. Guffey

[44 AMP]

First off, let's be clear, the "Trim to length" is NOT any kind of a standard. It is NOT a requirement you have to meet. It is a RECOMMENDED length that has no effect on anything, other than your convenience.

Trim before sizing?? sure, why not? I do, for most of my bottlenecked cases. Just easier, not having the pilot drag in a tight case mouth.

And, yes, maybe it grows a little during sizing, again, so what? the whole point of trimming (other than when absolute uniformity of length is needed) is to give the case some "room to grow".

Lyman recommends trim to length that is 0.01" shorter than max case length for most cases. Some, however have trim to lengths only 0.005" shorter. Its not a hard and fast, "must do" number, tis a convenient distance below max so that cases won't grow past max on the next reloading cycle. Often it takes several cycles before cases have stretched back to max length and need trimming again.

For what you are doing, I don't see any point in trimming shorter than listed trim to length. Even with some growth during sizing, they'll still be below listed max length.

you aren't making match ammo to be shot in a tight match cut chamber. A few thousandths of an inch difference in case neck length won't matter. Plus you're not crimping to shoot in a revolver or survive a tube magazine, or elephant gun level recoil. Exact uniformity won't get you any tangible benefit, your rifle won't know the difference.

[cw308]

The order I use in resizing is first I remove the primer , wet tumble , full size , trim and chamfer . Pretty simple . All my primer pockets are uniformed once also flash hole is sized to the same size using a #45 drill bit and deburred .

[big al hunter]

It appears that most have missed that the OP is looking to run a progressive press and NOT stop half way through the process with every cartridge

[LineStretcher]

Originally Posted by big al hunter

It appears that most have missed that the OP is looking to run a progressive press and NOT stop half way through the process with every cartridge

You got me.. LOL. Completely ignored that fact. Sort of like this puzzle.. Rita's mother had 4 children. One was named April, another named May and another name June. What was the 4th named.

[reynolds357]

I have one set of 'X' dies by RCBS. I also have read the instructions; first thing/straight away: Trim the case .020"

and then there is the moving the shoulder back by fire forming; I want to know how that is possible, when it comes to moving the shoulder and bad habits; I believe moving the shoulder is #1 when it comes to bad habits.

Me? I do not believe it gets any better than managing all that movement without moving the shoulder. I know, everyone is 'SOOO Confused,' like Vinnie.

F. Guffey

Everyone is "SOOO confused" because you type gibberish when you are sipping too much shine. When no one understands you, you are the constant variable. The X dies work great, despite the fact you seem to think RCBS has no clue how to size brass.

[Marco Califo]

It appears that most have missed that the OP is looking to run a progressive press and NOT stop half way through the process with every cartridge

That is easy. Just start by sizing all your brass separately, on a different press. Tumble off your case lube. Then Trim.
Then, take it all to your progressive press.

In other words, trimming is not something you do before sizing (which cause length to grow). And you Do Not Trim on a progressive press.

If you pre-size and trim, you can probable remove your sizing die from that station on your progressive press, for that batch.

[cw308]

I'm a single stage guy , never used a progressive press , I'm not burning up that many rounds to get one Even using a progressive press at station#1 size and deprime , station#2 prime , #3 powder dump #4 seat . Reading the question , he is trimming on a RCBS TrimPro 2 , I think your supposed to deprime before trimming , if trimming first then sizing on the progressive what o you do with the lube . You still have to chamfer inside and out . Sure it will work if you trim first but is it the best way to reload.

I like reloading , If I have the time I'll reload a double amount . I don't like rushing when reloading , I deprime first then in the wet tumbler for two hours , I have two or three clean case amounts ready to go so I don't worry about drying time . Maybe just me but if I would be looking for short cuts in reloading I wouldn't like it as much or I would have to cut down on my shooting volume . Bad things happen when you rush things.

[sevt_chevelle]

Have you looked at CH4D they can make a trim die that works with the rt1200?

[LineStretcher]

I just made up 20 rounds of 22-250 using new Lapua brass. All cases were within .5 grains and all were just under trim length. All were final annealed at Lapua and the annealing discoloration was not polished off.

Lapua recommends sizing all their brass prior to use so that's what I have always done. This is my first 22-250 so I had brand new RCBS Competition dies that were thoroughly cleaned and dry.

When I resized the cases they came out to be exactly at the spec'd trim length in the Hornady handbook. The cases chambered in my Tikka T3x perfectly.

Not sure how Lapua does it, but their method seems to work.

[valleyforge.1777]

Thanks everyone for your ideas and input.
I did not know about CH4D. I looked at their website and see that they do make a trim die for the 7.7x58 Japanese cartridge for the Dillon RT1200 trimmer. I am going to call them on Friday and order one of those trim dies.

That does mean using two toolheads and two press runs, which I was hoping to avoid having to do, but overall it will save me time by not having to individually load each case into the TrimPro2 trimmer and trimming it, then taking it out and loading the next one, etc.

I just need to order another toolhead from Dillon for the XL650.

Going back to my original post:
What I wanted to know was would something bad happen to the brass cases if I trim before sizing? I know that the final case lengths will vary a bit if I do it this way and that's OK because as has been stated by several people it will not matter for this rifle... But I wanted to know if something bad would happen, like the brass would be too thin at the case mouth, etc? Sounds like nothing bad will happen to the brass if I trim first, then size, so until I get the Dillon trimmer die from CH4D, I'll continue to do it as trim first (then chamfer and deburr) then lube, then run through the progressive press (first station being size and deprime). thanks again, everyone.

[jmorris]

That does mean using two toolheads and two press runs, which I was hoping to avoid having to do

You can get by without two tool heads if you use split set collar or set screw lock rings but two passes is the norm for rifle on progressives.

For a bolt gun, reusing brass fired from a particular rifle, send 3 fired cases to Harrell’s, have them make you a die and you might not have to trim again.

http://harrellsprec.com/index.php/ca...reloading-dies

[Mobuck]

"That does mean using two toolheads and two press runs, which I was hoping to avoid having to do"

You'd be better served to just buy a cheap LEE press and size the cases in a separate operation IMHO. I'm not at all sure you're justified in trying to run such rounds through a progressive anyway. If that's the way you've got to have it, trim the cases to min length and load them. As I said earlier, the rifle you're using is a 70 year old representative of a questionable quality battle rifle so why the concern over minute details?

[valleyforge.1777]

Thanks, Jmorris for the info about Harrell's. I did not know about them. I am going to get one of their sizing dies that is made custom to my fired cases. I've been looking for exactly that kind of option, and so thanks for letting me know about them. Obviously, there is no Wilson case gauge for this caliber, and anyway the chambers of the T99's vary so much that even if there was a gauge you could not rely on it anyway, so having this die from Harrell's made from fired brass should solve that issue for me.

I'll probably still get the CH4D trimmer die for the Dillon trimmer, just like to have all my options covered.

For this rifle, I have about 400 brass cases coming from commercial ammo made by PCI that I am pulling their bullets and dumping their powder and I will use their primed brass to load my own rounds. They are using .310 bullets in their ammo and I need .312 I had bought this ammo about 10 years ago and had a squib from one of their rounds when I got this rifle a month ago. I will not use their ammo but I will use their primed brass, a mix of Graf brass (? not sure where Graf's gets it from, but the headstamp is Graf) and PPU brass. Incidentally, the length of their unfired brass is about 2.275 I also have about 600 new PPU brass (probably will trim and size even though it is brand new from PPU's factory). And then I have about 250 pieces of brass (mixed Graf and PPU headstamps) that is from ammo I previously fired in my grandfather's bring-back Arisaka T99. I decided not to shoot that rifle anymore, and I recently bought a different T99 to be able to shoot. I'm using the Hornady 303 caliber, .312 diameter 150 grain SP bullets with WLRM primers (except for the primed brass from PCI, I don't know if they are LR or LRM primers), and I am using 43 grains of I-4064 powder. ONCE those rounds have been fireformed in my new rifle, I had planned to not need to trim for the next couple of reloads for each piece and to neck-size only instead of the full-length sizing that I am doing for the brass for this initial loading sequence. (I have two sets of RCBS dies, one for full-length and one for neck-sizing.)


With the load testing I've done so far, this rifle shoots great. Very accurate at 100 yards, my most common shooting distance. It has a chrome-lined bore, legendary-strong receiver, and I have mounted a scope on it. With the ammo I've made as test rounds (about 200 rounds) it has functioned flawlessly although the few rounds I tested with the Hornady 174 grain RNSP did not feed correctly into the chamber, although the spire-points work great. With the 150 grain bullets, the rounds and rifle are flawless.