Case trimming before or after resizing

LukeB · June 8, 2019, 10:09 PM

I have been reloaded for many years now on a single stage press. I am starting to research turret style presses to reduce my time and increase output. On my single stage I always resize my rifle casings and then trim if needed. However with many videos I have seen about how turret style presses work, no one ever takes the case out after resizing to trim. Which leads me to believe people are trimming before resizing. Here is my question. For those of you with a turret style press, where in your process do you trim your rifle casings? And if you trim BEFORE resizing how do you compensate for case length change after resizing?

hounddawg · June 8, 2019, 10:45 PM

I do it after on the reasoning that when you are sizing you are essentially cold extruding the brass and when the shoulder moves back the brass flows somewhere and since the neck is the thinnest part of the case it goes there. Least resistance and all that. Just a pet theory but since time wise it makes no difference then why not

surveyor · June 8, 2019, 11:24 PM

I load on a Lee classic cast turret and break up the bras prep from the load process.

I take a case and dip mouth in mica and lube outside of case between my fingers with imperial wax, déprime with universal decapper then size the case, pull from press with other hand, in the CTS trimmer it goes, then chamfer, deburr, brush neck, then invert case and brush primer pocket or remove crimp from primer pocket on case prep station.

I handle brass twice for this, and it is around 5 to 10 seconds although I haven't timed it.

I prime, chargé seat bullet in another step. I find this fits my work flow best.

LukeB · June 8, 2019, 11:48 PM

Hounddawg thanks for your thoughts. My intention with a turret press was to minimize time and effort but still have control over every stage (not going with progressive for that reason). However if by upgrading I am still having to remove the casing after resizing and then reinserting it for powder then all I’ve gained is the powder being dropped in with less effort than using my single stage. Doesn’t seem worth it to upgrade (and the time savings seems minimal). I admit I’ve never used a turret system. If I am missing something please let me know. Thanks.

Don Fischer · June 9, 2019, 09:09 AM

Only turret type press's I have any use for are for shotgun's! If you trim before sizing, your gonna stretch the case but I have never seen it stretch to far.I trim after sizing. Sitting here thinking, will the Lee collet die work in your press? I'd certainly give that a try as I do use one in a couple cartridges. Have to put more pressure on the ram to work it right but no case stretch! Problem with standard dies is the expander button, it pulls the case longer when the neck is expanded. With the collet die that stress doesn't exist!

berettaprofessor · June 9, 2019, 09:20 AM

I only use turret for handgun and for 223 that's going into AR's. In the latter case, I trim them beforehand or know they are already far under max case length.

F. Guffey · June 9, 2019, 09:26 AM

Quote:

Which leads me to believe people are trimming before resizing.

In most circles a reloader is not allowed to think; there are those that make it compulsory you 'repeat after them'.

I have a turret press, it has 6 positions. It is a cam over/pump press by Herter. In the big inning I started with 30/06 cases and then? I added forming dies meaning after I got the forming dies and I had 30/06 cases I was not concerned with the price of cases for my next rifle. And then there are all of those horror stories about chamber head space. All of those problems were solved when forming, I formed first and then fired. All other reloaders fire formed as in they chambered a round, pulled the trigger and then became fire formers.

Back to trimming: When forming with a forming die it should not take the reloaders very long to determine the forming die is also a trim die. Now I could ask the question you are asking about "when to trim; before or after?", problem, no one knows so I trim the case before lowering the ram when forming. It give me the chance to use the 'man tool', the hack saw and the file. Now; the case must be sized in a sizing die. I have never found a trimming procedure that is more accurate than the trim/forming die.

And I think it is nice the trim die is the same length as the case after trimming, UNLESS you are talented and are able to measure the length of the chamber from the shoulder of the chamber to the bolt face. That is where I start because when forming there is a chance I have to add to the length of the case from the shoulder to the case head; I off set the length of the chamber with the length of the case from the shoulder to the case head.

And I am very luck because my cases do not have head space.

And then, before the Internet trim tool manufacturers made pilots that would not fit the case neck after sizing without getting into mortal combat.

And then there are trimmers that trim while sizing and there are trimmers that set up on the shoulder of the case. I could say "think about it", when trimming a case off the shoulder the case head/case body in in the hand of the reloader. Meaning the distance from the shoulder to the case head is not a consideration

?

F. Guffey

cw308 · June 9, 2019, 05:29 PM

I use a single stage I size then trim . Thinking about your system , maybe on your single stage you could use a body die first then trim and chamfer .

Don Fischer · June 9, 2019, 05:42 PM

So if you trim after sizing, how do you do that? Isn't the next station after sizing, seating a primer? What do you do, size then stop the process to remove the case to trim? Sounds like the speed some people want get's interrupted right there. Shoot, just trim before sizing and take just a bit more off and it'll work fine. Even right from trim length your not gonna pull the neck to far sizing.

hounddawg · June 9, 2019, 06:10 PM

I suppose you could do a test. Trim 15 before sizing and 15 after sizing and see if there is
a difference in OAL in the 2 batches

I only single load theses days, 9mm and 5.56 is plentiful and cheap enough to make me keep my progressive under the bench at the moment but if anyone tests the theory I would be interested in the results

DukeConnor · June 9, 2019, 06:12 PM

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

Reloadron · June 9, 2019, 07:33 PM

hounddawg:

Quote:

I do it after on the reasoning that when you are sizing you are essentially cold extruding the brass and when the shoulder moves back the brass flows somewhere and since the neck is the thinnest part of the case it goes there. Least resistance and all that. Just a pet theory but since time wise it makes no difference then why not

Same for the same reasons. Take a once fired case and measure the OAL. Now size the case, normal full length sizing. Now measure the OAL again. Pretty sure you will find the OAL has increased.

Then too I do most of my loading on my old single stage RCBS Rockchucker and trimming is done on either my manual or motor driven trimmer. Once trimmed to length I just do a quick burr removal and chamfer then prime. Anyway, I do it this way for the same reasons hounddawg mentions.

Ron

Marco Califo · June 9, 2019, 08:49 PM

IMO, you should give up on the notion of trimming combined with any other steps. I am only speaking of rifle chamberings. I personally have never needed to trim straight-walled pistol brass. It is too different from on-press operations. Case prep is best done away from your press. I prefer to deprime, clean, tumble, size, and trim after sizing since sizing is where you case length grows. I also prime off the press.

I load primed cases, by dropping powder and seating bullets. After all the prep work was done as individual processes. I use a Wilson case trimmer. It works great, but you handle (and can inspect) every case as you do it.

Kevin Rohrer · June 9, 2019, 08:55 PM

Umm, size, THEN trim.

LineStretcher · June 9, 2019, 08:58 PM

Quote:

Originally Posted by LukeB

I have been reloaded for many years now on a single stage press. I am starting to research turret style presses to reduce my time and increase output. On my single stage I always resize my rifle casings and then trim if needed. However with many videos I have seen about how turret style presses work, no one ever takes the case out after resizing to trim. Which leads me to believe people are trimming before resizing. Here is my question. For those of you with a turret style press, where in your process do you trim your rifle casings? And if you trim BEFORE resizing how do you compensate for case length change after resizing?

Your once fired or new brass needs to be sized and then trimmed to "trim length". If you do that then you probably won't have to trim again for several reloads.

When you're using a turret press, you're reloading and some turret presses can produce very nice reloads. If you are wanting precision hand loads then stick to your single. The point here is that your tolerances can be much wider if you're not precision hand loading. As long as the case length doesn't exceed max length you don't need to trim after every resize. You still need to do your sorting and inspecting just like always but they probably don't show that in the videos.

pwc · June 9, 2019, 11:07 PM

Do sll brass prep on the single stage; size then trim, and reload on tge turret.

cw308 · June 10, 2019, 08:14 AM

Case prep to me is very important , I wouldn't skip anything . I full size using the expander ball , I only use a single stage but as I posted , I would size , trim and chamfer first then set up on the turret . If your full sizing like me with the expander , you could use only a body die , doesn't effect the fired diameter of the neck , the set up your turret with a F/L die with the expander on your turret. Makes extra work .

Stats Shooter · June 10, 2019, 10:22 AM

For me, it boils down to 2 questions.

1: Is it a straight walled case such as a 45-70 or most pistols? If so, I have never trimmed a straight walled case and I load them on either my 650 (pistols) or my 550 (rifles). So the point is moot here.

2: Next, am I making ammo for one of my semi-auto's or for my bolt action precision rifles?

If it is for my semi-auto's, I do not trim every single time. I do anneal every time, I do decapp and tumble every time, but not trim. When I do trim, I run them all through the sizing die, then trim, then take the sizing die out of the toolhead on the 550 (but you don't have too, you can work it again if you want, especially if you anneal it and worry about runout induction from your trimmer pilot).

Especially if all the brass is being fired in the same gun, with the same load, I find the case lengths after sizing not to vary by much over 0.001". Otherwise, as long as you batch it, you still do not need to trim. But, if you are firing different loads, in different guns, and just lumping all the brass together to process, then I would probably trim it every time...find the shortest batch and trim it all to that length. This is of course if you are trying for some decent accuracy in your semi-auto rifles. I don't really make "plinking" ammo for rifles so I am always trying for some level of precision.

With bolt guns I always trim, and all my bolt action ammo is done via single stage...so trimming after sizing is no big deal. I use the RCBS 3-way cutting head to chamfer and deburr in the same step for consistent results.

mikld · June 10, 2019, 11:34 AM

I think the videos you have seen leave out trimming for expediency. Most cases don't need trimming every reloading, so they just show how well, quick, their press works...

Trimming before sizing (F/L sizing) would be kinda worthless as the case length will grow after sizing. (When a metal tube is swaged/squeezed the metal is not removed and it has to go somewhere, and in a rifle case the metal moves to one end of the case).

hounddawg · June 10, 2019, 02:43 PM

I don't think straight walled cases grow. No shoulder to move back so no reason for the brass to move anywhere

daboone · June 11, 2019, 08:08 AM

Quote:

Originally Posted by hounddawg

I don't think straight walled cases grow. No shoulder to move back so no reason for the brass to move anywhere

For me, the M1 Carbine is the only straight-walled case that needs periodical trimming.

mikld · June 11, 2019, 11:50 AM

OP only mentioned rifle cases, not straight sided or belted, or rimmed, or "rimless". Just rifle cases...

While not common, straight sided cases can grow. If a tube is swaged, squeezed, the metal has to go somewhere. Like sizing a bullet. Run a bullet through a sizing die and make it .002" smaller in diameter, where did that .002" go? It moved to one end of the bullet.

But for all intents and purposes, they don't grow n length (I haven't measured any revolver or straight sided rifle brass in many years so I might be wrong...).

**Unclenick** · June 11, 2019, 04:00 PM

I once ran a single bulk purchase of Winchester .45 Auto brass through 50 reloads (light, lead bullet target loads) and they got an average of half a thousandth of an inch shorter at every load cycle. That happens because of the taper in the chamber. The case doesn't reach high enough pressure to stick to the chamber, so it backs up an inflates to fill the widest part of the chamber, which shortens it more than resizing recovers it.

For rifle, though, I put this illustration up many times to show, exaggerated, what happens to a fired case during resizing. Look closely and you will notice the black dots on the shoulder and body of the case become part of the neck and shoulder, respectively, after resizing.

LukeB,

If you want an accurate trim, it needs to be done after resizing. Rifle loading takes more total steps to do well than handgun cartridges do. This is why when Dillon came out with its electric trimmer it would mount in one station of a 550B. They knew with that trimmer in place you had no way to finish other rounds progressively, so they just assumed you would size and trime and then perform the rest of the loading steps.

That said, there are a couple of other choices around. You can trim first if you overdo it to make up for the effect of sizing. Different cases won't come out all identically, but if you are not crimping and you are trimming enough to stay away from going over the upper limit, you can do it. Some old M14 match shooters used to trim their military brass cases -0.020 below SAAMI minimum. They only ran those cases about 4 load cycles before pitching them our, and that short trimming let them trim each case once in its life. My point in mentioning it is just that you can get cases extra short without causing a general shooting problem. It just won't work if you are crimping with a conventional crimp shoulder in a seating die.

A more recent product is the RCBS -die. For those you trim them to the low end of the SAAMI range once, but then never need to trim again, as they control neck growth, making them a good choice for progressive loading.

1stmar · June 12, 2019, 02:11 AM

Nick as the case goes into the sizing die does any of the brass get squeezed downward expanding the case near the pressure ring? If so, assuming you are not fl sizing or using a small base sizing die, wouldnt that that expansion always exist?

F. Guffey · June 12, 2019, 07:49 AM

Quote:

Nick as the case goes into the sizing die does any of the brass get squeezed downward expanding the case near the pressure ring? If so, assuming you are not fl sizing or using a small base sizing die, wouldnt that that expansion always exist?

Only if the same rules and principal of case sizing applies to you as they do to me; I say that because most reloaders have their own set of rules. I do not know how they do it but they claim they can move the shoulder back, some claim it is so easy they can bump the shoulder back. Not me; I can not move the shoulder of a case back with a die that has case body support.

I understand we have a barn full of experimenters, I am not one of them even though I have moved the shoulder back on cases just to see how it could be done. I have turned cases in to cases that took on the appearance of a bellows like a Volkswagen thermostat. But we are talking about sizing fired cases.

So the case body is blown out when fired and reduced in diameter when sized. The shoulder moves out when the body is reduced in diameter when sized. Back in the 50s Lyman suggested the shoulder takes on the appearance of having a radius before the shoulder in the die contacts the shoulder of the case.

F. Guffey

June 8, 2019, 10:09 PM	#1
LukeB Member Join Date: November 21, 2017 Posts: 15	Case trimming before or after resizing I have been reloaded for many years now on a single stage press. I am starting to research turret style presses to reduce my time and increase output. On my single stage I always resize my rifle casings and then trim if needed. However with many videos I have seen about how turret style presses work, no one ever takes the case out after resizing to trim. Which leads me to believe people are trimming before resizing. Here is my question. For those of you with a turret style press, where in your process do you trim your rifle casings? And if you trim BEFORE resizing how do you compensate for case length change after resizing?

June 8, 2019, 10:45 PM	#2
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	I do it after on the reasoning that when you are sizing you are essentially cold extruding the brass and when the shoulder moves back the brass flows somewhere and since the neck is the thinnest part of the case it goes there. Least resistance and all that. Just a pet theory but since time wise it makes no difference then why not __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek Last edited by hounddawg; June 8, 2019 at 10:50 PM.

June 9, 2019, 06:10 PM	#10
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	I suppose you could do a test. Trim 15 before sizing and 15 after sizing and see if there is a difference in OAL in the 2 batches I only single load theses days, 9mm and 5.56 is plentiful and cheap enough to make me keep my progressive under the bench at the moment but if anyone tests the theory I would be interested in the results __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

June 9, 2019, 08:49 PM	#13
Marco Califo Senior Member Join Date: April 4, 2011 Location: LA (Greater Los Angeles Area) Posts: 2,598	IMO, you should give up on the notion of trimming combined with any other steps. I am only speaking of rifle chamberings. I personally have never needed to trim straight-walled pistol brass. It is too different from on-press operations. Case prep is best done away from your press. I prefer to deprime, clean, tumble, size, and trim after sizing since sizing is where you case length grows. I also prime off the press. I load primed cases, by dropping powder and seating bullets. After all the prep work was done as individual processes. I use a Wilson case trimmer. It works great, but you handle (and can inspect) every case as you do it. __________________ ............ Last edited by Marco Califo; June 10, 2019 at 10:22 AM.

June 9, 2019, 08:55 PM	#14
Kevin Rohrer Senior Member Join Date: May 19, 2010 Location: Medina, Ohio Posts: 1,049	Umm, size, THEN trim. __________________ Member: Orange Gunsite Family, NRA--Life, ARTCA, and American Legion. Caveat Emptor: Cavery Grips/AmericanGripz/Prestige Grips/Stealth Grips from Clayton, NC. He is a scammer

June 8, 2019, 11:24 PM	#3
surveyor Senior Member Join Date: April 13, 2007 Posts: 770	I load on a Lee classic cast turret and break up the bras prep from the load process. I take a case and dip mouth in mica and lube outside of case between my fingers with imperial wax, déprime with universal decapper then size the case, pull from press with other hand, in the CTS trimmer it goes, then chamfer, deburr, brush neck, then invert case and brush primer pocket or remove crimp from primer pocket on case prep station. I handle brass twice for this, and it is around 5 to 10 seconds although I haven't timed it. I prime, chargé seat bullet in another step. I find this fits my work flow best.

June 8, 2019, 11:48 PM	#4
LukeB Member Join Date: November 21, 2017 Posts: 15	Hounddawg thanks for your thoughts. My intention with a turret press was to minimize time and effort but still have control over every stage (not going with progressive for that reason). However if by upgrading I am still having to remove the casing after resizing and then reinserting it for powder then all I’ve gained is the powder being dropped in with less effort than using my single stage. Doesn’t seem worth it to upgrade (and the time savings seems minimal). I admit I’ve never used a turret system. If I am missing something please let me know. Thanks.

June 9, 2019, 09:09 AM	#5
Don Fischer Senior Member Join Date: March 2, 2017 Posts: 1,868	Only turret type press's I have any use for are for shotgun's! If you trim before sizing, your gonna stretch the case but I have never seen it stretch to far.I trim after sizing. Sitting here thinking, will the Lee collet die work in your press? I'd certainly give that a try as I do use one in a couple cartridges. Have to put more pressure on the ram to work it right but no case stretch! Problem with standard dies is the expander button, it pulls the case longer when the neck is expanded. With the collet die that stress doesn't exist!

June 9, 2019, 09:20 AM	#6
berettaprofessor Senior Member Join Date: November 23, 2008 Posts: 1,091	I only use turret for handgun and for 223 that's going into AR's. In the latter case, I trim them beforehand or know they are already far under max case length.

June 9, 2019, 05:29 PM	#8
cw308 Senior Member Join Date: September 2, 2010 Location: Plainview , Long Island NY Posts: 3,863	I use a single stage I size then trim . Thinking about your system , maybe on your single stage you could use a body die first then trim and chamfer .

June 9, 2019, 05:42 PM	#9
Don Fischer Senior Member Join Date: March 2, 2017 Posts: 1,868	So if you trim after sizing, how do you do that? Isn't the next station after sizing, seating a primer? What do you do, size then stop the process to remove the case to trim? Sounds like the speed some people want get's interrupted right there. Shoot, just trim before sizing and take just a bit more off and it'll work fine. Even right from trim length your not gonna pull the neck to far sizing.

June 9, 2019, 06:12 PM	#11
DukeConnor Senior Member Join Date: May 6, 2016 Posts: 224	Size then trim. Don't get caught up in speed.

June 9, 2019, 11:07 PM	#16
pwc Senior Member Join Date: March 21, 2018 Location: AZ Posts: 236	Do sll brass prep on the single stage; size then trim, and reload on tge turret.

June 10, 2019, 08:14 AM	#17
cw308 Senior Member Join Date: September 2, 2010 Location: Plainview , Long Island NY Posts: 3,863	Case prep to me is very important , I wouldn't skip anything . I full size using the expander ball , I only use a single stage but as I posted , I would size , trim and chamfer first then set up on the turret . If your full sizing like me with the expander , you could use only a body die , doesn't effect the fired diameter of the neck , the set up your turret with a F/L die with the expander on your turret. Makes extra work .

June 10, 2019, 10:22 AM	#18
Stats Shooter Senior Member Join Date: August 26, 2016 Location: North Dakota Posts: 1,636	For me, it boils down to 2 questions. 1: Is it a straight walled case such as a 45-70 or most pistols? If so, I have never trimmed a straight walled case and I load them on either my 650 (pistols) or my 550 (rifles). So the point is moot here. 2: Next, am I making ammo for one of my semi-auto's or for my bolt action precision rifles? If it is for my semi-auto's, I do not trim every single time. I do anneal every time, I do decapp and tumble every time, but not trim. When I do trim, I run them all through the sizing die, then trim, then take the sizing die out of the toolhead on the 550 (but you don't have too, you can work it again if you want, especially if you anneal it and worry about runout induction from your trimmer pilot). Especially if all the brass is being fired in the same gun, with the same load, I find the case lengths after sizing not to vary by much over 0.001". Otherwise, as long as you batch it, you still do not need to trim. But, if you are firing different loads, in different guns, and just lumping all the brass together to process, then I would probably trim it every time...find the shortest batch and trim it all to that length. This is of course if you are trying for some decent accuracy in your semi-auto rifles. I don't really make "plinking" ammo for rifles so I am always trying for some level of precision. With bolt guns I always trim, and all my bolt action ammo is done via single stage...so trimming after sizing is no big deal. I use the RCBS 3-way cutting head to chamfer and deburr in the same step for consistent results.

June 10, 2019, 11:34 AM	#19
mikld Senior Member Join Date: February 7, 2009 Location: Southern Oregon! Posts: 2,891	I think the videos you have seen leave out trimming for expediency. Most cases don't need trimming every reloading, so they just show how well, quick, their press works... Trimming before sizing (F/L sizing) would be kinda worthless as the case length will grow after sizing. (When a metal tube is swaged/squeezed the metal is not removed and it has to go somewhere, and in a rifle case the metal moves to one end of the case). __________________ My Anchor is holding fast! I've learned how to stand on my own two knees...

June 10, 2019, 02:43 PM	#20
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	I don't think straight walled cases grow. No shoulder to move back so no reason for the brass to move anywhere __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

June 11, 2019, 11:50 AM	#22
mikld Senior Member Join Date: February 7, 2009 Location: Southern Oregon! Posts: 2,891	OP only mentioned rifle cases, not straight sided or belted, or rimmed, or "rimless". Just rifle cases... While not common, straight sided cases can grow. If a tube is swaged, squeezed, the metal has to go somewhere. Like sizing a bullet. Run a bullet through a sizing die and make it .002" smaller in diameter, where did that .002" go? It moved to one end of the bullet. But for all intents and purposes, they don't grow n length (I haven't measured any revolver or straight sided rifle brass in many years so I might be wrong...). __________________ My Anchor is holding fast! I've learned how to stand on my own two knees...

June 11, 2019, 04:00 PM	#23
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	I once ran a single bulk purchase of Winchester .45 Auto brass through 50 reloads (light, lead bullet target loads) and they got an average of half a thousandth of an inch shorter at every load cycle. That happens because of the taper in the chamber. The case doesn't reach high enough pressure to stick to the chamber, so it backs up an inflates to fill the widest part of the chamber, which shortens it more than resizing recovers it. For rifle, though, I put this illustration up many times to show, exaggerated, what happens to a fired case during resizing. Look closely and you will notice the black dots on the shoulder and body of the case become part of the neck and shoulder, respectively, after resizing. LukeB, If you want an accurate trim, it needs to be done after resizing. Rifle loading takes more total steps to do well than handgun cartridges do. This is why when Dillon came out with its electric trimmer it would mount in one station of a 550B. They knew with that trimmer in place you had no way to finish other rounds progressively, so they just assumed you would size and trime and then perform the rest of the loading steps. That said, there are a couple of other choices around. You can trim first if you overdo it to make up for the effect of sizing. Different cases won't come out all identically, but if you are not crimping and you are trimming enough to stay away from going over the upper limit, you can do it. Some old M14 match shooters used to trim their military brass cases -0.020 below SAAMI minimum. They only ran those cases about 4 load cycles before pitching them our, and that short trimming let them trim each case once in its life. My point in mentioning it is just that you can get cases extra short without causing a general shooting problem. It just won't work if you are crimping with a conventional crimp shoulder in a seating die. A more recent product is the RCBS -die. For those you trim them to the low end of the SAAMI range once, but then never need to trim again, as they control neck growth, making them a good choice for progressive loading. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

June 12, 2019, 02:11 AM	#24
1stmar Senior Member Join Date: March 21, 2012 Location: Connecticut Posts: 2,378	Nick as the case goes into the sizing die does any of the brass get squeezed downward expanding the case near the pressure ring? If so, assuming you are not fl sizing or using a small base sizing die, wouldnt that that expansion always exist?