Trimming pistol cases

Status
Not open for further replies.
Atavar

Atavar

Member
Joined
Oct 1, 2021
Messages
1,118
Location
Bemidji, Mn
To avoid hijacking another thread I am starting a new one.
I have been reloading a fair bit of pistol ammo with range pickup brass. I’m noticing a bit of an issue with case mouth flaring not being consistent.
Within one batch of head stamp sorted .45acp or 9mm the flare on the case mouth may be so narrow as to barely be able to stand a bullet on it or so wide that it has a hard time starting in the taper crimp die.
I am suspecting variance in case length being the culprit by changing how deep the case goes in the flaring die by a few millimeters.
I measured a random batch of .45acp Winchester cases and case lengths danger from .85” to .96”
I was surprised to see a range of .11” difference.
Before this I had just done a quick go/nogo check for case length.
I think I’ll try trimming this batch to the shortest case at .85 and see if the flare is more uniform.
The case trim length is .893. Do you think I’ll be creating any problems?
Any advice and education is encouraged and appreciated.
Here is a picture of columns of case lengths.
9D14D256-3C74-4BF4-A1F3-3B85BE69D360.jpeg
 
9F0B622F-EEF6-4CD6-84D2-48AC3074880C.jpeg Yeah, the trick is that none of them are actually at the trim length, they are all a titch shorter, just with some being shorter than others.
I ran a batch through the trimmer for an experiment. I see why nobody trims bulk pilstol cases. Lol Now to chamfer the case mouths and do case prep.
 
I commonly trim .38Spl cases as cases, even within the same headstamp, can vary in length quite a bit.

The main reason I trim is because I'm aiming for an uniform roll crimp. The fact that it also makes for uniform expansion does make it easier to avoid shaving bullets. I also trim to the a shorter length, but not all the way to that of the shortest case. I don't trim 9mm or .45ACP cases. I usually load jacketed bullets

Looking at your case length dispersion, I'd likely trim to the length of median and a SD. With a low pressure round like the .45ACP, I don't think it will have much affect on pressure. Another approach you might consider is to use an M-die profile expanding die which offers parallel sides to receive the base of the bullet and to enter the seating die.
 
Last edited:
I trim my revolver cases. I got the Wilson trimmer with the Q type case holder. Works great. Not only can I get consistent length cases but the case mouths are also square.

I only use Starline brass. I sort my fired cases by length after I deprime, anneal, lube and resize them but before I expand the case mouth. Within a given batch (typically four or five hundred), I find the shortest ones and set them aside (not useless but not to be used). Most of the cases are some middle length and I put them in a bin to be expanded. Any cases two thou or more longer and they get trimmed, deburred, chamfered and then go to the bin to be expanded. My goal is for the batch to end up with length +/- 0.001", but if the deviation of a few cases is two or three thou, I don't sweat it. These aren't benchrest cartridges or anything. Even so, I can be totally confident my cartridges will be consistent not so much because I've made them perfectly uniform, but because I've eliminated the outliers.

Personally, I would not waste time trimming mixed brass. Start with new quality brass. It's not that costly. People throw brass away at the range all the time because it is worth no more than trash to them. As a reloader, their trash is not my treasure. A good quantity of new brass is worth something, maybe a couple hundred dollars for 1000 of a popular handgun case. After that, it gains value to me as a result of my labor. Range pickup only has scrap value and I'm not willing to waste my labor for the results. I might consider using range pickups if there were several thousand of the same headstamp to be had, but I don't reload (or shoot) 9mm, or even .40 or .45.
 
I have never ever trimmed pistol brass either. Note: as you shoot it and reload it repeatedly it gets shorter over time as well. You want to assure your brass necks are no larger than necessary. I use two size expanders, one for lead and a smaller one for jacketed. The flare is enough so no bullet is scraped or deformed when seating. Taper crimping will return the brass to the correct size for bullet type after the flaring opperation.
I do however trim my revolver brass so as to get a repeatable roll crimp to help with consistency between brands and batches of brass.
 
I've never trimmed pistol brass. Lee, in his reloading manual said he doesn't believe it's needed but his customers wanted pistol trimmers so he made them. Usually if pistol brass has stretched enough to need trimming it probably should be discarded. But to each their own. If it makes you happy trim away.
 
Success! I trimmed all the cases to the samre length.
Then as this was the first time I loaded this once fired brass I reamed and cleaned the primer pockets.
I like the small chamfer around the primer pocket that reaming gives me. It seems to make priming smoother.
Then I chamfered inside and outside of the case mouths to get rid of any burrs from trimming.
Finally I brushed the insides of the cases to remove any detritus.
Thank goodness for the Lyman prep station. It really saves a lot of work.
Expanding the cases gave me nice uniform flares barely big enough to let the bullet sit on top. I used SNS 230g red coated LRN bullets. Only the second time I have loaded coated lead.
Another first tonight was using my Hornady micrometer seater. It was nice being able to start the bullet, measure to see that it was seated .012 long and dial the micrometer to seat .012 deeper. No more twist and measure repetitions. Every seating die should have one.
 

Attachments

  • E2D0AB22-1060-46F9-8249-BF886733C19D.jpeg
    E2D0AB22-1060-46F9-8249-BF886733C19D.jpeg
    129.8 KB · Views: 23
  • 3447F496-9252-46B2-BF42-01101946C937.jpeg
    3447F496-9252-46B2-BF42-01101946C937.jpeg
    145.2 KB · Views: 23
  • F3A6B71D-436D-4246-9D5C-3156913EF4CA.jpeg
    F3A6B71D-436D-4246-9D5C-3156913EF4CA.jpeg
    157 KB · Views: 23
Zygodactyl said:
I've never trimmed pistol brass. Lee, in his reloading manual said he doesn't believe it's needed but his customers wanted pistol trimmers so he made them. Usually if pistol brass has stretched enough to need trimming it probably should be discarded. But to each their own. If it makes you happy trim away.
Click to expand...
Agreed. The reason I was trimming wasn’t because they were too long. It was because I wasn’t getting uniform mouth flaring because the expander die flares longer cases more than shorter cases.
I wanted a uniform case length so I would get uniform flares.
 
With all the mixed brass I reload for semi-autos, I’ve never had your situation where you had no flare to too much for a crimp die. I’m glad you had success with your trimming!
 
  • Like
Reactions: mdi
I use M-dies for the flaring operation and instead of sorting my 9mm for length, I set my M-die up to not excessively flare a longer case.
While I'm loading on my progressive, if some cases come around that the bullet won't set into, I consider them to short and pull them off. I don't want them in that particular batch. I load for accuracy.
You can decide what you want to do with the short ones later.
This keeps my 9mm cases closer to the same length and gives me better quality ammo, and does the sorting for me.
But yes, I run into the same thing when I reload pistol loads. I just have a different way of handling the issue.
 
Since the 45acp head spaces on the mouth of the case I would have not trimmed them. What's happening now is the extractor is holding the round, putting undue stress on it.

The uneven mouths are only a problem if your doing a roll crimp. TC makes no difference. The use of a M-die would help a lot in aligning the bullet so it seats straight.

Mfg are cutting corners anywhere they can. There is only one mfg that I know of that gets you close to the max length, PPU. All others are short to min. My last custom build I did I elected to cut the chamber short for this reason. So far I have run across 1 round in over 10k that would not chamber due to the case being long. 0.003" over my chamber. I just save those and shoot in my other guns.
 
I have loaded thousands of pistol rounds 9mm, 40S&W and 45ACP and have never once trimmed any cases. From time to time a bullet did not sit inside the flare which I am sure is caused by different brass lengths. To solve this on occasion I just hold the bullet in place with my hand and then lower the press until the bullet is captured in the die. No issues after all these years,
 
Jes my thinkin'. K.I.S.S.! I do not trim any handgun brass, revolver or semi-auto. Flare on a case mouth is not a critical measurement. A few thousandths of an inch variation doesn't affect anything so my flare/M dies are adjusted so even the shortest case gets enough flare. Too much flare is when the case scrapes the ID of the seating die or at worse won't enter the die. The flare is removed when the cartridge is "crimped" (Revolver rounds are roll crimped and semi-auto cartridges are deflared with a taper crimp die). When I'm done and boxing a bunch of handloads, no one can tell how much flare was in my cases. I tell newer reloaders to use as much flare as needed to get good handloads now, and worry about case life later...

But, bottom line is, if you wanna, jes do it. It's your brass, your handloads, your time, so if you want every case to within .001" in length, it's your choice.
 
Last edited:
Maybe sort by manufacturer, see if there is length consistency based on this and load by manufacturer?
OR, sort by length and load in batches? Seems a lot easier than trimming pistol brass
OR, expand enough that all works, and then FCD die to crimp and size it - though this might reduce the number of times you can reload a single piece of brass

Just some thoughts.
 
Walkalong said:
I trim revolver cases for consistent crimps, but I do not trim any auto pistol cases. I adjust the taper “crimp” die to just remove the flare on the shortest cases, which gives the longest ones a hair of inward movement, about .001. No more is needed.
Click to expand...
When I started, I followed this advice...it has served me well
 
I also trim revolver brass to have a consistent flair and roll crimp.
In checking brass it varies all over the place even within the same manufacturer. I do group them by length and keep trimming to a minimum and reload by group.
 
Nearly 50 years of reloading and I have never trimmed any straight wall pistol brass.

Bottleneck rifle, yes trim, then anneal.
 
With a Hornady or lee Ptx flaring die ( they are spring loaded) you can put the plug in a lathe (or drill) and take off some of the flare such that the case mouth bottoms on the top ledge of the die. You get the same flare no matter the length. If you then use a lee collett crimper you get the same crimp no matter the length. I have found this eliminates trimming pistol cases, at least for my purposes.
 
Last edited:
I also have never trimmed pistol brass and all pistol brass is taper crimped.
Revolver brass Is roll crimped.
 
Status
Not open for further replies.

Similar threads

Atavar
Pistol case length
2
Replies
29
Views
1K
jmorris
jmorris
L
  • Locked
? re case trimming
Replies
11
Views
546
Walkalong
Walkalong
AJC1
  • Locked
Trimming magnum pistol cases
Replies
13
Views
699
tightgroup tiger
tightgroup tiger
M
  • Locked
357 mag dies all the same????
Replies
6
Views
2K
ArmaLube
A
T
  • Locked
Brass is buckling
Replies
12
Views
552
The Bushmaster
The Bushmaster
Back
Top