Yes, I'm asking. Never trimmed a piece of handgun brass but my crimps are not allowing a few of my rounds to chamber. So, what do y'all use to trim 357 mag brass? I'm wanting something I can run a bunch of cases through quickly and easily.
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Trimming 357 mag brass
- Thread starter stan v
- Start date
Golphin
Well-known member
You can use the lee trimmers or any case trimmer I would think. I have a Hornady case trimmer but have never trimmed my 357 Magnum brass or any other pistol brass with it.
Quickly and easily, well, you might want to look into a power machine or a decent hand crank model. Forster makes nice stuff but it's expensive. I don't have to "usually" trim handgun brass but I use the basic Lee trimmer (case length gauge cutter and lock stud). Rifle rounds always get checked for length.
By the way, I meant some rounds failed to drop into cylinder, not chamber.
Anywho, I'm thinking a power trimmer of some sort. I hand crank my rifle brass to trim but not about to run 2000 or so 357 mag pieces on that trimmer.
Anywho, I'm thinking a power trimmer of some sort. I hand crank my rifle brass to trim but not about to run 2000 or so 357 mag pieces on that trimmer.
Geno44
Well-known member
Have you measured your brass after sizing to determine if it is too long? Are you sure the problem is not with your crimp rather than the length? Like others, I have never trimmed a .357 magnum case in my almost 60 years of reloading.
nicky4968
Well-known member
I have done thousands of .38 Special and .357 Magnum cases using the Lee Zip Trim and Lee cutters and mandrels. Lee stands behind their products.
Hair Trigger
US Veteran
You can trim any brass with any case trimmer, but why do you feel it will solve your apparently tight fit in the chamber? (You said the cartridge won't "drop in"), rather than fail to chamber, which implies they don't fully seat. What type bullet are you seating in the case, does it have a crimping cannelure? If not and you attempt to crimp (either a roll or taper), instead of crushing into the bullet or its jacket, it may be making a slight bulge in the case along the crimp edge, making it too tight a fit in the chamber. You'd either need to switch to a plated bullet that has a softer jacket, or straight lead bullets, or jacketed bullets with a cannelure, which is designed to be within the seating lengths for the completed cartridge. You may also be putting too much crimp into the bullet.
One other consideration about trimming brass is how much you're taking off. Take too much off (below the minimum SAAMI length) and you're effectively decreasing the case capacity, which will affect ignition pressures, which dictate a decrease in the powder load for a specific performance, or to be a safe load. There's only 0.135" difference between a .38 Spl. case and a .357 Magnum case length, and putting a magnum powder load into a Spl.-length case could create overpressure problems.
Of course, the brass needs to be within SAAMI specs for length when you process it for loading, which may mean trimming the cases back to spec before loading them. I can use my handgun brass many times before it gets out of spec for length. I start worrying about splitting the case mouth from too many sizings before I have issues with length, and that even extends to semiauto cases that headspace on the case mouth.
One other consideration about trimming brass is how much you're taking off. Take too much off (below the minimum SAAMI length) and you're effectively decreasing the case capacity, which will affect ignition pressures, which dictate a decrease in the powder load for a specific performance, or to be a safe load. There's only 0.135" difference between a .38 Spl. case and a .357 Magnum case length, and putting a magnum powder load into a Spl.-length case could create overpressure problems.
Of course, the brass needs to be within SAAMI specs for length when you process it for loading, which may mean trimming the cases back to spec before loading them. I can use my handgun brass many times before it gets out of spec for length. I start worrying about splitting the case mouth from too many sizings before I have issues with length, and that even extends to semiauto cases that headspace on the case mouth.
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AS I re-read the op's complaint...it is not an over length casing problem, it is a crimping problem. Too much crimp....
Size a casing without seating a bullet, insert into cylinder....should drop in if your dies are seat up properly.
Flare the case mouth only enough to seat the bullet.
Seat a bullet with the crimp backed of as much as possible.....check in cylinder or case gauge.
Turn stem down until it just barely crimps.....check in cylinder...
Usually this problem shows up when you have over crimped the casing.
Check it against a cartridge that chambers with no effort.
Randy
Size a casing without seating a bullet, insert into cylinder....should drop in if your dies are seat up properly.
Flare the case mouth only enough to seat the bullet.
Seat a bullet with the crimp backed of as much as possible.....check in cylinder or case gauge.
Turn stem down until it just barely crimps.....check in cylinder...
Usually this problem shows up when you have over crimped the casing.
Check it against a cartridge that chambers with no effort.
Randy
The problem is with some once fired, nickel 357 brass that I picked up from a friend. All my Starline stuff feeds/fires fine. But, about one in 5 of these nickel cases won't drop into the cylinder, some will with a little effort. Looking at the crimps tells me these cases are a little longer than the Starline.
I have no idea how many times they've been fired. Furthermore, I load RNFP and the crimp groove is tiny. I'm considering going back to a SWC keith type bullet cause crimp area is so generous.
RNFP feed my lever gun flawlessly.
I have no idea how many times they've been fired. Furthermore, I load RNFP and the crimp groove is tiny. I'm considering going back to a SWC keith type bullet cause crimp area is so generous.
RNFP feed my lever gun flawlessly.
Too much crimp or not removing mouth flare. I started reloading 38 Special in '69, 357 Mag in '72, 44 Magnum in '88 and also 6 other handgun calibers and have had no problems chambering any and never trimmed any brass. My crimped revolver rounds are very consistent and all chamber in 5 revolvers I reload for. I have 7 semi-auto pistols (and two handgun cartridge rifles) and all feed, fire extract and eject flawlessly with no "crimps...
In about 2000 I bought a Lee 45 ACP case trimmer out of curiosity and trimmed maybe 20 cases. The trimmer is now somewhere out in the shop, used just once.
In about 2000 I bought a Lee 45 ACP case trimmer out of curiosity and trimmed maybe 20 cases. The trimmer is now somewhere out in the shop, used just once.
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I use this one, chucked up in a drill to trim my .223/5.56 brass
Works just fine and it won't break the bank, as long as you already have a drill.
Lyman E-ZEE TRIM Hand Case Trimmer| Case Trimmers & Accessories
Works just fine and it won't break the bank, as long as you already have a drill.
Lyman E-ZEE TRIM Hand Case Trimmer| Case Trimmers & Accessories
muddocktor
Well-known member
My experience with 357 and 38 Special goes back to 1974 when I got my first pistol. And yes, I do trim 357 Mag brass every once in a while because it will "grow" over time, especially when you load on the hotter side. But I also find that it seems to be no rhyme or reason as to how much it will grow in a particular batch of brass too, in that some will be longer than others in a particular batch, which makes getting a consistent crimp and seating depth a problem. So I will take that batch of brass and process the whole bunch back to consistent OAL to some point near the minimum OAL for 357 brass.
I use my old Lyman case trimmer to trim my 357 Mag brass. I did change the trimmer shaft out on it to the one you can use with a drill, so it saves effort on the hand and trims faster. And I find that once trimmed, the 357 brass seems to keep pretty consisten thereafter on OAL.
I use my old Lyman case trimmer to trim my 357 Mag brass. I did change the trimmer shaft out on it to the one you can use with a drill, so it saves effort on the hand and trims faster. And I find that once trimmed, the 357 brass seems to keep pretty consisten thereafter on OAL.
Transamconvert
Well-known member
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I also use the Ezee trim, it's fast and effective. I had the same problem using mixed 357 brass I would get an occasional long case that would then over crimp.
4barrel
Well-known member
Nickel is a little harder to size. Make sure you are full length resizing<brass touching shell plate>. I have never resized a 357 case but would like to know the outcome. Resize some and drop into the cylinder or case gauge without loading. Also note that if it happens on the same cylinder. Do you have another 357 to try?
You might start by pulling the bullets..........
Full sizing the case and checking it's OAL.
1.290" is the maximum length for a case.
.379" is the Dia. for the case mouth.
Good luck.
Full sizing the case and checking it's OAL.
1.290" is the maximum length for a case.
.379" is the Dia. for the case mouth.
Good luck.
gregintenn
Well-known member
Measure them before going to the trouble of trimming.
I will run some of these nickel and do as you suggest. And yes, I have more than 1 357 revolver.
Thanks for all the suggestions. And I would have never thought of the Lyman trimmer. TY!
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stansdds
Well-known member
When I trim brass, it is with my old, trusty Lyman Universal Case Trimmer. I have found that with most straight walled handgun brass, one trimming is all it needs. I take a batch of new brass, resize it, measure to determine length and length discrepancies, then trim so as to get them all the same length. I guess straight walled cases can stretch, but I have yet to see enough to have to trim a second time.
