357 & 38 case length/stretch?

[NAVY SEABEE 303]

I couldn't find this in any search, I have been loading 38 & 357 Mags for a while but I do not know how much stretch is okay before I need to start trimming the cases. I am sure with all the knowledge here someone can tell me the correct case length for these two I hope. And how many times should you trim a case before it is junk? thank you in advance for any and all help.

 

[918v]

They don't.

 

[cfullgraf]

There are published trim lengths for 38 Special and 357 Magnum. I do not remember what they are at present and I am not near my reloading info. You do not have to trim if the case is shorter than the trim length.

Crimps are more uniform if the cases are all the same length.

30 years ago I did a bunch of trimming of 357 Magnum cases. I found they were not growing under the resize/shoot cycle so I stopped worrying about it. I have not trimmed a 357 Magnum, or any other straight walled handgun case, in 30 years.

If you do not trim 357 Magnum or 38 Special cases then you cannot exceed any number of trims that require you to scrap the case.

But even so, with rifle cases, I do not worry about the number of trims on a case. Something else happens that cause me to scrap a case.

 

[ArchAngelCD]

Like said above, straight wall handgun cases don't stretch and do not need trimming. There are those who do trim their handgun brass and I don't fault them. I just don't think it's necessary at all.

 

[NAVY SEABEE 303]

Thanks for the info, makes sense.

 

[918v]

You can trim them all to the same length so that your crimp will be the same from round to round. Whether that improves your accuracy will require testing odd a benchrest.

 

[243winxb]

38 special= maximum length 1.155" 357 mag. maximum lenght = 1.290" When trimming remove .005" All reloading manuals will tell you to trim when brass exceeds maximum.

And how many times should you trim a case before it is junk?

In bottle neck rife, Lymam has said 4 trimmings then scrap the brass. For the 38 & 357, keep shooting till primer pockets get loose or case splits.

 

[Walkalong]

I trim revolver brass to get those consistent crimps because I like it that way. I can't shoot well enough to prove it helps. The cases will stretch a little at full .357 pressures.

 

[NAVY SEABEE 303]

Thanks this is exactly what I was looking for. I have been hand loading 38/357 for a while and never thought about it until recently. I knew this would be the place to ask. Thanks again, time to out and pick up some H110!

 

[rcmodel]

Seems you need to get at least one reloading manual.

As 243winxb said, every reloading manual has MAX and Trim Too length clearly stated in the beginning of each caliber chapter.

rc

 

[NAVY SEABEE 303]

I do/did have a couple manuals but when I had all my gear in storage the rats got to them. :-(

 

[mrbro]

I trimmed all my 357 brass just to have everything at the same length to get a uniform crimp.

 

[Minnesota Wild]

Yeah, 38 and 357 do definitely stretch, though it is far less than with bottleneck rifle cases. The real reason to trim is as others have said; to get a consistant bell and crimp. I normally just trim new brass so it's all consistant. With revolvers it's easy to keep the brass in lots that are the same and have the same number of loads on them.

If you load on a progressive you may have to trim every 8-10 loadings. I load 38s on a single stage press, so I can set the dies to the length of the batch of cases I'm loading. Because the cases have the same number of loads on them, they are all pretty much the same length and I never have to trim.

 

[HOWARD J]

I have 2 GP-100's
I don't trim my 38/357 unless they jamb the revolver.
I don't have any problems crimping various types of bullets
I would never do this to an auto pistol---revolver yes.

 

[ArchAngelCD]

Thanks again, time to out and pick up some H110!

Remember, if H110 isn't available W296 is the same exact powder. I buy the one between the 2 that's marked at the lowest price.

 

[NAVY SEABEE 303]

Thanks for the tip on the W296, I didn't know that.

 

[murf]

and don't forget the magnum primers.

murf

 

[GLOOB]

The reason to trim revolver brass is because you rarely find range pickups, and you rarely lose cases. So it's worth trimming, because you'll only have to do it once. Just don't trim to the "trim to" length. Trim to the max length or the length of your shortest headstamp, w/e is shorter.

 

[ColtPythonElite]

The majority of my .38 and .357 brass is a tad over 20 years old. I have never trimmed it. I don't even rotate it. I throw the empties back in my ammo cans and fish most of them back off the top when I go to loading again.