357 case sizing

[Parks2055]

Hey Folks,
I have been loading 40S&W for a couple months and just starting to do some 38/357 as well.
I have noticed that the cases do not seem to get sized all the way down. It was a bit noticable on the 40 cal, but now more so on the 357 cases.
Loading on a Hornady LNL AP. The sizing die is definitely touching the shell holder, but I can see where the die has stopped sizing about 3/8" from the base.
I have had the same results using a Hornady nitride and with RCBS carbide dies.
The sized portion of the 357 case is about .372 and jumps up to .385+ towards the base. Is this normal or am I doing something wrong?
Thx,

 

[USSR]

That simply indicates that you are not getting expansion in the web area of your brass from overly hot loads, and there's nothing wrong with that.

Don

 

[Walkalong]

Normal. You can size just enough of the case to hold the bullet if you wish. There is no need to size all the way to the rim, nor is it feasible to do so with standard dies.

I sized 200 .357 last night, and mine look the same way. If I was there, I would take a pic of one.

 

[ReloaderFred]

What you are seeing is normal. There is a gap between the rim of the case and where the sizing die reaches. This is caused by the thickness of the shell holder and the radius of the opening of the sizing die. It's physically impossible to size the entire case using a shell holder, since the lip covers part of the case. A shell holder is required to be able to pull the sized case back out of the sizing die.

There are dies for sizing the entire length of the rimless cases, such as the .40 S&W, 10mm, .45 acp, etc. They use a rod to push on the inside of the case and push the whole case all the way through the die, with the case coming out the other end of the die. I have the Magma Case Master Jr. http://www.magmaengineering.com/component/banners/click/10/ for doing this. As Walkalong pointed out, it's not necessary with revolver rounds.

Hope this helps.

Fred

 

[Parks2055]

Perfect - Thanks.
Another question on these 357 rounds with 158gr bullet and 12.0gr of 2400.
How much is the presure affected by the COL?
Example: With a COL target of 1.585 with this load, which is not too heavy, maybe about 1,000 fps - how much of an effect on pressure will seating @ 1.575 cause?
And with a max COL of 1.590 - Am I still okay with a small vairance to 1.595.
When loading 40cal it never called for seating at the max COL for that round.
Many 357 loads call for max col of 1.590.
This is more curiousity than anything. I know I should not be getting any more than +/- .005 when seating and is also why I need to crimp heavier loads in a separate die..
Are revolver rounds generally more forgiving with COL?
Thx.

 

[Walkalong]

.010 difference is not going to show up much in this application. Does it make a difference? Sure, but it won't be enough to even show for sure with a chrono. Lots of extra space in that big case, and you are well under max.

Load them to the cannelure, or the crimp groove, and that is your OAL with that bullet.

 

[avan47]

And with a max COL of 1.590 - Am I still okay with a small vairance to 1.595.

If they stick out the front of the cylinder, it will not be able to rotate, and your revolver will jam when you try to shoot it. If your cylinder is long enough, then, no problem.

 

[joneb]

Normal. You can size just enough of the case to hold the bullet if you wish. There is no need to size all the way to the rim,

I tried partial sizing for 38 spl and 357 mag hoping for improved accuracy with the bullet more in line with the cylinder throat, I could not detect a advantage doing this, but I don't see any harm in it as the the case volume would be greater.

 

[gamestalker]

Because of the tapered throat in the cylinder, using brass that is longer than 1.590" could cause the mouth to get pinched. It is treading on thin ice in my opinion to load any brass that is above SAAMI spec. and in need of trimming, this is why all cartridges have a SAAMI spec. regarding maximum trim too lengths. And with regard to revolver cartridges, getting a consistent crimp is nearly impossible if brass is not all the same length.

Be careful and follow the reloading books to the letter until you've learned the ins and outs of reloading, and more hands on experience in this respect.
GS

 

[ReloaderFred]

gamestalker,

Brass that was 1.590" in length wouldn't be .357 Magnum brass, since the nominal length of .357 brass is 1.290". He's talking about the OVER ALL LENGTH of the loaded round, not the brass. I've loaded 180 gr. bullets in .357 Magnum to an OAL of 1.610", which worked fine in my revolvers, but were too long for my Marlin rifles.

Hope this helps.

Fred

 

[Parks2055]

Great tips and advice - Thank you.
What is the best tool for trimming 38 and 357 brass?
When I go to reload the brass for a second time, it may be a good idea to trim and get them all even.

 

[USSR]

What is the best tool for trimming 38 and 357 brass?
When I go to reload the brass for a second time, it may be a good idea to trim and get them all even.

In 35 years of loading .38 and .357 brass, I have never trimmed a case. It simply is not necessary.

Don

 

[kingmt]

I have never trimed handgun brass.

How would you pinch brass in a revolver? Can't happen in mine anyway.

 

[joneb]

I have a Lyman Universal and it is ok, I think there are better ones.
I trim .357 mag. brass to 1.280" this allows me to use a heavy roll crimp.
Here is a 170gr keith style the COL is 1.630" I can not afford any bullet jump with this bullet and 13gr of AA#9.

 

[gamestalker]

My bad Reloader Fred. I wasn't paying close enough attention I guess.

But regarding brass trimming, I do realize most do not trim any of their pistol brass, but this really isn't the correct and instructed manner by which to reload, which is why I have always trimmed all of my brass for several decades. If brass did not have a trim too length published, and my books didn't indicate such, I would not find it necessary to perform the rather cumbersome task.

If I ever KB a firearm I'll no for certain it had nothing to do with brass length.

I'm not trying to open a can of worms here, just simply stating the obvious published SAAMI specs. indeed have purpose.

GS

 

[Walkalong]

I like to trim .38 Spl and .357 brass, because my range brass of many makes has such varied lengths. I am a little picky (Understatement) about crimps, and brass that is close in length crimps more consistently.

My .32 Long, .32 Mag, .32-20 brass, .38 S&W, and .41 Mag brass is all Starline. It is consistent enough that I do not trim it, although I did deburr and chamfer it.

I have also trimmed all my .44 Spl, .44 Mag, and .45 Colt brass.

I have used untrimmed .38 and .357 brass for test loads, and could not see any difference on target. Perhaps a master handgun shooter could, but I surely cannot.

Reloader Fred, who I have great respect for, doesn't trim any .38 brass, and he shoots a ton of it.

To each his own.

 

[ReloaderFred]

You are correct, Walkalong. I don't trim .38 Special brass, nor any of my other handgun brass, though I did once have to trim some 357 Sig brass that was too long, but that was only a few.

Right now, I've got about 9,000 rounds of .38 brass to load by the end of summer, which I'm casting bullets for now. The thought of trimming that much brass makes my head hurt. Besides, I'm getting older and probably wouldn't get it all trimmed before I leave this earth............

Hope this helps.

Fred

 

[buck460XVR]

I trim brass for hunting loads in .357, .44 and .460. This gives me a consistent heavy crimp which I've found to be helpful when using slow burning magnum powders like H110/W296 and IMR4227. My chrono shows less deviation and my targets show closer groups when doing this. Altho the difference is small, I feel I owe it to my quarry. For plinkin' and range bullets I seldom trim.

 

[FROGO207]

I personally do not trim my handgun brass if it is straight walled either. But if you feel the need to I would recommend the Lee case length trimmer for that caliber. You will also need to get the lock-stud/cutter combo for the first one. I would get the one with the stud to mount it in a drill.. If you do that all you need to change calibers is get a specific trimmer assy and they are less than $4 each. The whole setup is lots less money than any of the bench mounted trimmers out there.