357 mag/ RCBS die problem


September 16, 2007, 08:54 PM
I just picked up a used colt trooper V 357 mag and wanted to make a few loads for it. My only dies are 38/357 standard RCBS dies vintage 1994, which I have used for years in a single stage press PITA. (new carbide dies are on order)

No problems sizing the 38 brass, but when I tried to size the 357mag brass I had considerable resistance. Imperial die wax was used and dies were just cleaned aswell.

The brass was stuff I picked up at the range and tumbled clean it seemed to be in very good shape most of it looked once fired with original factor primers.

Is this a die problem, the 38 special resized with eaze. The 357 almost got stuck a few times. HElP/ New carbide dies come in the week but this still concerns me.



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September 16, 2007, 09:05 PM
Change lubes. You'll have set up the dies for both cartridges too. Unless you have a .38 Special only revolver, you can load the .357 brass to .38 velocities and for get about changing the set up. It eliminatesthering of lube gunk in the cylinders too.
The only die in a carbide die set that has any is the sizer die. You could have bought just it.
Picking up brass from a range isn't that good of an idea. You have no idea how many times it has been loaded or with what.

September 16, 2007, 09:48 PM
One time I seen with my own eyes a die set that was stamped .38 special. It was not made for the .357. These were dies that was made back in the 1980s.
I think these were RCBS but I am not certain. Maybe yours is the same???

Other than that the only thing that makes sense is there is crud up in the very top of the die where only the .357 case goes making it tight.

lee n. field
September 16, 2007, 09:50 PM
Wait for the carbide. It will be worth it.

September 16, 2007, 09:59 PM

the resistance starts almost immediately. The dies are clean. I'm thinking maybe the brass was fired in a sloppy revolver and is now fireformed oversized. I will have to measure a few fired rounds to check .


September 16, 2007, 11:37 PM
I used RCBS carbide since the early 90'sfor .38spl/.357mag. they are still super :) I have been very pleased with these dies.

September 17, 2007, 02:16 PM
I had an RCBS .38/.357 carbide sizer that worked perfectly for over 30 years. I have no idea how many thousands of cases must have passed through that die over that time. Then, a couple months ago, the carbide ring pulled out. I sent it off to RCBS and a couple weeks later a brand new one arrived, no cost. Yeah, I know their stuff has a lifetime guarantee, but this was so painless I almost felt guilty. Great company with great products and service.

September 17, 2007, 03:08 PM
You're going to find that most .357 Brass is thicker than most .38 brass, and you're going to get more resistance, even when you receive your new carbide die. Thicker brass just produces more resistance.

Hope this helps.


Smokey Joe
September 17, 2007, 03:30 PM
Sunray-- Picking up brass from a range isn't that good of an idea. You have no idea how many times it has been loaded or with what.Not wishing to pick a fight; everybody is entitled to their own opinion; there exist a wide range of opinion on this particular subject. This is straightwall pistol brass, right? For which the general rule is, reload 'em until the neck splits, right?

So if someone is fool enough to leave their brass at the range, I will be a good citizen and help clean up. The stuff that looks to be in good shape, gets reloaded. The stuff that isn't in good shape, gets put in my scrap bucket. Likewise the stuff for which I don't have dies.

With rifle brass I am pickier--each of my rifles has a set of brass, and that's all that ever goes into that rifle--except my plinker autoloaders, and there, the pistol rules apply.

Last time I took my brass in to the scrap dealers, it was going for $1.65/lb. I got better than $60 for mine.

September 17, 2007, 08:57 PM
I went back to the brass pile, first I sorted by brand name and started to measure the O.D. of the brass from the rim to the neck at various locations.

--- all of the nickle brass regarless of manufacture was of a larger O.D .376 to .378 on fired cases.

--- the nickle brass with very flat primers also had a measureable bulge in the lower portion of the case starting about .250 above the rim, It measured a wopping .385 at the peak of the bulge.

--All of the brass cases with little to moderate primer flow sized very easy most of these cases averaged about .374--.376 O.D.

--a few brass cases had O.D. above .376, they sized with moderate effort. ALL of these cases had significant primer flow.

Executive Summary

Some of this range brass was hotttttttttt, and for some reason the nickle seemed to show more bulged cases than brass cases when primer flow was equal. Now I know primer flow is not a good measure of pressure, I've seen this first hand loading hot loads in the 17 remington and 17 Mach iv where only Rem 7 1/2 would work, all other primers even at moderate pressure would pierce.

Also, excessive seating presure on soft primers can mimick excessive primer flow.

Lesson learned--watch that range brass especially in high pressure cases like 357 mag. I think shooting and reloading the 38 special and 45 ACP for so long spoiled me, I've never had this type of experiance with either.



September 18, 2007, 04:30 AM
When I first started reloading I was making .38 special rounds day and night. When I finally got around to making some .357 Magnum rounds I also thought something was wrong with either my dies or the setup. The pressure required to resize the .357 Magnum brass was that much more. All the brass was once fires brass that I bought and shot so there wasn't a problem with the brass. Once I realized it was just heavier brass all was well...

BTW, how does that new Colt Trooper of your's shoot? Any pics you might share? :)

September 18, 2007, 04:07 PM
See if you can find or make a 7/8" I.D. flat washer that is .135" thick.
I think RCBS may even sell them now.

Once you adjust your .38 Spl. dies, put the washer on the expanding & crimping dies when you load .357.
(Don't use it on the sizing die.)

Now, you no longer have to adjust them back & forth all the time.

I've been doing it for about 40 years since making the first set of .38 & .44 washers on a surface grinder, and it works great!

.38 Spl. / .357 Mag is .135" washer.
.44 Spl/.44 Mag is .125" washer.
.45 LC / 454 Casual is .098" washer.


September 18, 2007, 10:54 PM
I have one of those washers and was using it before I bought a set of dedicated .357 Magnum from Lee and another 4 hole turret for the press. The washer works fine but I load so many of each it was worth it to me to buy a second setup.

October 1, 2007, 08:29 PM
I've fired about 300 round thru the colt so far, I'm stunned by the accurracy. Mostly 158 grain Lead RNFP. If I brace myself I can shoot 6 rounds into a 3inch circle at 50'. At 25 feet I can cut holes about every other round under an inch. Free hand well not so good but thats me.

I did fire about 5 rounds with 180 grain bullets and lilgun. From a rested position at 70 feet 3 rounds touched, 1 flyer about 3 inches high and the 5th round about 1/2" high from the group. The recoil was so strong I post in another thread to question if the Colt was strong enough to handle 180 grain with mag loads.

What gave me pause for concern was the gun starts to have cylinder rotation problems after around 40 to fifty rounds. I think the tolerance are so tight that the dirty gun starts to cause cylinder rotation problems.

I have not measured but I can visually see the colt tolerances are way tighter than my S&W and the Range Taurus.

I'll try to post some pics. later.

October 1, 2007, 08:45 PM

October 1, 2007, 08:53 PM

October 1, 2007, 08:59 PM
3rd try for pic hope this one works

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