base of 357 not reduced by sizing die?

I am using once fired 357 brass that I saved from previous ammo, fired in a model 19. My resizing die (Lyman) does not resize the whole way to the rim. There is a space due to the shell plate, and there is actually a small gap before the carbide section starts inside the die. This results in a section, maybe 1/8 inch that is not resized, and in some instances is beyond the .379 case spec. Some of these brass will not full seat in my Hornady case gauge. Most will still seat in in my recessed cylinder model 19. Others require just a slight push in the cylinder to fully seat.
Is there a way to rework these bulging bases to bring them back into spec?
Should I scrap the ones that will not fully drop into the case gauge without a push?

In my experience, "old-school" steel dies that require lube will size closer to the case head than carbide dies.

Carbide dies vary between brands. Some intended for progressive presses have a bigger "funnel" to make case entry more certain. The downside is even less sizing near the case head.

I would only scrap cases that won’t fit in the tightest cylinder of any 357 Magnum I own, but I don’t use case gauges for pistol cartridges and YMMV.

I recently started reloading 45 Colt and got a Lyman 3-die set. I can clearly see even on new Starline cases where the carbide ring stops, but haven’t had any problems with the cartridges fitting in a gun. I got the Lyman set because I like the M-Die expander so much and the 2 seating stems have worked well for other cartridges. The set includes a shell holder, and the price is competitive. However, if another brand’s sizing die does this significantly less I’d have to reconsider…

I've had this happen with hotter loads shot though my Rossi 92. Then I reload the cases and they won't chamber in my Python with tight chambers. But they will push into my S&W so I shoot em in there as a way to do a full length resize. After that I can reload them and they chamber in the Python. Gives ya another excuse to buy another gun.

You need to make sure the ram, with the shell holder is in it's full extension,
then the sizing die needs to be screwed down to just touch the shell holder
and tightened.
Some back off the die just a "Hair" to be safe, from maybe over stressing the unit.

The only 100% sizing die that I know of, might be the old Ideal handloader, that was used back in the 1800's.

A normal case will only be sized about 88% of its length, when a die is set correctly
with the new single stage dies.
However this will meet spec's for the case to drop into a revolvers cylinder, freely.

My first m 19 p&r had been loaded so hot previous to me, that the cylinder chambers bulged causing stiff extraction with any power load. S&W replaced the cylinder but the finish did not match the frame. Used purchases are a learning experience.

I have experienced this many times, and not only with .357 magnum brass. A primary function of the cartridge case is expanding to seal against the chamber walls when a round is fired. The case head is slammed rearward against the breech face resulting in some unsupported case wall, and variations in finished chamber dimensions contribute to this. That is the exact portion of the case that cannot be engaged by the sizer because of the need for clearance to permit the case to enter the die.

Newer sizing dies featuring carbide or nitride sizing rings require some clearance to avoid direct contract of the very hard (and potentially brittle) sizing element with the shell holder on the press ram, which would very likely cause the sizing element to shatter.

Krogen (post #2 above) describes the best remedial method, sizer dies made before carbide or nitride sizing rings became the norm will usually allow a more thorough result. I have used this method for the first resizing of once-fired factory brass, followed by reloading with less than maximum charges.

In addition, keep in mind that the cases will have a tendency to "spring back" somewhat after resizing. A second pass through the sizing die can help to overcome that, although nothing will completely eliminate the small portion of the case wall that remains untouched by the sizer.

Try dropping them into your revolver's chambers. Those chambers are bigger than your case gauge, which is cut to the minimum cartridge dimension.
Some die manufacturers will tell you to run the die all the way down to the shell holder, plus a little more so the handle cams over after contact. Some tell you to leave a hair's breadth between the shell holder and the bottom of the die. Either way, carbide dies just don't get the full length of the case. Is it possible that you have unusual bulges in the bottoms of your cases from over pressure loads, or an out of spec chamber? That's the only other problem I can imagine.

If you are trying to size clear to the rim you are causing the problem you describe because you are trying to size the solid portion of the case head. Try sizing about 1/16" less than you are doing the next time you have once-fired cases to load and you shouldn't have this issue. I have a prior post that thoroughly describes the problem, but it was several years ago and I have no idea when it was except for being probably at least eight years ago. This only happens when trying to size too deeply when using carbide dies, standard dies are slightly larger in diameter and do not cause this problem!

Alk8944 said:

If you are trying to size clear to the rim you are causing the problem you describe because you are trying to size the solid portion of the case head. Try sizing about 1/16" less than you are doing the next time you have once-fired cases to load and you shouldn't have this issue. I have a prior post that thoroughly describes the problem, but it was several years ago and I have no idea when it was except for being probably at least eight years ago. This only happens when trying to size too deeply when using carbide dies, standard dies are slightly larger in diameter and do not cause this problem!

Click to expand...

Are you saying that by sizing too much it is actually making the lower part of the case wider instead of smaller? I guess this could be proven by measuring before sizing then after and see if it actually gets bigger.

Rosewood

magnumb said:

I am using once fired 357 brass that I saved from previous ammo, fired in a model 19. My resizing die (Lyman) does not resize the whole way to the rim. There is a space due to the shell plate, and there is actually a small gap before the carbide section starts inside the die. This results in a section, maybe 1/8 inch that is not resized, and in some instances is beyond the .379 case spec. Some of these brass will not full seat in my Hornady case gauge. Most will still seat in in my recessed cylinder model 19. Others require just a slight push in the cylinder to fully seat.
Is there a way to rework these bulging bases to bring them back into spec?
Should I scrap the ones that will not fully drop into the case gauge without a push?

Click to expand...

This is an issue with the "bulge" you see in 10mm and 40 S&W cartridges sometimes. Since they are straight walled rimless, you can push them thru the Lee factory crimp die to iron out the bulge back to factory spec using their bulge buster kit. However, that won't work on a rimmed case for obvious reasons.

In your situation, I am not sure the shell plate is the problem, but the taper of the mouth of the die is likely why it isn't sizing far enough. That taper is to funnel the round into the die.

One thing you could do is buy an extra sizing die, someone mentioned a steel die. Then if it doesn't do enough, take a grinder or mill and take off maybe 1/8" of the bottom of the die to get to the straight part of the die. Resize first with your regular die, then use the modified die on the cases to straighten out your problem area. You will likely have to go slow and maybe guide it by hand since the "funnel" part has been removed. Lubing with steel die is likely needed.

I did something similar with belted magnum cases. Found some wouldn't chamber across different bolt guns. Guy sells a die kit that fixes the problem, but it is like $100+. I bought a Lee 7mm STW die in the clearance section at BPS (~$9), cut off the top to get past the neck sizing part and shortened the bottom so it would go down further. I then use it to knock the "bulge" off the belted magnum cases to the belt. It works to straighten up all belted mag cases. I know it isn't at the base like your problem, but similar concept.

You can also modify a shell plate by trimming it thinner so the die will go down further. I would only use it for the suspect cases and not in standard reloading though.

I don't think any standard sizing die sizes completely. You really don't have to go all the way. Sizing pushes the brass in the die to spec, and the brass out of the die is also pushed in for a short distance since the brass isn't getting crimped at the juncture, it is pushed in also. Not sure I am explaining this clearly, buy maybe you get the idea.

Rosewood

Tighten the shell plate so its snug. Have bottom of carbide die lightly kiss the shell plate. Ok if the die pushes the shell plate down gently.

Make sure other dies are not contacting the shell plate before the carbide sizing die.

Each station of the shell plate may be a different thickness, deck heigth, not wanted.

Unless the shells will not proceed, without more than a “push”, I don’t see a problem.

I have had a small problem with a few cases not being sized all the way.I have actually faced off the base of the die. Also removed part of the top surface of the shell holder. For progressive presses you need a bit of funnel. For most of my warmer 357 mag ammo I load on a Redding T7. I also have an OLD Herters carbide sizing die and another old RCBS carbide die. They have no funneling effect and they are what I use for most warm 357 mag ammo I load with a thinned old #6 shell holder. The chamber on my 94 Win 357 is somewhat tight. Carbide rings on newer dies are fairly thin compared to some of my old sizers. I have others in 44 and 45 cals too with very thick carbide rings clear to the bases

after a bit more research I located the SAAMI spec for 357 cylinders. At the mouth, the dia is .381, tapering down to .380 over about 1.2 inches. The 357 cartridge is SAAMI spec at .379. The best I can measure I suspect the Hornady case gauge is dead on .379, so some cases that have a slight interference fit with the gauge chamber just fine in my model 19 (where it really matters.

I can definitely see section near the base which is larger on my reused brass, some are right at .381, and this section is not resized by my die. I may consider getting a steel resizing die and if needed grind a small amount off the end to allow sizing further down. I hate to throw away brass that otherwise could be used!

I am wondering about how far towards the base to size. At some point there is the thicker brass that holds the primer. I suspect you don't want to resize that section. I will have to measure some store bought rounds to see what they measure in this section

any suggestion about where to get a steel resizing die. Every one on midway usa is carbide

magnumb said:

I am using once fired 357 brass that I saved from previous ammo, fired in a model 19. My resizing die (Lyman) does not resize the whole way to the rim. There is a space due to the shell plate, and there is actually a small gap before the carbide section starts inside the die. This results in a section, maybe 1/8 inch that is not resized, and in some instances is beyond the .379 case spec. Some of these brass will not full seat in my Hornady case gauge. Most will still seat in in my recessed cylinder model 19. Others require just a slight push in the cylinder to fully seat.
Is there a way to rework these bulging bases to bring them back into spec?
Should I scrap the ones that will not fully drop into the case gauge without a push?

Click to expand...

This is very common with carbide dies but I've never had a problem where the loaded rounds did not chamber.

Lee also makes a "bulge buster" die if it's really a problem. That will straight out the remaining part of the case.

I wouldn't even use a case gauge on straight-walled handgun cases. They don't generally grow in length with use, and they headspace off the rim (or case mouth, if semi auto). As long as they seat completely in your revolver chamber, and the max case length isn't exceeded, you're good to go. Case gauges become handy with bottleneck cases, where the case shoulder moves from multiple firing and can affect case length as well as headspacing.

Not meaning to be snarky, but, just put the cartridge gauge inb a drawer somewhere and "plunk" your handloads. I have used Lee, Hornady and RCBS 38/357 sizing dies for many years and If there was a chambering problem in one/some of my 6 38/357 revolvers I would find out why and fix it. A mass produced product like your sizing die can have a die out of spec/tolerance slip by, but first I'd look elsewhere...

magnumb said:

I am using once fired 357 brass that I saved from previous ammo, fired in a model 19. My resizing die (Lyman) does not resize the whole way to the rim. There is a space due to the shell plate, and there is actually a small gap before the carbide section starts inside the die. This results in a section, maybe 1/8 inch that is not resized, and in some instances is beyond the .379 case spec. Some of these brass will not full seat in my Hornady case gauge. Most will still seat in in my recessed cylinder model 19. Others require just a slight push in the cylinder to fully seat.
Is there a way to rework these bulging bases to bring them back into spec?
Should I scrap the ones that will not fully drop into the case gauge without a push?

Click to expand...

If the resized brass drop in the gun or need just a slight push, I don't really see any problem.

You are using a progressive of some sort I gather?
The 'ShellPlate' may be thicker than a common Single Stage Press reloaded Shell Holder.
As some have suggested, try resizing the brass using a regular SH in a Single stage press and see if that gets you some extra sizing depth.
Also slightly thinning the top surface of the SH to again allow a deeper sizing depth.
You can go even deeper by eliminating the SH all together. Pushing the stubborn case into the FL Sizer with just the Ram and a flat piece of steel under the case head.
Lots of Lube on that case!
You will have to knock out the case from the top of the FL Die with a brass or steel rod. I slightly round the end that goes down into the case so it doesn't chew up the bottom of the insde of the case.
A couple raps and the case comes out.
You will have a really Full Length Resized case then. Right to the rim.

I just had to do that with some new Bertrum Brass & orig Rem-UMC brass in 28-30-110 caliber to fit a new cut chamber.
FL sized cases simply would not chamber completely at the base unless that last little bit (1/8"+ )was sized/swaged down.
Simple in a RCBS RockChucker and CH4D dies.

Slow process, but you should only have to do it once!
You have to decide if the brass is worth it.

None of the FL size Die and Shell Holder combinations will size the case right down to the rim. The last 1/8" of so is a solid 'head' (and for good safety reasons).
You would be Swaging that solid brass head to reduce it's diameter and that takes a lot of leverage in a press.
That brass portion does not/should not expand upon firing. The walled portion in front can and will. The amt depends on the ever diminishing thickness of the wall as it goes forward and the pressure generated by the load.


Just my thoughts.