Seating Die for Cast 357 Magnum?

[Daekar]

I have been struggling for a while with shaving lead from the side of boolits when seating them. Not all the time, not all molds, but almost all molds. I have done some experiments with chamfering the case mouth, increasing the flare, changing boolit size, tried a Lyman M-die, etc, and I finally determined the reason I've been having trouble: even when adjusted so that it doesn't apply any crimp, my Redding seating die just squishes the case back in. If I perform the seating operation with an improvised tool which doesn't push the case mouth back in, everything works perfectly, and a separate crimping operation with my Lee Collet die is just the ticket. Perfect cartridge every time with no shaving.

My question is, what is a good solution to my problem with the Redding die? I absolutely adore the micrometer seating stem I have for it, so I would really love to have similar convenience for whatever I replace it with. Should I just buy a different seating die by a different manufacturer and get the micrometer for that die too? Should I just get a similar Redding die for 44mag or 45 Colt and use that? What about the Hornady Cowboy seating die? How about modifying the ID of the Redding die I already have (somehow... It's carbide...)? Is there a universal seating die with a flat-faced seating stem I should use? I'm not super concerned about cost here since this problem impacts the vast majority of cartridges that I load, but I don't want to waste money on whack-a-mole purchases if it's not necessary. Help!

EDIT: Ah, I should have said! One of the things that I already tried (and have continued to use this way, since it did help a little bit) is that I backed off the body of the Redding seating die so that it no longer applies any sort of crimp to the brass. It's so far out that the micrometer stem has to be almost all the way in to do my shortest OAL boolit, an Accurate 36-159S (almost a wadcutter)... this means that the brass never gets anywhere near the crimping point in the die. In fact, what I have found is that the ID of the die is tightly consistent all the way down, so that almost as soon as the brass enters the body of the die at all it is squished back in. If I examine brass which has been through only a partial stroke where the boolit isn't seated at all, you can see that much of the mouth flare is gone.

[Winger Ed.]

If you seat & crimp cast boolits in one step, it's real hard to avoid shaving Lead.
I've even seen Copper jacket material try to 'ball up' at the case mouth doing the single step operation
because the case mouth is starting to close up before the boolit is all the way seated.

I'd encourage seating and crimping as separate steps.
Even if you choose to use only the Redding die:
Set the die body to stop slightly above the crimp part.
Do the seating.
Then raise the stem above the COL, or remove it, and lower the die body down to set the crimp.

[Jackbrush]

My seating dies will shave off lead if i dont flare or bell the case enough. Also if i dont size them. For cast lead i usually use lees universal case expanding die and between hornady and lee seater dies I dont have any problems. Now im using dillon powder funnels for this purpose, no problems there either. All powder coated too if theres a difference between lubed, gas check whatevet idk.

When you say "pushes the case back in" are you referring to crimping? Most of my seater dies also crimp but if you need to you can only seat or crimp. Alot of progressive setups ive seen have a seater and crimp separate but i generally dont have a problem.

The case can buckle if your crimping too hard, maybe its that

[Daekar]

Ah, I should have said! One of the things that I already tried (and have continued to use this way, since it did help a little bit) is that I backed off the body of the Redding seating die so that it no longer applies any sort of crimp to the brass. It's so far out that the micrometer stem has to be almost all the way in to do my shortest OAL boolit, an Accurate 36-159S (almost a wadcutter)... this means that the brass never gets anywhere near the crimping point in the die. In fact, what I have found is that the ID of the die is tightly consistent all the way down, so that almost as soon as the brass enters the body of the die at all it is squished back in.

[Daekar]

My seating dies will shave off lead if i dont flare or bell the case enough. Also if i dont size them. For cast lead i usually use lees universal case expanding die and between hornady and lee seater dies I dont have any problems. Now im using dillon powder funnels for this purpose, no problems there either. All powder coated too if theres a difference between lubed, gas check whatevet idk.

When you say "pushes the case back in" are you referring to crimping? Most of my seater dies also crimp but if you need to you can only seat or crimp. Alot of progressive setups ive seen have a seater and crimp separate but i generally dont have a problem.

The case can buckle if your crimping too hard, maybe its that

I am definitely flaring enough, I considered that possibility and even bought a Lyman M-die to see if that would help and it didn't.

"Pushes the case back in" doesn't actually refer to crimping. The main non-crimping inner diameter (so everything below the crimp point) of the Redding die is so tight that it is actually pushing the flared mouth of the case back inward... you can literally hear the mouth of the brass scraping against the surface as the case moves upward. If you pull the brass for examination after only a partial stroke, you can see that the flare is almost gone before the boolit has been seated at all. With .357 projectiles I doubt this would be a problem, and might not cause any shaving, and for .358 it is less of a problem (still unacceptable in magnitude), but .359 and .360 are very bad.

[Yooper003]

I think I would try honing {polishing) the die couple thousands.

[Daekar]

I think I would try honing {polishing) the die couple thousands.

I had considered this possibility, but I confess that I don't know what kind of tool would be appropriate for it. Is there something I could pick up at Lowe's or Harbor Freight?

[Wayne Smith]

Contact Redding with this post and see what they say. I doubt they will sat it's within spec, but they might.

[1hole]

Try chamfering your case mouths a bit and set your seated bullets so they are crimped into the crimping groove, i.e., NOT on a driving band.

I've never thought of seating depth for handguns to require a micrometer.

[farmbif]

one of the reasons I like the RCBS cowboy dies, I Lube size all my 357 bullets at .360 and never have any problem. m dies sure are nice as long as seating dies does not crimp the shell back down.

[Mk42gunner]

I've been using a CH Speed Seater die that I scrounged somewhere for seating .38/.357 boolits for the better part of a quarter century. It works well for flat nosed projectiles, i.e. RNFP, WC, HP, SWC. I have no idea if it would work with RN.

Robert

[PJEagle]

There are threads from the past covering this.

The Redding micrometer seating die is designed with very tight tolerances to work with jacketed bullets. In most cases it will shave powder coating and/or lead when used with cast boolits.

I spent about six months learning this. The solution that worked for me was to sell the Redding die for half of what I paid for it and retrieve my old Lee seating die from the junk drawer. It was hard on my pride, but the solution worked. Since I load mostly SWC and WFN boolits, I ordered a custom flat seating stem from Lee and have never had a crooked or shaved bullet since.

I have several Redding reloading products and really like them. The only Redding products that didn't work for me were the Micrometer Seating Die and their case trimmer.

[Daekar]

There are threads from the past covering this.

The Redding micrometer seating die is designed with very tight tolerances to work with jacketed bullets. In most cases it will shave powder coating and/or lead when used with cast boolits.

I spent about six months learning this. The solution that worked for me was to sell the Redding die for half of what I paid for it and retrieve my old Lee seating die from the junk drawer. It was hard on my pride, but the solution worked. Since I load mostly SWC and WFN boolits, I ordered a custom flat seating stem from Lee and have never had a crooked or shaved bullet since.

I have several Redding reloading products and really like them. The only Redding products that didn't work for me were the Micrometer Seating Die and their case trimmer.

I spent a bit of time seeing if some sandpaper and a rod plus drill press would be a practical way to open up the ID of the Redding die I have. No bueno, that would take forever. I spent over an hour on it and maybe got it enlarged by .001 at most... at least we know Redding uses good steel. I'll keep it around for the one mold that it works really well with for a gun that won't accept anything larger than .358 boolits. I just ordered a 44 mag seat die with the flat bullet micrometer stem. It should be about the right length, and I know DARN SURE that the case won't touch the sides, lol.

[358429]

I spent a bit of time seeing if some sandpaper and a rod plus drill press would be a practical way to open up the ID of the Redding die I have. No bueno, that would take forever. I spent over an hour on it and maybe got it enlarged by .001 at most... at least we know Redding uses good steel. I'll keep it around for the one mold that it works really well with for a gun that won't accept anything larger than .358 boolits. I just ordered a 44 mag seat die with the flat bullet micrometer stem. It should be about the right length, and I know DARN SURE that the case won't touch the sides, lol.

Awwwe man thats an idea! I have the same problem with my lee dies! Sometimes I use the lee universal expander as a seating die if one of the two expanders is removed...

Sent from my SM-G930T using Tapatalk

[Petander]

I have some Redding dies and they all are too tight for seating even slightly oversize cast bullets. Goodbye coating!

People often end up with mixed brand die sets. I recently got the excellent RCBS cowboy set for 44 Mag.

I also use NOE expanders with everything cast.

[Daekar]

I have some Redding dies and they all are too tight for seating even slightly oversize cast bullets. Goodbye coating!

People often end up with mixed brand die sets. I recently got the excellent RCBS cowboy set for 44 Mag.

I also use NOE expanders with everything cast.

Yeah, that's where I am now. Primarily Redding, but now I also have Lee and Lyman dies as well, all with Hornady Lock-n-Load bushings on them. RCBS case trimmer, Lyman ingot mold, Lee and Accurate boolit molds, RCBS pot...

I have to say, the best of the recent purchases I've made is the Lee collet crimp die. It just does the job I need better than the standard crimp on the Redding seat die, and doesn't shave threads of metal off my cases to boot.

[Daekar]

I am happy to report that the 44 mag seating die arrived and I was able to crank out my first 100 rounds without a single problem. Everything worked perfectly!

EDIT: Did a few hundred more rounds yesterday evening and I'm happy to report that accuracy is improved as well. Damage was previously being done to the boolits even when I couldn't see it, and I'm getting smaller more consistent groups now.

[mdi]

I have seated many thousands of 38/357 bullets using my Lee dies and have shaved no bullets as long as there is suffecient flare in the case mouth (I started separating the seating/crimping in '72 or so, and now it's a habit)...

[Duckiller]

Lee universal expander will flair the case mouth enough to not shave lead then after boolit is seated crimp back to proper diameter. Not sure that makes sense. Use Lee di to flair and your seating di to unflair.

[Rapier]

Use a taper crimp on straight wall cases and never go back to anything else. You always seat then you crimp, two separate steps. I use two progressive presses to load with, and two holes in order.