357 Magnum Woes

[Olon]

Thanks so much for all the responses.

To address a few questions:

These are SNS Cast Bullets: 158 gr. semi-wadcutters with a diameter of .358" Previously I had used Berry's TP 158gr. FP with a diameter of .357 so no these aren't 9mm bullets.

The dies are some really old RCBS dies I got off ebay for cheap. I'm definitely not in love with them though they seem to work fine for 38 special.

When I resize, there is absolutely no resistance (i.e. cases not being swaged down at all). That said, the OD of the entire case is right at .379", which is undersized according to SAAMI. While I thought the dies were suspect, this would rule that out I suppose. Evidently the chambers in the guns I'm shooting are all incredibly small because I'm shooting near-max loads with bluedot.

I'm not home at the moment, but I'll get back with more measurements tonight.

 

[edwardware]

When I resize, there is absolutely no resistance (i.e. cases not being swaged down at all). That said, the OD of the entire case is right at .379".

I trust your comparator (the die isn't sizing the case) more than your measurement. You have a bad/wrong die. Get a used sizing die from fleabay, and I'll bet your problems disappear.

 

[Olon]

[

Well....we all want to know what projectile it is. I personally want to see you resolve this. It doesn't sound right.

I crimp how you aren't supposed to. I crimp and seat in the same step with my Lee seating die. This is in trimmed(just once) random .357 brass. This includes starline that I bought new 8 or so years ago. Just enough roll crimp to help feeding in the lever action. I doubt it adds much tension on the projectile.

Normally I crimp and seat in the same stage, too. These are hard cast 158 gr. SWC from SNS casting. I've had great success with their bullets in the past: both with 158 gr. RNFP in 38 special and 240 gr. SWC in the 44 mag.

 

[Glockula]

Interesting. I have used a couple thousand SNS projos in 125s and 158s for .38 and .357mag. I have bought 1000 star line 300 blacks that need sizing to fit in my chamber. The necks are over sized.

 

[buck460XVR]

The idea that you need not bell a case to get a bullet started(any bullet) tells me that your resizing die is not doing it's job. If it was one bullet, one type of bullet, I'd guess it was the bullet. If you had to flare the case to start a bullet and then there was no neck tension after crimping I'd say it was too much crimp or your dies need to be adjusted. The fact you have never been able to get a decent crimp using that set of dies, tells me they are probably the issue. That they were for sale cheap on ebay may be telling also.

 

[Obturation]

The idea that you need not bell a case to get a bullet started(any bullet) tells me that your resizing die is not doing it's job. If it was one bullet, one type of bullet, I'd guess it was the bullet. If you had to flare the case to start a bullet and then there was no neck tension after crimping I'd say it was too much crimp or your dies need to be adjusted. The fact you have never been able to get a decent crimp using that set of dies, tells me they are probably the issue. That they were for sale cheap on ebay may be telling also.

If I'm not mistaken the OP says the same dies work fine for 38 special though. Which makes me wonder how it can work properly with the slightly shorter case but not be able to at least properly size the top half of the 357 case.

 

[buck460XVR]

If I'm not mistaken the OP says the same dies work fine for 38 special though. Which makes me wonder how it can work properly with the slightly shorter case but not be able to at least properly size the top half of the 357 case.

I thought of this also. Maybe the lower pressure of the .38 rounds are not expanding the cases and thus there is more neck tension left? The fact that the bullets are loose in the case before crimping, and the bullets themselves are not undersized(supposedly) then it has to be either the resizing die, or the die adjustment. Adjusting the sizing die is so simple, I'm not really considering that. A few years back, I bought my two sons Ruger LCPs for Christmas. Never reloaded for .380, but I thought for them I would. Not thinking it would be a huge amount I went cheap and bought Lee dies. Had the same problem the OP is having. The bullets(Jacketed and different varieties) would slip right into the case after resizing. Then, after crimping the bullets could be pushed easily into the case. Contacted Lee and the said I needed their "undersized: die because of some varieties of brass. No....I needed it with all varieties of brass. Come to find out, the standard Lee .380 dies are known to be oversized. Ended up paying as much for the one Lee "undersize" die as I did for the whole Lee set. Ended up paying for for the cheap set than a decent set from RCBS. Still the "undersize" die, cured the problem, regardless of brass. If the OP is having issues with Starline brass(some of the thickest there is) and neck tension, it has to be in the sizing. Could the dies be wore out? could the carbide ring be gone from the sizing die? I resize new brass, even tho many don;t think it's necessary. I feel resistance when resizing this new brass, the fact that the OP feels no resistance when resizing fired brass points in a specific direction.

JMTCs tho, from the info I have seen.

 

[Olon]

I'll buy some different dies, as I think that must be the issue.

The seat/crimp die was so long with these that I couldn't thread it down far enough to reload 38s so I took about 3/4" off with a bandsaw and rechamfered it. Hopefully a new set of dies will allow me to get this sorted out.

 

[AJC1]

I'll buy some different dies, as I think that must be the issue.

The seat/crimp die was so long with these that I couldn't thread it down far enough to reload 38s so I took about 3/4" off with a bandsaw and rechamfered it. Hopefully a new set of dies will allow me to get this sorted out.

In a wild twist is there any chance that you're using 38-55 dies

 

[Olon]

In a wild twist is there any chance that you're using 38-55 dies

They say 357/38 on top so that's unlikely.

 

[Blue68f100]

Is this a carbide die? Is the carbide ring in the bottom of the die?

 

[243winxb]

the OD of the entire case is right at .379"

.379" is the maximum OD of a loaded round.
I would call RCBS & tell them the problem. Loose bullets. They should replace the sizing die. Make note of any markings on the die & numbers on the original box, if you have it.

Checked my loaded rounds in Starline Brass. OD of body .3748"
OD over the seated bullets is .3783" This gives me neck tension of .0035" More then enough, .002" would be perfect.

Info on top of my die- RCBS FL carbide 38-357 73. The 73 means 1973 year. Bought new then.

Expander is .356"

 

[film495]

I emailed RCBS for an issue I was having and they sent me new parts for dies before I could even ask them if they would send them. I was willing to buy the parts, since what I was doing was a little out of the standard, but - they just sent the stuff, worked good.

 

[Olon]

If I'm not mistaken the OP says the same dies work fine for 38 special though. Which makes me wonder how it can work properly with the slightly shorter case but not be able to at least properly size the top half of the 357 case.

You might be right, obturation. The threaded portion of these dies is incredibly long for some reason. Like I said, I had to cut a bit off the bottom of the seater die.

 

[Olon]

I emailed RCBS for an issue I was having and they sent me new parts for dies before I could even ask them if they would send them. I was willing to buy the parts, since what I was doing was a little out of the standard, but - they just sent the stuff, worked good.

They've been good to me, too. I could always try emailing them as you suggest. I gave them a call last week and they were closed but there might be somebody to answer emails.

 

[Olon]

.379" is the maximum OD of a loaded round.
I would call RCBS & tell them the problem. Loose bullets. They should replace the sizing die. Make note of any markings on the die & numbers on the original box, if you have it.

Checked my loaded rounds in Starline Brass. OD of body .3748"
OD over the seated bullets is .3783" This gives me neck tension of .0035" More then enough, .002" would be perfect.

Info on top of my die- RCBS FL carbide 38-357 73. The 73 means 1973 year. Bought new then.

Expander is .356"

Great idea, thanks for the measurements. That should save me a few bucks if they can help me out.

 

[Olon]

My first guess is that your bullet is too small can you take a measurement and share

The bullet is right at .3575" so maybe a little small by cast bullet standards
The case throat I just measured was .3585 so I am in fact getting -.001" of neck tension

I'll email RCBS and see if they can help me out. Thanks for the suggestions and help on an admittedly stupid question...
Should have just measured that from the get-go, foot in mouth currently. So far with other straight-wall cartridges things have gone smoothly for me so this is a good learning experience that sometimes dies can be out of spec (or designed for thicker brass).

Happy Easter, everybody! If you're at home celebrating remotely or with family I hope you have a good one.

 

[AJC1]

The bullet is right at .3575" so maybe a little small by cast bullet standards
The case throat I just measured was .3585 so I am in fact getting -.001" of neck tension

I'll email RCBS and see if they can help me out. Thanks for the suggestions and help on an admittedly stupid question...
Should have just measured that from the get-go, foot in mouth currently. So far with other straight-wall cartridges things have gone smoothly for me so this is a good learning experience that sometimes dies can be out of spec (or designed for thicker brass).

Happy Easter, everybody! If you're at home celebrating remotely or with family I hope you have a good one.

I totally expected the bullet to be small not the dye to be out of spec very interesting thank you for sharing

 

[Olon]

I totally expected the bullet to be small not the dye to be out of spec very interesting thank you for sharing

Neither was I, which I guess is why I didn't even think to check...

 

[Demi-human]

There are no dumb questions. It is what helps your brain to storm...

Hosanna!

 

[Olon]

Folks, I had a really dumb moment.

I'll preface this by saying that I started reloading in fall of 2018, so I'm still a little wet behind the ears.

Well, I was looking at this "resizing die" and realized that the hole is so big there's not a chance that was intended to resize cases. There is another die in the set, however, which I long put away thinking that it was the expander. This expander has "size" stamped on the top of it...

357 mag is one of the first cartridges I reloaded, so I hadn't considered the possibility of there being a die which just resizes, and then another which decaps and expands the case mouth. None of my other die sets is that way, but this one was made in 1978 and according to the RCBS guy, before '81 they did it this way.

Boy, I've got a lot to learn. Good news is now I'm a little better and RCBS is sending me a decapping pin which will screw into the sizing die, so I can still use my powder die as an expander and don't need to size on a different press.

Can anyone say green?

 

[Herman B]

I'm getting such little neck tension that the bullets can be spun around after crimping...

1. After seating a bullet and before crimping, check the neck tension. You should have a boatload. If not, examine your size die. Replace?
2. For grins, try inserting a bullet with your fingers into a sized and flared piece. If you’re getting any insertion, your size die should be replaced.

 

[Olon]

1. After seating a bullet and before crimping, check the neck tension. You should have a boatload. If not, examine your size die. Replace?
2. For grins, try inserting a bullet with your fingers into a sized and flared piece. If you’re getting any insertion, your size die should be replaced.

After actually sizing the die (not just using the expander die with the decapping pin), I have plenty of neck tension. Maybe even more than I would like. But that's better than being able to spin the bullet and seat by hand like I was previously doing...

 

[9mmepiphany]

I'll preface this by saying that I started reloading in fall of 2018, so I'm still a little wet behind the ears
...this one was made in 1978 and according to the RCBS guy, before '81 they did it this way.

Posting that the die set was older would have been helpful also. There are a lot of folks on this forum who have used the previous RCBS die sets...I learned about them here a few years ago

 

[Demi-human]

The dies are some really old RCBS dies I got off ebay for cheap.

I'll buy some different dies, as I think that must be the issue.

Of course if one didn’t know there was a difference, the age of the die wouldn’t enter the equation.

Likewise, I had know idea they were like that!