Boolits drifting out of case

[pt4u2nv]

Been working on getting a cast boolit to work with my 357 SIG and found one that shoots pretty decent so far and holds well during recoil which is a problem with 357 SIG on a lot of cast boolits . I am using the 9mm-124-CN sized at .358 w/ PB gascheck. Probably 80% of the boolits will not stay seated at the OAL I have my die set at. They will slowly creep out of the case, sometimes as much as .050". I am using a Lyman M die to expand the cases and have tried the 38P and 38AP expander plug to no avail. I have had to reseat them upwards of 6-7 times before they will stay long enough to get a slight taper crimp on them. After the crimp , obviously, they will stay put.I actually left the dial caliber on a few times while checking OAL and you can watch the dial slowly move up as the boolit creeps out. I have tried not using the gaschecks also which made no difference. It actually looks like air is trapped inside the case and is pushing the boolit out. By the way it is not a compressed load either. Using 6.5 grs of Unique and have tried tapping the cases to get the powder down in the case as far as possible prior to setting the boolit. I do not think this was necessary but tried it just for sh## and giggles which also made no difference. Any possible solutions that anyone can help me with will be appreciated. Thanks

[btroj]

Two words- different powder.

You have a compressed charge. You need either to crimp and seat in a single step so the crimp is made while bullet is held in place by a seating stem OR load with far more neck tension so,the bullet is held by the neck while you crimp.

That case has a very short neck. Neck tension isn't gonna be real strong anyway.

Use a less bulky powder. Compressed charges in your case are the issue, changing powders gets away from that. Try a ball powder like AA5.

[Hickory]

I might try a smaller expander and different powder also.

[bobthenailer]

I belive that for the 357 sig with such a short neck area to hold the bullet and specfiec COL for the bullet you would need a special designed bullet mould , a special mould was designed by a fourm member and one of the fourms custom mould makers made him one . do a search.
Also check the size of your case expander / powder drop tube it should be at least .002 to.004 smaller than bullet dia for normal neck tension and .006 to .007 for heavy neck tension , also you bullets may be soft and swedging down in size after seating & crimping operation , if so try harder bullets or water dropping bullets from the mould may help.

[randyrat]

The only fix I can figure is to take your expander plug out and finely sand it down until you get more grip..
This may be a balance act, because if you reduce your expander down too much, your case could squeeze the cast boolit and down size it causing leading, tumbling, Key hole from a small boolit.
Take one thousand at a time, test and do another if all is ok.

[RobsTV]

Had that happen with 380 rounds, and it was expansion plug not expanding the case fat and deep enough. Case squeezed boolit back up a little, just like you describe.

[pt4u2nv]

Had that happen with 380 rounds, and it was expansion plug not expanding the case fat and deep enough. Case squeezed boolit back up a little, just like you describe.

I did check the ID of the case neck after expanding and it is right at .356. Sizing boolit to .358 so I quess that is possible. I thought that should be OK at .002 under with the small neck configuration I am dealing with and having to keep some pressure on boolit to stop setback from occuring

[pt4u2nv]

The only fix I can figure is to take your expander plug out and finely sand it down until you get more grip..
This may be a balance act, because if you reduce your expander down too much, your case could squeeze the cast boolit and down size it causing leading, tumbling, Key hole from a small boolit.
Take one thousand at a time, test and do another if all is ok.

May have to try that but I do use this M die for other loading. Maybe get a custom plug made ...

[fredj338]

It may be the bullet is just too large. You should not get compression with 6.5gr of Unique w/ any bullet. I run the Saeco 124gr TC in mine, no issues seating or crimping. I size 0.356" though, Dillon dies & powder thru expander.

[pt4u2nv]

It may be the bullet is just too large. You should not get compression with 6.5gr of Unique w/ any bullet. I run the Saeco 124gr TC in mine, no issues seating or crimping. I size 0.356" though, Dillon dies & powder thru expander.
My bore is .3563 and I tried .357 and got keyholing and a little leading. Went to .358 and keyholing went away along with most of the leading. Went to PB gaschecks at .358 and the leading disappeared completely. So......not sure where I go from here. I am going to try AA5 and see if I am compressing the powder but I really do not believe I am. I am going to load a few with no powder but that may not represent the case being somewhat full with powder and a lot more air space ??????? I also had the same problem at .357 but not quite as bad.

[Ed_Shot]

I saw the problem with some 9MM and .380 rounds and narrowed it down CBC and S&B brass no other headstamp had the problem. I use M-Die 38 AP for 9MM and the Lee expander die for 380. Quit using the offending brass and no more problems.

Are the loose boolits associated with a particular type of brass and what method are you using to crimp?

[pt4u2nv]

I saw the problem with some 9MM and .380 rounds and narrowed it down CBC and S&B brass no other headstamp had the problem. I use M-Die 38 AP for 9MM and the Lee expander die for 380. Quit using the offending brass and no more problems.

Are the loose boolits associated with a particular type of brass and what method are you using to crimp?


Taper crimp. Did not look at the types of brass but will have to do that. Tried AA5 last night and problem was a little better but still had 2 cases out of 10 that never even gave me a chance to crimp before they crept out of spec for my OAL.

[243winxb]

I am using a Lyman M die to expand the cases and have tried the 38P and 38AP expander plug to no avail. Looks like Lyman does not make an M die for the sig. Expanders for a 38 are to large. http://www.saami.org/PubResources/CC_Drawings/Pistol/357%20Sig.pdf

[Foto Joe]

I've had this happen with Black Powder cartridge loads and determined that it was of all things....the bullet lube. The lube was actually creating an air-tight seal when seating the bullet thus compressing the air inside of the case. The compressed air then pushed the bullet back up before I could crimp it. Is it possible that your lube might be doing the same thing?

[Nickle]

You'll want an M die for the 9mm, they do exist.

Midway is out of them right now, but this is it.

http://www.midwayusa.com/product/600695/lyman-neck-expander-m-die-9mm-380-acp-38-super

[bobthenailer]

Since your your expander is sizing the inside of the case to .356 and the bullet is @ .358 dia that is the min difference of .002 for a correct neck tension, normal is .002 to .004 . IMO you should decrease the dia of your expander by 0.002 to make it 0.004 min you may have to go even smaller for the correct neck tension for your application .
for all of my 380s, 9mms & 38 supers i use bullets sized @.357 dia, my expander plugs measure 0.353 and 0.354 dia. so im useing from .003 to .004 neck tension with straight walled cases , in the case with the 357 sig you have a very short neck to hold the bullet with only .002 neck tension.

[pt4u2nv]

That is my observation also but not sure how to correct it. Tried seating these with no primer on an empty case and they stay put every time. As soon as case is primed and loaded with any powder they creep out. Quess I could drill a vent hole in the side of the case ........LOL.

I have been using an M die for 9mm by the way. Holding the boolit once it is crimped has not been a problem just making it stay long enough to crimp is the issue.

Does appear that the less case capacity I use up with powder the less it creeps. Another reason for thinking the air compression in the case may be causing this issue.( as crazy as it sounds )

[Foto Joe]

Apparently it's not as "crazy" as you think. What are you using for boolit lube?

[jonp]

I had this exact problem. Using a separate crimp and seating die solved it for me.

[Nickle]

I had this exact problem. Using a separate crimp and seating die solved it for me.

That's smart business anyways, as you will get a better, more consistent crimp. I generally load pistol ammo in a Dillon 550, and the stations are size, expand/drop powder, seat and crimp. I decap and prime before starting, as I don't care for the Dillon primer, and I decap with a dedicated decapper die.

[pt4u2nv]

BAC Lube



Apparently it's not as "crazy" as you think. What are you using for boolit lube?

[pt4u2nv]

I do use separate crimp ad seating die all the time with cast. That is why the boolits are creeping and I am not able to get a crimp on them fast enough


I had this exact problem. Using a separate crimp and seating die solved it for me.

[snuffy]

1. Your expander is too big. Reduce the outside diameter of the expander plug. Chuck it in a drill motor, spin it while holding some fine Emory against it, go slowly checking with a micrometer. Test it often, even go so far as putting it back in the die, expand some brass to see if it takes more pressure to seat.

2. You're belling too much, which decreases bullet pull, IE neck tension even further.Just use the Lyman "M" to barely start the bell if you must. Don't go all the way to the 2 diameter step.

3. Just use a chamfer tool inside the neck, no belling.

4. Get a lee factory crimp die. It works just like the rifle dies, it's a collet type die. I had problems with J-words not staying seated
until I got the lee FCD.

The so called neck on the sig has so little inside surface, it already lacks much grip on the boolit. I use a bevel base lead boolit, the lee 125 TCTL, it loads without shearing any lead from the boolit.

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