I've read the relavent threads from the archive and they've been very helpful. I made sure I ordered the correct additional seating stem for the 300gr FN/HP bullets.
archive.ar15.com/forums/topic.html?b=3&f=121&t=142408&page=19
archive.ar15.com/forums/topic.html?b=3&f=118&t=157701

However, I was intending to use the original seating stem because I wanted to load the Barnes 300gr X Spitzer. My understanding from the aforementioned threads is that the seating stem sold with this die set (CH-D) was intended for the Barnes X bullet. I've been unable to load a bullet without the shoulder collapsing on the case before I can seat the bullet much past 1/8''. I've cleaned and chamfered the cases. I've adjusted my dies as suggested in the aforementioned threads. No luck.

On a hunch I used the other seating stem to load a 300gr Hornady HP. It worked like a charm. Now I'm really confused. I measured the diameter of the Barnes bullet to ensure I was using the correct bullet. It's almost as if it's too big.

Please help; I'm a newbie to reloading.

I bet you have the die turned too far in with the spitzer seating plug and are getting into the crimp ring.  That caused the die to try and crimp the bullet without the crimp groove being in line with the case mouth and that causes the shoulder to buckle.

Remove the seating stem completely.
Loosen the lock ring on the seat die, back it almost all the way to the top of the die.
Put a case in the shell holder.
Run the case (with no bullet in it) all the way to the top of its travel.
Start screwing in the seating die.
You will reach a point where the case mouth hits the crimp groove built into the seating die.  At that point back off the die ONE FULL TURN and lock it into place.
Now your die is set to not crimp the bullet.
Put a bullet in the case mouth and and just start the spitzer seating stem.
Put a bullet in the case mouth and run it up.  Turn the seat stem in until you make contact with the bullet.  Back off the case and turn the stem in another turn or two.
Continue turning the seating stem down until you have the bullet seated to the proper length.
If by chance you end up with the seating stem turned all the way in and still do not have the bullet seated far enough you will need to order a longer seating stem.  Send a dummy round loaded to the length you need even if you have to press the bullet in with a vice and send it to Dave and they can make a seating stem to fit.  
Once you have all your bullets seated to depth, IF the crimp groove in the bullet is in line with the mouth of the case, back off your seating stem all the way or remove it.  Unlock the die lock ring and turn it down until you feel the mouth of the case contact the crimp ring.  Turn down the die 1/2 turn and lock it in position.  Now you can crimp all your case.  If your bullet does not have a crimp groove or the crimp goove is not in line with the case mouth, DO NOT CRIMP.  The .458 SOCOM does not recoil so much that you must use a crimp. It will work just fine with no crimp at all.

The reason it did not do this with the FN seat stem is the bullet seating stem does not need to be turned as far into the die and with that stem you did not get into the crimp ring.  I bet you were turning the die body down instead of the seat stem and that is what got you into the crimp ring with the spitzer bullets.

No-Go.

Followed your instructions to a T. I can't get it to seat past the chamfer on the inside of the case. I'm not having the slightest problem seating the HP bullets using the other stem. It really seems like there is something wrong with the bullets I'm using (like I have the wrong ones). or there's something wrong with the seating stem (like my assumptions about which bullet it's used for is incorrect).



ETA: Thanks for the help tho.

It would be odd for the wrong bullets to be in the box but it has happened before, but you said you already measured them.
The correct seating stem for the X bullets will of course have a very deep hollow in it to fit the nose profile of the bullet.  The FNHP bullet stem will of course have the flat profile of the bullet it is designed to seat.
Do you use an neck expanding die or just the exanding button on the FL sizer?  Long ago, too many years to count, I dumped all my primer stems that de-prime and expand the neck.  I deprime with a separate die, size, and expand the neck with a Lyman M die or other type of similar expanding die.  These dies expand the neck going IN to the case and not when coming out.  The normal expander buttom will cause a case to grow in length by about .001 to .003 inch as you withdraw the case from the die.  the M-Die expands the neck going in and does not stretch the case.  Since doing this I have to trim much less often and I really hate trimming.  I also use the M-die to very slightly bell the mouth of the case.  Then I use the seat die crimp ring to very slightly push the neck back against the bullet (but not to crimp) if I am not going to crimp using a separate step.  The bell on the mouth helps get the bullet started without shaving and seems to make bullet seating easier.  
CH-4D makes this die also so a call to Dave will have you one in no time flat.  He got me one for my .500 Phantom in about 5 days and it works as well as the Lyman M-Die or RCBS neck expanding die.

On a lark, measure the expanding button on the deprime stem.  On the .458 it should measure .456 max and .454 minimum.  If it has a .449 to .451 expander button there is the problem (it has the pistol expander button on it).  Normal jacketed lead core bullets compress much easier than the solid copper X bullets.  If the wrong expander button is on there it would work fine with lead core bullets but be too tight for the X bullets.

I am rapidly running out of ideas on how to correct this problem.  The one thing you do not want to do is lube the inside of the case neck.  There should be no lube on the inside of the case neck during seating but you already know that.

Measures right at .456". I'm going to order some of the Barnes XFN and try those. Otherwise, I guess I'm stuck loading HPs.

Here's some pic...(left-to-right)
Barnes X 300gr bullet-attempted seating-seating stem used--unused brass case--Hornady 300gr HP-attempted seating-seating plug used
Also a closeup of the shoulder compared to a fired case.

If you have done everything Big-Bore advised... da-da-damn.

From the pics, I would say that you have the wrong shellholder in place because it looks like you are way into the crimp depth of the seating die.

But I've been blind before.

Dave S

Bigsapper,

I'll add my 2 cents, in the event that you are still having problems.  Bigbore and Dave appear to be spot on, from your pics.  I am guessing that the crimp ring on the brass in your picture on the left is from previous crimping, and that this case is at least once fired.

I have seated and used just about every high 200 low 300 grain 458 bullet successfully.  I actually have both the CH and Lee dies.

As bigbore suggested, I flare my case mouths slightly before seating, and crimp in  a sperate operation.  I also slightly chamfer the insides of my cases.  One easy way to do this with the same die is to set the crimp depth and lock it in place with one of the allen wrench style locking rings found on most die sets.  Then to use the same die to seat, I add an additional lock ring under the main lock ring that is tightened before screwing the entire die into the press.  This allows me to keep my crimp setting, and ensure that I am getting no crimp during the seating operation.  Sometimes the seating stem will have to be turned very far in, to accomplish this with two lock rings.  If your seating stem will not reach, you can buy die shims that work just as well, that are not quite as thick as a second lock ring.  

Whether or not you decide to crimp the round, you can save yourself a lot of headaches with two die rifle sets by treating them as three steps as outlined above.  If you flare the case mouth at all, you will have to crimp at least a small amount to get the case mouth at least snug with the surface of the bullet.  As was pointed out, the Barnes is a very hard bullet, and does not deform well during seating.  The neck will almost certainly collapse, as you have found out.  The slight chamfer might be all that you need to get the Barnes bullets going in.

I have my fingers crossed now that we have a couple makers in the 458 game that more companies will get together on dies.  Like Redding and/or RCBS.  I am only slightly satisified with the CH dies, and typically hate Lee dies due to the inferior metal quality and losening of tolerances.

Craig

I had the same problem even to the point that I ripped the case neck off when extracting the cartridge.  I learned from my questions that the CH4D dies were created from Marty's original drawings and that the case neck dimensions were too small.  I turned the neck on one piece of brass down to .010 and had no problems crimping.  I finally followed everyone’s advise and backed the die out to the point that the case neck never enters the neck of the die and haven't had any problems.

I got a box of the Barnes 300gr X Flat Nose. I'll try making a dummy round this weekend with that. Interesting, in that the Barnes X bullets are made of solid copper. I wonder if that is a contributing factor in my problem.

I'll also try backing the die out some more. As well as measuring the I.D. of the brass after sizing.

OK, on a suggestion from FALARAK, I measured the I.D. of the brass after a resize. .455 was the result. I tried hand fitting the brass over the expander and it wouldn't go. This was after a full-length resize. I can visually confirm that the brass went all the way in and based on the adjustment should have sent the expander past the shoulder.

Any ideas?

Big,

The neck measures properly. .455 would give you 0.003 of neck tension, which should work.

If you are absolutely sure that your seating die is backed out enough that you are not getting crimp while seating, I would say the next step is to either bell the case mouth, chamfer the inside of the case and/or put a very small amount of lube on the inside of the neck.  I do not like using lube, but it might help you with trouble shooting.

If you have not double checked the depth on your seating die to only seat and not crimp, this is critical.  What I do is actually set the die for a small amount of crimp, then set the lock ring on the die.  I then back it out and use a spare lock ring or one of the die shims that you can buy to set the die up for seating.  The second lock ring or shim will ensure that the die is up high enough so as to not try and crimp while seating.  The die shim is better than a second ring, as the thickness of the second ring could leave you with not enough depth to seat all the way.  You can use a live good round to set your crimp.  Measure what you have on a good round (diameter), then slowly screw in the die and check to see that the crimping is just at the good round, or slightly more.  This will eliminate the crimping variable.

I use the expander die in my Lee set to slightly flare my case before seating.  I also use a case mouth tool to slightly chamfer the inside of the case.  It is also used to remove burrs from the outside of the neck and inside after trimming.  You do not want too much flaring as this would reduce neck tension which is critical in an autoloader.  

If you have confirmed that you are not crimping while seating, I suspect that the culprit is the square mouth on the lip of the inside of the case dragging on the Barnes bullet.  The bullet material or hardness is not the problem.  No bullet of any construction should be too hard to seat without collapsing the shoulder.  It is also possible that the seating stem is not holding the bullet square to the case while it is going in, which could drag significantly on the inside of the case and cause collapse.  I would go very slow while seating, and make sure that the bullet is very straight on top of the case.

From your original post it sounds like you are doing things correctly, just not sure why the stem is not working.  Slightly flaring the case mouth would certainly solve your problems, but you probably do not have a way to do that if you do not have the Lee set.  Perhaps CH might have a recommendation as to what other die might work to flare the case mouth.

Let us know,

Craig

Quoted: I would go very slow while seating, and make sure that the bullet is very straight on top of the case.

Just so you know that I have not been ignoring this post, I have been reading it and scratching my head.  Brouhaha came over after the very first GB when he was having the same problem with neck collapse using the Rem 300 JHP.  I walked him through how I load them, using all of his components.  I sized his brass, trimmed to length, picked up the case tool to chamfer/debur and he stopped me and said "What's that?".  Solved the problem right there.  Loaded up several rounds without issue.  He went home and called to say that he was still having the problem.  So we went over his load set up and procedure.  Turns out he was using the Dillon 5XX or 6XX (do not recall).  I use the RockChucker but used the Dillon at the Tromix shop.  MAJOR difference.  With the RC I can finesse it, whereas the Dillon with that huge "shovel arm" cranked down so fast, it was doing the same thing.  Force of friction is velocity related.  Go slow and you can make it work, go fast and it might get you.  When Craig typed "go slow" it set off a light bulb.  I collapsed a few cases myself, even with 300 JHP.  Looking back, I was in a hurry when making those and did not follow all my normal steps and really cranked on the RC to get these loaded fast.  Between the bullet being slightly cocked to one side and me going fast, it led to several trashed rounds.

If that doesn't work, I will simply have to figure out a way to get to your location and work with you at your location, with your gear and components.  By TX standards you are just down the road ...

Thanks Marty.

I appreciate the offer, but don't bother coming up (yet). I still have a date with FALARAK to try to work this out.

I showed my brass to FALARAK at the last dinner and he was puzzled too. He did suggest a couple of things. I'll also try going slower (using the Lee Hand Press). If all that doesn't work I'll clear out the garage and get my RockChucker mounted and go that route.

Thanks all for the advice and help.

There is much to that statement.  I have usually loaded all of my .458s on an old RCBS cheapy press.  Recently I obtained the new rockchucker (with longer lever, etc) for Phantom reasons, and the first few loads of .458 that I did I was amazed at how easy the bullets seated - guess what - I set some shoulders back myself.........Only had this problem once with my old press but I managed to be in a hurry the other night and set back about 5 of them in one sitting.

FINALLY!

I finally got some in person help from FALARAK and SmallChange. No more problems!
In a nutshell, use a full-size reloader. My problems are rooted in using the Lee HandLoader.

As an addendum, I noticed that FALARAK adjusted my seating die setting based on a fired case and not a re-sized case. Risking ruining another brass and bullet, I used that same "trick" with the HandLoader and Viola!, it worked.

So maybe the real problem was I just had the die screwed down too far. Any, on to the next step; adding primers and powder.

Just don't collaps any primer pockets!

Quoted: FINALLY! I finally got some in person help from FALARAK and SmallChange. No more problems! In a nutshell, use a full-size reloader. My problems are rooted in using the Lee HandLoader. As an addendum, I noticed that FALARAK adjusted my seating die setting based on a fired case and not a re-sized case. Risking ruining another brass and bullet, I used that same "trick" with the HandLoader and Viola!, it worked. So maybe the real problem was I just had the die screwed down too far. Any, on to the next step; adding primers and powder.

Glad you got it worked out, now I don't have to drive 4 hours to help

But, um, shouldn't you add the primer first, powder second and THEN the bullet?  Maybe I've been doing it wrong all this time, or else I see another issue brewing

I did add powder one time to a case that didn't have a primer in it.  Didn't work out too well!!!

I'm a newbie at this, what can I say.

tag.  now that i have my chrono i feel confident enough to load rifle rounds.

Quoted: I did add powder one time to a case that didn't have a primer in it.  Didn't work out too well!!!

Knee slap while laughing, Knee slap while laughing, Knee slap while laughing. I cant believe you would do something like that.
Ya well, I know how you feel. I didn't think anyone had done that besides me.

I also had the same problem with seating my bullets, I found that it was the depth I had the body of the   seating die set, and the seating stem wasn't long enough. I took the seating cups that lee sent me(the wrong one, 3 of them) after I sent them the die set, bullets, & brass to make me a custom cup for the bullets(300gr JHP, 400gr RNSP, & 500gr RNSP) and the wrong seating stem that CH sent me and made a seating stem that was long enough to seat the bullet without crushing the brass neck.

Well I finally borned my first babies.

Barnes 300gr XS Spitzer using Reloader 7 (40.0gr), 2.25" COL.
Barnes 300gr XS Flat Nose using Hogdon 110 (38.4gr) 2.02" COL.

I've loaded 10 rounds each at the listed amount and -5% & -10%. I was going to use the Reloader 7 for the XS FN but it was compressing the load because of the seating depth of the bullet; so I switched to the H110.

Can't wait to get to the range to try them out.


ETA: Once again a big thanks to FALARAK for helping me getting my dies adjusted correctly.

Also, I'm proud of the fact that I loaded every bit of this using a Lee Hand Loader press.