I'm stumped on .500 S&W rounds not chambering

[wonderwolf]

Sat down last week to load up a batch of ammo for my .500 S&W John ross gun, Same dies, same bullets sized to the same and mic'd to double and triple check. Same cases that have been loaded about 5 times now with a mild load of 14.2gr of unique. Nothing in my set up has changed dies are clean, brass is clean, gun is clean bullets do not have excess lube and gas checks are parallel with bullet shank.

Pretty much everything is how it should be in terms of cleanliness and pre loading condition. LUCKILY I only loaded 20 rounds before I thought something looked weird, I loaded 5 rounds in my speedloader and the loaded rounds don't go past 1/4 of the way in to their respective chambers "odd" I thought, so I tried individual rounds, none wanted to chamber any further. Spinning the cases their is a slight bulge on one side of the case. It seems to be enough to cause a "warped" effect to the case overall and not allow them to chamber? This is not a case of over crimping where the neck folds a little, the crimp is as gradual as its ever been and not excessive, Is this a sign of brass fatigue? The case wall thickness is the same as the factory stuff i've measured .015" add a .502" bullet you get .532" give or take but when I mic the LOADED round they come out .535" give or take.


I'm leaning towards worn out brass but this isn't a symptom of brass fatigue I've ever come across before, only with new annealed brass have I run into a one sided bulge but those still chambered.

[BK7saum]

We're the cases resized? That's the only thing that comes to mind at the moment. Is the diameter of the bulge the same to the case head or does diameter decrease lower down the case.

[wonderwolf]

We're the cases resized? That's the only thing that comes to mind at the moment. Is the diameter of the bulge the same to the case head or does diameter decrease lower down the case.

Yes, Although the cases were resized a few months prior I measured some I didn't expand and they were same as ones I resized just to check. Using carbide RCBS dies. One concern was the bullet is not seating straight but there seems to be no run out there. bulge is only present where the bullet takes residence.

[BK7saum]

Then that only leaves Boolits diameter as the culprit. Were these Boolits sized in a different die? Or treated any differently?

[wonderwolf]

Nope, bullets mic out same as the die sizes them at .502

[oneokie]

Are the cylinder chambers clean of any and all fouling?

[rockrat]

Lube on the nose of the seating stem causing the booits to not seat straight?

[MtGun44]

Overcrimping with a roll crimp die can cause a bulge at the front.

[44man]

I use Hornady dies with the inline seater. I had the bulge problem with other dies.
Your brass is not worn out, I am shooting brass fired well over 40X.
I don't have the S&W but use .500 S&W dies to load the .500 JRH and I lost count how many times some brass has been loaded.
It is very possible to have revolver boolits seat off center, you do not want the run out either.
If the bulge at the boolit base is more on one side then the other, it is your seater. All of my loads show the base but it is even all around.

[RED333]

Do unloaded cases fit?

[ole 5 hole group]

Cases resized, bootlit sized correctly and charge-holes cleaned - everything seems a-go, so I'll have to go with MtGun44 on this one. Too much bell and not enough crimp might be the culprit but too much crimp would be my best guess.

Run a loaded round through your sizing die - after that, the round should just drop right in the charge hole - that should tell the tale.

[BCRider]

If the seating die isn't gummed up and pushing the bullet noses sideways then another possible cause to look into is not enough flare and crimping down too much. Too little flare may be leaving an edge that digs into and galls the lead as it's seated. And that can hold back the bullet on one side and cause it to seat crooked.

I've also had some .45acp that I tried to load where the cannelure groove was very small and the die which was set up for a combined seat and crimp in one go crimped down early and plowed some lead ahead of the mouth rim. In your case if it were doing such a thing then the excess force might be causing the casing to deform.

Can you pull one of the rounds apart and check the bullet for any odd features? Like bad grooves and possibly lead build up in the lube grooves? And possibly a plowed ahead ring of lead from the crimp closing too early and catching the skirt?

This issue is why I'm now a huge fan of seating and crimping in separate operations if using a single stage or separate stations on a progressive press.

EDITED TO ADD- Speaking of off axis it would not hurt to check that something has not gone askew and your dies are not lining up with the ram or with the shell plate. Run a round through and watch carefully for any hints of the casing wanting to kick to one side or the other or to tip as it engages the various dies. If you see anything it may be a grunge buildup in the shell holder or shell plate grooves. Or it may indicate that something isn't aligned. But either way a casing being pushed at an angle into the die could produce out of kilter bullet seating forces and possible bulges.

[44man]

I make my crimp grooves large enough so the brass has entered the region before the crimp shoulder touches.
Lee boolits get problematic with the small grooves but I just put a thin shim washer under the die.
One fella at work sold a few boxes of ACP rounds to friends and none would chamber. He did not flare and there was a large ring of lead on the brass. He did a good job shaving lead and the stuff was stuck so tight it could not be peeled off.
Anyway, here is my JRH, you can plainly see what they look like when seated and crimped properly. The boolit is .501". Attachment 150957Snake with a pig inside! 1/2" capable at 100 yards. Drop in fit to my BFR and a .500 S&W.

[Ithaca Gunner]

A Lee Factory Crimp die may solve your problem. I loaded several boxes of .45 ACP with cast and didn't use a Lee F C die, just the RCBS taper crimp and none would chamber without forcing them in the gun. Ran all of the several boxes through a Lee F C die and no more problem. I'm a believer, never more shall I sin and not use a Lee F C die.

[starmac]

Any chance you have switched gas checks, and the ones you are now using are a hair thicker?

[44man]

Any chance you have switched gas checks, and the ones you are now using are a hair thicker?

Most will not see this. The check should never be larger then boolit diameter. If the boolit is .501, so must the check be .501".
.502" might be too large for the Smith, slugging must be done. I doubt the throats will pass a .502". Cambers might be tight too.

[Tackleberry41]

Those Lee FCD dies do come in handy. Got my 'new' 1917, and some cast 230gr I had loaded a while ago, some wouldn't go in without help. Quick trip thru the FCD, no issues.

[BK7saum]

I know this has been beat to death, but the Lee pistol FCD is an answer to a question that shouldn't exist. If the Boolits were sized correctly and the cases and chambers are normal and not too thick or cut undersized then normal reloading dies should load ammunition that fits. The Lee FCD is swaging down Boolits inside your cases to a diameter less than you have already determined that you needed. Will ammunition sized with the FCD fit in the chambers? Absolutelty, but is a bandaid to fix an issue that shouldn't exist.

[44man]

I know this has been beat to death, but the Lee pistol FCD is an answer to a question that shouldn't exist. If the Boolits were sized correctly and the cases and chambers are normal and not too thick or cut undersized then normal reloading dies should load ammunition that fits. The Lee FCD is swaging down Boolits inside your cases to a diameter less than you have already determined that you needed. Will ammunition sized with the FCD fit in the chambers? Absolutelty, but is a bandaid to fix an issue that shouldn't exist.

Keep beating, I will stand with you. The FCD gives a false feeling. It is as bad as someone telling a person to run a loaded round back into the size die.

[ole 5 hole group]

Keep beating, I will stand with you. The FCD gives a false feeling. It is as bad as someone telling a person to run a loaded round back into the size die.

OK JAMES, running a loaded round back through the sizing die will tell you where the problem was/is. When I had trouble with the 500 JRH loading 465 and 500 grain cast bullets not going into the charge holes - I did just that and saw where the problem was and as you now know the 500 JRH brass has a taper to it and that is the problem using cast bullets much over 440 grains. It's where the loaded cartridge stops is where the problem lies and by resizing you just confirm it. Might not be up to eastern standards but it sure works in the upper mid-west.

For those with the 500 JRH - the 500 grain Hornady jacketed bullet loads right up and drops in due to the small base bevel.