Ring residue in Pistol's chamber

[Lagamor]

I'm having problems with Cast 9mm rounds jamming my CZ 75 variant(slugs pushed through barrel measure 0.356")Attachment 196899Attachment 196900 I like the potential of these rounds. Very accurate, without much recoil, no noticeable leading etc.

130 grain 9mm hp's
0.357"
1.010"
4.1 grain Bullseye
Winchester Sm Pistol Primer

About 5% of my rounds will jam my gun hard. I can't rack my slide by hand. I have to put the edge of my slide on a table and push the back of the grip. The retracted round will pull the boolit out about 0.010-0.010".
The rounds(all of them, not just the ones that jam) are leaving rings of lead/PC on the throat of my chamber. This is obviously compounding the problem.
Attachment 196899Attachment 196900
Attachment 196901Attachment 196902


I think reaming my barrel would help, but I'm looking for other ideas before I modify my gun.

Thanks in advance, Charlie.

[kmrra]

looks like you need to bell the case more in my opinion, and if the are not cycling right they may not be sized to the right size .... with out actually playing with them that all the info I can give you, Now If you want to send me a case of them I can give you a better explanation LOL

[Lagamor]

I thought about that too and forgot to put it in the post. Having trouble posting pictures.
Checked out the stickie, but it might have been outdated.

[Lagamor]

Testing...
https://imgur.com/a/QrYv7

https://i.imgur.com/unnYHCy.jpg

https://i.imgur.com/CCbVnVy.jpg

[Dan Cash]

Bell the case mouth and loose the paint. If you must paint bullets, get a smaller bullet to accomodate the thickness of the coating.

[rockshooter]

this is a fairly common problem with WFN bullets that are PCd. Try another style bullet like the traditional 356402 or look at the NOE 358-124TC, 358-126RN or 358-128. What you are looking for is a dramatic decrease in nose diameter at the case mouth. The amount of belling cannot be seen once the case mouth is taper crimped so it may not be an issue. My CZ has a short throat and has the same issue with the style of bullet you are using.
Loren

[clum553946]

Or try sizing .356 and seating a little deeper, have you tried taking out your barrel and using it to see if your rounds seat (the plunk test?) Do you size after PC'ing?

[popper]

seat deeper or get a different profile nose. Dings from the feed ramp and push back scraping of the nose at crimp. Thick coating doesn't help any. COAL is just a safe suggestion. Cycle loaded dummys until you find what works, adjust powder as appropriate. Plunk test all of your rnds before using.

[Lagamor]

I will look at another mold. The MP Luger molds I have large diameters towards the nose of the bullet.
I will also contact NOE and get some new sizers 0.356". Any smaller and I think I'll lose accuracy and run into other problems.
I don't want to seat deeper because 1.010" pretty deep for Luger, but I may have to.
Generally I do plunk test, but not this round.
This is my second cast boolit project. The first was 9mm Makarov and it didn't give me any problems.

[David2011]

If you have to seat deeper you might want to consider dropping the powder charge down and working back up to keep the pressure at a proper level.

[Moonie]

I've found that when seating semi auto rounds to seat and crimp in separate steps helps this issue.

[DougGuy]

Might want to have the barrel throated, this cures a LOT of issues with the ogive of the boolit being jammed into a throat that is too small.

After throating:

[OS OK]

It looks like you are seating and crimping in the same station.

Looks like these PC'd rounds are not sized after PC'ing. If they were we'd see some sizing on the radius above the crimp.

You need to give more complete information...step by step in what you have done in assembly.

Sizing after PC'ing will sometimes get you by if your throat is not too abrupt.

[Lagamor]

I use Dillon dies in a Dillon press, so seating and crimping are separate. I also sized this batch twice, before and after coating to 0.357". I'm didn't plunk test this batch, but looking them over quickly I didn't notice any shaving of the boolits when packing them up for the trip to the range.
I will adjust the belling on the next batch before I spend money.

[runfiverun]

might want to also do some internal measuring after sizing and flaring the cases.
Dillon dies are meant for jacketed bullets.

[slownsteady22]

Short answer is you need to seat deeper, if shooting a near max load you will have to rework up your load, also I would bet that your green ring is from shaved lead/ PC in your case.

Sent from my SM-G925R4 using Tapatalk

[Grmps]

Sizing the bullet smaller will not help the size at the nose.
You could try some without PC coating to see if they work
If you PC coat, make sure you knock all the excess powder off
some powders are thicker than others, you could look for a thinner powder or try Hi-Tek coating
+1 on seating the bullet deeper

[Walter Laich]

I had the same 'crescents' in my reloading machine

turns out all I needed to do was bell the cases a bit more. fixed it right up

YMMV

[sutherpride59]

Make sure you always do a plunk test with a new load to make sure your seating depth is right.

[gwpercle]

These new 9 mm barrels seem to have little to no throat , the boolit jam(b)s into the start of the rifling.
Two solutions 1.) have the barrel throated.
2.) Use a bullet like the NOE 358 - 124 - TC.

The Noe's truncated cone nose is rebated just enough to solve the problem you are having , you still have to seat the body of the boolit deep enough if it is sized .357 but the jam(b)ing is taken care of with this design. I don't Know how to get a NOE picture posted here but if you go to their site you can see what I'm talking about...the nose rebate .
I was having this very same problem with two 9 mm's, this mould fixed it.
Gary