Problems trying get proper crimp in 9mm

[Bozrdang]

I've been trying to work out problems with my reloaded cartridges not always passing my case gauge. In trying to fix this issue it seems to come down to crimp. If I apply enough crimp then almost everyone will fit perfectly. The problem is when I do that it leaves a well defined impression on the base of the bullet when I pull them to check.

I've tried only resizing over 50 cases and then testing them in the gauge and they all pass like a dream. That would seem to rule out any case length or resizing issues. Once I seat a bullet in and crimp those same 50 cases things change and I can't understand why. I've taken measurements on both passed and failed cartridges and I get the same measurements. For example, I measured one of each that measured. 0.378 at the case mouth, 0.388 at the base and a 1.122 COAL. Why would one pass and one fail?

Fact of the matter is that even just seating the bullet with no crimp leaves the faintest mark on the bullets I've pulled.

I am using 115 grain RN-NLG coated bullets from Acme and Dillon dies with mixed headstone cases.

 

[Sunray]

The only 'gauge' that matters is the chamber. If your loaded ammo drops in and sits properly you're fine. If they don't fit an aftermarket gauge, it's possible the bullet is seated a bit crooked. Doesn't matter if the round drops into the chamber.
A taper crimp should be enough to take out the flare and no more.
1.122", if anything, is 3 thou short. Not enough to matter.
.378" at the case mouth is 2 thou undersized. Shouldn't matter much if the bullets are the right diameter.

 

[Dudedog]

Have you tried measuring the bullets to see if any are oversize?

If you are using mixed brass some cases have thicker walls than others.
It is also possible as mentioned earlier that the bullets might be seated crooked, not likely but possible.

If they shoot well and the crimp is not hurting accuracy I would not worry about it.

You could mark the case of the "problem" ones with something (sharpie) and then put them in the guage and see where things are hanging up. Sounds like the case flair/bullet is the issue but it could possibly be the base or someplace else.

People may cringe but I have never trimmed any 9mm cases in over 10000+ rounds.

I never guage any of my 9mm or .45.
I have different 9mms and if my rounds plunk in the one with the tightest chamber I consider them good to go. It is possible that they might not work in someones elses 9mm but I know they are ok for mine. ( I also use the Lee FCD)

 

[Bozrdang]

The bullets are 0.356 and the measure that consistently. I've Sen people mention the case thickness before but wouldn't the crimp die make the OD the same regardless? I would think that a thicker case would just mean that case will be swaged into the bullet a little further. Either way, I am getting a consistent OD on my case mouths.

 

[Dudedog]

So if you crimp the ones that don't fit more do they fit?

 

[Bozrdang]

Yes.

 

[rcmodel]

If you measure factory 9mm crimp, you will find it hovers around .376".

.378" is not enough crimp.

Since your coated bullets are .001" larger then jacketed bullets, I would adjust the die for .377", and no more.

BTW: .380" is SAAMI Maximum dia.
That probably won't fit in most gages, and some tight chambered guns.

So go for .377" and try that.

rc

 

[Bozrdang]

I have tried 0.377 and they pass fine but I get noticeable deformation on the base of the bullet like this:

 

[joem1945]

If you reloads chamber in your firearm, just go shoot them. Are you trying to overthink this?

 

[Bozrdang]

No, I am trying to make good ammo. Some of the worse ones that fail the gauge hang up in my barrel too. I'd rather get them to pass my gauge than have to take apart my gun whenever I reload.

Additionally, I am trying to learn the right way to do things. Are you saying it's not possible to make ammo that consistently passes the case gauge?

 

[njl]

I would say that's an obviously overcrimped bullet. What bullets are you using and what dies (particularly seating and crimp)?

 

[Bozrdang]

That's what I keep hearing. Bullets are Acme coated 115 grain RN 0.356 and I'm using Dillon dies.

 

[2bfree]

I've tried only resizing over 50 cases and then testing them in the gauge and they all pass like a dream. That would seem to rule out any case length or resizing issues.

I know you said you tried this but may I say just go back to basics. Adjust your sizing die again, if you are using a dillon press with your Dillon dies, there is a little bit of play is the Dillon shell plate so you can't just "eyeball" it. I know this may not make sense, but try it just for the heck of it. After making a couple dummy rounds, see if your problem goes away.

 

[Bozrdang]

I'll give it a shot. Can't hurt. I am using a Dillon XL 650 press.

 

[njl]

Also, when adjusting your dies, when you tighten the lock rings, do so with a case/cartridge in every shell plate position. This helps make sure the dies are properly centered.

 

[gamestalker]

I know lots of reloaders are using gauges these days, but in more than 3 decades of reloading I've never used anything but the chamber as my gauge, and to date I've never had a malfunction, or anything failures what so ever.

What might be causing your inconsistencies, is not all the cases are the same length, thus your crimp depths are going to be inconsistent. Trimming may seem extreme to most reloaders, but when having to deal with constant bothersome issues, I find it a justifiable step in the process..

In addition to the above, I rarely ever bell or crimp my cases, I trim them, then I just give the mouths a quick chamfer, then seat the bullet, done. This may seem extreme to most reloaders, but in retrospect, I find it far less cumbersome and time consuming, in that I never have any issues.

GS

 

[Rule3]

It is not very hard to remove a barrel from most any 9mm handgun

From the looks of your picture you have to much crimp, There should not be that deep dent in the bullet,

Use your barrel, drop the loaded round in it should plunk in and turn over it should fall out. The "plunk test"

Use rc models post to measure the crimp.

I load every common handgun caliber and never use a case gauge, I do use one to set up 5.56 and 308 rifle due to the shoulder spacing and setting up the sizing die,

Walkalongs thread on Plunk testing. It is a 1911 but the principle is the same,

http://www.thehighroad.org/showthread.php?t=506678

 

[9mmepiphany]

No, I am trying to make good ammo.

I don't think you're over thinking it, but I do think you're overlooking the obvious.

The 9x19mm was designed to be loaded with a .355" FMJ bullet. 9mm chambers are sized to feed this cartridge.

You're choosing to load a .356" soft lead bullet which has been coated.

Why would you not expect that oversize bullet, loaded into a correctly sized/crimped case, not to show some deformation?

 

[Bozrdang]

I wouldn't think that extra 0.001 deformation would be visible. I haven't measured it, but I know that deformation in my picture is more than 0.001.

 

[Milt1]

Bozrdang, what does your Dillon instructions say regarding how to roll crimp and are you following their instructions?

 

[Bozrdang]

I'm not roll crimping. I'm taper crimping.

 

[9mmepiphany]

Have you tried running your loaded cartridges through a Lee Factory Crimp die?

 

[Bozrdang]

I haven't tried the Lee FCD in a while. I had read not to use it on oversized bullets because the resizing ring will swage it down in size.

 

[Bozrdang]

It is not very hard to remove a barrel from most any 9mm handgun

From the looks of your picture you have to much crimp, There should not be that deep dent in the bullet,

Use your barrel, drop the loaded round in it should plunk in and turn over it should fall out. The "plunk test"

Use rc models post to measure the crimp.

I load every common handgun caliber and never use a case gauge, I do use one to set up 5.56 and 308 rifle due to the shoulder spacing and setting up the sizing die,

Walkalongs thread on Plunk testing. It is a 1911 but the principle is the same,

http://www.thehighroad.org/showthread.php?t=506678

I know it's not hard to remove a barrel. I have a 20 hole case that makes things really convenient so I prefer to use it.

You say I have too much crimp and to follow rc models post about measuring crimp. Well that bullet was pulled from a cartridge that measured 0.377 after crimping (rc model suggests 0.376). Do you see my dilemma?

 

[Dudedog]

I have used the Lee FCD in 9mm with lead bullets/coated lead without issues.
Some people like it some hate it. I happen to like using it in 9mm.
It might be worth giving it a try if you have one.

You said you had a 20 hole case. Did you mean a 20 hole case guage?
Wondering if maybe the guage is just on the "tight" side.