What is going on with this reload? Bulging on sides vs Non bulging cases??

[Member 5605]

I'm gonna have to chrono some of these as I expect that this will add to the overall pressure yes/no?

No.

Measure bullet (.355) then measure case inside diameter. Quickly you will find that the ID is smaller than the OD of the bullet. If you want it gone get a factory sizing die, that will make the exterior uniform. Nothing to worry about. It's not the dies or the bullet, it's the different types of brass. Heck my .38specials will do it and some 357 Mag, almost all of my .40's do it because I'm loading cast in them.

 

[ageingstudent]

No.

Measure bullet (.355) then measure case inside diameter. Quickly you will find that the ID is smaller than the OD of the bullet. If you want it gone get a factory sizing die, that will make the exterior uniform. Nothing to worry about. It's not the dies or the bullet, it's the different types of brass. Heck my .38specials will do it and some 357 Mah, almost all of my .40's do it because I'm loading cast in them.

Nothing wrong with running them over your chrony. You may or MAY NOT see any difference.

I have some factory UMC in 45 that have some bullet bulge. It is not uncommon even in factory fresh ammo. If they fit, fire, and hit what you are shooting at they are good to go looks notwithstanding.

If the chrony gives you piece of mind do it. You should be ultimately confident in your handy work.

 

[John Gault]

This is why I posted here.... I appreciate hearing several points of view and options to consider.

I got a quick NO from you Dygital. Have you done some chrono testing to confirm that no value is added? I tend to load at the top end of load data at times which leaves me some concern that the bullet being tighter in a smaller case could add value to a pressure number. I'm assuming that it would be like too heavy crimping could do the same..? Still pretty new to reloading and Brand New to Progressive loading so I'm more anxious than ever to get it right.

Thanks again guys for input.

 

[ageingstudent]

Well even loading at max the amount of tension exerted on that projectile may not be raising pressure significantly. You are dealing with tolerances in the .00x range. I think a human hair is .003.

If you are really concerned about that brass do a workup with just that brass starting at the minimum. Chrony 10 rounds each up to the max and examine your results. Like I said if it gives you confidence in your ammunition it's worth the extra effort. For sure you will learn something about neck tension, measurements, pressure, and velocity.

Don't be surprised if you find that the bulging rounds are actually better in performance than the non bulgers.

Science...

 

[fxdc]

I would hope the cbc brass is SAMMI SPEC.

I'VE NEVER had this issue with any pistol or rifle brass, but I dont seat crimp in the same station. This one baffles me, brass thickness? Is cbc marked with a date? Or nato stamp? Crimped primer pocket?

 

[ageingstudent]

I would hope the cbc brass is SAMMI SPEC.

I'VE NEVER had this issue with any pistol or rifle brass, but I dont seat crimp in the same station. This one baffles me, brass thickness? Is cbc marked with a date? Or nato stamp? Crimped primer pocket?

I don't think his crimp is the issue. From the pic you can see where the base of the projectile rests in the brass. The crimp doesn't look bulged.

The brass probably is in spec, it's likely just on the thick side of within tolerance. Couple that with a bullet on the thick side of "within spec" and you get a bulge you can see.

This is more common with cast bullets as they are usually slightly bigger in diameter, but I have seen this with both jacketed and plated. It usually is not a problem.

 

[Certaindeaf]

It'll probably ensure more consistent ignition/smaller velocity spreads because of the higher neck tension. The pressure might be slightly higher due to smaller case volume because of the thicker brass. Some brass is thicker than others.
What you don't want is little bullet tension.. it could/can cause inconsistent ignition and or bullet setback.. the latter easily leading to a blown up gun.

 

[fxdc]

I don't think his crimp is the issue. From the pic you can see where the base of the projectile rests in the brass. The crimp doesn't look bulged.

The brass probably is in spec, it's likely just on the thick side of within tolerance. Couple that with a bullet on the thick side of "within spec" and you get a bulge you can see.

This is more common with cast bullets as they are usually slightly bigger in diameter, but I have seen this with both jacketed and plated. It usually is not a problem.

True

 

[ageingstudent]

John, another thing you can do is size one piece of the CBC brass and size a piece of brass that does not show the bulge and measure the ID and OD of each and compare. If the difference is appreciable you can be fairly certain that your CBC brass is just thicker than most.

 

[fxdc]

I think it's his POS press.

LMAO
Just kidding John!

 

[John Gault]

Just measured the CBC brass and a federal Nickle and a Blazer brass. "Post sizing die"

All external values were within my measuring ability with quality dial calipers.
Internal values show that the CBC is measurably thinner I.D but not by as much as you'd think it would take to show that bulge....

NO date code or NATO info or crimped primers that I see on CBC brass.

I may get a chance to shoot some tomorrow which sounds like a lot more fun.....

 

[PaulB47]

Zinc cases? I assume you mean nickel plated.

Obviously one case is a bit harder than the other.

Your cases are bulged because you are shooting a Glock. Seriously, some manufacturers have a deeper feed ramp than needed, and bulges are what happens. It's the feed ramp, not the case that is causing you problems.

 

[Certaindeaf]

The usual way to measure brass "thickness"/case capacity is to measure how much water it holds (there are tables on the internet as a general guidline for different makes of brass). I just weigh the empty brass if I'm curious.. for whatever that's worth.

 

[John Gault]

Zinc cases? I assume you mean nickel plated.

Obviously one case is a bit harder than the other.

Your cases are bulged because you are shooting a Glock. Seriously, some manufacturers have a deeper feed ramp than needed, and bulges are what happens. It's the feed ramp, not the case that is causing you problems.

Yes- Nickle, not zinc... We're talking about non chambered fresh reloads. NO feed ramps where involved in the equation, not even a Glock's....

 

[John Gault]

The usual way to measure brass "thickness"/case capacity is to measure how much water it holds (there are tables on the internet as a general guidline for different makes of brass). I just weigh the empty brass if I'm curious.. for whatever that's worth.

59 grains = CBC Brass
57 grains = Blazer Brass
54.5 grains = Federal Nickle

 

[Certaindeaf]

Just measured the CBC brass and a federal Nickle and a Blazer brass. "Post sizing die"

All external values were within my measuring ability with quality dial calipers.
Internal values show that the CBC is measurably thinner I.D but not by as much as you'd think it would take to show that bulge....

NO date code or NATO info or crimped primers that I see on CBC brass.

I may get a chance to shoot some tomorrow which sounds like a lot more fun.....

"Internal values show that the CBC is measurably thinner I.D".

Inside diameter measures less than others? That means that the brass/case mouth is thicker.

 

[ageingstudent]

59 grains = CBC Brass
57 grains = Blazer Brass
54.5 grains = Federal Nickle

That's not at all uncommon. I've even seen brass in the same headstamp vary as much as 4 grains. Average out 10 of each. If you do a water test like certaindeaf suggested above make sure the cases are sized first so everything is same/same OD.

 

[Member 5605]

My brass that does it deflects like this:

.357 Mag: .001-.002", they all still drop in a case gauge fine
Loaded brass measures: .375
Empty brass:

.40 deflects .0025"
Brass that's loaded measures .422"
Brass that's not loaded measures .418"

9mm:
.374" empty cases
.378" loaded cases

.44Magnum:
Maybe .001" deflection. Using jacketed rounds and I also use a factory crimp die so they look like factory rounds.


All drop free of the case gauge that I have. Lyman pistol combo gauge.

I guess I could go chrono these loads here that are like yours..... but using a volume based powder drop that's within +\-.2gr either way won't give a true scientific result for accuracy. I also load on the low->mid level...

I'm not minimizing your issue.

What's your measurements now?


Edit:
A better look with those crappy images (yes I understand it's hard to take photos of brass...) it's hard to tell... I've had too much crimp before on .357 and it buckled the case, doesn't appear that way on yours though. Bulging stops at bottom of projectile??

Turn the lamp up and use indirect light.

Is yours worse than the top two in the image?
9mm, .40, .357, 44Mag


FYI:
9mm above is .381" at the bulge...
My belief is the brass is inconsistent in its strength causing the bullet to deform the softer side instead of evenly deforming all around which leads to it looking like an AMC Pacer (pregnant) with heavy bulge on one side.

Interestingly enough, the calibers that do it the most are ran using RCBS and not in the Lee factory crimp/uniform sizing setup....

 

[elsie]

Looking closely at the pics in the OP, it looks like there is a bulge below the bullet base. Normally, I see a slight bulge from the case mouth down the the base. Also in the second picture, it almost looks like a wrinkle running down the length of the case, but this could be a trick of the light.

In the first picture, it looks like the case is being expanded too much, then sized down in the crimp, but I can't figure out how this is possible with the crimp die. I would start by checking the diameter of the expander ball in the sizing die. After that, I'm not sure because the crimp die shouldn't be sizing to the bullet base, only at the last bit of the case mouth.

In the second picture, it looks similar to a bottleneck rifle case when the shoulder gets pushed back to far. To me, this means that longitudinal pressure is being exerted which is more than the brass can handle. Since it's below the bullet base, I would look at the seating die for that one. Does it seem it takes excessive force to seat the bullet?


elsie

 

[Tilos]

RCBS carbide dies on a PRO 2000. Again, after further workups 3 out of 4 brass brands seem to work without any "bulging"....

You don't mention it, but if you are using a powder thru the expander type setup, the spring pressure applied to the case mouth/end could be enough to bulge a case that is soft, thin, or both.
I have found that spring on a Lee rotary powder measure to be quite firm.
just sayin'