Question about brass

OldNavyVet · Jan 21, 2019

While sorting brass this morning i came across a couple of these 9mm with grooves. What are they? Disclaimer: I know nothing about reloading. Was saving brass for brother in law who has given it up for now. Most of it is my factory ammo with whatever was on the deck when I cleaned up. Just curious.

John from MD · Jan 21, 2019

It is called a "cannelure" and they have several purposes. If on the bullet, it is to facilitate crimping. If on the brass case, it is there to keep the bullet from going deeper into the case. You can load them just like you load everything else. The failure mode on handgun brass is usually splitting at the mouth unless it is fired in a Glock. :innocent0

OldNavyVet · Jan 21, 2019

John from MD said:
It is called a "cannelure" and they have several purposes. If on the bullet, it is to facilitate crimping. If on the brass case, it is there to keep the bullet from going deeper into the case. You can load them just like you load everything else. The failure mode on handgun brass is usually splitting at the mouth unless it is fired in a Glock.

Thanks John. And thanks for your service.

Biggfoot44 · Jan 21, 2019

Brass with cannelures is slightly more prone to stretching . Go ahead and use it , just be aware to monitor case length .

Pinecone · Jan 21, 2019

Have you ever had a straight walled (or close to straight like 9mm) stretch enough to have to trim it?

John from MD · Jan 21, 2019

I haven't ever trimmed a 9mm case that I can ever recall. Oh yea, I did trim off 1 mm when I used to make 9x18 cases in the '70's. :rolleyes:

10xclean · Jan 21, 2019

so I remembered that LC 308 brass and M118 LR brass had similiar rings... googled it up and on those cases if signified 'not for combat use'. I had assumed it was used for 'holding the case in the chamber for just milliseconds longer with the knurling. I have 5000+ pieces of that brass still. Those were the days were LC Match was handed out with the entry fees at high power matches...

from - https://www.ar15.com/forums/armory/LC_87_Match_brass/42-336421/

"Sir, IIRC LC M852 match cartridges were stamped LC, year, and "MATCH". The longitudinal lines around the perimeter of the case near the base were to facilitate recognition that the cartridge was "not for combat use" and the boxes the ammo was packaged in were so marked. I believe production of this ammo ceased sometime in the early '90s and it is becoming more and more rare."

I shot an entire can of M852 during the National Matches two years ago, now I only have one can left. I've reloaded thousands of cartridges using this brass for use in my M1As and will reinforce the comment that four reloads is the limit. While the lines on the case perimeter have nothing to do with it I can testify that the case head seperations I've experienced occurred further up on the body of the case away from the lines. The Sierra reloading manual has an article that includes some comments regarding this phenomena but my own experience does not support their conclusions. HTH, 7zero1.

Postell · Jan 21, 2019

10xclean said:
so I remembered that LC 308 brass and M118 LR brass had similiar rings... googled it up and on those cases if signified 'not for combat use'. I had assumed it was used for 'holding the case in the chamber for just milliseconds longer with the knurling. I have 5000+ pieces of that brass still. Those were the days were LC Match was handed out with the entry fees at high power matches...

from - https://www.ar15.com/forums/armory/LC_87_Match_brass/42-336421/

"Sir, IIRC LC M852 match cartridges were stamped LC, year, and "MATCH". The longitudinal lines around the perimeter of the case near the base were to facilitate recognition that the cartridge was "not for combat use" and the boxes the ammo was packaged in were so marked. I believe production of this ammo ceased sometime in the early '90s and it is becoming more and more rare."

I shot an entire can of M852 during the National Matches two years ago, now I only have one can left. I've reloaded thousands of cartridges using this brass for use in my M1As and will reinforce the comment that four reloads is the limit. While the lines on the case perimeter have nothing to do with it I can testify that the case head seperations I've experienced occurred further up on the body of the case away from the lines. The Sierra reloading manual has an article that includes some comments regarding this phenomena but my own experience does not support their conclusions. HTH, 7zero1.

I have LC Match brass from the 70's-80s that i have reloaded 30 to 50 times and never had one of them fail in the body, neck yes, but never the body.

John from MD · Jan 21, 2019

Postell said:
I have LC Match brass from the 70's-80s that i have reloaded 30 to 50 times and never had one of them fail in the body, neck yes, but never the body.

That's because the guns you were using it in had good headspace.

I have had a few fail just above the solid base in 1917 Enfield and No1 MkIII Enfield.

Magnumite · Jan 27, 2019

Pinecone said:
Have you ever had a straight walled (or close to straight like 9mm) stretch enough to have to trim it?

357 and 44 Magnum, yes. 45 ACP and 40 S&W...no.

John from MD · Jan 27, 2019

Periodically I will find a few 44 mag cases that need trimming. I'm guessing they are from the rounds made with 24 grains of H110 and 240gn bullets. :evilgrin3

Magnumite · Jan 28, 2019

The high pressure are the ones which grow quick, typically needing trimed every three firings. Higher the pressure the more they grow. They will even separate the case head from the body if you don’t check for the stretch ring just in front of the case web. The mikder loads will grow with several loadings possoble between firings.

I know several are aware Lee offers the FCD for straight wall pistol cases. One of the advantages advertsed is the need not to trim for a consisent crimp. That s because the crimp is not as tight. I will get bullet creep with higher velocity rounds using that die than I do with the RCBS crimp die. The RCBS will overcrimp if you set it up a heavy crimp for trmmed to length cases and put in some untrimmed ones.

John from MD · Jan 28, 2019

Magnumite said:
The high pressure are the ones which grow quick, typically needing trimed every three firings. Higher the pressure the more they grow. They will even separate the case head from the body if you don’t check for the stretch ring just in front of the case web. The mikder loads will grow with several loadings possoble between firings.

I know several are aware Lee offers the FCD for straight wall pistol cases. One of the advantages advertsed is the need not to trim for a consisent crimp. That s because the crimp is not as tight. I will get bullet creep with higher velocity rounds using that die than I do with the RCBS crimp die. The RCBS will overcrimp if you set it up a heavy crimp for trmmed to length cases and put in some untrimmed ones.

All true and well worth remembering. :thumbsup:

Magnumite · Jan 28, 2019

Thankie.... I shot my Ruger Redhawk in Hunter's Pistol Open Sight class for years. It was my "treat" after shooting the more competitive scoped Contenders in two other classes. I won a couple state championships with it...one in AAA, iirc. Getting those 5 and run pins for each 'animal'. I remember building real match grade ammunition...no detail over looked. Then there were the 'good' loads built without case length trimming, primer pocket cleaning, bullet weighing. They didn't shoot much different except at longer range, then the difference in effort showed up. I do know the right powder and good bullets are of paramount importance.

EDIT: Sorry, senior moment...

Pinecone · Jan 28, 2019

Interesting.

I have not shot that much .357. And don't own a .44, yet.

Biggfoot44 · Jan 28, 2019

For heavy recoiling straight cases ( and/ or needing substantial bullet pull for proper ignition of slow powder ) the key thing is Case Tension .

Crimp per se is just one part . The other necessary thing is the neck expansion . ( Ie too large = not enough tension regardless of crimp . And generally a cast bullet needs tighter than jacketed * of same diameter *) If you either polished your expander down another .001 smaller, or requested smaller expander from LEE, or sized your bullets a hair larger. Ie instead of sized .429 , then .430 or even .431 .

The ultimate Crimping Die is the Redding Profile . Every other roll crimp die , including FCD are lumped closely .

John from MD · Jan 28, 2019

For rimmed cartridges, I find the RCBS Cowboy crimp die works very well with Keith style bullets

Biggfoot44 · Jan 28, 2019

Bingo . The RCBS Cowboy Dies are optimized for cast bullets .

Magnumite · Jan 29, 2019

Biggfoot44 said:
For heavy recoiling straight cases ( and/ or needing substantial bullet pull for proper ignition of slow powder ) the key thing is Case Tension .

Crimp per se is just one part . The other necessary thing is the neck expansion . ( Ie too large = not enough tension regardless of crimp . And generally a cast bullet needs tighter than jacketed * of same diameter *) If you either polished your expander down another .001 smaller, or requested smaller expander from LEE, or sized your bullets a hair larger. Ie instead of sized .429 , then .430 or even .431 .

The ultimate Crimping Die is the Redding Profile . Every other roll crimp die , including FCD are lumped closely .

In all my magnum reloaded ammo, light to full bore, I run a tight crimp for high bullet pull force. One less variable and it yields desirable results.

Some of the cases I have are over 30 yewrs old. I would use specific case head stamps and bullet combinations to identify a load. A few years back I was chrono’ing some loads and noticed the velocities were dropping going around the cylinder. This particular load wasn’t particularly brutal and was always very uniform. On the third cylinderful I stopped to check rounds 4, 5, and 6. Sure enough, bullet creep. I just pushed the bullets back into the cases and fired them one at a time. Uniformity was back. Back home, got to checking pre- and post- sized case neck diameters were not much different. The cases were work hardened, wouldn’t keep adequate tension on the bullets. Loaded up same brand low fire count brass and the chrono and visual checks indicated no bullet creep and the uniformity was back.

John from MD · Jan 29, 2019

Good info. Work hardening happens when you reload a lot and will definitely affect your velocity.

I anneal my 30 cal and up rifle cartridges but I don't worry about it in my pistols due to the distance I shoot at.(25 yds or less) Since I use cast bullets exclusively, the cases get additional stress as they are belled too.

Question about brass

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