Crimping and metal shavings

I have 45 brass (85 WCC with about 7-8 reloads on them) that I just acquired and when I crimp the brass I am getting a LOT of small brass shavings…almost like brass dust from the area that is being crimped as a result of the friction between the brass and the crimping die. Using LSWC bullets and .466” crimp. Currently not using sizing lube but I guess that is an option to consider. 

I have several other lots of brass that I use and none of them have this problem of creating micro-metal shavings from the friction of the crimping between the brass and the crimping die. 

I’m looking for insight about why this may be happening only with this one lot of brass and how to stop it. 

-Trevor

How much are you expanding?

chiz1180 wrote:How much are you expanding?

I never measured expanded case mouth with a caliper. I expand until bullet sits deep enough into the case so it doesn’t tip over when case goes into seating die. 

 Is there a specific amount of neck expansion that is used?

I have run into that issue when I expand heavily, their isn't really a specific amount, just a goldilocks feel thing.

Greetings,

Have a look at the inside of the crimping die.

You may be getting "chip welding" on the surface of the die.

Also, look at the finished cartridge. Do there appear to be small scratches/streaks on the crimp? This is a good give away.

Cheers,

Dave

I checked the case necks on the problem brass and on other lots. The necks on all lots appear to be the same to me and they show some small amounts of scratches on the last .020” or so of the case neck. 

I also loaded a batch of nickel plated cases and they did not have any scratches or produce any shavings/brass dust like the problem lot does. 

I’ll try to reduce case mouth expansion by a small amount to see if it helps.

fc60 wrote:Greetings,

Have a look at the inside of the crimping die.

You may be getting "chip welding" on the surface of the die.

Also, look at the finished cartridge. Do there appear to be small scratches/streaks on the crimp? This is a good give away.

Cheers,

Dave

I cleaned out the crimping die and there did not appear to be any evidence of chip welding. I also used the blade of a pocket knife to scrape around and feel for bumps with the blade that may indicate brass chips have welded to the die. Nothing seemed out of the ordinary.

Often once fired and new brass has a slight rolled egpdgecon the case mouth. This essentially is a burr that gets broken off during crimping.  If you take a few sample cases and deburr the outside edge with one of those tools for that job.  If the shavings disappear then you have the culprit.

chiz1180 wrote:I have run into that issue when I expand heavily, there isn't really a specific amount, just a goldilocks feel thing.

I measured the neck expansion that I was using and it was increasing the NK mouth by 0.020”. I reduced that expansion to only .010” and added a little One-shot lube to the brass and it seems to have alleviated the problem.

Expanding too much and crimping too much.
I periodically have that issue when I fuss with things.

Take a Qtip and clean out the crimping die to see if you have shavings in there.

Reduce crimp

Texasref wrote:Expanding too much and crimping too much.
I periodically have that issue when I fuss with things.

Take a Qtip and clean out the crimping die to see if you have shavings in there.

I’ll reduce expansion and try reducing crimp.

Here's a thought, most all has been mentioned. Take several pieces of the fired brass which is the brand which causes the problem, that has not been flared and measure the brass wall thickness, at several points around the perimeter. Ideally the brass would be cleaned, maybe resized, but not flared. Compare these wall thickness measurements to other brass which is not known to cause the problem.

My thought, subject to being wrong is this: When you resize that deals with exterior dimension of the case. To an extent, brass wall thickness doesn't matter for purpose of the resizing. However, when you expand the resized case, this uniforms and expands the inside dimension. Given the same die settings, the outside diameter of the flared thicker case will have a larger diameter than a thinner wall case. Further measure case length. If the brass is slightly longer, it will also get slightly more flare.

My guess is that the brass in question is either slightly longer, or case is thicker and this is increasing the outside diameter of the flared case, causing it to snag just a tad during the crimping phase, thus leaving thin partial rings of brass, or simply brass shavings. Since you are loading lead bullets, I would think the brass (neck) would shave lead, before the lead would shave brass. Thus IMO, the crimp die is shaving the brass.

The best solution is segregate the brass. Die settings for that. Die setting for other brass may be slightly different. Another option may be to set crimp die, for the longest, thickest brass, then see if that is suitable for the other brass. Other than a minor bit of clean up, if the shavings are minimal, it may not be a problem. Accuracy and functionality testing may be in order too. Good luck, Colonel, on your quest.