over trimmed my .223 brass??

JB11rx · Mar 21, 2014

so I trimmed some .223 brass, id say 80% got trimmed between 1.750 and 1.720 but some of them got trimmed from 1.750 and 1.740....

my question is this. are the cases shorter than 1.750 garbage?

GunRightsCoalition · Mar 21, 2014

Can't answer for sure on their use for .223/5.56 loads however they can probably still be used for .300 AAC loads if not so don't toss them.

bellarum · Mar 22, 2014

What are you trimming with to get those random lengths? (I'd get rid of that.) L.E. Wilson makes a nice stainless trimmer that is very consistent. I do reload a lot of Federal bulk pack ammo that is below trim length after resizing and shoots just fine. Some of it needs trimmed after a few firings. If it were me I wouldn't load anything below 1.740. Make sure you set up your crimp die accordingly.

Trailboss · Mar 22, 2014

The shorter case length will be a problem if you don't use a factory crimp die but if you use the factory crimp, they should be fine and will lengthen when fired. Don't make a habit of it though. Back your die seat off but drop the bullets to the same overall length as recommended. Then when you factory crimp, some will have a deeper crimp, some less deep but all should hold fine.

JB11rx · Mar 22, 2014

I'm using a brand spanking new Lyman Universal Case Trimmer...

I'm at a loss as to why the lengths have veried as much as they have... They are all once fired mil brass. I'm wondering if it has to do with the differnce in the size of the primer pocket since I'm having to remove the crimp. The Lyman trimmer has ball bearing thing that goes into the primer pocket to help keep the case in place. If the primer pocket is a little bigger then wouldn't the the case length be longer than a case with a smaller pocket?

.

Well thanks for the info.

Jamie6.5 · Mar 22, 2014

Cases that are .030" short aren't garbage, but you may have trouble getting them crimped with a combo bullet seater/crimp die.
They present no problem other than the possibility of a carbon ring developing in the neck area of the chamber, if they are shot consistently by themselves.
If you pay attention to the chamber in your cleaning process, and spin a brass brush through the neck area it shouldn't become a problem.

bellarum · Mar 22, 2014

JB11rx said:
I'm using a brand spanking new Lyman Universal Case Trimmer...

I'm at a loss as to why the lengths have veried as much as they have... They are all once fired mil brass. I'm wondering if it has to do with the differnce in the size of the primer pocket since I'm having to remove the crimp. The Lyman trimmer has ball bearing thing that goes into the primer pocket to help keep the case in place. If the primer pocket is a little bigger then wouldn't the the case length be longer than a case with a smaller pocket? .

Well thanks for the info.

That could absolutely be the problem. Did you measure the cases before you started trimming? Some once fired cases are below the trim to length to start with. When you load them up make sure that you are at least crimping in the canalure and not below it.

JB11rx · Mar 22, 2014

bellarum said:
That could absolutely be the problem. Did you measure the cases before you started trimming? Some once fired cases are below the trim to length to start with. When you load them up make sure that you are at least crimping in the canalure and not below it.

Yes, there were a few that didn't require trimming. Out of 500 cases I believe there was less than 10 that measured below 1.750.

bellarum · Mar 22, 2014

The only other thing I would suggest is cleaning the primer pocket well after completely removing the crimp. If you can't get a consistent trim after that I would consider a different trim tool. (chamfer-debur the case mouth after) Good luck!

Nwcid · Mar 22, 2014

With mixed brass I have that trouble also. I had a lot that was way shorter, it should be easy to tell from the lack of trim on the neck. I do use a 3-way trimmer so no extra steps to deal with.

When I trim if there is no shavings and no mark on the neck I throw them in my "other" box. These will get used either for plinking ammo vs my target ammo, or get cut down for .300 Whsiper brass.

Same as TB, I too crimp as a separate step from seating.

Trailboss · Mar 22, 2014

Because I use a factory crimp as a separate step from the bullet seating, the over all length is perfect and the amount of the factory crimp that is visible varies slightly between the cases that I trimmed (which are all the same length) and the cases that were a bit too short to need trimming. I load range brass so I have a mix of other folks cases mixed with my own. No worries here. Perfect rounds every time.

ripcity · Mar 23, 2014

Just get a brass stretcher and stretch them a little.

AMProducts · Mar 24, 2014

Min/Max on COL is 1.740-1.760, I typically trim to 1.745" as this makes certain that I'm always "trimming something". This way my rounds are always exactly the same. 1.720" is a bit short, but probably still usable, the only real danger you run into is inadequate neck tension.

PotshotJim · Mar 28, 2014

JB11rx said:
I'm using a brand spanking new Lyman Universal Case Trimmer...

I'm at a loss as to why the lengths have veried as much as they have... They are all once fired mil brass. I'm wondering if it has to do with the differnce in the size of the primer pocket since I'm having to remove the crimp. The Lyman trimmer has ball bearing thing that goes into the primer pocket to help keep the case in place. If the primer pocket is a little bigger then wouldn't the the case length be longer than a case with a smaller pocket? .

Well thanks for the info.

The function of the ball is to center the case on the primer pocket, not to support the case head.
I have one of these trimmers and I get very consistent cuts with it. There is probably a detail in setup that got overlooked, like a loose setscrew in the depth adjuster. This can cause the adjuster to rotate as you operate the tool and move it toward the crank handle, increasing the depth of the cut.

cookie · Mar 29, 2014

I trim .010 under minimum length.

Otter · Mar 29, 2014

My two factory .223 rifles, a Wby Vanguard and a Remington 700 are reamed in such a way that I can let my brass grow very long. Suppose to trim at 1.760 down to 1.750 right? The Remington can handle a case as long as 1.790 and the Wby can handle a case as long as 1.770. Before you do any trimming, buy one of the Sinclair tools that allow you to measure this distance. I like to seat near the lands and I want as much neck as possible, so I trim accordingly.

Really no harm in using the shorter brass but I would sort into a batch itself. As long as you have enough neck to hold the bullet in place with enough tension. There is the risk of a carbon ring forming, but you should be using some JB or Isso to keep the throat clean anyway.

joie777 · Mar 29, 2014

on the Lyman trimmer you get it adjusted where you want and then drill a small bump where the set screw goes for the length you want so it will hold the right length ask me how i know hehe the hard way and it will stay where you want it mine would move and tighten it down and then your brass will come out the right length and the brass will stretch back out when you shoot it if you have a bolt gun would be best but make sure you get a crimp on it

YOURSUPREMECOMMANDER · Mar 31, 2014

Champher the crimps on the primer pockets B4 you trim. When you de cap, the crimp often sticks out past the case head. This will cause trim and other problems.