Shoulder bump question

[skeasor]

Hello,

I've only been reloading for about a year and have a question in terms of some once fired brass I picked up at the range.

I noticed that someone left a pile of brass (223) at the range so I decided to pick it up, take it home, inspect, clean etc

Since this wasn't fired from my rifle, I setup my resizing die to do a full resize. After resizing the batch, I used my hornady head space gauge to see what the shoulder bump was sized to... There were 3 different sizes (3.447, 3.442 and 3.437).

Any idea as to what would cause these different should bump sizes? I am using a Lee pacesetter resizing die. One thing I can't really guarantee is that the, 'once fired brass' was shot from the same rifle, but based on where the brass was on the ground, I would assume it was from the same rifle.

Attached is a picture

Thanks!

 

[okie]

GUFFEY!!!
sorry skeasor, i dont know the answer --I just had to get that out!!

 

[jpx2rk]

How many different brands/headstamps are included in this batch of bras? Different brands of brass will size differently due to the differences between each companies "receipe" for their brass. Some pieces of brass will not size the same as other pieces even from the same lot/brand of brass, probably due to a slight difference between the pieces of brass. Each piece of brass, while uniform in a lot of ways, it is still a unique piece of metal, and will react to heat and pressure differently. Some pieces of brass expand/contract at different rates when fired, some appear to remain the same size when measured for some reason.

You can have a reasonable level of confidence that the brass is 1x fired IF the primer pocket crimps are still present. Did de-priming the brass take a bit more effort to "pop" the spent primer out?? If you can see evidence of the crimp being removed via cutting the crimp out, ( a small shiny ring will be evident around the primer pocket), then you can only guess on the number of firings. Some 223/556 brass do not have a crimp on the primer pocket, some do. Is there a cross cut pattern on the leading edge of the case neck, if yes, the brass has not been trimmed or chamfered, just re-loaded if the crimp ring is gone.

when I pick up range brass, and see the cross cut pattern on the leading edge of the case neck, no chamfer and the primer is a bit more difficult to remove, I feel like it it 1x, but still cannot be 100% certain. If I see the shiny ring around the edge of the primer pocket, I know it is 2x or more, and check the primer pockets for enlargement (reloaded with higher powder charges) and may just discard those.

 

[Jeff Porter]

Different spring back from the different brass. Also varies with how many times it has been reloaded. Which is why many anneal to get all the brass in a lot to the same state of hardness so they will size the same.

 

[Tommie]

GUFFEY!!!
sorry skeasor, i dont know the answer --I just had to get that out!!

Beat me to it

 

[L.Sherm]

Anytime you pickup range brass expect the worse and hope for the best.
The ones that are .010 shorter I would treat them like new "fireforming " and seat the bullet into the lands and back the charge of atleast 1 grain from max.
I wouldnt try to get the short ones completely formed in one try either, back off the die a little next go round and basically just neck size them will probably work. Keep the short ones separate from the longer ones untill they get a few more firings on them

 

[K22]

Anytime you pickup range brass expect the worse and hope for the best.

Yes - double yes especially today with the vast majority of 223 Rem brass coming from semi-autos.

Users beware.

 

[6MMsteve]

as long as your going to blast it through an 16 style rifle it will be fine, especially if your loading for bulk cases to send thru your akrf rifle, I use the ar style for a defensive outlook long as the cases function and fire that's my only concern

 

[6MMsteve]

if you have 2 16 style and one for accuracy and one for blasting I would use specific ammo according to what I'm lookin for out of each rifle

 

[Martin52]

Different spring back from the different brass. Also varies with how many times it has been reloaded. Which is why many anneal to get all the brass in a lot to the same state of hardness so they will size the same.

Skeasor - anneal all those cases if you can and then resize. If you haven't done this before do a search on this site, as a start, use a drill and deep well socket to hold the brass, use a blue propane gas torch.

 

[BoydAllen]

The point of the gauge is to have a desired "bump to" measurement for your rifle and to set your die to produce that measurement. Sounds like you are still in the screw the die down to the shell holder and lock it stage. I know that the die maker's instructions were likely to have told you to do that, but it misses the whole of limiting the difference between the shoulder to head dimensions of sized and fired brass. The problem with what you did was that the brass was of mixed hardness so that the same die setting produced the results you got. That is one of the main reasons for avoiding range brass unless you are able to actually confirm that it is once fired, from the person that shot it. Even so it is best if the cases are of the same brand and from the same lot. I start with new cases and fire and size the cases of a given batch in rotation so that they all have the same number of firings and sizings, which makes the shoulder bump more consistent.

 

[Coyotefurharvester]

I have a stash of ammo, made from range brass, that I will fire and never pick up. Everyone should have a supply for that type use, these days. It has minimum SAAMI specs, it will run thru ANY AR. I sized the brass, left it for one year and checked size again(before loading), wanted very stable brass I can COUNT on. This was once fired(no full auto), I had to remove crimps before cleaning.

 

[243winxb]

There were 3 different sizes (3.447, 3.442 and 3.437).

When fl sizing, the case shoulder has not moved forward to contact the dies shoulder on the short ones. May take 3 firings.

What measurement do you get from fired factory ammo, in your rifle? Not good if sized range brass is shorter by .010" or more. Separations.

 

[skeasor]

Thanks for all the information that everyone has posted.