Houston we have a problem.....seperation iminent

[cloverleaf]

Ok, the photos below are for your purusal (sp?) and hopefully our mutual education. Let me start out by saying that I was just bored, and needed somthing to keep my mind busy so I tried my hand at case trimming. Bought a pilot and a shell holder for Dads Hornady case trimmer and started experimenting with some cases that were 15 to 20 thousandths over max. :shock: . The brass is almost 20 years old and has been reloaded 4-5 times. Trimming for most of the box went OK and once I got the trimmer set where I wanted it things went pretty smoothly. Except that is for three of the four cases you see in the photo below.
These cases working left to right would not fit on the pilot of the trimmer. Thought this was odd but being a neophyte, I pushed a little harder :roll: . When they still wouldnt go I set them aside and finished the remainder of the box. When I got out the caliper and measured the inside diameter of the neck, the were all less than .250.... :? Considering that these cases were fired in a 250-3000 Savage (.257 ) this seems ...um, well strange. I can only assume that over the firings the brass has "flowed forward". There were no other signs of cracks in the necks or cases prior to my trying to trim them. However as you can see, my heavy handed efforts to get the pilot in the case neck must have found some weak spots in the brass. Catstrophic seperation appears just one trigger pull away.

Again, I do not suggest you take my approach to reloading....I was just horsing around with some "dissposable" brass in an effort to get the trimmer set and a feel for how its done. I think I'll pitch the remainder of the box of brass..... comments are welcome though. CL

Again, the "worst" case is on the left, the one with out visible cracks or "wrinkles" is on the right.

 

[JD338]

Typically as a case grows and gets trimmed, the case wall near the web thins. You can check this with a paper clip. Bend the clip into an "L" and run it inside the case. You will feel a ring down near the web area of the case, many times before you see it on the outer side.

JD338

 

[Elkman]

I have a short piece of heavy wire that I bent at the end (very small bend) and atteached it to a short round piece of broom handle for a handle. It looks kind of like a ice pick with a 90 degree bend at the end. The best way to learn the "feel" is to use your tool on the cases you already have. Magnums are famous for this trait.

 

[tjen]

The lighter colored ring should draw attention. cases swell there but that Gold ring says its thin.

 

[IdahoCTD]

It looks a bit like a rather large chamber and a FL die shrinking it down too much. You can clearly see where the brass changes color near the head of the case. That is where it goes from the case head to the wall and get's thinner. After repeated firings and sizing operations the brass work hardens and cracks. The stretching also doesn't help because it makes the area thinner over time and it's even easier to crack.

 

[Gm weatherby man]

All good advice above, I also believe with only 4 or 5 firing that maybe the charge of powder be backed of at least a full grn.To me it looks like some heavy bulging from as described above as chamber size in access. I find this in the old brittish anytime I push max loads .

 

[cloverleaf]

Thanks guys - I'm learning..... hope somebody else is too. CL

 

[Ridge_Runner]

my GUESS would be, the overlength cases were jammed into the throat on the last firing and thats why they wouldn't go on the pilot, also the last round if jammed was very high pressure due to the neck not being able to release the bullet.
RR

 

[OldMan]

I also have made a tool from acet welding rod by grinding a point on one end and bending it in a tight 90 degree then give it the length of my hand with another bend. The tool is used to reach all the way inside the case and applying pressure to the point, then drag it all the way to the neck. You will usually find the separation a short way up from the base. Take those cartridges in question and cut them in half from the base forward to open up a window to see the problem area. If you find a few that are thinning, keep them and practice feeling the problem with your tool. You will eventually get where you can feel the problem as fast as you can pick up a case and test it! I started my testing when a case separated in a West German Mark V Weatherby, leaving a permanent defect in the chamber. Can you imagine shooting the largest bull in your life and not having a follow up shot because the front of your case stayed in the gun??? I test every case on every rifle before attempting to re-load since that day!!!

 

[cloverleaf]

Interestingly enough, I measured a couple different lots of once fired brass. They come out right at max length before re-sizing. Would that be "normal", or would that be indicative of an "oversize chamber" as suggested? CL

 

[IdahoCTD]

CL,

A oversized chamber usually happens at the back of the chamber. So if you look at your pictures you see where the darker color at the base of the cases turns to a lighter color? If you look close you will see that the diameter where the lighter color is is larger. That is because the brass thins out enough there to expand more under pressure. A tightly cut chamber won't do that (at least not to that degree). That is because there is less clearance between the brass and the chamber wall so it doesn't let the brass expand so much.

When I first started chambering my own guns I use to use the tail stock of the lathe to push the reamer in. Well come to find out the tail stock didn't come in perfect alignment when I got the lathe so it pushed the tail of the reamer out to one side. So it progressively made the chamber larger the closer you got to the action.

One thing you can do is measure the back of the cases and find the largest dimension. Then you can look up SAMMI specs on your chamber. If the brass is within a thou (.001) of the measurement on the print it's on the large side.

 

[bullet]

Check you head space

 

[cloverleaf]

Check you head space

According to my smith and his 22-250 "go, no go" guage my hedspace is fine.... My wife has another opinion. Oh yea, I dont use that smith any more. :? :roll: The wife still tolerates me.... CL

 

[bullet]

Check you head space

According to my smith and his 22-250 "go, no go" guage my hedspace is fine.... My wife has another opinion. Oh yea, I dont use that smith any more. :? :roll: The wife still tolerates me.... CL

:mrgreen: :mrgreen: :mrgreen: