Ejector Extrusion, Can I Reload The Casings? Ladder Test Questions Too

[lee1000]

So I did a ladder test and while shooting I didn't notice these faint ejector marks but once I got home I did. It was sunny and due to the light I just couldn't see them. They started to appear at 42 and 42.6 grains. Some cases had them some did not, My velocities were inconsistent but I believe that is due to my POS Pact scale. I think they were loaded inconsistently because I had pulled several bullets and weighted the power, many were -.1, some were -.2 from what they should have been.

Can I shoot them again? Is the rule of thumb that if I can feel them with my finger nail that should discard them or just use them for practice? It could affect head space I suppose.

What maximum vertical dispersion should I expect at 600 yards with the following 308 load?
175 grain Nosler Custom Comp
Between 41.4 to 44.2 grains of AR-Comp
Velocities 2732 to 2879
Lapua Cases
BR-2 Primers
OAL ~2.810 (6 mil jump to the lands)
At 44.2 grains I started getting prominent ejector marks.

These were shot out my Savage FTR in 308

Thanks guys and gals, your experience is invaluable

 

[243winxb]

Ejector marks are on some factory fired brass. I would look for a loose primer pocket and/or gas leakage between the primer & brass. You said some have it, some dont. I would guess your Ok and may just have some soft brass??

Normal load right. Working up to Hot load on left, with expanded primer pocket. Primer fell out. Caused by high pressure. The primer pocket may open with 1 loading that is very hot. Or it may take several reloads at maximum to slowly expand the web area of the primer pockets. Your 44gr loads are HOT when compared to Alliants data.

 

[lee1000]

Ejector marks are on some factory fired brass. I would look for a loose primer pocket and/or gas leakage between the primer & brass. You said some have it, some dont. I would guess your Ok and may just have some soft brass??

Normal load right. Working up to Hot load on left, with expanded primer pocket. Primer fell out. Caused by high pressure. The primer pocket may open with 1 loading that is very hot. Or it may take several reloads at maximum to slowly expand the web area of the primer pockets.

Can I reload the ones that have minor extrusion?

 

[243winxb]

I dont know, depends on how the primers feels on seating. Alliant lists a 175 gr Sierra bthp with a maximum of 41.4 gr with AR-Comp powder. Lapua Cases tend to run up the pressure even more. Wait till you get other reloaders opinions.

 

[bigedp51]

Can I reload the ones that have minor extrusion?

How much are you willing to let the case lean in the shell holder and what is a "MINOR PROTRUSION" in the foundation of your cartridge case? (get the picture)

Have you ever heard of a banana shaped case, and the base of the case not being 90 degrees to the axis of the bore? The brass "pimple" on the base can cause the bullet to be out of alignment with the bore.

See 1 and 3 below.

 

[243winxb]

Nosler is showing 41.0gr maximum with your 175 gr bullet.

 

[lee1000]

How much are you willing to let the case lean in the shell holder and what is a "MINOR PROTRUSION" in the foundation of your cartridge case? (get the picture)[/quote]

For some it appears to only be a mark, other I can feel with my finger nail. I would only use them for practice, at this point I'm probably able to reload ammo that is more accurate than I am.

 

[lee1000]

Nosler is showing 41.0gr maximum with your 175 gr bullet.

I'm new to reloading but I've been under the impression that I can exceed max as long as back it off once pressure signs are observed. Is that wrong, just want to know.

 

[dkhunt14]

As long as they hold the primers you can use them. Take and rub them back and forth on fine grit sand paper and a flat surface till ridge is gone. Take the primer out so it doesn't interfere. Matt

 

[243winxb]

Nosler is showing 41.0gr maximum with your 175 gr bullet.

I'm new to reloading but I've been under the impression that I can exceed max as long as back it off once pressure signs are observed. Is that wrong, just want to know.

If you know all the pressure signs to look for, then its your call. I won't tell anyone to go over published data. All guns are different.

 

[lee1000]

Just found this great article on pressure signs if anyone is interested.

http://riflemansjournal.blogspot.com/2011/02/cartridges-long-range-reloading-safety.html

 

[jonbearman]

Do you have any other brass other than federal to try like winchester>?

 

[lee1000]

I only have Lapua. Will probably be buying some more soon

 

[Jeff Von Rosenberg]

I agree with dkhunt114 I have a AR(7.62 POF) Thant leaves ejector marks no mater what I do . I have slightly sanded and had no problem. Be sure to FL resize after your sanding. In an ideal world throw it away, but mine is Lapua so I tried to salvage it! JVON

 

[broncman]

If the primer pockets are tight, loadem back up for practice...they will flatten back out.

 

[243winxb]

Just found this great article on pressure signs if anyone is interested.

http://riflemansjournal.blogspot.com/2011/02/cartridges-long-range-reloading-safety.html

Great article at your link. I saved this from an old Olin PDF.

modulus of elasticity- Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI
when work hardened.

So if i understand this correctly, after a few loadings, the brass will become stronger from work hardening?? :-\