Powder or primer degradation

DWier

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I ran into a similar problem with .243 ammo, which was reloaded by my dad and stored in a Pennsylvania basement 20 years or so earlier. Read about chemical welding of case mouth and copper jacket. When I went back and re-seated the bullets by a thousandth or so, I noticed that several of them felt like they "broke loose" during re-seating. No pressure problems after that. Of course these were 20-25 years old, not 12. But, worth a try?
Being stored in a south (actually Central) Georgia barn at 100-120° for many summers and 35°for many winters would probably play havoc with all components especially powder, primers and brass. Just my thoughts.
 

26Reload

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I would go with bullet welded....one piece of brass looks as if the stamped face is concave....
 

Stammster

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Will do. Again thanks.
Good suggestion. Do you have a kinetic bullet puller? 6-10 sharp blows should dislodge the bullet, or at least get it moving.

I pulled a 25-06 round apart a few months ago that was loaded in the early 1990’s, in order to verify the charge weight. The bullet came free after 16 strong blows, but only because the case separated at the base of the neck. The neck was still around the bullet - as a perfect little shrink fit donut.

I shot the rest of the batch (35+ rounds) without any pressure signs and the ES was less than 30 for 20-25 rounds I shot with the magnetospeed on. Velocities were consistent with the exact same load that I had just rolled.

Therefore, in my recent (albeit limited) experience, “bullet weld” did not directly correlate to excess pressure.

These old loads also shot well (<.7 MOA) with the magnetospeed on, but closed up nicely with it off. So accuracy didn’t appear to be effected either.
 

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jpndave

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You can also seat them slightly deeper to break it if not crimped. If they don't move or fold the case, definitely cold welded.
 

epoletna

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I think 270Jim has it. Measure the diameter of the bullets— the Hornet does not use .224” bullets, and they could easily cause overpressurew. It’s not old powder or primers, in my estimation.
 

Stammster

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According to my info, the Model 43 era (1948-1953) Hornet’s use .224 diameter bullets.

Also this wouldn’t explain why only 2 rounds out of the bunch showed issues.
 

Canadian Bushman

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According to my info, the Model 43 era (1948-1953) Hornet’s use .224 diameter bullets.

Also this wouldn’t explain why only 2 rounds out of the bunch showed issues.
The only two cases with different head stamps.

Cold welding and powder degradation only affected these two cases.
 

LoneTraveler

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J E Custom I like your suggestion of checking the Firing pin length.
I would suggest that the Firing pin spring be checked for tension and replaced. That rifle has not been built in a long time. Old age and maybe being stored with the firing pin cocked has taken its toll on the firing pin spring.

Those 2 shells may be loaded a little different load or may have less capacity and up the pressure a little. May been cleaner cases when loaded and cold welded case and bullet a little.
The chamber pressure over rode the firing pin spring tension and drove the firing pin back into the bolt and sheared the firing pin en-dent and it went back in the bolt or was returned loose into the punctured primer.

A new spring would probably make the old war horse rifle shoot better groups to.
Have seen that same problem on some old Rem. 721 and 722's and other old rifles.
 

Canadian Bushman

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There is a handful of things that blank primers.

Too much pressure - you have
Small cases with big firing pins - you have
Excessive headspace - dont know
Firing pins with improper shape - dont know
Too big of firing pin hole, loose - probably not
Thin cups on primers - dont know
Weak firing pin springs - dont know

I highly doubt firing pin length is your problem. The primer cup and anvil stop the firing pin not the stop collar. This is why the dent in you primer is usually shallower than firing pin protrusion.

You have two cases, with different head stamps, with severely flattened primers that are also punctured.

The cases with different headstamps that dont have severely flattened primers are nut punctured.

I can also tell by looking that you have a large dia firing pin. Much larger than is needed on such a small case. Common on older rifles. Also looks like it has a bit of an edge near the OD but cant see well enough.

Both high pressure and excessive headspace can make primers look flattened. Both can result in punctured primers.

Small cases build pressure faster than large cases. Primers push out of the pocket towards the boltface and over the firing pin much quicker.

Small cases are WAY more susceptible to pressure spikes due to volume or powder changes than large cases. 1gn variations to a 10gn charge is a 10% increase, to a 100gn charge its 1%.

Because only 2 cases have punctured primers, The same two with similar headstamps, the primers that are not punctured are neither flattened, cratered, or punctured.

Id say excessive pressure is most likely
Excessive headspace is 2nd
Wrong size or mis-shaped firing pin is 3rd


Check inside of bolt for primer bits
Check firing pin for flame cutting
Revert to starting charges and minimum headspace
Use fresh, thick cup primers
And im betting youll be just fine.

If you wanna be thorough, check the volume of the cases with punctured primers to one that isnt. If its smaller you know excessive pressure is the culprit.
 
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DWier

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There is a handful of things that blank primers.

Too much pressure - you have
Small cases with big firing pins - you have
Excessive headspace - dont know
Firing pins with improper shape - dont know
Too big of firing pin hole, loose - probably not
Thin cups on primers - dont know
Weak firing pin springs - dont know

I highly doubt firing pin length is your problem. The primer cup and anvil stop the firing pin not the stop collar. This is why the dent in you primer is usually shallower than firing pin protrusion.

You have two cases, with different head stamps, with severely flattened primers that are also punctured.

The cases with different headstamps that dont have severely flattened primers are nut punctured.

I can also tell by looking that you have a large dia firing pin. Much larger than is needed on such a small case. Common on older rifles. Also looks like it has a bit of an edge near the OD but cant see well enough.

Both high pressure and excessive headspace can make primers look flattened. Both can result in punctured primers.

Small cases build pressure faster than large cases. Primers push out of the pocket towards the boltface and over the firing pin much quicker.

Small cases are WAY more susceptible to pressure spikes due to volume or powder changes than large cases. 1gn variations to a 10gn charge is a 10% increase, to a 100gn charge its 1%.

Because only 2 cases have punctured primers, The same two with similar headstamps, the primers that are not punctured are neither flattened, cratered, or punctured.

Id say excessive pressure is most likely
Excessive headspace is 2nd
Wrong size or mis-shaped firing pin is 3rd


Check inside of bolt for primer bits
Check firing pin for flame cutting
Revert to starting charges and minimum headspace
Use fresh, thick cup primers
And im betting youll be just fine.

If you wanna be thorough, check the volume of the cases with punctured primers to one that isnt. If its smaller you know excessive pressure is the culprit.
PROBLEM SOLVED!! Seating depth off by 0.010. Measured OAL (yes, I know), pulled bullet and weighed powder, brass, and bullet. Seating depth off 0.010. Fairly certain that is the problem.
Thanks everyone,
Daryl
 

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