Case implosion causes?

[vinny]

During reloading just now I recognized that 4 of my cases 1 fouler 2 record sighters and a record string case,(probably the one that hit the front bank) had 1 to 4 little dents just below the shoulder. I thought if it was the first case fired, it could be some residual cleaning fluid. I'm pretty careful with drying the chamber so I discounted that plus if that was the problem, why 4 cases especially being the dented ones aren't the first four down the tube, well one was but not the other three. Too hot or too light a load? Any feedback would be great!
vinny

Perhaps a scale issue?

 

[Lynn]

Vinny

Vinny if your loads are too light or your powder is to slow burning it will cause your cases to dimple in.As you already said cleaning fluid or a powder kernel will do the same thing.
You said one dropped in low so I would suspect a light charge.If your scale is a RCBS it is somewhat easy to bump it just right and your charges will be 5 grains lighter.
Lynn

 

[vinny]

Vinny if your loads are too light or your powder is to slow burning it will cause your cases to dimple in.As you already said cleaning fluid or a powder kernel will do the same thing.
You said one dropped in low so I would suspect a light charge.If your scale is a RCBS it is somewhat easy to bump it just right and your charges will be 5 grains lighter.
Lynn

Thanks Lynn
I'm using an apx-153 by Denver instruments. You think it could be over-annealing? I think the one that fell into the bank was my fault, but to make 4 light loads, I don't know! I'm shooting a 308 Baer, 210 Berger's in-front of 76 G. of R22 215 w/primers.
vinny

 

[Lynn]

Vinny

Thats pretty close to my Baer load so I don't think its your problem unless something came up short 4 times in a row which is unlikely.
I use 77 grains of RE25 a 220 gr Norma case a 211 gr bullet and a 4.5 gr primer.I can put my loaded rounds on the scale and see if they all weigh 512.5 grains.If you didn't weight sort your brass you can't do that as the cases will vary by 20 grains or more.
I would look again at solvent in the chamber.My 308 Baer brass doesn't last long enough to anneal so I'm no help there.
Lynn

 

[oneflyer]

load info

That's not too bad a load. I've seen better results with a grain and a half more powder. Also I have had better results with 210M primers. I know that Federal says that any load over 65 grains should require 215's but I've seen better results on paper with the 210's.
The dimpled cases have usually been the results of too light a load. My experience only.

 

[vinny]

I guess its possible to have 4 non consecutive cases be loaded light. I guess I inadvertently entered the Twilight Zone. I'll start weighing completed rounds to make sure all the components weights add up. As it stands my cases weigh between 220.00 and 220.5 with the primer weight at 5.6 and the 210s. I'll pay closer attention to the finished weight.
My experience as limited as it is, is that R22 is usually 3-4 grains lighter then 25 to achieve the same velocity. I guess lot to lot variations could effect this. I'll check it next week.
oneflyer
What load are you referring to "That's not to bad a load"? 210s ya say!
Vinny

 

[Lynn]

Vinny

Vinny if your cases are sorted to within 0.5 gr just weigh your loaded rounds and look for anything way outside of the envelope.
A 308 Baer with RE25 will shoot a 3 grain wide window from 75-78 grains very well with the lots I have tried.It will shoot anything from 200-215 grains well with this same load depending on your freebore.I think your load using RE22 is not the problem unless it got short scaled somehow? I would look elsewhere if your positive all your charges were equal.You can usually feel or hear when you have a squib load so if you didn't notice it chances
are your load is just fine.
Did you get alot of powder residue on the outside of the cases? If not it was probaly something else.
Lynn

 

[vinny]

Vinny if your cases are sorted to within 0.5 gr just weigh your loaded rounds and look for anything way outside of the envelope.
A 308 Baer with RE25 will shoot a 3 grain wide window from 75-78 grains very well with the lots I have tried.It will shoot anything from 200-215 grains well with this same load depending on your freebore.I think your load using RE22 is not the problem unless it got short scaled somehow? I would look elsewhere if your positive all your charges were equal.You can usually feel or hear when you have a squib load so if you didn't notice it chances
are your load is just fine.
Did you get alot of powder residue on the outside of the cases? If not it was probaly something else.
Lynn

Lynn
Excessive powder residue? No different then any of the other cases. Could be just a freak thing, if its possible. I was going to ladder test my new HG with 25 I'll bring along the LG and try it. I shot 78 G of R22 last match in the HG a 308 Baer w 210 Bergers and GM215M primers didn't shoot to poorly for the conditions and that was a loadem and go type deal.
Thanks for the help.
If I find anything interesting I'll share it!
vinny
oneflyer
I'll even give the GM210Ms a chance.