Baffling headspace problem

[Mattnall]

I've been loading .308 successfully for years using a Redding full length sizing die and competition shellholders.

I clean the die occasionally with Pro-Shot copper solvent as it gets a build up of brass which scratches the case necks.

This may be irrelevant to the problem, but on the last clean I left the solvent in for a few days by mistake.

Anyway, of all the rounds I've loaded since then approximately half will not chamber due to insufficient headspace.

Any ideas what could be causing this inconsistency?

Mattinall - If you think you have a headspace problem -

Not me, mate, Racalman has the conundrum.

[Racalman]

What about the case length? Are some cases longer than others or are they all about the same length give or take a few thou?

At what point do they not chamber? Do you only feel resistance when you rotate the bolt handle or do you feel the resistance whilst feeding the case into the chamber?

The cases are all pretty much the same length.

The resistance is felt while trying to close the bolt.

[Racalman]

I've been loading .308 successfully for years using a Redding full length sizing die and competition shellholders.

I clean the die occasionally with Pro-Shot copper solvent as it gets a build up of brass which scratches the case necks.

This may be irrelevant to the problem, but on the last clean I left the solvent in for a few days by mistake.

Anyway, of all the rounds I've loaded since then approximately half will not chamber due to insufficient headspace.

Any ideas what could be causing this inconsistency?

Mattinall - If you think you have a headspace problem -

Not me, mate, Racalman has the conundrum.

Indeed I do and maybe I'm using the wrong terminology. The problem is with the sized cases, not the chamber. Using a Hornady headspace comparator I'm seeing up to a 10 thou variation between sized cases.

Anyway I need to get on and reload for the next competition so I've ordered a new die as I can't think of anything else.

[Alpha1]

Are you using a hornady headspace comparetor.? or a cartridge over all lentgh gauge How many times have the cases been fired.

[StanDeasy]

Suggest you review your case lube technique

Inconsistent application of case lube --> inconsistent shoulder set-back.

Insufficient application of case lube --> build up of brass in die due to metal-to-metal galling.

[Racalman]

Are you using a hornady headspace comparetor.? or a cartridge over all lentgh gauge How many times have the cases been fired.

Yes, and 3.

[Racalman]

Suggest you review your case lube technique

Inconsistent application of case lube --> inconsistent shoulder set-back.

Insufficient application of case lube --> build up of brass in die due to metal-to-metal galling.

I've been using a lube pad for years and always had consistent results (until now).

There has been some galling in the die which is why I clean it with copper solvent periodically.

[WelshShooter]

Thinking of the sizing process, have you noticed any difference in the resistance during full length sizing? Does it feel like you need to exert a wee bit more force during sizing? When I started reloading around 9 years ago I was using a lube pad and the RCBS squeeze bottle lube. Couldn't really get on with the stuff and have been using imperial sizing wax since then.

Is it possible that your lube pad was drying out whilst lubing your cases? Galling is metal on metal contact which might suggest lack of lubrication, but it's a bit strange that a steel die would be damaged by softer brass unless the cases are dirty from the range and the galling was caused by debris.

Otherwise I'm all outta ideas. If nothings changed other than the soaking of solvent in your dies for a few days, then that's the assignable cause in which case you might need to get a new die.

[Racalman]

Thinking of the sizing process, have you noticed any difference in the resistance during full length sizing? Does it feel like you need to exert a wee bit more force during sizing? When I started reloading around 9 years ago I was using a lube pad and the RCBS squeeze bottle lube. Couldn't really get on with the stuff and have been using imperial sizing wax since then.

Is it possible that your lube pad was drying out whilst lubing your cases? Galling is metal on metal contact which might suggest lack of lubrication, but it's a bit strange that a steel die would be damaged by softer brass unless the cases are dirty from the range and the galling was caused by debris.

Otherwise I'm all outta ideas. If nothings changed other than the soaking of solvent in your dies for a few days, then that's the assignable cause in which case you might need to get a new die.

No real difference in the sizing experience. I keep the pad well lubricated. The galling has been mostly on the neck area of the die. All my cases atre clean and shiny when I size them. If the problem I'm getting was consistent then I could assign it to my setup, but it varies from one case to another which is what has me baffled.

I have a new die arriving today so will report back tomorrow if that has solved the problem.

Thanks for listening.

[artiglio]

You can chase your tail for weeks with such things. A bit of extra pressure ,for whatever reason ,or the brass being a bit “softer” than usual MAY have resulted in the case head expanding a touch more than usual , a small base die MIGHT help.
But Vince’s suggestion is a better place to start, get some new brass load it and fire it, at least then you’re starting from a known datum, when resizing.