Another reloading question re: trimming

[pharmseller]

The brass I use is all Remington (7mm-08, .30-06, 7 Rem Mag, .223). It just worked out that way.

I'm processing my first batch of once-fired brass in 7mm-08. The 7mm-08 loads were fired in 5 different rifles so I expect some variation in OAL changes, especially given that the loads themselves differed as well.

I lube properly (Goldilocks) so I don't think I'm unduly stretching the brass in the sizing die.

So my question is, after which firing is it normal to need to trim? Many of the cases are over length now after the initial firing. Am I doing something wrong, or is this normal?


Thanks,




P

 

[DrMike]

Much of the brass coming from factory loads is at or over maximum length. Normally, after the first trim, brass will give me about three firings before it stretches enough to need trimming. Of course, this is dependent upon chamber size and how hot you roll your loads.

 

[kraky]

Get these and you may never have to trim again. Alot of factory chambers are set. 030" over spec.
2 other advantages are less carbon build up before the bullets entrance to your specific dimension....and....possibly less bullet distortion as it does so.....

http://www.sinclairintl.com/reloading-e ... 32925.aspx

I have them for virtually every caliber I load for. Between the "real" measurement of my rifles chamber and using lots of lee collect dies and redding body dies I never have to trim on some guns. I have several guns of the same cartridge and keep notes in my die boxes so I know what's correct for ea gun.

 

[Alderman]

I use the Lee trimmers as part of my normal brass prep. Over the years I have made up my mind it is just about impossible to predict how much brass will stretch given the fact they don't all come out of the rifle at the same length. At least this is the way it works for me.

 

[jimbires]

if the 7-08 brass came from 5 different rifles , will it be used in 5 different rifles ? if so , you should keep the brass in lots for the different rifles and adjust your dies shoulder bump for each rifle . by doing this it will help brass life .

 

[pharmseller]

if the 7-08 brass came from 5 different rifles , will it be used in 5 different rifles ? if so , you should keep the brass in lots for the different rifles and adjust your dies shoulder bump for each rifle . by doing this it will help brass life .

Yes, the brass will get used in several rifles, I think we're down to four.

I'm not detailed enough to index brass to a particular rifle.


P

 

[SJB358]

The only way to keep it even would be to measure headspace on your tightest rifle and size for that one. If your shooting it out of 5 different rifles, it'll grow differently on each one of them. How much is hard to say.

I generally only trim the brass that needs to be trimmed. I measure everything when it comes out of the sizer and trim anything over. Anything under is shot until it grows above specs.

 

[BD1]

Krakys post about Sinclairs chamber length gauges is great info, additionally the use of tapered neck expanding mandrels with full length sizing dies also reduces some stretching.

 

[kraky]

Forgot to add...the Sinclair tools can "advise" you on throat erosion. I suppose I should recheck my 30-378 some day...ouch!
At a whopping cost of about $6 ea they are a really good investment in tool inventory...lol!