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Case Trimming????
Posted: Thu Jul 10, 2008 7:16 pm
by Buffy
Fellas just curious to know how neccessary it is to trim your brass before loading??? im up to my 3rd firing of my 308 brass and wondering if i should do it??? will i notice any accuracy changes or chambering problems if i dont trim it up??? if i need to trim it i will have to buy the doova lackies (cant remember the name of them
) to put in my trimmer... any ideas on what they are worth??
Fellas please enlighten me
Cheers BB
Re: Case Trimming????
Posted: Thu Jul 10, 2008 7:47 pm
by justjeff
Hi There,
How much your cases will lengthen depends on a few factors, like how hot a load, whether or not you full length size every reload, and what type of dies you use. The equipment can be basic and shouldn't cost too much, certainly less than $100.00, if someone wants to charge you more than that for a length trimmer, let me know, I have one I don't need that bady. You will need calipers to accurately measure your case length.
In terms of pressure, if the case was to grow so long it started to protrude into the leade each time you chambered, then you could see some big pressure spikes. Do you know what your current length is? My reference list 308 Win as overall length of 2.015 in.
Sinclairs sell a little plug you could buy which inserts into a shortened case to accurately measure the chamber length for your actual weapon, but if I had access to a lathe I would turn one up myself, outside dia would need to be 0.340 in
Jeff
Re: Case Trimming????
Posted: Thu Jul 10, 2008 7:49 pm
by paz
Just measure your cases, will soon see if they need trimming or not. I have to nearly trim my 22-250 cases every reload, its a real pain in the ass for stretching. I do trim all my other calibre cases to minimum length just cause i have the gear and it is habit for first reload.
A 308 should have a maximum length of 51.18mm and trim them to 50.92mm, from Nick Harvey's book, eighth edition.
Paz
(beat me jeff
)
Re: Case Trimming????
Posted: Thu Jul 10, 2008 7:52 pm
by macca
BB,Eventually some cases will grow so much they will not chamber.In your reloading manual you will have a max length for all your cases.
308 is 51.18mm and you trim back to 50.92mm.
A lyman case trimmer with 8 pilots retails at about $100.A redding is a bit dearer(130,160) you may be able to get one cheaper on sale somewhere.
You'll eventually need,particularily for the RUM.
Macca
Re: Case Trimming????
Posted: Thu Jul 10, 2008 7:54 pm
by macca
All quicker then me.
Macca
Re: Case Trimming????
Posted: Thu Jul 10, 2008 8:37 pm
by Buffy
thanks fellas, Jeff we may be able to work out a deal, pm me if your interested, as i think as Macca said the RUM will streatch a bit i think...
Cheers BB
Re: Case Trimming????
Posted: Thu Jul 10, 2008 8:47 pm
by Buffy
Sorry forgot to mention that my dies are RCBS Full length sizing dies....
Cheers BB
Re: Case Trimming????
Posted: Fri Jul 11, 2008 2:33 pm
by Peter O
BB
I would suggest that you get a neck die and use that instead of the full length one. Your cases will last much longer and require less trimming.
Re: Case Trimming????
Posted: Fri Jul 11, 2008 10:13 pm
by chris.tyne
If you can seat a flat base projectile lightly in the case and chamber it that will give you arough idea as to the chamber length if you measure from the base of the case to the end of the projectile.
If you set your dies up correctly you may not have the cases stretch as bad either,dont bump the shoulder back to far when fl sizing,all that brass that gets trimmed of comes from somewhere,usually the web of the case(not all that good).
Regards Chris.