Chamber spec's / Die spec = Die set-up

[stimpylu32]

calvon brought up a very good point in another thread about how a die sizes compaired to what a chamber is cut at . A lot of new loaders ( and some of us old timers - even ME    ) will sometimes assume that you can just screw the die into the press and then your ready to load and shoot ammo .

This is in most cases not true , the problem arises when your dealing with dies that are not cut with the same reamer's that are used to cut the chamber's . All gun companies have more than one reamer that are used to cut chamber's with , as well as do all die companies , so what does all this mean ?

All reamers , be they chamber or die , are only cut to fall with in a certin spec. range , yet they will very quite a bit , so proper die set-up is key , and part of the set-up is to insure that the brass that is being sized will properly fit the chamber of the weapon that it is to be fired in .

Just something to think about .

stimpy

PS - calvon , I did the samething awhile back so don't feel like the 

 

[Catfish]

I would think that a man in your profession would know that it is very hard to put something in a hole with zreo clearance.  And that is not even considering the spring back when you resize. I know, I now can let you get anything on me now, but I just had to take that shot. How about I but you a cup of coffie Sat. morn. ??

[wncchester]

"All reamers , be they chamber or die , are only cut to fall with in a certin spec. range , yet they will very quite a bit .."

Good point.  The truth of that makes it amusing when some guy spouts that "brand Z dies are made to tighter tolerances than brand Y." Truth is, they are all cut to fall within the SAAMI tolerance range, no more.  Ditto chambers.  The tolerances can stack to our advantage or disadvantage and brand has nothing to do with it.  We have to set our dies for best match to our chambers and hope it works or buy another die set and hope it's a better match.  Or send spent cases to someone who cuts custom sizers for a lot of money!

The popular term "partial FL sizing" appears to mean (to those who use it) FL sizing to actually match the chamber it will be used in.  I see nothing "partial" about that.  I've been sizing that way since '65 and have never had any sign of a head seperation.

[stimpylu32]

"All reamers , be they chamber or die , are only cut to fall with in a certin spec. range , yet they will very quite a bit .."

Good point.  The truth of that makes it amusing when some guy spouts that "brand Z dies are made to tighter tolerances than brand Y." Truth is, they are all cut to fall within the SAAMI tolerance range, no more.  Ditto chambers.  The tolerances can stack to our advantage or disadvantage and brand has nothing to do with it.  We have to set our dies for best match to our chambers and hope it works or buy another die set and hope it's a better match.  Or send spent cases to someone who cuts custom sizers for a lot of money!

The popular term "partial FL sizing" appears to mean (to those who use it) FL sizing to actually match the chamber it will be used in.  I see nothing "partial" about that.  I've been sizing that way since '65 and have never had any sign of a head seperation.

The reason I like to Partial Size is it allows me to work the neck and the mid 1/3 of the case for better feeding , while not moving the shoulder away from its " Fire Formed " shape , this works very well in most of my bolt guns but not always in my single shots  .

stimpy