neck sizing/case capacity/ velocity??

[Aimsmall55]

Just wondering.... I hardly ever necksize, but I was thinking about playing with it. My question is say I do necksize, does the extra case capacity(since the case has expanded) produce the same velocities as when full length resized? I guess in a simple way to put it is the excess case volume going to effectively make the ignition process different???

 

[Oneteam]

Re: neck sizing/case capacity/ velocity??

No it won't be different. You are not increasing the case capacity by any significant proportions.

 

[Hookturnr]

Re: neck sizing/case capacity/ velocity??

When you full length size you return the case to SAAMI spec or therabouts but it only stays in that state until microseconds after you intiate the firing sequence at which point the brass goes plastic and conforms to the chamber dimensions. The only gain to neck sizing I have seen is perhaps a little brass life. That being said, I now FL size everything and trim to a specific length EVERY loading as I feel it makes for more consistent ammunition. I may be wrong on that but it works for me. So, short answer NO no difference.

 

[Fuzzball]

Re: neck sizing/case capacity/ velocity??

"You are not increasing the case capacity by any significant proportions."

True. The yield strength of a thin brass case is far below the normal pressure of a cartridge, the final volume is limited by the steel chamber, not the starting volume of the case.

Most cases fail due to neck splits. With conventional neck dies and expanders the necks get worked just as much as they do in a FL die so there is little if any difference in case life no matter how we size. (Except if we use Lee's Collet Neck die.)

 

[turbo54]

Re: neck sizing/case capacity/ velocity??

Shameless Lee collet die plug there, huh Fuzzball??

Not disagreeing, though I've never used one.

I neck size with a bushing, then finalize neck with a sinclair expander. Works real nice...

If FLSing is your desire, but want to work tge brass as little as possible:

Redding body die, bushing neck die, sinclair expand (or Lee collet die)

 

[targaflorio]

Re: neck sizing/case capacity/ velocity??

Now, how about seating bullets longer? How do you take advantage of that extra case capacity?

 

[Fuzzball]

Re: neck sizing/case capacity/ velocity??

"Shameless Lee collet die plug there, huh Fuzzball?? Not disagreeing, though I've never used one."

Yeah. Shameful ain't it? I got just one to try it, I soon had one for each of my more accurate rifles/cartridges.

They aren't fine examples of machinist's art but a few strokes with a fine cut file and some medium grit sandpaper easily smooths things up well enough; I like doing that for my self rather than paying a bunch to get it purty from the box.

Anyway, given the low cost of that die and its excellant design, why not try one? It has a moving part (the collet)so it's not just a 'push the case in, pull the case out" sort of thing but learn to use it correctly and you just may be surprised.