Best FL dies for 7mm

[Rogmay]

I recently purchased a Cooper 7mm with chamber to the small side of the SAMI specs, I have a set of rcbs competition dies that doesn't quite reduce my case enough just above the belt, what recommendations would anyone have for replacing or fixing this problem? I've heard of a few places that due custom dies! Are they worth the money and would they extended case life? Also, what is the best way to check the headspace on these 7mm's to make my load the most consistent and accurate? Your thoughts would be appreciated, thanks in advance!

 

[bigedp51]

You wouldn't be having this problem if you had read more Jack O'Conner stories and understood that the .270 Winchester is the worlds best non-belted magnum.

Innovative Technologies
Belted Magnum Collet Resizing Die
Innovative Technologies - Reloading Equipment


Digital Headspace Gauge (at same website)

Hornady Lock-N-Load Headspace Gage 5 Bushing Set with Comparator

Hornady Lock-N-Load Headspace Gage 5 Bushing Set Comparator


Below a Lake City 5.56 case fired in my AR15 carbine.

Below the same case after full length resizing and .003 shoulder bump.

 

[SidecarFlip]

John Whidden bushing dies.......of course.

 

[bigedp51]

The OP thinks he has a chamber on the small side of SAAMI specs.

My bet is the more common cause of "case bulge" just above the belt.

Meaning his fired cases have a fat *** and needs the collet die at Innovative Technologies to squease the case just above the belt.

If the OP would measure a unfired case just above the belt and then a fired case and finally one of his resized cases he would have his answer.

On top of this we live in a plus and minus manufacturing world and he might have a "minus" size chamber and a "plus" size die.

This subject has come up many times in the reloading forum at http://www.accurateshooter.com/ and the vast majority of these problems are fixed with a collet die from Innovative Technologies.

I myself never have this problem because my .270 Winchester doesn't have or need a belt.

All humor aside the type/manufacture of the belted cases has a lot to do with expansion above the belt. Meaning the thickness and hardness of the brass just above the belt.

Read the link below on belted cases.
Understanding Headspace

So just remember you can have three causes to this problem. Chamber diameter, die diameter and case diameter.
(or all of the above)

 

[Rogmay]

Thanks for the responses, I will look into all of thoses options!

 

[Bart B]

Larry Willis is wrong about what headspace is. He has been asked to get it right but so far has not done it. Go to SAAMI's web site then open its glossary under Info and Specs, then look up "head space" and "head clearance."

http://www.saami.org/specifications_and_information/index.cfm

The Willis collet die is great to size down belted case bodies all the way to the belt. Used after a Forster full length die they've honed its neck out to .002" less than that of a loaded round has sized the fired case bumping its shoulder back .002", that as good as it gets. Before that collet die was made, a standard full length die had its top cut off just behind the shoulder. Then it's bottom was cut off just above the case belt clearance. Both ends were squared up then set in the press to size the case body all the way to the belt. Standard dies don't size the case all the way to the belt.

That area interferes with consistent case positioning from shot to shot. This is why new belted cases typically shoot more accurate than traditionally full length sized ones.

 

[bigedp51]

Bart B

Headspace is just a word and my gauge below is called a "Hornady Cartridge Case Headspace gauge.

Headspace is also the distance between your ears and how you use it. And as long as people understand what you are saying its no big deal.

And the glass below also has excess headspace and you will not find "beer" in the SAAMI definitions.

And since this is a reloading forum and not a English class "YOU" need to lighten up. Because the next step is you correcting our spelling and grammar.

 

[Bart B]

So it's OK for Hornady to use "headspace" for two different dimensional things when one can be several thousand times larger than the other. In spite of suscribing and agreeing to SAAMI standards stating otherwise. All of which confuses people new to the details of arms and ammo.