Lee Collet Neck Tension Question

[RangerEd]

Im using a Lee neck collet for reloading my .308 Win. I have been reloading Federal cases (they were left overs I saved before getting my reloading equipment. The cases have beed shot 3 times now. About 1/2 of them aren't neck sizing correctly. They are really loose. I can easily place a bullet in them. need trimming yet. My load through them have bee 44gr Varget with a cci br2 primer and a SMK 175 gr.
Any ideas on whats going on with them?

 

[woods]

Lee Collets are notorious or infamous about sizing the neck with very little bullet grip. I ordered undersize mandrels from Lee one time and they argued with me that increased bullet grip would increase runout. They sent them anyway at $5.00 each

Some have chucked them in a drill and held and abrasive against it (sandpaper, krochus cloth?) but I did not have good luck with that. The entire mandrel needs to be exactly the same diameter and perfectly round since you have to pull it back out of the neck after sizing.

Your brass gets work hardened and will have more springback after several firings. When you size the brass onto the mandrel, a work hardened case will spring back more and have a slightly larger ID. Perhaps you could anneal the case and that would help.

 

[RangerEd]

So, when annealing, I just want to get the neck and shoulder a dull red/ Is that correct?

 

[woods]

So, when annealing, I just want to get the neck and shoulder a dull red/ Is that correct?

Annealing is another subject and there are lots of opinions. Best to do a thorough search here and on other forums and form your own opinion.

That being said, IMO....NO you do not heat the necks until they are dull red, you have gone way too far! Best to get some tempilaq and put some on a case and time it until the tempilaq melts. Do it 3 or 4 times, then you can rely on the timing of spinning the case in the flame. Better to do too little annealing than too much.

YMMV

 

[boomtube]

".....NO you do not heat the necks until they are dull red, you have gone way too far!"

BIG ditto.

You may try heating necks in a darkened room until you barely detect a glow starting but you have to drop the case into a water bucket immediatly or you will have gone too far. Over annealing isn't "dangerous" but it will destroy any effective bullet grip because the metal becomes too soft and loses it's "springback" qualities.

Lee is correct that any neck smaller than about 1 - 1.5 thou under bullet diameter simply increases the lever pressure needed to expand the neck during seating. That extra resistance WILL increase runout. But smaller necks won't do a thing to increase "bullet tension" - the brass will simply exceed it's elastic limits as it's stretched larger so the actual bullet grip will remain quite steady after about 1 thou or so of stretching.

Check me on that if you disagree, mike a loaded neck, pull the bullet and mike it again at the same place. What you will see is the amount of neck "springback" and that's all the 'bullet tension' you gonna get, no matter how much smaller the neck was before seating.

 

[RangerEd]

So the answer to my original question is that the cases need annealing. Correct?

 

[boomtube]

Well, since the harder the brass gets the more it springs back to the larger size, I'd say yes. Anyway, it's what I do and have been for more than ten years.

 

[woods]

Worth a try. Like boomtube said the springback with a Lee Collet will give you a larger ID unlike the springback with an expander type of die. Since you are sizing the neck down onto the Lee Collet mandrel, after the sizing pressure eases the brass will springback toward the direction from whence it came making the ID larger.

Now with an expander type die the expander expands the case outward so it will springback inward. Thus giving a smaller ID on cases.

Personally I like to use Lee Collet mandrels that are .003" less than caliber but I take a lot of care to ease the bullet seating process so the tighter neck does not cause me runout problems.