Case Neck Stretch

[Ray]

I am a rookie at reloading and need some help with excessive neck stretch after full length resizing. This is LC processed brass, (from RVO) that I trimmed to 0.005 under max length, loaded and shot. After resizing, almost every case neck is longer than the case gauge, some worse than others. I am using an old Pacific/Hornady die. I have also tried lubing the inside of the neck with Hornady One Shot, mica, graphite and RCBS Case Lube 2. I also polished the expander.

I am considering 2 options:
-buy a Lee collet die to size the neck after full length resizing.
- buy a new die set, Hornady New Dimension or ?

Any help will be greatly appreciated.

Ray

 

[swifter]

I think you're on the right track. If your chamber is a tad wide, the brass expands to fill it. F/L resize squeezes it out like toothpaste. Then the expander ball pulls it out some more... Sometimes at an angle...

First off, set your sizer to bump the shoulder back about 2-3 thou, no more. If you don't know how, and nobody tells you, Email me.

The Lee Collett neck die works well, and doesn't cost a lot. It confers the same benefit as a more expensive bushing die in a different way: neither size the neck too small, then expand it by jerking a ball thru it, and the brass benefits.
Hope this helps,
Tom

 

[KP95DAO]

Get the RCBS X-die and follow the directions. Your problem will disappear. It has for me.

 

[Bill St. Clair]

Reloading 308 for my M1A, I get the same problem. Have to trim the cases every time I load them.

Using a Lee Collet die for my .30-06, I almost never have to trim. Same with my AR (most people will tell you not to neck-resize for a semi-auto, but it works with my AR. The M1A on the other hand, does NOT work unless I full length resize; never fired a neck-resized round, but I loaded one without powder and discovered that it's very difficult to get out of the chamber, likely to break the op rod. I've decided to mostly stop reloading .223 and .308 since I can buy plinking quality for less than my reloading cost).

My 444 Marlin, a straight-walled case, requires full-length resizing and flaring. I have never had to trim one of those cases.

The only disadvantage I find with the Lee Collet die is you have to press hard to make it work (Lee's instructions say 25 pounds). Full-length resizers require very little pressure. A nice advantage is that the Collet die requires no case lubrication.