FL sizing / headspace adjustment

[paul223]

I am using a 700 SS 5R in 223 cal. with Lee collet die set and Nozler once fired brass from the same rifle. I have obtained some very accurate numbers from my Hornady OAL gauge and the distance from the head to the shoulder datum from the once fired brass. I am trying to get as much accuracy as possible. My questions are ;

1) How much shorter should the resized brass headspace distance be ?

2) Is One firing a reliable amount of fire forming - opinion please -I know I could do a study between once fired and 5 times fires. I just want a consesus opinion.

I was very pleased with the performance of the Hornady OAL on my Remington - I still cant get a valid number for my Savage 223.

I thank you for your response and sharing.

 

[Win94ae]

1) How much shorter should the resized brass headspace distance be ?

Work the brass to the least amount possible.
When my brass gets a little tight in the chamber, I full length size it trying to bump the shoulder .001". I hope to be as close to fitting as perfectly as possible.

2) Is One firing a reliable amount of fire forming - opinion please -I know I could do a study between once fired and 5 times fires. I just want a consesus opinion.

Yes.

 

[300 RUM]

Personally I FL sizing to the exact number each time this renders the highest amount of accuracy one can achieve from shot to shot. Bump the shoulder back .001 like Win said. Fire forming doesn't always give you you an exact brass match like FL sizing does.

Like I said Personally my opinion

 

[BoydAllen]

The collet die is neck only. It will not touch the shoulder. If you want to do that, buy a Redding body die, and do a two step process. When I have done this, I got the best results using the collet die first.

 

[amlevin]

The collet die is neck only. It will not touch the shoulder. If you want to do that, buy a Redding body die, and do a two step process. When I have done this, I got the best results using the collet die first.

I agree although I'm getting better results by using a Forster Neck Size/Shoulder bump die. I just leave the bushing and de-priming rod out. This way I don't loose as much case capacity as F/L sizing. Just set the shoulder back without touching the rest of the case. I use this die after de-priming and neck sizing with my Lee Collet die. Only complaint about the Lee collet die is the "bumps" it leaves on the neck. To minimize I rotate the case about 45 degrees and repeat the process. That "smacks down" the bump/ridge that the collet die creates.

 

[BoydAllen]

The reason that you are getting the bumps is that you have the die set a smidge too low. If you need to gain neck tension over what you get with less toggling feel, order a mandrel that is a thousandth smaller than the one that you have, or spin it in a drill with a piece of 320 wet or dry abrasive paper wrapped around it. I used to have the same problem. I believe that a smaller mandrel will get you where you want to go.

 

[amlevin]

The reason that you are getting the bumps is that you have the die set a smidge too low. If you need to gain neck tension over what you get with less toggling feel, order a mandrel that is a thousandth smaller than the one that you have, or spin it in a drill with a piece of 320 wet or dry abrasive paper wrapped around it. I used to have the same problem. I believe that a smaller mandrel will get you where you want to go.

This happening on my .308 cases with the die screwed in so there's no toggling feel (caming over).

I have the mandrel polished and keep the "feel" on the press lever to a minimum, just enough to give me .002" of neck tension. Still get the "bumps". I just make sure I neck size my fire formed new brass with a different die before I Neck Turn.