308 neck diameter of fl sizing die

[gambleone]

Wanting to know the neck diameter of rcbs fl sizing die. My neck diameter is .343. Using a lyman fl sizing die, it is bringing the neck to .330. I thought the average fl die, no matter what brand, would size to 4-6 thous under the sammi spec of .343. Why would they make a die to size that much smaller? Bought this die used.

 

[RegionRat]

I checked a FL RCBS die from the 80's and it will pass a 0.327" pin but not a 0.328"

 

[CJ6]

I checked a FL RCBS die from the 80's and it will pass a 0.327" pin but not a 0.328"

What is the expander dia. ?

 

[RegionRat]

What is the expander dia. ?

I can't say with 100% certainty because I have so many expanders in that box and have not used them in decades, but, the notes seem to say the original was 0.30525"

Please don't hold me to that cause I made expanders in many steps above and below to control seating force. I won't take the credit for the actual grind work because my cutter grind guy saw what I was up to and pushed me aside and took over lest I screw up the Monoset. I made my own custom expanders and Lee Collet die mandrels to keep from having the neck tension drift. I didn't use the expander balls as much because I got much better controls and much better runout using a Redding Body die in combination with a Lee Collet die, and that required less annealing and trimming. But hey, it was the 80's, what did we know......

 

[gambleone]

I checked a FL RCBS die from the 80's and it will pass a 0.327" pin but not a 0.328"

That's even smaller yet. That's way too tight on bullet. Guess I'll have to go to a bushing die.
Thanks much for the info.

 

[SmokinJoe]

Hone it out to what you want, a good winter project and not hard to do.

 

[gambleone]

Hone it out to what you want, a good winter project and not hard to do.

That's a thought. Thanks I don't have a lathe, but my buddy has a machine shop. Going to pay him a visit.
Thanks again.

 

[Sandstorm]

I had the same problem..and Whidden made a bushing die for me...
Im thinking that will work better..and a mandrel to get final tension right will be the way to go..
I will let you know when the die arrives and i test my theory.

 

[NZ_Fclass]

Gave away the RCBS and bought Forster. Loaded Lapua or ADI cases finish at .336, chamber .340. I had issues with the Forster seater, but polishing the cup's edges cured that. Nex tmove is to lose the expander ball and use a mandrill.

 

[RegionRat]

That's even smaller yet. That's way too tight on bullet. Guess I'll have to go to a bushing die.
Thanks much for the info.

Yup, I would say it is always good to have all your bases covered.

Regular dies used to overwork brass and then the expander balls would pull the necks off center. They also lead to more trimming than necessary. Our brass was nothing to brag about in those days either. If you had put the work in to make a set of carefully selected cases, you tended to want to take better care of them than running them through a regular die. We are spoiled these days.

Having the diameter opened up isn't rare or difficult, but then you still need a set of expander balls to insure you end up where you want it. You will still want a FL die at your chosen diameter in order to size the whole neck all the way to the shoulder in case you ever want to turn necks.

 

[SmokinJoe]

You don't need a lathe, in fact I think it works better to let the die float a little as you run the lap in a hand held drill. Check out Rick Averill's article on doing this @ https://rickaverill.com/projects-past-and-present/lapping-reloading-dies/

 

[divingin]

Standard sizing die (with an expander) works by sizing the neck way smaller than it needs to be. The expander is what sets the final diameter, as it is dragged back up through the neck. This is done so as to work with any manufacturers brass, of any neck thickness. By sizing from the inside, you get a usable finished product despite any differences in the brass, at the expense of working the brass a lot. Sort of a one-size-fits-all scenario.

 

[gambleone]

Well, seems I found a problem. Didn't pay attention to the expander ball, cause when I got the die it was there, in the die, but I should've looked closer. Here, somebody had put a 22 cal expander ball in place of the standard 308 ball. Never touched the inside neck on the up-stroke. Just going to lap it out. This being just a hunting rifle, I don't care much. Thanks for all the input.

 

[gambleone]

Standard sizing die (with an expander) works by sizing the neck way smaller than it needs to be. The expander is what sets the final diameter, as it is dragged back up through the neck. This is done so as to work with any manufacturers brass, of any neck thickness. By sizing from the inside, you get a usable finished product despite any differences in the brass, at the expense of working the brass a lot. Sort of a one-size-fits-all scenario.

Thanks for the reply. I should've paid more attention to the expander ball. It was there, & I just didn't realize it was smaller. Bad on me.

 

[gambleone]

You don't need a lathe, in fact I think it works better to let the die float a little as you run the lap in a hand held drill. Check out Rick Averill's article on doing this @ https://rickaverill.com/projects-past-and-present/lapping-reloading-dies/

Thanks for the article SmokingJoe. Good info.