FL sizing die precision

[nksmfamjp]

How do you determine if FL sizing die is precise enough for your needs?

Also, how do you know if the precision is limited by your die or press?

What are you measuring and why?

 

[Carlos88]

1. L.E. Wilson FL bushing die. Fantastic.
2. Measure shoulder and set back .002-.003
3. Check concentricity (runout) on Sinclair gizmo
4. The die(s) need to be square with your press. Raise ram and seat and set your die to the press.
5. Use the same shell holder every time. Make sure it is clean from any primer residue.
6. Measure runout on loaded rounds.

The predicate being having brass with consistent neck thickness and your chamber was drilled properly. Either of those is off and you're adding more variables to the equation which are not "fixable" without your due diligence.

 

[nksmfamjp]

L.E. Wilson FL bushing die. Fantastic.

I need to try one of those some day.

 

[Carlos88]

I bought one to use in my Kimber 7mm WSM. Midway had one on sale for about half price. Turned out to be a great purchase.

 

[L.Sherm]

I dont care what die it is needs to FL size correctly to your chamber, and that can depend on brass and what caliber.

 

[QuietTexan]

Judge a sizing die by repeatability of sizing, lack of induced runout, what the .200" line measures at vs chamber.

Judge if it's the press by using the same die in different presses.

If it works it works. I'm not in the business of comparing dies so I won't say one brand is better than another, just that individual particular dies I have either do or don't do what I need them to.

 

[vmaxmike]

You'd need to buy some measuring tools, below are the ones I currently use after trying a few other brands.

Your measuring shoulder bump in reference to your gun's chamber

also measuring concentricity of the case neck.

M.

Lock-N-Load® Headspace Comparator & Anvil Base Kit - Hornady Manufacturing, Inc

Lock-N-Load® Headspace Comparator & Anvil Base Kit Lock-N-Load® Headspace Comparator The Lock-N-Load® Headspace Comparator extends brass life, improves accuracy, and enhances safety. The gauge measures...

www.hornady.com

https://www.hornady.com/reloading/precision-measuring/precision-tools-and-gauges/lock-n-load-concentricity-tool

 

[RSRW]

I use a Whidden, click adjustable full length bushing sizing die. I have found it to be very precise. The click adjustable die is really nice. If you want to bump back two thou, you just turn two clicks and you're there. Very easy, you don't have to estimate how much to turn to get your two thou.

 

[nksmfamjp]

Well, in looking at my Whidden die set, I see that I'm pushing the shoulder back 0.0025", shoulder diameter is no measurable change, 0.200 diameter is about 0.002" smaller, but may not of expander fully since this was a lower pressure COW load. Runout is about 0.002", but this too needs another firing to confirm.

 

[30BR]

How do you determine if FL sizing die is precise enough for your needs?

Also, how do you know if the precision is limited by your die or press?

What are you measuring and why?

Search for Jack Neary videos. He did a series of them for shooting benchrest, but one of them details how to determine if your die is right for your chamber. Just can't remember which one it was. View them all and you'll have a masters degree in precision shooting. But the die determination is crucial for every gun to shoot its best.

 

[vmaxmike]

The expensive premium dies that have micrometers make precise adjustments much easier than the trial and error method. However once you've properly set up your dies to match your rifles chamber, assuming you use quality lock rings they can be removed and replaced with little or no adjustment.

If you load for multiple guns in the same caliber you then need to decide if you are going to readjust for each rifle or size to the smallest chamber and let the brass grow for the others.

Fire formed cases often are most accurate, and then you can explore just neck sizing knowing that the brass is now gun specific.