243AI case comparator

[Gregg C]

Want to start load development for a 243AI. I'm needing a comparator to measure datum line to cartridge base to set up the size die. Was thinking to split the difference between the neck diameter and the shoulder diameter, and use that measurement, as the ID for a bushing. Which pencils out to .368, or so. Sound about right?

The action is a Savage.... Kind of a pain in the keester to strip the bolt for a bolt drop method.

 

[Coyote Shadow Tracker]

Want to start load development for a 243AI. I'm needing a comparator to measure datum line to cartridge base to set up the size die. Was thinking to split the difference between the neck diameter and the shoulder diameter, and use that measurement, as the ID for a bushing. Which pencils out to .368, or so. Sound about right?

The action is a Savage.... Kind of a pain in the keester to strip the bolt for a bolt drop method.

Check out Redding Instant Indicator Headspace and Bullet Comparator.
We use them on a lot of our Cartridges. Great tool.
They have one for the 243AI. You can purchase with or without the Dial Indicator if you already have one. If not the Dial Indicator can be used on all their other Comparators.

 

[Koda_]

Want to start load development for a 243AI. I'm needing a comparator to measure datum line to cartridge base to set up the size die. Was thinking to split the difference between the neck diameter and the shoulder diameter, and use that measurement, as the ID for a bushing. Which pencils out to .368, or so. Sound about right?

The action is a Savage.... Kind of a pain in the keester to strip the bolt for a bolt drop method.

My guess is that would work but why not just use the standard 243 datum diameter bushing?

 

[Gregg C]

Check out Redding Instant Indicator Headspace and Bullet Comparator.
We use them on a lot of our Cartridges. Great tool.
They have one for the 243AI. You can purchase with or without the Dial Indicator if you already have one. If not the Dial Indicator can be used on all their other Comparators.

That looks interesting.... Think I'll check price. Thanks

 

[Gregg C]

My guess is that would work but why not just use the standard 243 datum diameter bushing?

Well..................umm..............cuz............hmmmm why in the nether regions of seven shells didn't I think of that? Just trying to over complicate it, I guess. Thanks!

 

[Seabeeken]

I use the sinclair set which is based on shoulder angle. Works well on all my ackleys and standard cartridges. Stainless steel so no wear like the aluminum units. One 40 degree bushing covers all my ackleys

 

[Mikecr]

You don't need some exact shoulder datum. You only need a general measure to reproduce.
You should fully fire form, with no body/shoulder sizing, and then use a stripped bolt/handle drop test to sneak in on zero headspace and correct bump.
Then measure with any gizzy of the right shoulder angle (that fits over the neck).
Log your measure, forever setup your die to reproduce it.

I keep whatever gizzies I use, along with dies, specific shellholder, etc., in a box for THAT chamber.
And of course I keep a log and dummy round for THAT chamber, with every measure.
Just makes reloading a lot easier, when I sometimes go years between reloading for a specific gun.

 

[Gregg C]

You don't need some exact shoulder datum. You only need a general measure to reproduce.
You should fully fire form, with no body/shoulder sizing, and then use a stripped bolt/handle drop test to sneak in on zero headspace and correct bump.
Then measure with any gizzy of the right shoulder angle (that fits over the neck).
Log your measure, forever setup your die to reproduce it.

I keep whatever gizzies I use, along with dies, specific shellholder, etc., in a box for THAT chamber.
And of course I keep a log and dummy round for THAT chamber, with every measure.
Just makes reloading a lot easier, when I sometimes go years between reloading for a specific gun.
View attachment 517499

Should I strip the firing pin as well as the ejector, or can I leave the pin in it ? Aw, furz, I'll just quit bein lazy.

 

[Gregg C]

I gotta get the short holders from Redding, anyway. The ram cams over on the bottom of the die, and doesn't move the shoulder.

 

[Mikecr]

Should I strip the firing pin as well as the ejector

Yes

When you set the barrel, did you use go/no-go gauges?

 

[QuietTexan]

I gotta get the short holders from Redding, anyway. The ram cams over on the bottom of the die, and doesn't move the shoulder.

The Competition shellholders are TALLER, not shorter. They won't do anything for a die that doesn't size as is.

 

[Gregg C]

Yes

When you set the barrel, did you use go/no-go gauges?

I did. Or rather, the Smith did.

 

[BillLarson]

Should I strip the firing pin as well as the ejector, or can I leave the pin in it ? Aw, furz, I'll just quit bein lazy.

I WOULD......

 

[Koda_]

If you bump the shoulder .002" and the assembled bolt closes easy on it why disassemble the bolt for the bolt drop test? Whats the advantage?