Accuracy of Cartridge Length

[Bart B]

What's the comparator reference diameter?

 

[Groot]

What's the comparator reference diameter?

Im at work currently and will have to get back to you on that, you're talking the diameter of the 22 cal comparator opening correct?

 

[BoomFlop]

Why not seat them all to 1.8585? Largest spread is .002.

Comparator for .22 is .330 bushing.

 

[Groot]

Why not seat them all to 1.8585? Largest spread is .002.

Comparator for .22 is .330 bushing.

Thanks BoomFlop, I think that is what I am going to do.
In general I was just curious to know what tolerances others hold their reloads to.

-Groot

 

[Bart B]

Why not seat them all to 1.8585? Largest spread is .002.

Comparator for .22 is .330 bushing.

That's the case shoulder reference for case head to shoulder dimension.

I'm referring to the bullet diameter reference for cartridge base, or case head, to where the bullet touches the throat. That's near the .222" diameter on the bullet ogive.

Note the chamber throat touch point on bullets advances down the bore .001" every few dozen shots due to erosion.

 

[rsmithsr]

just not so
the tool is a reference number to where the bullet touched the lands. no one said it is the actualy number. all that matters is that you measure and track.
the measured number and the actual number are just numbers on paper...not bullets down range.

Yes, because that's the controlling factor. And the ogive reference diameter that touches the lands in the throat is about .002" bigger than barrel bore diameter.

If the gauge reference diameter is smaller than bore diameter, its not going to touch the ogive where the lands do.

As you're working tolerances seen to be 1 to 2 thousandths, I'm pointing out things that effect that. And assuming there's no case shoulder setback from firing pin impact.

 

[BoomFlop]

I'm not sure a seating depth of .002 will have any impact on groups unless you are shooting bench rest, with a very high powered scope and an extremely accurate rifle.

With that said, I would think everyone that reloads for Precision will strive for .0000, what one allows is totally up to the individual. I personally will measure everything and get as perfectly consistent as my tools and my reloading skills will allow.

My recommendation for this situation is to seat them all the same to shortest length. Then, run the same number of rounds as a test at a distance either closer to the lands or further away and see the difference. I would believe if you have a good load, you will not be able to tell the difference.

Good luck!
Steve

 

[L.Sherm]

Why use the .223 Rem case head as the rear reference? It's not against the bolt face when the round fires. The case shoulder is hard against the chamber shoulder when fired; driven there by bolt face ejector or spring loaded firing pin before firing. Case head clearance to bolt face spread is equal to the case head to case shoulder (case headspace?) spread.

CBTO= Case Base To Ogive

 

[Mikecr]

You haven't completed full seating testing, so you don't know where best CBTO is anyway. And you don't know best seating window width without testing.
As far as cause of inconsistency, I suspect variances in headspace and seating friction.

If it's not a problem then all is fine. As you refine your reloading these normal inconsistencies will decrease.

 

[Groot]

Steve[/QUOTE]

You haven't completed full seating testing, so you don't know where best CBTO is anyway. And you don't know best seating window width without testing.
As far as cause of inconsistency, I suspect variances in headspace and seating friction.

If it's not a problem then all is fine. As you refine your reloading these normal inconsistencies will decrease.

Mike,

what do you consider a full seating test?

-Groot

 

[Mikecr]

https://www.longrangehunting.com/th...-from-berger-vld-bullets-in-your-rifle.40204/
This applies to all bullets and situations. Until you've done every bit of this, you haven't tested bullet seating for best.

 

[Groot]

https://www.longrangehunting.com/th...-from-berger-vld-bullets-in-your-rifle.40204/
This applies to all bullets and situations. Until you've done every bit of this, you haven't tested bullet seating for best.

It appears this applies to VLD bullets (specifically berger bullets) but if im not mistaken believe the 53 grain vmax shares ogive characteristics with vld bullets so I will give this a try, In general though it was a good read,

thank you!

-Groot

 

[misterc01]

I use the Hornady comparator as well, I had a once-fired case machined by Hornady so I have a consistent measurements. There is difference between my OFC and the standard Hornady case, and as long as you take the difference into account when finalizing you seating depth. I also us BOTH the Hornady and Sinclair Comparators bases to measure with. It gives me two references to check against. I double check each round with both for consistency purposes. I measure to the lands, and the back off for optimum seating depth.

 

[LaHunter]

Hello all,

I've been reloading for a few years now but i just recently bought a hornady comparator set to try to improve my reloading and get a better idea of how long my reloads need to be batch to batch.

I measured 6 of my remaining rounds for my 223 Rem with a 53 grain VMax over 26.6 grain of CFE223 (safe in my rifle maybe not yours, slightly over recommended max) These rounds may have been loaded into the mag box with or without rounds being fired, they may have been cycled though the action to unload the gun as well if that matters at all.

1 - 1.8585"
2 - 1.8605"
3 - 1.8595"
4 - 1.8595"
5 - 1.8590"
6 - 1.8595"

So my question is how much error is okay? Is the variation in the above measurements something to be real concerned with?

In my opinion, I don't think that is a bad spread. The real measurement is to shoot them and see how they shoot. There is going to be some variation from bullet to bullet, even in the same lot. There will be some error in how firm you make contact with your calipers also. Remember, your comparator contacts the bullet in a location on the ogive, which is going to be different from your seating die, and both of these contact points are going to be different than the location of your rifle bore / rifling.