OAL varies from 2.445 to 2.450 in 6 dasher

[Jerry Snyder]

I am using a K&M arbor press with my Whidden arbor die. I seem to get varying OAL using the following:
Berger Hybrid 105 target projo's
Newer, 3x fired Alpha 6 Dasher brass which has been prepped by annealed (AMP), trimmed (Giraud), sized with Whidden sizing die (bushing .267).
CCI 450 primers
32.9 grains of Varget on my FX120i scale
Shoots about 1/2 MOA at 100 yards for a 5 shot group.
My ES is 15 and SD of 5.2
Velocity averages 2945 FPS using my Garmin on 10 shot groups
When using the arbor press, I get fluctuations from 2.245 to 2.250. It loads a bit longer on some, so I then reseat to what it needs.

Any advice on more consistent OAL from the press?

 

[praveen]

Different bullet lengths?

 

[Chaotik]

Are you measuring OAL because the rounds need to fit within a magazine?

 

[Jerry Wick]

You can measure the actual bullets and get more than 0.005 variance. The way the jacket tip forms when they are made will cause length to vary. Whether that matters or not is another subject. Cartridge overall length is pretty meaningless unless you have a limit, as mentioned above.

You need to measure the length from case base to the bullet ogive or where it would contact the rifling in your chamber to know if you have a problem.

 

[Bill Norris]

OAL will vary with any reloading set-up. Bullet lengths vary so that cannot be remedied. Ogive measurements will be much more consistent.

EDIT: Actually when you vary the seating depth by COAL it is changing the distance the ogive is positioned from the lands causing varying numbers there which in turn will be detrimental to accuracy.

 

[Martin52]

I seem to get varying OAL using the following:

Any advice on more consistent OAL from the press?

Before seating, have you tried measuring the overall length of the projectiles and batching them within your preferred range, for example batched within 0.002 OAL ? A step further is then to batch based on projectile base to ogive.

 

[bpd459]

I am using a K&M arbor press with my Whidden arbor die. I seem to get varying OAL using the following:
Berger Hybrid 105 target projo's
Newer, 3x fired Alpha 6 Dasher brass which has been prepped by annealed (AMP), trimmed (Giraud), sized with Whidden sizing die (bushing .267).
CCI 450 primers
32.9 grains of Varget on my FX120i scale
Shoots about 1/2 MOA at 100 yards for a 5 shot group.
My ES is 15 and SD of 5.2
Velocity averages 2945 FPS using my Garmin on 10 shot groups
When using the arbor press, I get fluctuations from 2.245 to 2.250. It loads a bit longer on some, so I then reseat to what it needs.

Any advice on more consistent OAL from the press?

Does your seating die have the VLD seating stem?

 

[R L U]

Does your seating die have the VLD seating stem?

Yes check seating stem. Sometimes it will clogg up tip some causing bad consist contact.

 

[JMayo]

I use to separate by oal and put them in lines of same length then follow them chain style putting them in the box. Bto is the same.
I did well those couple of seasons... Maybe I should start doing that again ....

 

[Ccrider]

Why not just trim your brass to the same length and sort your bullets if f you are trying to get consistent OAL?

 

[Jerry Snyder]

Does your seating die have the VLD seating stem?

Yes, I purchased it separately from the die maker. Thanks

 

[Bc'z]

Yes, I purchased it separately from the die maker. Thanks

But not all bullets are the same, I'd pull my seater stem and see if it's making full contact to bullet or wiggling, if it wiggles 1 iota I'd say that's the problem.
I can seat bullets out of various sorts of same bullet and be with .001 on depth, the few thousands difference just gets pushed deeper into case.
FWIW I sort bullet OAL

 

[Jerry Snyder]

What tool would you all recommend for measuring the BTO - bottom to ogive - so I get a more consistent reading on my loads? Thanks

Are you measuring OAL because the rounds need to fit within a magazine?

Seating depth in the chamber.

 

[Bc'z]

What tool would you all recommend for measuring the BTO - bottom to ogive - so I get a more consistent reading on my loads? Thanks

Seating depth in the chamber.

I use digital calipers to sort bullets by OAL, I have a 2nd set of calipers that I leave my Hornady comparator on for measuring CBTO.

 

[6BRA]

Fastest way I've seen to sort 1000 BTO.

Bullet Comparator | Gold Standard Comparator | Holland Guns

Enhance your reloading precision with the Holland Guns' Gold Standard Bullet Comparator and improve accuracy. Shop now for the best bullet comparator at Holland Guns.

www.hollandguns.com

 

[L1986]

Amazon has these…great set and invaluable in my opinion. Hornady makes a set as well. Not sure which is more affordable.