Cartridge Jamming before OAL max

[berettaprofessor]

I have a Savage Axis ii 6.5 Creedmore that, measured with a Hornady straight gauge and using a Hornady 147 grain ELD bullet, has a maximum OAL of 2.965. This weekend, doing a fine-tune on a load, I was loading OAL of 2.800, 2.840, and 2.880 with the same Hornady 147 ELD to try to find the best OAL for consistency. I can't close the bolt on the 2.880 rounds. Anyone have a reasonable explanation why a finished cartridge OAL of 2.880 is too long in a gun that measures a max 2.965 with the same bullet in a Hornady gauge ((cases all trimmed appropriately to the same length)?

 

[VoodooMountain]

Is the brass sized correctly?
Is the base of the cartridge riding correctly on the bolt face?

Are ther rifling marks on the bullet?
Is the gauge in spec?

 

[whughett]

OAL has nothing to do with head space. That ok?

 

[MEHavey]

1. If the empty case will chamber, it's not a headspace problem.
2. Hornady bullets have a long straight shank that -- ipso facto -- requires reduced OAL if they aren't going to jam in the leade
3. Hornady's own data shows the 147 ELD/6.5 Creedmore to MAX out at 2.800"
https://www.hornady.com/assets/site/hornady/files/load-data/6-5-creedmoor-147-153gr.pdf


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[berettaprofessor]

Voodoo mountain; yes, yes, no, yes. I use a Wilson gauge to confirm trim and sizing. I thought it was interesting that there were no rifling marks.

MEHavey; the empty case chambers. So do the 2.800 and 2.840 rounds. Hornadys 2019 data says to seat it at 2.800 but I don’t think that’s max. SAAMI specs say the max is 2.825”

I guess what I’m really wondering is where all those folks who talk about seating 0.020 off the lands would set OAL in this rifle. Or how they would get close to that magic -0.020 (2.945!) here.

 

[Walkalong]

what I’m really wondering is where all those folks who talk about seating 0.020 off the lands would set OAL in this rifle. Or how they would get close to that magic -0.020

 

[berettaprofessor]

Okay, Walkalong, I've seen that before,, but thanks for the reminder. Around 5:10, this guy probably solves my dilemma because he talks about the Hornady tool pushing bullets into the lands, i.e. overestimating length to lands...and I've been pushing HARD when I measure with it. So my 2.965 number is probably way over.

 

[Walkalong]

and I've been pushing HARD when I measure with it. So my 2.965 number is probably way over.

Yep, it is very seat to push a bullet into the lands with finger pressure. It's very hard to feel the initial contact.