I am trying to use from 162 7mm Eldx in the 7/57 mauser in a 550 cz American .
I use a compairator to find max o.a.l. The bolt would not close at 20-30 and I had to go 50 thou.
I set the bullet back 70 on o.a.l. I always try oal. On a dummie case.
I just set the case length on some Balitic tip no problems, Eldx 4 measurement
The gun has a 8.66 twist from cz
I am wondering if the shape of vld. Has somithing do with it.

I was hoping I wasn’t the only one.

It sounds like this is your problem (see image below). ELDX and the BT will have a very different ogive to tip length.

So are you using a comparator at the ogive, or are you using C.O.A.L.? The way the first post is written, it is difficult to decipher.

I am using case overall from the bolt face to the tip of a seated bullet with a Sinclair gauge (tool ).
I then a dummie case and checked the bolt to see if it will close. I use the dummie to ser my seating die.
I normally seat 20 thos. of of the rifling , instead iI had to go 50 to close the bolt.
I back a total of 70 thousand to be safe, Fireman I didn't mean to be confusing .
This is the first Eldx I have loaded, I just want to have a safe load.
Chad I see shape difference . How wold a comparator work,to set oal?
Thanks

Since you are not measuring to the ogive of the bullet, where are you getting your bullet jump measurement to the lands? Using tbe bullet tip, as a measuring point, you don't know where the lands are.

https://www.midwayusa.com/product/101273...-with-6-inserts

Cut the neck of a piece of brass longitudinally, seat a bullet long, write down the measurement, chamber it, extract, write down the new measurement, adjust the seating stem, pull the bullet, load it again, write it down, chamber, extract.

The rifling will shove the bullet farther into the case, when loaded long, showing you where your case head to rifling distance is for that chamber. You can eventually work your way to "even" with the lands, and then produce what ever jump you want.

Something isn't right, or making sense to me. If you are seating a bullet off the lands, then the bullet will not be making contact with the rifling to cause the bolt not to close. Something else will cause it not to close. The BT bullet will have a much shorter tip to ogive than the ELD-X will. The ELD-X is a longer bullet with a longer ogive to tip length. So, you need to account for this. You can not figure where the ogive of the bullet hits on the ELD-X, come up with a set COAL, then use the same COAL for the ballistic tip (BT) bullet. The BT bullet's ogive will be much further forward than the ELD-X and will (possibly) make contact with the rifling.

Take a look at this Berger PDF about their bullets. I use it all the time. This chart tells you the lengths of the various bullets, and specifically the "Nose to Tip" length, which is the ogive to tip length.

http://www.bergerbullets.com/pdf/Quick-Reference-Sheets.pdf

I use this Hex Nut to measure Ogive length for almost ALL my ammo. The ogive it the most critical part of the ammo, even more than the COAL. Hornady also has their comparator tool, and it works fine. But the Hex nut is much faster to use and more versatile.

Once you establish an ogive location for YOUR rifle, you can seat the bullet to the same ogive depth for all bullets. Just make sure the COLA doesn't go too long where it will not fit or feed out of your magazine.

https://www.hornady.com/reloading/precis...llet-comparator

I don't have the exact ELD-X numbers, but I do have the 162 A-max and BT info in my books.

The ogive to tip length on a 162 A-max is .750". This should be close to the ELD-X also.
The ogive to tip length on a 150 grain BT is .710" and the 120 grain is .733" ogive to tip length (you didn't specify which one).

So, if you seat the 150 grain BT to the same COAL (over all length) as the 162 grain ELD-X, the ogive of the 150 BT will be .040" closer to the rifling (.750" minus .710") assuming the A-max and ELD-X are the same (it will be close). If the ogive length is longer than .750", then the BT will be seating even deeper into the rifling.

Fireman with the Sinclair tool you push a bullet in throat set a collar, then you place the second collar on rod.
Then you measure from the bolt face to tip of the bullet your first collar.
I have been make dummie cases without the cut in them which is a good idea thanks
Chad thank for helping me understand how the ogive controls the coal the. I never saw the reason a for case comp!