Long story short I'm having a custom .257 Weatherby built.  SAAMI chamber Fast twist 1-8" - 28" long want to shoot the blackjack 131 ACE bullet.   Problem is there is no published data that I can find.  I've talked with the manufacturer and he gave me some loose places to start, but I'd feel a little more comfortable seeing some more solid data before I start working up.  Next problem is I'm running a MAC computer and don't know anyone personally that has something like Quickload.  Also thought I ran across a post somewhere saying Quickload had this bullet.  

I have some RL25, H1000, H4831, and IMR 8133.  Also have the ability to source 7828SSC last I checked.  

Any help/advice at all would be great, Thanks!

Rifle isn’t finished and I purchased loaded ammunition instead of new brass as the cost was similar,  so I don’t have any brass to measure at this time.

Nosler load data for 120 grain bullet indicates 81.2 gr h2o.  81 gr H2O for 100-117 bullets.  84.8 gr h2o for 85 grain bullet.  

Other sites list useful case capacity for wby brass at 85.6 gr h2o.  

Thats usable capacity. You need capacity. Meaning without the bullet in the case.

Shoot that factory ammo. Then weight it. Then fill with water then weigh again. Very important NOT TO SIZE FIRST!

List the difference. If no one else helps and its listed ill run you a report after.

Ok thanks!

This might be a silly question but how did/do people work up a load with an unknown powder/bullet combo and no quick load?  The nearest data for this situation is 11gr different bullet weight at 120 vs 131....?  

Quickload will have no data for your latest-greatest boutique bullet.

If you select a conventional bullet in Quickload of similar weight, the program will still get you close.

Thats the problem right there.  I've looked through all of my manuals (7), online powder/bullet manufacturers, forums, etc.  120s are the heaviest I can find published for the 257 Wby, and other quarter-bores in general.

Hammer makes a 128gr in .257 but I can't find any data for those either.

Ok, finally got my rifle.  

Measured 15 cases.  (all I've had the chance to shoot so far)

Average capacity = 86.6gr

Highest capacity = 87.3gr

Lowest capacity = 85.5gr

Brass weighed from 229gr to 233.1gr.

@sincerd

Anything?

I’ll take a stab at this. I just got Quikload and am experimenting with it so keep that in mind.

I input your barrel and case capacity. I used the 120gr Sierra as a starting point but increased the length of the bullet to 1.416 and the weight to 131. Max pressure of 55839 and max fill of 102%. OAL 3.170.

These are max charges.

Fastest powder appears to be VV N570 at 75.0 gr. 3263 fps.

RL25 64.6 gr 3168 fps
H1000 67.0 gr 3177 fps
H4831 61.8 gr 3118 fps
IMR 8133 Enduron 70.0 gr 3212 fps

My version of quickload doesn't have that bullet.  I can enter a new one, but I need some measurements.  I've taken screenshots of the heaviest .257 bullets QL has, the data for the 120 SMK and where to take the pictures.



The BC doesn't matter, I'm not doing drop charts.  The shot start / initial pressure is default 3626 for jacketed rifle bullets.

The next thing will be the length you're loading to.  COAL will allow QL to calculate the seating depth of the bullet (also given the length of the bullet that I'm asking for) and then adds back case capacity calculated from the base geometry on the boattail.  You've already given us your fired case capacity, so we're good there.

In short, I'd need all the numbers in white in either the inch or mm columns shown in the projectile data window.

All that allows QL to calculate the usable case capacity to use as the volume of the 'container' for pressure calculations.

Ok thanks for the help!!!

All numbers are averages on 10 randoms.

Length - 1.428 (nominal from manufacturer =1.440)

Small boattail diameter - .2063

Large boattail diameter - .257

Taper length - .2127

PMAG coal can handle 3.50”. My initial COAL will be 3.45 to ensure feeding.  

Trim length = 2.549

Seat depth =.539

The only question I would have would be the longest max coal I have in a manual is 3.30”.  But the nominal bearing surface is .401”, and the nose is super long,  I’m not sure what would be the issue with loading that long.  

SAAMI spec freebore is .375” and I cannot enter the lands, even with the bullet at insufficient seating depth.

G7 BC advertised at .345

I keyed your inputs to the best of my ability, if I screwed them up, let me know and I'll fix the issue.  But you and you alone are responsible with what you do with this output.

Here's what I input for your bullet.  The values I changed from the 120gr SMK highlighted in yellow.


The values I entered for the rifle and cartridge highlighted in yellow for the first powder.  Some of those values came in from the bullet input.  I did key your cartridge length, case length was default, barrel length from the first post, maximum case capacity from one of your other posts, chose the first powder on your list and set up the load table to go by one grain increments and chose my initial value so the heaviest load shown in the table was DANGEROUS.

My method for this would be to start low at a reasonable charge weight looking at the the factory data for a 120gr SMK.  Then I'd shoot a few over a chrony to see if the predicted fps was in the ball park of the measured fps and tweak the model (Ba) to make it even a closer match, then work up, changing Ba to keep predicted and actual fps the same.  It's an iterative process you can't do without QL.

To emphasize, I am not saying to start with what I have plugged in for the charge weight.  I chose that number to give the dangerous warning as the last line of the table.  For the first powder, RL-25, for all I know, the load is dangerous 69.01 grains or considerably lower.







My QL database does not have IMR 8133

Here's you a bonus table of the powders that theoretically give the highest velocities at a max of 62000 psi or a max of 107% of case capacity.  Same caveat, what you do with the data is your responsibility, not mine.

Hey thanks for all of that.  That’s awesome!  

Yeah my initial plan was to use 120 start data backed down 10%,  but this will help a bunch to reference.  Also it makes what info I did have more useful.  

I’m open to other suggestions if anything I’ve mentioned seems unreasonable.

Thanks again!  

Go and register and download a copy of Gordon's Reloading Tool here:  https://grtools.de/

It's not as a mature a product as Quick Load, but I've found it very reasonable in comparison to Quick Load.  The last time I downloaded a copy, it was still free.  Since it's not mature, the executable expires at some date so you have to go and download a new copy so you keep current on their updates.

With it, you should be able to tweak your model as you collect data from what you shoot.  If you don't have a crony, get one.  Short of a ballistic pendulum, the only info you have to compare to the model is velocity which is an indirect measurement of pressure - although it will be unique to your barrel.

Grtools has lined up well for me as well.