How to determine a starting point on a wildcat that no one has done before?

[blygy]

So I had this rifle built. A 6.5 X 300 Win Mag.

Now most everything is here. I'm still waiting on shell holder. But I thought I start asking around now..

Where does one start when working up a load for which no data exists. I'm planning to start with 264 win mag loads but of course finding data for that round with the 142gr Wildcats is proving difficult @ best.

So any suggestions.. Does anyone load the 264 with the wildcats?? Care to share your data??

Thank you

[338hammer]

Page 399 in Sierra manual starts data for the .264Win Mag.

I would not hesitate using the .264 data and working up.

SO we know that the 300 case is somewhat larger than the 264/7mmRem. These two are somewhat over bore capacity and you have gone to a larger case so recommend the slower burning powders.

Be interested when you are working up loads what your velocities are. The .264 Winchester came into its own with 26 inch and longer barrels. A bit anemic with 24" barrels.

338

[britz]

I haven't loaded for either of them, but just looking at the case demensions I think you would be safe starting with 264 140 gr data and carefully working up watching for sticky bolt, flat primers... you might want to use a soft primer as an early warning sign of pressure. Look at Bounty hunter's post on tuning a load part 2 Tuning a Load (part 2).

happy shooting, Mark

[edge]

I am interested in any replies here too.

Would Powley start out too low, since it tries for a mid 40kpsi load?

edge.

[338hammer]

Actually this has been done before in different ways with basically the same unhappy results. P.O. Ackley volume 1 page 374. Originally called the 6.5 Mashburn.

Years ago I found a chronigraphy invaluable in wildcatting. In particular the smaller cartridges. I would take the data in the afore mentioned book,reduce loads shown by 10% and begin without scoping the gun. Load one cartridge with a base charge and increase at 1 grain increments and record velocities. Watch your primers and the chrony. AT a point your chrony will stop making advances and at a point you will actually go in reverse while your primers start cratoring. You have now reached the upper pressure level and have gone to far. Metal flowing out of the primer pin mark may or may not show at the point of velocity loss. That cratoring will begin and the amount of flow will increase in increments as powder is added until you peirce the primer or blow it out. The first sign of velocity loss is what the industry calls diminished returns.

THE FIRST SIGN OF CRATORING IS A BIGlight bulb. STOP< DANGER WILL ROBINSON!!

I have survived 30 years of wildcatting without incident or injury by paying attention to the above information.

For what its worth

338

[dirtball]

Reloaders Nest has 264 Win Mag loads up to a 160gr bullet, will give you a start
.264 Winchester Magnum @ www.reloadersnest.com

[blygy]

Thanks guys. My uncle is going to get me the PO Ackley info when the weather gets good enough to fly back into his hunting lodge in northern BC.

I did find one load using US 869 in the 264 win Mag which is the powder I want to try first.