338 Tejas load development,please help)

[Cruizin]

I finally received my new rifle. I had a custom gun made from:

Rem 700 action
Rock Creek Polygonial barrel 1-9 29"
McMillian stock
Jewel Trigger
Night Force 5.5 x 22 NP R1

The case starts with a 300 RUM and I have opened that up to .338 in order to hold a 300 grain SMK.

This is a improved chamber and the shoulder will end up being somewhere around 60 or 70°.

I am after a fireform load right now and need some help. I will be putting the bullet up against the lands to push that shoulder out the best I can. COL of 4.090" using cci 250 primers and H1000 powder.

How many grains would you recommend starting at?

Thank you very much for any suggestions.

 

[jthyttin]

Having a wildcat built, you're pretty much on your own. But your cartridge sounds a lot like 338 Edge by Shawn Carlock.

You can do an Internet search on "338 Edge" and some guidelines will show up. At least http://www.reloadersnest.com/ lists one load with 300gr SMK and H1000.

Maybe you could use that as starting point, and then compare water capacities between your case and 338 Edge? I'm sure Edge water capacity can be found in the Internet, and your case should hold more, based on quite radical improving.

 

[Cruizin]

Well I was originally just looking for a load to fire form with. Now I have 40 fireformed cases and my shoulder doesn't even hurt. Well actually I guess it does a little.

I did a water capacity comparision on the new fire formed case and here is what I ended up with:

Rem Factory Brass 300RUM 114.2 gr.
Fireformed 338 Tejas 120.6

Anybody have any suggestions on a starting point for the next load? 300gr bullet and H1000.... and what you think I could work up to?

Any replies are much appreciated.

 

[MLC]

You have slightly more capacity than a 338 Lapua if your measurement is correct.

 

[FALPhil]

That sounds about right. Seems like he should use the 338 Lapua data as a guideline.

 

[Byron]

Pushing those 300 gr pills can generate just a little bit of recoil.

For my .338 RUM,I'm using the 300's also) I decided to add a Badger Thruster brake. It really tames down the recoil.