Starting seating depth for A-Frames

Matt_WY · Apr 12, 2020

I can call wSift this week and ask, but because I'm impatient and want to work on some 300 win loads today....

Does anyone know what Swift recommends as a starting point for seating depth on A-Frames? I have 0.05 off the lands in my head, but I don't know where that came from. I can't find any reference in their manual.

Obviously, I will tweak as needed, but just want a good starting point. Thanks!

Rob404 · Apr 12, 2020

The Swift book gives a loaded 180 A Frame oacl at 3.340

Matt_WY · Apr 12, 2020

Yeah, their book has the coals, but I am looking for how much jump their bullets like. (Again, as a starting point.)

Wyatt Smith · Apr 12, 2020

I’m no expert, but I would just load them to the crimp groove, try a few, then adjust if needed.

Rob404 · Apr 12, 2020

I had a 270WBY that had a long throat, I started with the bullet dead up against the lands and moved the round back at 5thou increments and check fps and accuracy I did that until the fps and accuracy dropped off then set it were I got the best performance. Good luck with your bullet development

Matt_WY · Apr 14, 2020

Talked to Bill (owner) at Swift today. Thought I would pass along his info in case it helps someone else here out down the road.

He said A-Frames typically like to be 30-50 thousandths off the rifling, so I'll be using that as a starting point.

Also want to say... It's the second time I have called Swift and both times Bill has called me back. He has been very helpful. Really nice to have a company that is willing to talk to and help their customers.

shootist~ · Apr 14, 2020

Not a 300 WM, but my 30-06 with 180 A-Frames shoots good at .050 off, but best at .135 off. I was chaising my tail on seating depth until I bedded the rifle, btw.

Matt_WY · Apr 15, 2020

shootist~ said:
Not a 300 WM, but my 30-06 with 180 A-Frames shoots good at .050 off, but best at .135 off. I was chaising my tail on seating depth until I bedded the rifle, btw.

Thanks. That's good to know. Loaded up a couple ladders last night with different loads and seating depths so will see what it likes soon!