Yes, the action and barrel carry proof marks. Proof paperwork was with the barreled action when I bought it. I have misplaced the paperwork.

The picture below is NOT of this barreled action but another I bought on the same day. Posting only as an example of the paperwork that was included with each of the 8-9 I bought that day.

So, I have no doubt that it left the factory wearing this barrel.

Yes, I know I can cycle rounds through the action without a stock. Cycling that way vs. cycling quickly from the shoulder is not always a good comparison since the magazine box almost always ends up modified at least slightly.

The .400 idea is interesting, but I am stocking these to sell, and unless I had the correct customer I could own a .400 rifle for a long time.

I wonder if 7mmSTW would work.

Off to my copy of Cartridges of the world.

(Not serious)