Hi Aladin! You and I have been down the same path. My full power castloads are unsized and usually heat treated. The bases have to be square and the checks have to fit. I spread the checks with a punch so they slide on the base without damage to the bullet and then are crimped on. They "bottom" out this way and make the bases "square" if the bullet bases are. I made a tool to "pinch" the checks on. (think bullet puller collet with nose machined out to crimp a check on.) Even homemade checks work quite well if applied in such a manner. Now I don't shoot much for groups anymore- I like offhand and field conditions. I don't weigh bullets ( I might if there was money or pride on the line.). I only visually inspect. I like a big load of a SLOW powder for full power. The rounds have to fit and work thru the magazine. the lube has to be covered and the round is treated like a jacketed round in every respect. I have no more time- gotta go. Hope to add more later. Dale

Sky,
I've never seen a fin on a gas check.

No doubt plain base bullets will create fins, especially on those long base bands that Elmer was so fond of.

Aladin-

The post contains much interesting information. For the sake of argument though...

How say you to the comments of Sharpe & Keith et al regarding bullets being sized so large... That is - they claimed to have witnessed significant degratation in accuracy with oversized CBs due to the "fins" that would develop at the bases of the bullet as a result of being swaged down by the barrel. The claim is that at the moment the bullet exits - the fins catch powder gases unevenly and impart tipping or yaw to the bullet?

I don't know - but am quite curious.

Best regards-

Sky C.