Data point: group size of first shots in a new 'Max Accuracy' 22lr barrel

[adamg]

There's lots of well-aged conventions in the 22lr world surrounding group size from a rifle from freshly cleaned, or from new, or when switching ammo. Any number of scenarios will bring forward claims of "you've got to shoot a bunch of ammo through it before it can shoot its best groups."

Here's a good data point with evidence that suggests this is simply not the case. I interpret this as a very well-made barrel in a reasonable-quality action and top-end ammo can shoot its first group just as well as its hundredth group. More specifically, for one sample barreled action the first shot was a bit off from others; the second action had the first shot within the others.

The above is the second video in this series. A few weeks back the same guy posted a video showing how he gunsmiths the barrel onto the CZ 457 action. So he has now shown the results from three separate CZ 457 barreled actions.

 

[Biologist]

Those results look very impressive.
The CZ designers may have to look at their designs for the aggressive grub screw notches and maybe add more meat back to the tenon?

I can imagine that the micro dimensions of how that chamber and barrel are bored out and lapped is hugely influential on the performance. That is also a very heavy barrel at a straight 1 inch contour, and that probably helps for accuracy in supported shooting. It is a weight issue that not everyone wants, especially if they are going to hold the rifle for positional shooting disciplines. That is alot of weight for that small action to support free-floated. I wonder if that accuracy is going to last with alot of use?

I know both my factory CZ 452 and Anschutz 1907, when cleaned really thoroughly, need many rounds down the barrel to stabilize and center the groups. The first round down my clean barrels may be up to 1 to 1.5 inches, almost always high from the group before it settles downwards and starts to group tight. Worst I experienced once (I forget the target ammo brand, but it was either Eley or SK), required 20 rounds to settle down the group. Usually it takes me only about 5 to 10 rounds to settle in the group on a very clean barrel.