Load Testing | 22 Hornet

[pjinoz]

The comparison on case capacity of different brass is based on FL sized cases for the reasons you state above, everybody's chamber is different. I generally FL size the hornet, in my rifle it gives better accuracy probably down to more consistent neck tension with the thin brass, some of my brass is on its 7th or 8th firing with no issues. It will probably get retired soon as at £22/100 for PPU why push it?

There is a difference between limiting case stretch with minimal sizing and the rifle headspacing somewhere it is not designed to headspace, the rim headspacing being the main reason the k-hornet chamber is a benefit is having a 'proper' shoulder to headspace on. Guess we'll just agree to disagree.

Hi Boydy,
What I am trying to emphasize is that even if you use 0.065" thick rims, the firearm manufacturer must allow clearance on this dimension. A FL sized or new case will have greater than 0.065" clearance between the bolt face and chamber and there will be partial head space on "air". If one wishes, it is easy to insert shim metal between the head of a FL sized case in various thicknesses until a light crush fit is achieved on bolt closure. The thickness of this added metal shim plus the rim thickness is the true head space of your gun. Some guns may have very little (yours might) but others more. I prefer to head space on the shoulder. When I had the 300 H&H with its very sloping shoulder I found that after a number of firings resulted in harder and harder to chamber neck sized only rounds. By adjusting the FL die closer and closer to the shell holder I found that chambering did not "free up" until the very sloping shoulder was contacted by the die. There was very minimal differences in the body dimensions during this whole process; this was not the problem, base to shoulder length was.
Cheers
pjinoz

[223AI]

Hi Boydy,
What I am trying to emphasize is that even if you use 0.065" thick rims, the firearm manufacturer must allow clearance on this dimension. A FL sized or new case will have greater than 0.065" clearance between the bolt face and chamber and there will be partial head space on "air". If one wishes, it is easy to insert shim metal between the head of a FL sized case in various thicknesses until a light crush fit is achieved on bolt closure. The thickness of this added metal shim plus the rim thickness is the true head space of your gun. Some guns may have very little (yours might) but others more. I prefer to head space on the shoulder. When I had the 300 H&H with its very sloping shoulder I found that after a number of firings resulted in harder and harder to chamber neck sized only rounds. By adjusting the FL die closer and closer to the shell holder I found that chambering did not "free up" until the very sloping shoulder was contacted by the die. There was very minimal differences in the body dimensions during this whole process; this was not the problem, base to shoulder length was.
Cheers
pjinoz

But the 300 H&H has a much more pronounced shoulder to headspace on, at 5 degrees the hornet hasn’t really got a shoulder at all hence the k-hornet improvement. If it was possible to remove case stretch and improve headspace by undersizibg brass the k-hornet would never have been necessary.

Out of interest what is your hornet? Mine’s a CZ 527 which are well known for supporting the hornet rim.