Load Testing | 22 Hornet

[223AI]

Hi Boydy and other readers,
Sorry to have to disagree with you; although the Hornet case is wedge shaped it DOES have a shoulder (5 deg. 38') and wedge or not it will still make contact in a wedge shaped chamber. I once had a 300 H&H and it had a wedge shaped shoulder (8 deg. 30') and "head spaced" on the belt and if cases were F/L sized it sure did stretch and cause case separation. However, when cases were neck sized only I easily doubled my case life. You are quite correct in suggesting that Hornet cases of thicker rim are better as there will be less head space, BUT even if the Hornet cases you have are 0.065" thick will STILL BE HEAD SPACE as the firearm manufacturer must set head space so that even cases of maximum thickness will easily chamber! One must be careful in saying that Euro cases have correct head space and US not. I have 1000 Winchester cases spread over my Hornet and K-Hornet and they average 0.065", even got a few Rem. cases of the same thickness and was given some Norma cases that were 0.060"- 0.005" below standard. I firstly select cases in the shop with a vernier micrometer to check if they are "on spec". Whilst it may be true that some Euro cases may be of lesser capacity; load limitation can be very strongly influenced by case construction and hardness. A softer case will excessively expand before a hard case. I think it is more worthwhile to determine case capacity after it has been fired and before resizing. Why? Case volume will depend on chamber dimension and unfired "small dimension" cases will expand more than unfired "large dimension but essentially end up equal in exterior dimension after firing. So, back to head spacing on the shoulder. The firearm manufacturer starts out with a NEW "maximum dimension" reamer allowed under chamber tolerances and then begins to cut chambers. When it dulls it is resharpened and is "smaller" in dimensions and continues to cut chambers, resharpen etc UNTIL IT IS TOO SMALL TO PASS SPEC. Then it is thrown in the bin. What are the chamber dimensions of your gun and Fred's down the road? You might have a "magnum" chamber and he a "standard" chamber. You can go a lot further and take a chamber cast with Woods Metal and find out what its internal dimensions are in reality. The last one I took was for my departed Boys .55 cal Anti tank rifle which in this instance confirmed my belief that the "Poms" had simply necked up a Yank .50 cal Browning case to .55 and added a belt. So, I still strongly advocate using every means possible especially with the standard Hornet case to keep it "jammed" against the breach face when it is fired therefore I will stick to neck sizing over relying on correct rim thickness and the gun manufacturer reaming to ZERO head space.

Cheers to all
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.

[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.