22 K hornet: Does crimping increase the chances of case splitting?

[PigButtons]

I've been handloading some 22 K Hornet rounds and after 50 decided to use a Lee Factory Crimp Die to see if it would improve accuracy. After crimping I noticed that 3 of the 30 crimped cases had cracks where only one of the first 50 did. I'm using PRVI cases that I annealed before loading, they are all new, and I'm fire forming to 22 K. I've been using 10.2gr to 10.6gr with 34gr Dog Town and 55gr Hornady FMJ BT. The cracked cases came from multiple load recipes and not just one. The load data I've been using gives a range of 8.5 to 11gr of Lil Gun, others I've found online go as high as 13C. There are no other signs of over pressure. All of the cases' cracks look the same, there are two small cracks 1/8" long, 1/8" apart, 1/4" below the shoulder, running inline with the case lengthwise.

This is in a MGM, Encore 24" barrel.

I'm just wondering if anyone else has seen crimping leading to higher cracked case counts.

 

[Catfish]

The more you work the case necks the shorter case life, but I have never seen cases crack where you are talking about. The splits usually start at the mouth of the case. I have had hornet cases come a part about 1/4 in. above rim with hot loads. Hornet cases are pretty fragile and are designed for low pressure, but I still can think of no reason the cases should split where you say they are splitting. I guess it is possible it is the Lee crimper. :

 

[bheadboy]

if the crimp die is producing downward pressure in addition to squeeze possibly causing a buckle, this could cause the case to do what you indicate,

reduce the crimp pressure and see if that helps,

Bob

 

[rogn]

Just guessing from what youre observing that your chamber is not well matched to your sizing die, or your anealing is not extending into the zone below the shoulder( kinda touchy). Id go with the brass being overworked. Or older brittle brass.

 

[snert]

Just guessing from what youre observing that your chamber is not well matched to your sizing die, or your anealing is not extending into the zone below the shoulder( kinda touchy). Id go with the brass being overworked. Or older brittle brass.

+1

I don't think I would try to crimp a varmint bullet, even with thin hornet brass. Proper neck tension comes from good sizing and new cases. This stuff doesn't last like some of the other 22's.

 

[DanConzo]

I think you indicated you were fireforming. This happens every now and then when fireforming. Seat the bullet into the lands if you are not now and lightly oil the case (shoulder down) just before shooting and see if that improves on the losses. The oil will also form the cases better from case to case. I would also try not to crimp at all while fireforming. Seating the bullet into the lands will really help.

 

[DanConzo]

Also I see you are using Lil Gun Powder, if I'm not mistaken Lil Gun produces a lot less pressure than other suitable powders for the Hornet. Perhaps you might need a little more pressure to form to K Hornet better.

 

[snert]

Also I see you are using Lil Gun Powder, if I'm not mistaken Lil Gun produces a lot less pressure than other suitable powders for the Hornet. Perhaps you might need a little more pressure to form to K Hornet better.

I have seen pressure tests done on a k with Lilgun and other favorites. The other favorites all showed a graph that was predictable and :normal" The Lilgun looked like a patterning board. I would not bet it produces less pressure.

AA1680 is now my choice for speed and pressure

 

[DanConzo]

I assume the OP is shooting 22 hornet cases in a 22 K Hornet chamber and I just looked up on the Hodgdon site three or four different powders with a maximum load for a 45 grain bullet in a hornet case and Lil Gun had the least pressure 31.600 CUP. I always got the best results fireforming with a maximum or very near maximum load and the bullet seated in the lands with the least split cases in other wildcat calibers.. I had problems about 50 years ago and wrote to P.O. Ackley and he recommended oiling cases so that the case would expand more evenly. I found in my experience he was right. I shoot a 22 Hornet Model 43 Winchester which isn't known for a high strength action so I use Lil Gun because I don't want headspace problems and bulged cases. However, I'm not blowing the case out to K.

 

[DanConzo]

Snert--Thanks for the info.

 

[PigButtons]

A picture for those interested.

Thanks for all of the responses. I will definitely oil the cases from here on out, and maybe use some 110 for the fireforming instead of LilGun, ( I didn't have any of the cases split when I used it early on).

This was new PRVI brass that was annealed before anything else was done. I may not have gotten the annealing process far enough down the casing so the area just behind the shoulder may have still been a bit brittle, thanks for pointing that out.

I will definitely stop crimping until after the forming process from now on, and only then if it improves accuracy, it was just a test anyway.

I will seat the bullet so it touches the lands as a test as well, but if someone could explain why that would be better than .010 off the lands I'd appreciate it. That's just so my brain can process it better, as we humans will make something up if we don't have the real engineering basis for what we see.

Again, thanks.

 

[DanConzo]

Seating into the lands keeps the cartridge from moving or barely moving back and forth to keep the shoulder in the same position, and increasing pressure slightly. Oiling the case is supposed to help the case form more evenly. I always seated the bullets into the lands just touching for other wildcats. Probably just try one test load to see if you have to reduce powder weight.