AusVarmint

From a new thread on Saubier:

I have a few 22 Hornets that are great for shooting high volume on the cheap. However, two of them are single shots, and the other has a whopping 6-round magazine that only works with stubby bullets. I picked up a 30-round 30 Carbine magazine years ago and thought it would be neat to make a small 22 varmint rifle using it. So the 30 Carbine necked down to 22 is the Spitfire. I picked up a spitfire reamer, but the problem with the spitfire is that pointy 22 bullets don't fit a 30 Carbine magazine. I decided that I could just run the 5.7 Spitfire reamer in short to be able to use long pointy bullets in the 30 Carbine magazine. The plastic tipped bullets like the Nosler Ballistic Tip give the longest loaded cartridge length, which is limited to 1.69" by the magazine. The cases start at normal 30 Carbine length at 1.28" and by forming and trimming them to 1.15" I can use any bullet I want loaded out near the lands. This gives a case capacity of around 14.8 grains, which is approximately 1.5 grains more than a 22 Hornet. As expected, moderate loads in this configuration slightly exceed the performance of the 22 Hornet. So I can use all the same components I have on hand for the Hornets. My favorite varminting load is the 40 grain Ballistic tip, and my cheap plinking round is milsurp 55 grain FMJ. I've also had good luck cutting the back ends off of surplus tracer tips to yield a 40gr FMJ. The barrel I'm using is 9-twist so I can shoot whatever cheap 22 bullets I can find.

I wonder if anyone else has already done this wildcat cartridge? It's not radically different from the FN 5.7x28mm round, so I could call this one a 5.7x29 or 5.7x30. Or I could call it a 5.7 Spitfire Short, or maybe a Spitwad for being smaller, but hardly anyone has heard of the Spitfire anyway. For me, it's the Hornet I always wanted and one-ups the K-Hornet, so maybe L-Hornet fits?

So basically it's like a 22 Hornet with a bit more oomph that works well in the numerous 30 Carbine magazines and uses cheap and available reloading components. I'm already building another little bolt action to use these magazines and this round. Pet load is 13gr of W297, pistol primers, and a 40gr plastic tip at around 3200fps from a 20" barrel. When the big guns are cooling down this one gets to play.
Marcus

I read that and it sure is interesting, unfortunately I am now selling off my stuff so will be confining myself to just enjoying these type of experiments.

Some years back I imported a Universal Vulcan carbine a 44 magnum on the m.1 type receiver but pump action.
I had ideas of of converting a semi auto 30 m.1 to the 5.7 MMJ but operate as a pump action thought it would be a fun little thing.

Unfortunately, and I think this is in very state " once a semi auto always a semi auto" it was disappointing
If you were thinking to do something like the bloke on saubier I would stick with the standard 30 carbine case and not shorten it as it feeds no problems from a CZ hornet magazine, it really is a nice round. There is also a bloke on saubier selling the correct Clymer reamer for the 5.7 MMJ but he would'nt post to Australia, never being lost for a word I told what I thought so he's stuck with a reamer no one wants.

Johno