I apologize for my ignorance, but how do we get a pistol out of a 110?This was already taken into account from the very beginning of course and the pistol will be built legally--starting from an action registered as a pistol from Savage.
For anyone now reading who didn't follow the evolution of this oddball thread, let me recap the chain of events from the beginning:
The idea for a new cartridge started from the Illinois law for whitetail deer hunting with pistol (shotgun/muzzleloader/pistol are the three propellant-driven choices). The law has a strange requirement for "bottleneck" cartridges. It is stated that a bottleneck cartridge must be minimum 30 caliber, have a case length not exceeding 1.4", and has to have a commercial box of ammo accommodating the round to show that it has a minimum of 500ft-lbs energy. Straight-wall cases must be 30 caliber minimum but have no case length limit, so on the contrary to what's discussed here, one could use a 4" long case with a taper down to 30 cal at the front to achieve a long-range capable cartridge with sufficient powder capacity (as a taper is not considered a "bottleneck" so long as no actual shoulder exists).
From the above you can see they are trying to stop most bottleneck cartridges from being used, though it can't stop the development of a new cartridge conforming to those specs of the developer can create commercial ammo with specs on the box. I have access to a commercial supplier who agreed to load the new round commercially which we are developing--this is probably the requirement which would stop many from creating such a round, of course.
To date, there has only been 1 other round ever developed to meet these requirements in Illinois, it is the 30 Bellm. It is made from 444 Marlin brass, necked to 30 cal, 1.4" case length. It is only capable of driving a 125gr projectile to around 2350–2400fps max.
Anyways, my first thoughts to developing a new round began with an initial requirement of some arbitrary case capacity value far enough above the 30 Bellm in order to do anything considerably better than it could do. I chose the 308 Winchester because this seemed like a very satisfactory set of ballistics for deer hunting in Illinois, and it was quite the jump above 30 Bellm ballistics even at that capacity.
I knew I would need to use one of the larger cases that exist to be able to meet 308 Win capacity from just a 1.4" length case. My first two cases that I would model and inspect for potential volume were the 404 Jeffery and the 505 Gibbs. It appeared that I could actually land very close to 308 Win capacity using the 404 Jeffery, and if needed, slightly exceed it by using a very short neck for max length to the shoulder. Though as it turned out, I had just discussed the idea with a friend of mine where I pitched to him that I was considering the 505 Gibbs as well as a parent case, and he said he had close to 150 of the Gibbs cases new that I could get from him. With the current state of affairs of reloading component availability, I would be lucky to even find 404 Jeffery for some months through the normal routes of ordering online, so that pretty much sealed the deal--I'd take his new cases and design this cartridge on the 505 Gibbs instead.
Immediately I thought about rim size being 0.640", so I thought about "what Savage action would give me a booty face big enough to machine to grab this rim size?", and I came up with the Savage 220 shotgun action. But I needed to use a stock which allowed AR-style components for a Sig brace, which was the 110BA stock. That's how this thread started! The act of adapting a 220 action into a 110 frame, was the initial idea. As soon as I decided to simply modify the Gibbs case to have a 404 Jeffery rim size, all of the problems went away and I could simply use the 110BA right from the get go.
I attached a drawing of the cartridge as it theoretically exists at this point, the shoulder is drawn a little over exaggerated at 45°, it will in fact be 40°, and the rim is drawn to 505 Gibbs size instead of 404 Jeffery. To be honest I'm content with actually having a 45° shoulder, however I don't find many (any?) Ackley Improved cartridges using a shoulder steeper than 40°. I suspect the reason may have something to do with shoulder bumping when sizing--45° may be beyond something workable in sizing where cases tend to crush if the shoulder is sized. This dimension I still will look into for reference data, because here in this instance the steepest shoulder possible actually benefits the cartridge design since most capacity at a given length is ideal here. The neck length is 0.100" and a short neck can play a potential important part in obtaining accuracy--though this idea is more trivial in nature at this point since there are few circumstances pointing to anything which is inherent in nature. Anyways, besides those two changes--rim and shoulder--the drawing is effectively what the cartridge will otherwise look like, drawn to scale next to a 308 Win case.
Eta this concept itself is fascinating, not nitpicking, genuinely curious!
