Friday, January 07, 2011

The Modern .22 IMP

I found Byron's post very interesting and worthy of further discussion. I'm quoting so we don't have to go back and forth to reference the post...
First shot square in the chest head-on at about a 30 degree angle.....flinched hard and ran like hell for about 50 yards....not a drop of blood anywhere except a bit in the mouth....heart...lungs....blown up....a few bullet fragments as far back as the liver...bullet path of about 24".....

Second shot walking just above the shoulder joint...dropped at the shot....stood up and was shot in the upper neck...DRT....no bullets recovered....

M262 spec max handload of Varget and the Yugo 75 gr OPMBT
http://www.wideners.com/itemdetail.cfm?item_id=8438&dir=278|281|727

Load is a solid killer and highly effective on fine boned thin skinned creatures under 300 lbs within a quarter mile when shot from a full lenght rifle.....carbines give up range...

Lots of good eating here...

Byron
As many probably know, the heavy bullets in the .223 do about what the once vaunted .22 Savage Hi-Power did with the same weight bullets, i.e. about 2700-2800 fps.

The .22 Savage Hi-Power (also called the "Imp") is a .22 based on the .25-35 Winchester necked down and used with 70 gr. .227" bullets. (Note:  I had thought that the original bullets were 77 gr. but some quick research shows all ammunition boxes of all eras showing 70 gr. bullets.)  Velocities were about 2800 fps. I was reading in the latest issue of Handloader an article on the IMP by Terry Weiland that the Savage guns were rifled with 1:12 twist (like the early .223s). A 1:7 or at least a 1:9 twist is said to be necessary to stabilize bullets but I don't think I've ever seen why they used such a slow twist then.

There's a point to all this (I think) more than it being personally interesting. There's a bit of "what was old is new again" and a bit of adaptation of a particular tool to different conditions. Clearly, those bullets at the velocity achieved in the rifle is effective when well placed. Unfortunately, it isn't legal for me to use my .223 rifle on deer in the Commonwealth of Virginia so I probably won't get to try these on such large game anytime soon. More likely is that I'll have an opportunity to shoot a coyote or groundhog. I'm certain that such bullets will suffice for that use.

My carbine has a 1:9 twist. I bought 1000 of the Winchester 64 gr. SPs to make up my using load for my .223s. However, I was interested to learn that the 77 gr. Sierra has stabilized in other guns like mine so bought a box to try. I'm likely to get less velocity with my carbine than I would have with a rifle. I'm going to use W748 with the 64 gr. Winchester bullets and either W748 or BL-C(2) with the 77 gr. Sierras. I hope to achieve 2800-2900 fps with the 64 gr. bullets and 2600-2700 with the Sierra 77 gr. That will pretty much make the .223 an Imp but the bullets will fit the bore and the brass will be less problematic.

Over the years there has been a lot of discussion of the .223/5.56mm cartridge and what it will and will not do. I am tempted to believe, in my old age, that 50% or better of what has been written and 90% or better of what is said in the gun shop can't be supported by real world experience. I note that while there are complaints about the use of the FMJ 5.56mm rounds on combatants, that data is flawed by lack of scientific method and reliance on anecdotal evidence. On the other hand, there is (or was) a widely circulated video of hog culling operations in Texas which used the AR-15 and factory 55 gr. ammunition to kill numerous hogs. As these shots were from a moving helicopter one has to assume that shots weren't always perfectly placed. The round still seemed to work.

1 comment:

James Passmore said...

Just commenting on the .22 imp article - where I come from the .222 Remington has been used to kill ten of thousands of red deer, perfectly successfully, throughout the sixties and seventies, usually using the factory Norma 50 grain soft points of the day.

Today the .223 is still used from choppers for commercial market hunting and many recreational shooters still use their .222's while AR15-type rifles in .223 are now becoming more popular too. Note that red deer here are much larger than in the UK and Scotland also.
There is no question of the killing power of .22 centrefires like the .222, .223, and therefor also, old .22 Hi-power.
Proper bullet construction in the .22 centrefires is the only siginificant thing diffrent to larger cartridges.