maybe I just have a sick mind...

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bigghoss

New member
I was reading an article today about the FNH PS90 and the author kept mentioning how he thought in and it's 5.7 cartridge might be nice for varmints. in the article they had a picture of a .22 mag round, .22 hornet, 5.7, .221, .223, and a .30 carbine all lined up. now I haven't looked up actual case dimensions but the 5.7 and the .30 carbine looked to be very close dimensionally (with the obvious exception of the bottleneck). the rim, outside case diameter, and overall length looked very close, not identical, but similar. you all know where I'm headed now. It looks to me like it wouldn't take much to chamber a ps90 in .30carbine. and since he kept talking about the round as a possible varmint bagger the idea hit to do the exact opposite, make an m1 carbine clone in the 5.7 for a light, easy handling carbine that will have more familiar ergonomics for most of us (the PS90 doesn't look like it would benefit much from a bench rest, having almost no forend). but hey, I'm weird like that. most guys would probably think they're both pointless ideas.

while you're at it you could probably make a Five-seveN pistol variant in .30 carbine but I bet the little .30 would be pretty weak sauce from the short barrel
 
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5.56RifleGuy

New member
I would want to know how the hell you would get it to feed. Im not sure what you could do to that mag to make it work.

But I would opt for keeping it in 5.7 anyway.
 
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44 AMP

Staff
Don't know about a P90 in 9mm...

But a 5.7mm M1 Carbine has already been done. In 1963!

MMJ 5.7mm; "also known as the .22 Spitfire was introduced in 1963 for the Johnson Guns alteration of the M1 Carbine. 10 or 20 shot semi auto with a folding stock and advertised as a survival weapon....The package was designed by Melvin M. Johnson, author, Marine Colonel and the man responsible for the Johnson semi-auto rifle and light machine gun of WW II fame." - Cartridges of the World 4th ed.

This necked down .30 carbine case gets 3,000fps with a 40gr bullet and 2700fps with a 50gr.

The main problem with the idea is that the M1 carbines are not tackdrivers. Which is something usually sought in a varmint rifle. They would make a fine pest rifle, but are outclassed by other calibers in bolt actions for dedicated varminting. Basically you would have something a little less powerful than an early Mini-14, and just as accurate.;)
 
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bigghoss

New member
I would want to know how the hell you would get it to feed. Im not sure what you could do to that mag to make it work.
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why do you say that? is it due to the case taper of the .30 carbine that usually requires curved mags in higher capacities?

The main problem with the idea is that the M1 carbines are not tackdrivers. Which is something usually sought in a varmint rifle. They would make a fine pest rifle, but are outclassed by other calibers in bolt actions for dedicated varminting. Basically you would have something a little less powerful than an early Mini-14, and just as accurate.
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well the author of the article kept saying varmint but I was thinking more of a pest/truck rifle. I suppose now that I think about it the terms aren't entirely synonymous. I would think that by keeping the outside diameter of the .30 carbine barrel but with a smaller 5.7 bore it would stiffen the barrel as well as any other design changes that would help in the accuracy department, this all may end up becoming cost prohibitive in the end however. it might not be as powerful as a mini14 but it would be about a pound lighter. I guess you could just say nuts to that and get a 4.8lb kel-tec .223 rifle, I know I had considered it.
 
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bigghoss

New member
well obviously you can't just load a mag designed for the 5.7 with .30 carbine the same as you can't load a 9mm glock mag with .40S&W but I see no reason why a design that works for one would work for the other. maybe the case taper may hinder a 50 round mag since 30 round M1 carbine mags have a curve to them but I think with a tilting follower you could compensate for that possibly. I see no real hurdles to this other than market interest.
 
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Longdayjake

New member
well obviously you can't just load a mag designed for the 5.7 with .30 carbine the same as you can't load a 9mm glock mag with .40S&W
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Um you CAN load a 9mm glock mag with .40. They won't feed but they go in just fine.

I actually really like the idea. The only problem you run into is that the .30 carbine is probably too tapered to run reliably in the p90 mags.
 
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Magnum Wheel Man

New member
the 5.7 is a higher pressure round than the 30 carbine...

I have a FN 5 seven handgun, & a custom Contender barrel in 5.7 X 28... also have 3 gun s in 30 Carbine ( an Automag 3, a Ruger Blackhawk, & a Carbine rifle )

IMO, the 22 Hornet is a closer match to the cartridge... there just arent many handguns chambered in 22 Hornet ( although I do have one... a custom Dan Wesson style switch barrel modiied Taurus "Raging" 8 shot revolver) & no semi autos chambered for it ( semi autos likely because of the rim )

I think there were some guys that were converting the US carbine to the 5.7 X 28... my local builder wouldn't even think about it, because of the pressure differences, but he is pretty conservative, as far as I know, those converted guns are working... switching the FN to 30 carbine would probably be tougher...

one thing to consider, is the FN handgun & carbine are both blow back guns, & rely on a laquer coated case to help delay the bolt from coming back... still the shoulder is pushed forward almost an 1/8" every time the gun is fired... makes reloading much more difficult, & brass life much shorter...
 
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BlueTrain

New member
I mentioned in another thread how people, Americans in particular, evaluate all military cartridges according to their suitability for hunting, and this thread is no different. Not a bad idea, though.

Oh, and I'd never shoot a truck with anything less than a .45. That is what you meant by truck gun, isn't it?
 
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