.40 reload question.

[Guest ochretoe]

I am thinking of getting one of these,

http://www.keltecweapons.com/our-guns/rifles/sub-2000/

in .40 cal

What do you think the differance in ballistics would be between a 4" and a 16" barrell? I shoot 185 grain winchester ammo if that matters. Thanks

Edited January 6, 2012 by ochretoe

[leroy]

och:____________

Check these guys out: BBTI - Ballistics by the Inch :: Home

leroy

[Jonnin]

Its probably marginally more powerful but not really all that much. To be honest its just an oversized pistol, with a very small bit of extra range and hitting force. If I had that gun I would use lighter bullets to extend the range; I would bet a 150 grain bullet would get you several hundred FPS which would translate to a number of extra yards worth of usable range.

I do not know how strong the action is on that gun, so if you were to reload it I do not know if you could push it harder than a pistol. Often a well made carbine can handle a stouter load than a pistol, but its a case by case thing and you should find out before doing anything unsafe. The KTOG might have some thoughts on the best ammo for these guns.

Edited January 6, 2012 by Jonnin

[Guest ochretoe]

Thank you Leroy. That broke it down very well. I'll get right at 200fps with a 16" over my Glock 22.

[deerslayer]

200 fps sounds a little optimistic, but never say never. I have a 9mm AR and can't get 100 fps more than my Glock 34 w/ WWB. If you chronograph each, let us know the results.

[myg30]

A friend of mine purchased one of them a while ago but never got to crony it. They shoot well.

Let us know what ya think of it if you get one.

[Guest Lester Weevils]

A dumb question-- Apparently the sub-2000 is a blowback gun. My Beretta 9mm PX4 rifle is a blowback gun with a really big bolt.

In ignorance was for a long time distrustful of blowback mechanisms as dubious or cheezy, though the Beretta seems accurate enough and vast internet wisdom agrees that PX4 Rifles are fairly accurate.

Seems that many of the pistol-caliber semi-auto rifles are blowback guns.

Haven't got around to chronying any of my rifles, ought to do that some day.

I've made full-tilt-boogie max .357 Mag loads for the Henry lever gun that give all appearance of being lots stronger than what a 4" .357 pistol can do, but the Henry appears to be a strong gun and it isn't blowback.

Was just wondering-- If a blowback rifle has been tuned so it will function reliably on typical commercial pistol practice ammo-- What is the likelihood that full-tilt-boogie slow-powder pistol rounds customized for the rifle, would tend to under-perform in a blowback rifle?

[Guest ochretoe]

Lester, I think I get what you are saying. I don't know much about blowback guns but I agree that it might rob performance of the round the hotter you go. As for it being 200fps over the pistol, thats what the link sugested. Who knows. If I get it I'll try and chrono it.

[Guest Lester Weevils]

Hi ochretoe

Dunno nothin about blowback guns. Found a link where people claimed that the inertia of a blowback bolt doesn't get moving until after the bullet is out of the barrel, and hot ammo won't degrade performance.

Maybe that is so, but for instance if a real hot load happened to be double the power of the minimum load that can successfully work the system-- Maybe that isn't a big enough differential to open the bolt early. But it stands to reason that SOME level of extra power ought to be able to open the bolt early? Maybe they design-in sufficient bolt inertia so that the max conceivable load for that caliber, can't ever open the bolt too quick?

Dunno if it can happen in the real world. Was just curious if anyone knew.

[Guest ochretoe]

I just picked up one of the sub 2000 in .40 cal. It uses the clips from my duty Glock 22. Let me tell you, it is a shooter. I started at 15yds at a 2"x2" square. It shot a little low but held a good group. I got back to 25yds and it held the same 3" group all the way back. It did better with service ammo, 186 gr. jhp but shot really well with winchester 180gr. FMJ