240 gibbs

[merrjm]

posting for a buddy that recently bought a .240 Gibbs. I havent seen the gun but he says it is built on a mauser action back in the early seventies.
it came with a box or 2 of ammo and he is looking for some load data on it. says he cant find anything on it even in some of his old loading books.
any of you guys familiar with this round? any help would be great

 

[bohem]

Re: 240 gibbs

PM coming

 

[merrjm]

Re: 240 gibbs

just got off the phone with him he is gonna come by tomorrow with it. will do some investigating on twist. he said the only thing on the barrel was ".240 gibbs" we will try and figure out the twist rate on it.

thanks for the info so far.

 

[ksthomas]

Re: 240 gibbs

Don't know how much experience your buddy has at the loading bench, but unless he's pretty well seasoned, the 240 Gibbs is the wrong place to get a start. They can be touchy, and reading pressure signs off any of the Gibbs cartridges can be problematic. If they show any indication of sticky bolt lift (for example) you're already well into proof load territory, Due to the expansion ratio involved with this one, there's also a very narrow range of powders that are suitable for this one, and fairly limited range from "Start" to "Max" loads. I currently own, and have owned, a number rifles chambered for the Gibbs cartridges over the years. Some are downright impressive, and a few are a bit on the sensitive side. The 240 is one of the latter. Just tell him to watch his step with this one.

Wolfe Publishing has a pretty good collection of articles on the Gibbs rounds, complete with histories and loading data, compiled into book form. Might want to consider checking that one out, there's some good info in there.

 

[BuzzBoss915]

Re: 240 gibbs

I seem to recall that the Gibbs cartridges were similar to Ackleys but with a 45 degree shoulder, minimum taper and very short necks. In other words, all hotrods. I'm guessing the 240 Gibbs is based on the same case as the 240 Page, like a 244Remington? Just a guess. BB

 

[merrjm]

Re: 240 gibbs

thanks for the info guys, we will try and get some things figured out on this one. he is a pretty seasoned loader and when he gets here this afternoon i will let him read this thread.

again thanks a bunch

 

[ksthomas]

Re: 240 gibbs

All of the Gibbs cartridges were based on the 30-06 case, and GI brass specifically. Have to remember that Rocky Gibbs introduced these rounds at a time when GI surplus 30-06 cases were virtually everywhere at dirt cheap prices. And you're correct that they all had very short necks, with the shoulders repositioned drastically forward. In essence, they represent about as much as you can possibly get out of a 30-06 case. The body taper was reduced to alomst nothing, which was one of the problems when it comes to reading pressure signs. As I mentioned, it's nearly impossible to stick a case in these chambers, and that's not a good thing. Bolt lift is quite easy with Gibbs cartridges, even after pressures have wandered well into the danger zone. Probably the most comparable commercial cartridge to the Gibbs would be the 240 Weatherby, at least in terms of capacity and performance. The Gibbs still has greater capacity, but it's similar. That, and the fact that the Weatherby is a proprietary (belted) case, not based on anything else.

 

[BuzzBoss915]

Re: 240 gibbs

That's very interesting, Kevin. My only recollection of Gibbs was years ago, I think he used to advertise in The American rifleman and maybe he was in Florida? I mean, maybe in the 60's and after a short time, kind of faded away, but not before leaving a few impressions and cautions. I wouldn't be afraid of such a gun, but armed with a borescope because these bores might be long ago shot out. There has been some resurgent interest in the 6MM/06 amongst hardcore predator hunters and loading for maximum performance will generally erode accuracy sooner than later. But with perhaps less feeding problems because of the '06 shoulder angle? Always brings up the concept of "overbore capacity". BB

 

[ksthomas]

Re: 240 gibbs

Yeah, he did some advertising in AR back in the day, and O'Connor wrote up a few of his cartridges (he was a tech editor with AR at the time). Don't seem to recall Florida, but it's possible. He wound up in the NW, Idaho, or Washington if I recall correctly. Experimented with some other things too, including front ignition cases, that is, using a flash tube that extended almost to the case shoulder, and began ignition from that point backwards. Intersting guy with some good ideas, some not so good ideas and a bit of BS mixed in. I've had several Gibbs chambered rifles ove the years, some of which were fairly impressive, others, not so much. I still have a 30 Gibbs, but shot the 240 out may years ago. And rather quickly at that. It gave some serious performance, but you sure paid for that speed!

 

[BuzzBoss915]

Re: 240 gibbs

Artillery flash tubes, the next big thing, was BS?

Good trip down memory lane. I once had a 25'06Ackley bought from P.O. and it was a damned tack driver. Always building a dream, this year's edition is close to reality. The concept evolves. BB

 

[ksthomas]

Re: 240 gibbs

Yeah, something like that! I've read that the flash tubes gave some really impressive results in a number of arty rounds, and probably aren't all that difficult to incorporate into a 105mm case. Imagine it got a little tedious with a 6mm, though. The Wolfe books have some diagrams and drawings of the rounds that Rocky did, and I seem to recall that Elmer Keith played with these as well while he was at Ogden Arsenal during WWII. In the 50 BMG, if I remember correctly.

Truly was the golden age of wildcatting back then. Of course, they also didn't have to deal with the excessively high population of lawyers we have today, either!

 

[merrjm]

Re: 240 gibbs

i actually got to see the gun yesterday, it looked to have an old school bench rest stock on it, a real heavy barrel, and a scope without turrets. the coolest thing was the scope, the tube started out small , then midway up the tube increased in diameter. there was a spring on the scope and it moved back and forth in the rings that had the adjustments on them. the front mount was actually mounted on the barrel instead of the action. all and all it was a real clean weapon,good bluing, no pits or anything. he said he had the paperwork for the tasco scope that cost 129.95 back in '71.

 

[BuzzBoss915]

Re: 240 gibbs

Let me guess; a copy of the original 6X24 B&L Balvar? Now, that was a scope!

Eek, somebody's dream rifle! The guy should have been arrested!
BB

 

[merrjm]

Re: 240 gibbs

he paid some pretty good coin for it, with the stipulation that it was not to be sold other than back to the original owner or his son when he grew up.