240 gibbs

Posted by: colson

240 gibbs - 12/15/17 07:36 PM

I am looking at getting one of these rifles. Does anyone here have any experience with the cartridge?


Thank you, Chris
Posted by: Rustydust

Re: 240 gibbs - 12/15/17 10:14 PM

Should be quite a hot rod. Found it in my old PO Ackley book. Appears to be a more or less a .25-06 Improved necked down to 6mm. Book says 3450 fps with a 100 grain bullet. At least brass should be easy to come by. I doubt if barrels last all that long.
Posted by: B23

Re: 240 gibbs - 12/16/17 12:03 AM

The Gibbs wildcats like the 240 and 6.5 Gibbs are about as much as you can get from the 06 case. They are a step above the Ack. Imp. even.
Posted by: K22

Re: 240 gibbs - 12/16/17 06:44 AM

I had one for several years back in the 1970's. I still have a few rounds and the dies. This was back when I was not so knowledgeable about reloading and zero knowledge about wildcat loads. Mine was built on a HVA action with a Douglas airgaged barrel that was a stovepipe. The stock was a thumbhole laminated job and the whole thing weighed a ton. The Harris bypod I used with 6" legs would sway and twist because of the weight. A Timney trigger and a Bausch and Lomb hubble telescope rounded out the setup. I knew nothing of annealing brass and barely much about loading, so I went through a lot of 30-06 brass. Lots of split necks. I finally had Fred Sinclair set the barrel back and rechamber it to a 6mm Rem.
If I was looking to do something like that again I would do a 6mm 06 and call it good.
Posted by: ackleyman

Re: 240 gibbs - 12/16/17 08:10 AM

A freind has one with two barrels, uses copious amounts of IMR 4831 with a 70g Nosler, velocity is north of 4100 fps...rock chuck rifle

Posted by: B23

Re: 240 gibbs - 12/16/17 01:31 PM

Originally Posted By: K22
I had one for several years back in the 1970's. I still have a few rounds and the dies. This was back when I was not so knowledgeable about reloading and zero knowledge about wildcat loads. Mine was built on a HVA action with a Douglas airgaged barrel that was a stovepipe. The stock was a thumbhole laminated job and the whole thing weighed a ton. The Harris bypod I used with 6" legs would sway and twist because of the weight. A Timney trigger and a Bausch and Lomb hubble telescope rounded out the setup. I knew nothing of annealing brass and barely much about loading, so I went through a lot of 30-06 brass. Lots of split necks. I finally had Fred Sinclair set the barrel back and rechamber it to a 6mm Rem.
If I was looking to do something like that again I would do a 6mm 06 and call it good.


You are a bold and brave man if your first wildcat was a Gibbs chambering. Nothing like jumping straight into the fire. smile The Gibbs line of wildcats is probably not the best choice for a persons first experience into wildcat cartridges but I bet you learned a lot real fast and sometimes knowing what not to do is as valuable as knowing what to do.

For me, the 6-284 is just so darn easy and even though it isn't quite at the performance level of the Gibbs, it's close enough for me and a heck of a lot easier.

I have a brand new 6-06AI built on a Stiller w/Broughton 5c barrel that I'd be happy to sell if anyone is looking for a hotrod 6mm.
Posted by: Winny Fan

Re: 240 gibbs - 12/16/17 05:11 PM

At the link is some interesting reading on the Gibbs cartridges.

http://shakeypete.blogspot.com/2009/08/rocky-gibbs-and-his-cartridges.html

Although the Gibbs cartridges were revolutionary in the 1960's era, they never achieved factory status where they might have been an improvement in some cases (pun intended). Gibbs was to some extent trying to outdo Ackley's AI concept with his own ideas. With the 30 Gibbs, which probably made the most sense of his cartridge designs, he even played with front firing cartridges utilizing a long tube from the flash hole and duplex powder loads with fast burning powder up front near the case neck and progressively slower powders (maybe 2-3 different ones) moving back toward the base of the cartridge.

As has been mentioned, the 6MM-06 or the 6-284 are probably better choices today unless a guy just has to have something radically different from the guy across the street.

Years ago I played with a 30 Gibbs rifle by making brass from 30-06 cartridges by necking them up with an 8MM expander button and necking back down to 30 caliber, leaving an 8MM false shoulder to head space from in the Gibbs chamber. What you got after the fire forming effort (done with either cream of wheat over a fast pistol powder and a wax bullet, or actual chamber firing with bullets) was a short necked improved case that didn't due a whole lot more than what the 30-06 cartridge that you started with was capable of. But it did occupy my idle time for a period in my then young life.

IIRC, I lost money when I sold the rifle to someone who "just had to give it a go", but I was forever freed from playing that particular game in my life. Que Sera. grin

EDIT - I never played the front firing/duplex powder game at the time. I stuck to a single powder and a conventional primer set-up. Even back then front firing and duplex powder mixtures was too racy for my mind to absorb. Today is scares me just thinking about it
Posted by: colson

Re: 240 gibbs - 12/17/17 05:01 AM

Thank you all for the information. This is my first wild cat, so we will see what happens.

Chris
Posted by: K22

Re: 240 gibbs - 12/18/17 06:22 AM

Bold and brave is likely not the case, more like young and dumb.
Posted by: jcs271

Re: 240 gibbs - 12/18/17 10:14 AM

I have no experience with the .240 but I have killed a lot of game with his other great cartridge, the .505 Gibbs! One hit with that 600gr slug and they are DRT! smile

Oh wait, I thought we were talking about George, not Rocky Gibbs. My bust.
Posted by: ViperACR

Re: 240 gibbs - 12/21/17 11:05 PM

I have a new unfired 240 on a 700 if you have any interest. I actually have two but would keep the used one.