What did I buy???

I attended a gun auction and picked up what was listed as a 223 Winchester bolt action. The gun is in decent shape but is actually a 240 Gibbs. I have been having the most difficult time finding much information on this rifle.

Any information on it would be helpful. Particularly if you have a reloading manual with info on how to convert brass and tips on loading new rounds. Unfortunately, given the scarcity of shooters, I will have to make my own ammo.

I will see if I can post a pic of the rifle.

Thanks!
 
Just to fill you in, this is what I know/read about the caliber;
- it's very rare
- the projectile is a 6mm bullet used in the 243 Winchester
- it uses a 30-06 case necked and annealed to the 6mm bullet
- the casing of a 25-06 is less necking down but for some reason the cases are more likely to split
- the velocity is between 3,500fps and 3,800
- it's a very flat shooting caliber
- you must know what you're doing when making the ammo (I cant find any reliable or trustworthy data)
 
You got me curious so I did some Googling. The dies for it aren't at all cheap. Midway lists them as special order only. You might be better off dollar wise to just rebarrel it.
 
Not saying you would/should do this but if the gun auction misrepresented the rifle then is it possible to get all your money back?

And for load data : I'm no expert so take what I say with a grain of salt, but could you take 6.5-06 data of same or similar bullet weights and get some load data that way. Otherwise I'd be getting on the phone with Hodgdon or bullet makers to see if they can help you.
 
Gibbs had a distinct way in experimentation. I don't know much about Gibbs but would be willing to bet it is a 30-06 with the shoulder pushed forward and the should set at just under 40 degrees. This in theory will held a bit more capacity.

I know that with the 30 gibbs there can be quite a difference in chamber dimensions depending on when/who the barrel was cut. Not sure if this applies to the 240.
 
Here are some pictures.

To address some concerns, the auction has a "Sold As Is" policy and the owner of the auction is actually one of my coworkers husbands. I don't intend to try to get my money back because it's not worth complaining about given the circumstances.

When we had a few minutes to preview the firearms, I thought the barrel looked thick but was unable to open the chamber due to the large zip-tie holding the bolt shut. I figured the 240 Gibbs stamping was just a model that I have never heard of. I thought it was strange that .223 was not stamped on the barrel but figured the auction house was correct in representing it as a 223.

I might try to see if there are any "wildcat" loaders in the area to see if they would want the gun, but at the same time, this could be a fun and rewarding project!

CarJunkie, thank you for the suggestion to call a powder manufacture. I didnt even think about that but could be very helpful!

Thanks for everyones input already!
 

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Model 670 Winchester in 240 Gibbs (like a 6mm-'06 Improved, Very Improved). 240 Gibbs is a '06 case blown out straight, necked to 6mm, but with the shoulder blown forward .050" and a 35 degree shoulder. Designed and marketed by a Canadian gunsmith/wildcatter back in the 1960s. Gain about 100-200 fps over a 6mm-06. Takes an extra 5-6 grains of powder. It is waaay over bore, barrel life is short.

In order to form brass, anneal, neck the case up to 35 caliber, then neck down to 6mm with the Gibbs dies. This will give you a headspacing shoulder at the base of the chamber neck. Fire form with a 60% load, then load as usual.
 
Midway used to sell a CD with Gibbs reload data. I had a copy of it but can't seem to find it. It has reload data on all the Gibbs line of cartridges. It also has the history on Rocky Gibbs and what his thinking was on the cartridges. To have a Gibbs rifle built the way Rocky would have, your barrel must be 26" long measured from the tip of the bullet on a loaded cartridge not the bolt face.

There is reliable load data on Wolfe Publishing's Load Data web site. However, you must have a paid subscription to read it. You can also use Quick Load to extrapolate load data, but again you must pay for the software. Plus with Quick Load your results are only as good as the information you put in.

One thing I'd do is take that rifle to a gunsmith and have them run a bore scope down the barrel. I'd check for throat erosion and heat cracking of the rifling. Gibbs cartridges are rough on barrels especially the smaller bores such as yours. If The barrel checks out then make a chamber cast to take measurements from to order your reloading dies.
 
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CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

I don't know much about the Gibbs caliber. But I'll bet its fast do to its being a Wildcat cartridge. In attempting to build a loading recipe for it and not able to find a published recipe. Consider slow burning powders like 4831 and alike and maybe try mimicking the 25-06 loading's in lighter weight bullets equivalent to 24 caliber weights. Advice: start low in 25-06 powder charge weights and slightly build up 2-3 tenths at a time until your Gibbs sweet spot in accuracy shows itself.
 
It's definitely something different, even if it is not what you expected.
It might have some collector value, so keeping it could prove a good decision.
I'd get something else you actually want and hang on to it as it is.
An acquaintance had a similar experience in buying an odd ball rifle.
At first he was mad because it didn't use anything like ordinarily accessible ammo.
It turned out to have collector value far in excess of what he paid for it.
 
CH-4D has .240 Gibbs dies for $125.
Rocky was a careful wildcatter. He recommended what brass to use - US GI NM of specific years was his favorite - and said to load no heavier than what would allow 10 uses of the brass before primer pockets got loose.


As said, I would check the barrel condition before sinking money into dies and supplies.
If the barrel is worn from much extra high velocity shooting, you pretty much have an action and stock to work with for any '06 head diameter cartridge.
Collector value is nil unless Rocky did the work himself.

I have before seen people disappointed by relying too much on auction descriptions. Written on the tag vs written ON THE GUN.
 
"...a Canadian gunsmith/wildcatter..." Don't blame us. We've nothing else to do in January except make wild cats and complain about the weather. And Rocky Gibbs was American. snicker.
What you have is a rebarreled rifle. Not a factory thing. Also isn't necessarily a bad thing. No collector value though.
Midway has a picture of the cartridge.
http://www.midwayusa.com/product/612842/quality-cartridge-reloading-brass-240-gibbs-box-of-20
Likely best made out of .270 or .25-06 brass. Post #10 & 11, here, for a how to on forming the cases.
https://www.shootersforum.com/wildcat-cartridges/9284-240-gibbs.html
 
I found that info I was talking about.
 

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