25 gibbs?
 

i know that this has probably been discussed here before but with all of the lost posts i could find no info. what is a 25 gibbs and what advantages does it offer over 257 roberts 250 savage and 25-06 rem? also is is better than 257 wby?

RE: 25 gibbs?
 

Back in the 50's Rocky Gibbs came out with a line of wildcat cartridges and also built rifles.
All were based on the 30-06 case, typically the case taper was blown out, the shoulder moved appx .200" foward with a 35-40 degree shoulder ala P.O. Ackley's. With that done the case will hold appx 5-7 more grains of powder than the parent 06 case. He didnt have the slow [powders we have today and alot of folks claimed he was nuts at some of the velocities he was getting. Loading data is scarce to say the least, when loading it's best to use an ackley improved starting load and work up.

Forming case is kinda time consuming andyou have to form a false shoulder on the neck and either fire form with a stout load of handgun powder and cotton or use a reduced load with a bullet.

Your question on how the 25 Gibbs would preform....With a "fast" barrel being 28-30 inches it would be on par with the 257 Wby without burning as much powder. The only reason I say that is.. I have a custom6.5 Gibbs based on a M700 action and it's quite fast, it will run or surpass the 264 Win.

Simply stated the gibbs cartridges could be called maximumly improved....being simular to the ackleys and the shoulder moved foward.

With all the different cartridges we have today I would bet there is little interest in the Gibbs, it's not for everyone. Hope this helps and I will try to post a pic to show the transformation of a 30-06 into a gibbs.

RE: 25 gibbs?
 

Hopefully this works, not the best picture in the world but this will show the basic steps in the forming process of my 6.5 Gibbs. In the above post I mentioned the o6 as the parent case, but due to necking down and the possibilty of worked hardenind the brass either 270 or 25-06 brass works better. With the 270 win case the neck is actually a few thousandth's longer.

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