25 Gibbs

 

 

I have always been a fan of the 25 calibers cartridges and a crazed fan of the 25-06 Imp.

The 25-06 Improved has accompanied me on some exciting hunts. They have always performed flawlessly every time I pulled the trigger. So when some one suggested I should try the 25 Gibbs out I was exited about the prospect of trying another 25 Wildcat.

 

The 25 Gibbs is a cartridge that has to be fire formed from the parent 25-06 case. The shoulder is pushed forward slightly in the forming process to produce a larger powder envelop.

 

Great care has to be taken when forming the 25 Gibbs cases. THE BULLET MUST BE FORCED INTO THE LANDS TO FORM A TIGHT FIT BETWEEN THE BOLT FACE AND THE OVER ALL CARTRIDGE LENGTH.  If this is not done then the cases will not fire form properly.

 

One problem cropped up when forming the 25 Gibbs, some of the cases did not have enough brass to form the new shoulder. Some case split in the shoulder area.  I thought I had solved this problem by using Remington cases. Remington cases are thicker than and  weigh more than the Winchester cases, but about 3-5% of the cases still split at the new shoulder  when fire forming.

 

 Split cases from Fire forming.

 

Loading data:

Bullet                weight              Powder            Charge             velocity comments

100 Hornady    100                  Reloader 22     63.0gr              3741                .577” group

100 Hornady    100                  Imr. 7828         62.0gr              3670                .389” group

100 Hornady    100                  H4831             63.0gr              3631                .603” group

 

117 Sierra        117                  Reloder 22       60.0gr              3397                .473” group

117 Sierra        117                  Imr. 7828         60.0gr              3442                .581”group

117 Sierra        117                  N165               60.0gr              3383                .389” group

117 Sierra        117                  H4831             60.0gr              3404                .623” group

117Sierra         117                  Imr. 4350         45.0gr              fire form load

 

All load data should be used with caution.  Always start with reduced loads first and make sure they are safe in each of your guns before proceeding to the high test loads listed.  Since Weaver Rifles has no control over your choice of components, guns, or actual loadings, neither Weaver Rifles nor the various firearms and components manufacturers assume any responsibility for the use of this data.

 

L-R: 25-06 Remington, 25 Ackley, 25 Gibbs

 

Components used in testing:

Remington cases, Remington 91/2 primers, Velsoity were measured with a Pact coronagraph (average of 5 shoots), Custom 98 Mauser rifle with a 25” Pac-Nor super match barrel with a 1-10 twist.

 

The 25 Gibbs equals the performance of the 257 Weatherby and faster than the 25-06 Imp., by only a 100 or so feet /second.   The 25 Gibbs is a fine old wildcat more.  Information on the Gibbs line of cartriges can be found in Po Ackley’s book: HANDBOOK FOR SHOOTERS AND RELOADERS VOLUME 1.

 

Test Rifle- More information on this rifle can be found in the articl titled ”Building a Custom Rifle on a Budget.”