HI guys

I was thinking of rechambering my 25-06 sendero to 25-06 improved ,but the 25 gibbs case looks really impressive and fast.Does anyone have loading info. for the 25 gibbs in 85 & 100gr varmint bullets ,this gun will only used for long range varmint vaperizing. thanks

Didn't the Gibbs line of catridges use some kind of front ignition system involving a copper tube to get the spark to the front? I may be getting senile - but I seem to recall something of that nature.

Front ignition was something that Gibbs (and Keith, and the US Army, and a few others) played with. Apparently it promoted more complete ignition of powder loads, especially duplex loads. I don't know about that, but the Gibbs line of cartridges (sans frontal ignition tube) are about the most you can improve the -06 case. I like them and have a 240 and a 7mm. Good cartridges. - Dan

Hey'
I have several Gibbs calibers,including the 25 Gibbs.They are not front ignition.If you don't mind fire forming,you do pick up some velocity.It's not 200/300 fps,as some people claim.Every rifle is different,I never was able to get more than 175 fps on any of my Gibbs.Maybe I don't try to push the envelope to far.Try it,you will like it.
1geejay
www.shooting-hunting.com

Over the past two years I have been experimenting with a wildcat that has the same case capicity as the 25 Gibbs but with a 25 degree shoulder. Blown out shoulder area and straightened case walls etc. I used a 700 action to build the rifle. I am not pleased with the results. As mentioned above, keeping within what I feel is safe pressures. What I ended up with is a very well built custom 25-06 that gets around 50-100 fps more. 257 Weatherby it is not. Note there is load data floating around on the forums for the 25-06 AI that just makes me go hummm!

[ 07-26-2002, 21:20: Message edited by: wildcat51 ]

I had a Rem 700 rebarreled to 25 Gibbs several years back. I was a bit disappointed in the velocity increase over the 25-06 and later rebarreled to another wildcat. I could get about 3175 fps with 120g bullets (26" bbl).

I still have my Redding dies in 25 Gibbs (as new) as well as about 50 fireformed cases if you or anyone else is interested...LR

I have to agree with wildcat51.There are a lot of "claims "out there about 200-300fps gains with the Gibbs or or someone else's wildcat but they are usually without any supporting evidence. Two years ago I started a little experiment.I had a new 24 in barrel chambered for the 30-06 that I installed on a mauser98 action.I developed max loads with 150,165 & 180 gr bullets with IMR4350,RL19 & RL22 and chronograghed them all.I then had the SAME barrel re-chambered for the 30-06 Ackley Imp and worked up max loads with the same components. The largest velocity gain was between 60 and 70 fps. Accuracy with the Ackley imp is very good and I,ve yet to loose a case but then the std 06 is not really hard on cases either. I have another std 06 with a 22 in barrel that produces velocities that are higher than the 06 imp with a 24 in barrel.

I have a 6.5 Gibbs, and I really love it.

If you want to play with a wildcat, or you just want to say you have wrung the maximum potential possible out of an '06, I say go get one.

If you are counting on major velocity gains, don't bother.

In my experience (which has been corroborated by a number of sources now), you may get 100-150fps on average more than a standard '06 variant, and 50fps more than the Ackley Improved versions, if all other things are equal. Whether you have a fast or slow barrel can make all the difference.

So if your decision hinges on the velocity gain, don't set yourself up to be dissapointed. I love mine for many other reasons though, and will build another when the opportunity arises.

Canuck

[ 07-28-2002, 00:49: Message edited by: Canuck ]

I have to agree with Canuck. If big velocity gains are what you are looking for, go to a bigger case. A slight velocity increase is normal. Individual rifles will vary, some fast and some slow. One of the gunwriters (Bob Hagel, I think) had a formula that basically said that whatever your case increase was, your velocity increase would be half that. I think in the majority of cases, and with sane pressures, that is true; there is no free lunch, or magic cartridge. I own quite a few improved and wildcat cartridges, and I'll own more in the future (they're fun to play with), but don't expect huge gains form a small increase in case capacity. - Dan

One advantage of the Gibbs over the .25-06 improved is that you won't have to set your barrel back in order to clean up the old chamber when rechambering.

The advantage of the .25-06 over the Gibbs is that you can fire standard factory ammunition, if need be.

Having a great disdain for and prejudice against factory ammunition in centerfire rifles, I would not find the latter of much interest, but then that's just my personal preference.

Thanks for all your info.I would like to max. out the 06 case and I don't want to open the bolt face so, the 25-06 imp. would be easy thing to do, and if the 25 gibbs can only give me about 50ft/s.over the improved. The ackley makes sence.
Thanks again.

Here is a pic of the 257 wildcat that I am working with. 25 degree shoulder. 270 winchester brass. Six grain increase in powder. Nice looking case but maybe not as sexy as the Gibbs.

[ 07-30-2002, 20:26: Message edited by: BC Shooter ]

Wildcat51

What kind of velocity are you getting with the case and how hard is it to fireform.

When I first had the rifle rebarreled, I used a Hornady 25 cal neck die to produce a false shoulder on 270 winchester brass. Just enough neck reduction to chamber the case and keep the case tight against the bolt face. I then fireformed the brass with a case full of corn meal over a small charge of bullseye to form the new shoulder. The cases were then finish fireformed using a top drawer 25-06 load. I continued to neck size the same brass for at least three firings to eliminate brass spring back. I then sent a few of the cases to Neil Jones to make a custom full length resize die. Pricey yes! But made exactly to match my chamber. The die incorporates a shoulder bump bushing that can be replaced to change the neck sizing. The slickest die I own. Cases just flow in and out sized to fit my chamber. I started with new cases after the dies was received. I have never lost a case throughout the entire process.

Velocity, only a 100 fps (120/117 grain bullets) more before I felt case expansion and other pressure signs appeared. Like I said earlier my attempt to equal 257 Weatherby velocities was a failure. With reloader 22 I did manage to reach the speeds I wanted but I did not like the pressure signs. If the round was chambered in an action other than a Rem 700 maybe the results may have been different. What I do have is a totally custom rifle that will shoot better than I can. I do not regret the journey knowing that it was an experiment to begin with.

Cost Factor:

Rem 700 action: $XXXXX

Chamber new SS 25" barrel: $400

Rework action: $150

Trigger: $190

Custom FL die: Check the Neil Jones web site. Sit down first.

[ 07-30-2002, 21:26: Message edited by: wildcat51 ]

Do you think a longer barrel would help the case.

I have seen data posted for the 25-06 AI that has to be pushing the pressure limit. Most folks are using barrels 26-27" barrels and using 100 grain bullets. But the load data is hot either way. Since I don't have anyway of knowing the exact pressures in my barrel I stopped at the first indication of trouble. I did test some loads that went up to the 3300 fps range (again with 120 grain bullet). Pressure signs leveled off which real made me wonder what false sense of security some maybe having.

If the desired effect is speed the simple fix is to make up a custom rifle in 257 Weatherby. Of course you have the problem with needing a action with a magnum bolt face or modifying a standard bolt with a sako extractor mod.

[ 07-30-2002, 22:57: Message edited by: wildcat51 ]

Wildcat51
Thanks for all your help.

Postive update to my 257 wildcat story. Tried Retumbo with the Nosler 115 BT. Broke the 3200 fps mark with minimum case expansion and no sticky bolt lift. The powder shows promise. But I am here to tell you that it meters through my Redding mearsure like crap. Every other charge bridges. You have to tap the measure to make sure it dumped and weight every charge to make sure.

Hey'
Using the Nosler 85 grainers,I get 3566fps.I have been over 3600,but the groups opened up.I rechambered a Tikka 26-06 to .25Gibbs.
1geejay
www.shooting-hunting.com