Anybody ever play with a 6mm short gibbs?

kimberman

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I've been wanting a 6mm rem, then I figured a 6mm Ai would be a good cartridge and then someone suggested the next step.... the 6mm short gibbs. Now the 6mm rem is a dandy cartridge itself, but, I seem to enjoy the world of wildcatting. I have a couple other gibbs cartridges so I know all about forming brass and $200 redding custom die's. I'm just wondering if you get much gain in performance when you improve the 6mm rem to the ackley version and again to the gibbs? If you have had a 6mm ai or 6mm short gibbs how did you like it?
 
I had Bevan King barrel me up a 6mm Ackley Imp many years ago. Also had a 240 Page Sooper Pooper for a few years. Both were very accurate and would get way over 3300 fps with 100 gr bullets. :cool:

Case life was amazing. The brass lasted forever!

Ted
 
Loaded to safe pressures, how much speed does a 6mm short gibb offer over the plain old 243?

The short gibbs data is hard to come by. I have a neighbor who has one, he says with a 90 grain bullet his load chronographs around 3800 fps. He has loaded it to nearly 4000 fps just to "see what it can do" but does not reccomend that. Nosler manual shows the .243 win and 6 rem around 3300 fps, and I believe the 6 rem ai would gain another 200 fps to around 3500 fps. I would expect another 200 fps for the gibbs conversion again, however not all chambers, barrels, cronographs, and reloading mauals are created equal.;)

The 6 ai should keep right up with the .243 wssm and the .240 wby which I think is kind of cool.:cool:
 
The short gibbs data is hard to come by. I have a neighbor who has one, he says with a 90 grain bullet his load chronographs around 3800 fps. He has loaded it to nearly 4000 fps just to "see what it can do" but does not reccomend that. Nosler manual shows the .243 win and 6 rem around 3300 fps, and I believe the 6 rem ai would gain another 200 fps to around 3500 fps. I would expect another 200 fps for the gibbs conversion again, however not all chambers, barrels, cronographs, and reloading mauals are created equal.;)

The 6 ai should keep right up with the .243 wssm and the .240 wby which I think is kind of cool.:cool:

wow, I wouldnt have thought it would have that much over the 243 - especially loaded to the same pressure.
 
Considering the various case capacities of these rounds, I think those speeds would be shading the pressures a tad, but everyone has to ride their own broncs. With the full sized Gibbs and sane pressures (no higher then a regular magnum) I can get over 4000 fps with lighter bullets, but not with anything over (and including) 90 gr though. Still, guns vary, so it is probably possible. If I want to go faster then that, the 6mm Mk IV comes out. - dan
 
If pressures are held the same, improving a standard 'modern' bottle neck case will yield 50 to 100fps increase over the parent case, all things being equal.

However, most wildcatters will also open the throttle and step up to magnum type pressures. Because the sharp case handles elevated pressures so well (limited case growth, stretching), the perception is that you get super big increases in performance with a sharp shouldered limited taper rd.

Run the parent case to the same elevated pressures and you will also get improved performance and when the dust settles...

The improved case will be 50 to 100fps faster.

Jerry
 
I'm thinking sako, possibly remington. The shilen barrel or a gaillard are what I'm thinking... #5 contour 8" twist to shoot 105 gr berger match hunting vld's. Possibly a mcmillan sako varmint stock.
 
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