Need some info on the genesis for this family of
rounds.. If anybody is loading for any of the Gibb's would you tell me your Pro's and Con's with the chambering your loading for..
I've been looking at a certain rifle for sale and if it's not to demanding and the benefit is real I'd buy it..
Thanks,
AK

Rocky Gibbs did a number of "improved" cartridges based on the 30-06, starting back in the fifties I believe.

All his cartridges had minimum body taper and short necks with steep shoulders to give larger powder capacity. Is that what you are looing at? If so, don't look at his predicted velocities, PO Ackley once said Rocky loaded them thangs to the gills, significantly over normaly pressure, to attain the speeds he got!

Even so, his line does provide some gains for heavy-for-caliber bullets even when loaded more sane. Not a tremendous difference, perhaps that's why they died out but his cartridges do have great eye appeal!

If the what you are looking at has a good barrel and looks/functions good and the price is right - that is, no more than any other rifle with that action and stock in the same general condition - I'd say get it.

If it's, say a 30 Gibbs, it's no worse than a 30-06 and may be a good bit better with 180+ bullets and a proper powder.

I once had the hots for a .240 Gibbs on an FN action but someone saved me the decision by buying it before I could. Probably just as well, the .24 cal. was way over bore capacity anyway.

here's a .30 Gibbs compared to a .30-06....it has a bit greater capacity than a .30-06 AI but still lacks enough extra capacity to make a real difference.....

Also if it helps Rocky gibbs measured his barrels from the tip of the chambered round to the end of the barrel...or in other words by the distance the bullet traveled in the barrel.

When comparing barrel lengths one shout add about three inches to the lengths stated for his performance data as they were actually that much longer.

Like the AI conversions.....they were a creative way to generate an improved round but in the end turned out to be a pipedream.

There was even a frontburning round with a pipe from the flash hole to the front of the case to burn the powder from the fron to the back but that too wasn't to make a difference.

Jim C/ Vapodog
Thanks for your replys.. In your opinion's would the 8mm Gibb's make much sense over some of the other 8's out there ..
AK

quote:

Originally posted by akrange:
Jim C/ Vapodog
Thanks for your replys.. In your opinion's would the 8mm Gibb's make much sense over some of the other 8's out there ..
AK

First off If I bought a Gibbs chambered rifle it'd have to be cheap enough to allow me to install a new barrel.....I just have no time for one!
Are we comparing an 8 X 57 Mauser to a 8MM-06 Gibbs?.....if it came with dies (and you can fireform 8MM-06 gibbs from .35 whelen cases after partial neck resizing to form a false shoulder) it just might be a good deal...and I'd think offer a couple hundred extra FPS over the 8 X 57

The conversion of Virgin Brass to this IMP/Gibb's is not as easy as to the ACK's..
The Rifle I'm looking at is worth a new tube..I'll approach it that way..
Many Thanks,
AK

Years ago the Publishers of Handloader Magazine had a book out on Mr. Gibbs and his contributions. I seem to recall he was Greek, came to US for opportunity, and had a disease as a child that shortened his life. Don't think he made it to 65. Right after WW II there was a great interest in firearms and limited supply. He took the /'06 case as far as he could. Blew shoulders forward, and steep. I think he wanted "1 caliber" of neck.

I think they said he was a member of a Denver Rifle Club. The club had a competition. "Least drop" at 500 yards. Mr. Gibbs used the .270 WCF as the basis for his competitor much changed and won repeatedly.

Springfields were available for around $18.00 to your doorstep (REA, Railway Express Agency). Rechamber or screw in a new barrel... Much cheaper than Winnies and Remmies at $75.00 per. approx. Ammo, surplus, was $0.01 per round with the rifle... .30/'06s were $0.50 for fifty and .22 Long rifle were about $0.50 for fifty.

As stated, he did not follow todays' "rules" because then there were no rules of today as yet. His "barrel lengths" were the rifled part, less chamber. Adjust for this in comparison and things are pretty fair. There was no attempt at deceit.

This laid the groundwork for the shortened .300 H&H magnums. .308 Norma for instance. Even bigger case, but not free.

There was an emphasis on the care with which he made chambers. Great care. My guess is that he sought the clinging of brass under pressure to make somewhat safer the hot loads he developed. ['06 came out in '06 --surprise-- and was standardized at 45K CUP. .270 came out in 1925 and was standardized at 55K CUP. ...]

And, to end, he sickened and died and did not trust anyone to "carry on" and had his wife burn his papers... Oh wellll

You want to burn these amounts of powder and don't mind the barrel wear, it is a "classic" option. Many modern cartridges provide similar performance and with the FREE '06 brass long gone... Why? [Yes, the government used to leave fired '06 lay for anyone to pick up that cared to...] A "classic" suit you? A factory "suit you" better? Your decision. Luck.

iiranger, excellent post.....

iiranger
You wouldn't have a set of 8mm Gibb's Dies do Ya.. Umm..
I 2nd Vapodog..
Thanks,
AK

quote:

Originally posted by akrange:
iiranger
You wouldn't have a set of 8mm Gibb's Dies do Ya.. Umm..
I 2nd Vapodog..
Thanks,
AK

I have no AI or Gibbs dies anywhere and would gladly send them if I did....try RCBS or Hornady...If the gun you buy comes with a few rounds then sending one of the rounds to Hornady will assist you in getting new dies and they're reasonably priced.

AK

I developed my own version over the years. Before I happen to read about Rocky Gibbs. Mine uses a 40 deg vs his 35 and I used 280 brass vs 06. I've built it from 257-416 caliber. I think that size case is at it's best in the 6.5-358 range. I can share with you my findings. They are close to Gibbs data if you adjust for barrel length.

What I found with mine is I can beat factory magnum data from the same length barrel and even many of my own handloads if I add a couple inches of barrel and use the lighter bullets. When you get to the heavier bullets of each caliber the larger capacity of the magnums pulls away. I use a 338 cal for elk and took a 7mm to africa last year.

You can have dies made and RCBS sells custom. Issue I would have is there really is not a std for the Gibbs. Most dimensions were taken from measuring his cases. If I was building one I would form cases in my rifle then have dies made to make sure everythng matchs.

Even though I have made mine I wouldn't recommend it simply for someone for the extra velocity gain. Since they are a full wildcat you must form the brass. You can not use factory ammo.

I do have published Gibbs data if you want it. A far cheaper way to get real close is contact American hunting rifles. They have their Howell line it is a 2.6" improved 06 case they do the chamber work, sell brass and dies. Cheaper than going with a Gibbs.

PM me if I can help you.

Paul
Thanks for your input .. The more I learn about the Gibb's the more I think I should place value on the rest of the Rifle and not on the barrel.. Go from there..
One thing I did learn from all was that at least it has a "06" Bolt Face which makes for other options..
Thanks,
AK

quote:

One thing I did learn from all was that at least it has a "06" Bolt Face which makes for other options..
Thanks,

You looking at that 8mmGibbs magnum on gunamerica?

Yep the gibbs is an 06 head. Heck for just a few $$ that bolt can be opened to magnum face so the sky is the limit.

With todays powders it could be interesting to play with Gibbs cartridges. Would it be worth
it?

probably not. When people started measuring
pressure Gibbs, and others lost popularity.
Good Luck!

quote:

Originally posted by hawkins:
With todays powders it could be interesting to play with Gibbs cartridges. Would it be worth
it?

probably not. When people started measuring
pressure Gibbs, and others lost popularity.
Good Luck!

So true Hawkins.....when I look at the huge difference between the .308 and .30-06 case capacities and then see the difference in velocities even with all the powders available today it truly makes one wonder how they expect to garner greater increases in velocity by such miniscule increases in case capacity.

Ramrod340 has stated a very good rule.....1/4 of the percent of powder increase will yield a 1% increase in velocity....in other words...if one wants to see a 10% increase in velocity he should plan on a 40% increase in powder capacity......even the .300 magnums barely provide this over the .30-06 and yet somehow we're expecting some minor improvement like the Gibbs and AI changes to do it for us!?????

quote:

With todays powders it could be interesting to play with Gibbs cartridges. Would it be worth
it

Like I've said it depends on what you want. I've done mine across the range. With light bullets you can match the factory magnums. I happen to load in the 60-65,000 range. Could they be loaded hotter sure. But why? Fun to play with sure. If you really need the velocity the the magnum case and long barrel will win every time. This picture shows the various 338 versions from 338-06 up to 338-66. You will notice the 338Gibbs, Howell and my PDK all have shoulders in basically the same point differenct angles. Please ignore the 125gr mark it was added for another purpose. My PDK is my own wildcat. Gives nothing the Gibbs couldn't do. If you want to play with one go with the AHR Howell version. Nice long brass, dies, reamers all available by far the cheapest way to go.


I have played with my wildcat case in various calibers since 1980. Can I match some magnum loads. Yep. To do so I need to form brass and then find the perfect powder for each bullet. If you can't find a powder to allow you to use the gain in capacity without hitting the pressure limit the only thing you get is to burn more powder for the same velocity. I do get an extra round in the magazine. A magnum case and barrel is still the easiest way to get velocity. I built the first because I believed much of the AI stories and figured to add to that. I hadn't heard of Gibbs at the time. With a lot of early pressure testing I found that a lot of posted velocities for AIs and many other wildcats were at pressures I didn't care to load to. I build and load my widlcats for several reasons. I love to be different. I had the reamer so why not play with it in various calibers. Probably the most important they make one heck of a discussion around the campfire.

As I will tell anyone. Build one if you want. Be real in your velocity expectations. Wildcats are really no different than many of the NEW cartidges put on the market over the last several years. They will REALLY do nothing that any number of existing rounds haven't already been doing nicely for a lot of years. But what fun would it be to only own 1 or 2 rifles?

I shot a 30 Gibbs for about 12 years. Funny thing was, I was using the old H205 (Hodgon, please bring it back!) but had no chrony. When I finally clocked my loads (which would print an inch or less at 200 yards when I did my part), I was shooting 150 grainers at 2800 fps. I finally got them up to ~3200, but the accuracy was only ~1.25" at 100 yards. The cases are a pain in the a$$ to make, but once formed, the loaded rounds look cool. I don't miss the rifle...or any other of the wildcats with which I used to be so enamored.