This cartridge is something I want to know more about.

Is this a standard 30-06 with the shoulder pushed foreward and a short neck. Does it also have the body taper reduced?

Does anyone have performance data for it?

I read an article comparing the 30-06, 30-06AI, and 30 Gibbs back in January comparing in one of the gun rags that compared these cartridges.

By my read, assuming equal pressures, the end result wasn't worth the work you needed to glean it. There simply wasn't that much difference between to the Gibbs and the 06 to really bother with it. However, once you jack the pressures way up, the Gibbs will perform well - but at high pressure.

That's my input...

As usual, somebody has created a website....

http://www.30gibbs.net/

local gunstore owner loves the 30 Gibbs, and does get some phenomenal speeds from his ( pressures unknown..), and a friend has the 240 Gibbs ( just a wee bit overbore, but fun!).

Look for a book by Wolfe Publishing called "Gibbs Cartridges and Front Ignition Technique". (or something like that). Its got dimensions and load data for all of Rocky's cartridges. Watch it tho they are pretty stiff loads.

quote:

Is this a standard 30-06 with the shoulder pushed foreward and a short neck. Does it also have the body taper reduced?

The Gibbs is blown out.

I posted this to show the 338s but the 308 would look the same with just a slightly smaller bore.


The base of a 180 would be at the same spot as the 225gr 338. And it should read 338-06 & 338-06AI.


Small dia and short bullets is where the larger cases shine. When you get to larger dia and heavy bullets being able to seat the bullet out really adds net capacity.

My PDK case gives a little more capacity than the Gibbs I have used it from 240 to 416. Where it really shines is the 6.5-.358. Med to lighter bullets will give you best gains. IE equal to or less than the 210 .338 or 165 .308. As you can see as you the heavier bullets use a lot of case.

Mulerider, thanks for that link.

here's what it says:


The .30 Gibbs is a .30-06 case with most of the body taper blown out and the shoulder blown forward .196 inch. This increases the capacity of the cartridge about seven grains when using IMR 4350 compared to the .30-06 parent case. The 30 Gibbs was designed in the 1950's by R.E. (Rocky) Gibbs as a front ignition cartridge. Gibbs designed several cartridges ranging from .24 caliber to .30 caliber all based on the 30-06 case.. According to the load data listed in Cartridges of the World, 10th edition, the 30 Gibbs has a 389 fps advantage over the 30-06 and a 139 fps advantage over the .300 Win mag.

quote:

According to the load data listed in Cartridges of the World, 10th edition, the 30 Gibbs has a 139 fps advantage over the .300 Win mag.

Key thing to remember. If the FPS came from something Gibbs wrote himself he measured his barrel length from the front of the bullet.

The data posted above is from an article using normal barrel length measurement.

I did a lot of comparing my 7mmGibbs+ to my 7mag. While I can match and beat factory loading I can't beat my own reloads with the same length barrel. Capacity rules. Factory 7mag are 61,000 or less. While I loaded to 63-65,000 for handloads.

At equal pressures equal barrels the larger case will win.

Vapodog,

We must be kindred spirits. I too had an intrest in the Gibbs line of cartridges, I find them to be just about the optimum capacity.

They arent real popular but I find it funny how great everyone says the 9.3X62 is. Imagine if you will a 9.3 gibbs, same-same!

If I were going to go back to being a one gun hunter I would have to give the 30 Gibbs some serious thought, it should just about equal the WSM without the FAT equation. But I have trouble finding time for the rifles I have now, much less another wildcat. They can be kind of high maintenance, wildcats. If you know what I mean.

I do think a 7mm through 338 Gibbs would be an outstanding performer though. The laws of physics tell us that the Gibbs should land balistically between the 06 and the WM, which isnt a bad place to be.

I may yet ream out a millsurp bbl to 8mm Gibbs just for shits and giggles.

quote:

Imagine if you will a 9.3 gibbs, same-same!

A 9.3X62 case neck would start at about the same point as the 338 Hawk shown above. A 9.3 Gibbs would give you a little more capacity. What would really help would be a long mag box and throat.

My primary deer rifle for 13 years was a 30 Gibbs. It was a very accurate cartridge and got lots of oohs and ahhs at the range but I finally traded it because I was tired of making the cases and I really had to load hot to get much above '06 velocities on my chrony. Mine had a 22" barrel and would likely have benefited from 4" or so more length. I fireformed cases 1)with cream of wheat, 2) with a false shoulder, ~40 grains of 4895, and a 100 grain plinker bullet, and 3)with virgin '06 brass, the starting load of RL22,and a 200 grain Speer seated to the lands...the last method worked best. IIRC, the 150 grain load clocked 3250 fps and the 200 grain load ran ~2750 fps. It was a fun cartridge until I developed oldtimer's disease an allergy to wildcats. Now my fav is the 7x57 with 175's at 2400 fps...slow, like me!