Some very interesting comments concerning the 30 Gibbs, part of the enjoymnet of shooting and reloading is the "what if" aspect of shooting... My what if is --should I rechanber a Ruger #1 with 26 inch ballel to 30 Gibbs and what will I end up with??? I know I could rechamber to 300 Win Mag, belt and all.. Ackly Improved requires setting the barrel back and pretty much a no-no..So what if and what would I have in the end. I plan to keep the gun till death do us part. Then the girls can hang it on the wall and decorate it with flowers and stuff like they do with my old fishing creels...

I've asked those question numerous times. What should I do? Bottom line is what do you want? If it pure speed then go with the magnums. If you want to be have the fun of load development, fireforming, and being different then go for it.

With that said let me muddy the water a little more. Let me muddy the water for you a little more. Check out http://www.hunting-rifles.com/ and look at their 300 Howell. They have formed headstamped brass. There is also the Hawke.

If it turns out you are dissatisfied with the Gibbs you can always turn it into a 300 Mag. You'll be stuck with some expensive dies though.

The .30 Gibbs will give you...long case life, easy extraction, and higher velocities than other .30 caliber rounds based on the .30/'06 case. Will it equal a hot-loaded .308" belted magnums? No, but it will come VERY CLOSE!! Anyone who doubts this should read Roger Stowers' book on the Gibbs line. For some reason the Gibbs line of cartridges has been put down prety hard over the years. This may be because ol' Rocky made some performance claims for his cartridges that he could not substantiate with chronographed results, because he didn't have a chronograph. However, a lot of his claims have subsequently been proven by people who do have one. After trying a Gibbs rifle, even Jack O'Connor concede that Gibbs' claims for his cartridges seemed to be born out by results. Jack said that, having expected difficult extraction due to the excessive pressures he though Gibbs was using, he was "amazed to find that you could open the bolt with one finger". And, today, we have even better powders to optimize the increased case capacity you get by shoving the shoulder forward! People complain that Gibbs case necks are too short. But they're not as short as the .300 Savage!!

I don't disagree with the Gibbs as a viable choice, and think that, except for limited brass sources, the Howell would be quite interesting. But let me ask, why do you believe that an Ackley improved would require setting the barrel back? This should only be the case if the factory chamber were overly-long to begin with.

It is my understanding that the proper chambering for any AI it slightly shorter then a factory chamber at the junction of the shoulders and neck. This allows a factory case to be properly held while formfiring.
If the barrel was not setback as discribed above to keep the case from pushing forward from the blow of the firing pin the bullet could be seated out into the lands thus holding it against the bold face.
I hope I have said this right. Pete

Pete....you stated it perfectly.

The explaination by Pete in Idaho is good. So is Stonecreeks speculation as when you look at the standard and improved cartridges the junction of the neck and shoulder seem about the same.

It's too bad that the barrel must be set back to fire factory loads but such a chamber does fireform the standard case very well.

But when you look at the long neck that you end up with you think about blowing it out. However the bullet is held up there and with a standard length magazine of 3.3 COL you don't gain all that much with a .30 Gibbs.

The Nosler #5 says that the 30/06 Ackley Improved will drive a 180 gr at 2,985 fps!

That seems like enough velocity with a lot more flexability. Once you have got the rifle to the range and back the thrill of a special cartridge cools some. I am really, really glad that my old FN 30/06 is a AI and not a Gibbs!

I agree that by setting the barrel back when rechambering for an improved cartridge, you can tighen up the headspace (which is usually somewhat loose in most factory chambers). However, the Ackley line was intended to allow simple rechambering without barrel set-back and allow the firing of factory loads in the improved chamber without headspace any more excessive than in the original chamber.

If your chamber really is on the long side to begin with, you could go ahead and rechamber to the Ackley version and create fireforming loads by moving the shoulder forward like this: Run an expander of the next larger size (maybe a .323") through the '06 cases to expand the necks. Then resize with the Ackley Improved dies, but only enough to allow the case to enter the chamber. Now you will have a small "false" shoulder to headspace on which will make your headspace as tight as you want it.

Gibbs cases should be formed the same way, so actually, except for the marginally useful ability to shoot factory '06 loads without sloppy headspace, the length of the new chamber is somewhat academic.

I believe you will find that Ackley himself recommended that the head space on the improve chamber be set .004 shorter than standard. The issue is the small contact area. The factory ammo headspaces only on the shoulder neck junction not on the entire shoulder.

Clymers go/nogo guages are set so that the IMP is .004" shorter.
Per Clymers Manual
"As outlined previously the distance from the breechface to the neck/shoulder junction in an "improved" chamber must be .004" shorter than a standard chamber in order to hold factory ammunition scurely during fireforming. Since reamers can't cut a chamber shorter, the barrel must be set back (some gunsmiths suggest setting it back a full thread so that screw holes etc will line up.....

My gunsmith told me that to fire factory cartridges that he would have to set the barrel back. So that's what I have.

But my buddy who had the (30/06 Improved) idea in the first place had a post 64 M-70 featherweight that he wanted improved but he did not want the barrel turned around so the stampings would not show or for that matter he didn't want the tiny Winchester Featherweight barrel shank cut away. You know how small that is where the barrel has that inside radius.

So he rented the reamer and we split the cost. He had the smith run the reamer in until the old 30/06 shoulder was gone. He does not talk about that rifle and that was ten years ago. I have no idea what happened to it but he never brings it to the range.

Go a head and say it, you think it flopped!

This guy is the kind that I don't want to cross. Besides every time the story comes up of the woodchuck that he saw me hit on three tries at long range he says the yardage was greater than I think it was.

This is friendship.

DonMartin Your buddies rifle probably isn't ruined. If he had it rechambered as you discribed and then he tried to fireform std 30-06 rounds,the firing pin would move the case forward until the shoulder of the case came in contact with the shoulder of the chamber.This would effectively create an excessive headspace situation and it would result in lots of case head separations and likely a fair number of misfires during the fireforming.If your friend started with new cases and either seated the bullets out far enough to firmly engage in the rifling when he closes the bolt or to neck the cases up to 338 or 358cal.Then slowly resize the neck until he can just chamber the case . He should feel firm resistance on the last 1/2 in of bolt travel.Either method will keep the case head firmly against the bolt face during fireforming and result in properly fireformed cases. He then has to make sure he does NOT move the shoulder back when he resizes the fireformed cases.He will basically have a wildcat half way between the 06 Ackley imp and the 30 Gibbs. Maybe you could ask him if he had difficulty fireforming brass and if he admits to it you can offer the solution. You could have him bragging about your shooting skills and your reloading knowledge.

Steven - I did the exact same thing you are contemplating to my #1B in a factory chambered .30-06. This was my first foray into the "Wonderfull World of Wildcatting." I lopped off 1/2" of barrel so I could get a target crown - so I ended up with a 25.5" tube.

For about $190 ($80 to rechamber, $25 to recrown and $85 for dies) I was all set. The short neck makes no difference in a single-shot action. Mine has a long throat, so I can seat 200 gr bullets to touch the lands with an OAL of 3.45".

Last year's hunting load reached 3,007 fps with a 180 gr Nolser BT. Need to get to the loading bench as I'm going to try the Partition Gold (w/o moly) for this year's field load.

I've got lots of data for this one. My own and some published (I have it scanned) data. I will send it your way if you profile has an e-mail addy.

Stonecreek - I'd like to try and answer the question of why you must set back the barrel on an Ackley Improved (you don't have to for a Gibbs, though.)

Recall that the headspace datum for the .30-06 is part-way up on the shoulder - pretty close to half way. If you run the AI reamer to the datum line, up end up with a 40 deg shoulder to the datum line and an 18.5 degree shoulder the rest of the way. I've seen the "dual-shoulder" on a crappy chambering job.

I'm going to send you a JPG drawing of the .30-06 Std with the AI superimposed on top of it. I think a picture is worth a thousand words. I should make perfect sense when you see this. Just remember where the headspace datum line is (not shown on the drawing.)

My 30 Gibbs does NOT have a cloudy history--it started life as an A-bolt Stainless Stalker 30-06, was rechambered, consistently shot less than MOA groups, killed (almost) everything I shot at with it, and was traded after 13 years for a 300 WSM.
Good Hunting

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Andy Cooper