The 30 Gibbs was a follow-up to his first cartridge which was the 270. Tales of 3000fps with 180's were mostly just tales but I don't doubt Gibbs did achieve that velocity in at least one rifle. His belief was that any load which did not destroy the brass was a good load. In other words, he felt the weak link was the brass case. He found one lot of GI brass which was very strong and which would handle higher pressures without loosening the primer pockets and it was with this brass that he achieved his best performance figures. I suspect the standard 30/06, loaded to the same pressures in the same brass, would have reached close to 2900 with 180's.
I have, on several occasions, improved 30 Gibbs rifles at the request of their owners. This improvement consisted of rechambering to 300 Win Mag or, in some cases, to 30-338 (required setting back) or 308 Norma (ditto). In all cases the owners reported they were now getting the velocity they had been led to believe they would get with the Gibbs.
The first time I was in Gibbs' shop, I was 14 years old and was just in awe. I mean, here I was in a shop where a guy actually MADE custom rifles. In addition, I knew his name not just because he made my grandpa's rifle but his cartridges were shown in my PO Ackley handbook. Pretty exciting stuff!
I'm not a fan of wildcats in general; factory cartridges will do whatever we need. If one has a real need to spend some time fireforming and stays away from the chronograph, the 30 Gibbs will be a good fit for him. GD
