The 7mm Fatso - The Ultimate Short Magnum! By Greg Duley

[ADMIN]

The short magnum craze has taken the gun world by storm, with most manufacturers now producing rifles and ammunition for these cartridges. Based on the old British medium bore African cartridge, the 404 Jeffrey, these modern beltless cartridge designs are supposed to give you 2.5 inch case length medium magnum ballistics out of a short action, compact and lightweight hunting rifle. In factory ammunition they achieve this goal by loading the short magnums to higher pressures or by using the latest progressive burning powders. Handloading ammunition to the same pressure with the same powders in the same barrel length, the 7mm SAUM falls 100 fps short of the 1962 vintage 7mm Remington Magnum while the 7mm WSM drops about 50 fps short. When comparing the 300 short magnums with the 300 Winchester Magnum, they fall further behind due to the 300 WM’s 2.62 inch case length, which is longer than the other medium magnum's.Read More...

This is a thread for discussion of the article, The 7mm Fatso - The Ultimate Short Magnum!, By Greg Duley. Here you can ask questions or make comments about the article.

[JeffVN]

This cartridge sounds incredible!

I have to admit that I would not have signed on to build such a beast if I had been the one trying to create the cases. The new 338 Norma Mag cases should speed up the process, but its still huge amount of work.

JeffVN

[Tyler Kemp]

TOOOO much work for me!

[learning]

That can't be much differant than the short action lazzeroni.

[liltank]

So when you going into production on this rifle caliber. I like everything you had to say about. Granted it looks like a pain staking process that I don't have the machinery for, but looks like and excellent caliber. I am looking into building a short mag off of the 300wsm and mounting a 180 grn. 7mm. This is suppose to be efficiency at its best, but I like what I just read. Let us know how the Norma's work.

Tank

[NZ Longranger]

We designed the first Fatso 5 years and built the first one 3 1/2 years ago now. Don't know much about the short 7mm Lazzeroni or when it was released. I know we're getting significantly better performance than that listed for the 7mm Tomahawk when both are loaded to the same pressures. As far as I'm aware, the Fatso is the ultimate short magnum, unless someone wants to shorten the Cheytac to WSM length, but that wouldn't fit in a lightweight hunting rifle which was the whole purpose of the exercise.
We've built a few now, but wouldn't suggest it to the average gun tinkerer until we've sorted an easier brass solution. Hopefully that's coming in a week or so with the new Norma brass!
Greg

[KIWI AL]

thanks for taking the time to writing another artical Greg, and updating those of us who already knew of the round.
with that new norma round brass do you think the standard extractor will be ok?
cheers