What actions were originally used for the likes of the 505 Gibbs?
That is a fat, long monster, and I can't imagine Enfields or Mausers handling it.
(And there are others.)

The 505 Gibbs was originally built on magnum length mauser actions.

The 505 can be done on a Enfield with a
little work.It has large action diameter that
helps with putting in bigger barrels for
fat cases...Ed

Brevex magnum mauser actions and 1917 Enfields/model 30's-Rob

What are your thoughts, with regard to the reboring and rechambering of M77 MkII Magnum Rugers to the 505 Gibbs? There is a company in Tennessee, Bowen Custom Arms, performing this conversion. They advertise it on their website.

The enfield is large enough.. it's a frickin huge action. The larger magnum actions are very expensive, except the coming attractions of the MRC PH.

it's very possible to build a 50 cal HUNTING rifle on a cz 550, if you are not dead set on a 505.

for the most part, get a 550 in 416 rigby, do a barrel swap for a 500 asquare, a 510 wells, or a 500 jeffery. They are all on the same casehead diamater, which is the same as teh 416 rigby.

You would need to do A LITTLE feed work as all three of those rounds are slightly larger diameter, by body and rebatted rim, or case belt, than the 416 rigby.

If i knew THEN what I know NOW about the 500 jeffe, I would have built a wells. The brass is abotu 1/3 the price, you can get it from midway, it's not dogturd soft bertram, and all the rest is right there.....

Of course, I would have loaded it at 500 jeffery ballistics, not the higher wells/a2.

All in all, your real choices, today, are in terms of increasing price of the action, as related to the 505.

p14/m17 100-200 action
rem mod 30 200-400 action
cz 550 650, deliveried, every day
MRC PH (when it comes out) ???
<other mag mauser sized actions> 1500-4000

jeffe

I mus' ha' bin asleep when it were discussed. Who is dis MRC PH and where dey gonna cum frum?