Is this conversion possible/practical in a DR?

the breech end would have to be big enough for the new case head and length.

the extractors would need a total rework from rimless to rimmed.

and it would have to be re regulated & probably resighted too.

what kind of rifle were you considering doing this on ??

Why not a .30R Blaser?

Was designed to clean up break-open rifles in 30-06 to a flanged cartridge.

Performance between 30-06 and 300 WM - good accuracy.

yes.. though other than having a flange, the gain would not be worth the $$$$, imho.

use RL22 and 180 bullets.

jeffe

The 300H&H flanged is one of my all time favorite cartridges, for double rifles, itended for large deer hunting! However, ammo is not east to come by, and brass supplies are not in every Wal-Mart.
I think today what I would do is go with the 30 Blaser instead! factory ammo is available, theough not in Wal-mart, is is far more available that the 300H&H FL. The chambering reamer will clean out the 30-06 chamber, and only extractor work will be needed. The existing extractors can be tig welded up and re-cut, not a hard job. The balistics of the 30 Blaser, is real close to the same as the 300H&H fl!

Either one will work, but IMO, the 30 Balser makes things a little easier!

I had it done to a set of 30-06 512 Tikka barrels, and there was nothing to it. Just rechambered and milled the original extractors back a bit. The Valmet/Tikka is easy to re-regulate.

I got tired of chasing brass for the 30 FM and sold the set, but it worked perfectly.

Does't Marlin have a new 30 cal rimmed 308 class factory case for lever guns. I know it may be to short for this rechamber.
jd

AzGuy : I have some experience with the 30 R Blaser, and can tell you is a wonderful calibre, but I think is far more powerful than the 30 Flanged ,that delivers a 180 grain bullet at 2575 fps with an energy of 2653 fp. ; in comparisson the 30R Blaser delivers the same 180 grs at 2870 fps. with an energy of 3290 fp. The source of this data is "Cartridges of the World ". The 30R has been very accurate with all the combinations of powder and bullets that I have tried. I will be happy to share my reloading experiences .

Dreadful amount of work to get virtually obsolete chambering.