Welcome to marlinowners.com from an Old Soldier in Olympia, WA; in the Great Pacific Northwest - "The Original 444 Marlin®" Country! Hooaaahhhh!!!
This ^^^^^Finding ammo or brass can be tough for a new owner of a .450 today. I've owned two .450 Marlins and still have one (BLR). Perhaps some folks here can help you at least find some loaded ammo or brass to get you started.
As far as a good scope to mount on it, both mine wore Leupolds, a 1-4 and a 1.25-4. Depending on the loads you choose to use, I'd be sure that any scope you consider gives at least a full 4" of eye relief. The Leupold FXII in 2.5x would also be a great choice for short to moderate ranges as it has 5" of eye relief IIRC. The two Hornady factory loads were all I ever used (and still use) and they are relatively stout loads; a 325gr @ 2225 FPS and a 350gr @ 2150 FPS, so be sure and get a scope with enough eye relief.
Were those new inventory at your LGS or had they been sitting on the shelf covered in dust?Hornaday is making ammo for the .450 Marlin. I do not know the run dates but have picked up 4 boxes from my LGS's since about February. 325 gr FTX.
It would require a lot more work than just a re-barrel. There are quite a few internal dimension differences between the two receivers.have it rebarreled to 45-70 and it will live forever.
I understand that, I had a 450 legend rebarreled to 45-70It would require a lot more work than just a re-barrel. There are quite a few internal dimension differences between the two receivers.
New boxes - no dust. Same load Hornady has on their website. As I commented I do not know run dates for Hornady. It was a matter of walking in and on the shelve. Not there last week but was the day I walked in. Was talking to the the one person that orders ammo for this store - he gets a list of available ammo from his supplier, more like a broker, same mail goes to who knows how many other stores and he checks off what he wants and slams order in. About 6 weeks ago there was 6 boxes of Hornady in .35 Remington on the list and I am on his radar to order for me if possible. He got the order form but was at lunch and saw it about an hour after it was sent. Another store had already grabbed the .35 Remington. I have been on Ammo-seek but do not know if they deal with every LGS in the USA. Does anyone know how Ammo-seek works or how they get their information?Were those new inventory at your LGS or had they been sitting on the shelf covered in dust?
I haven't seen any evidence that Hornady has produced 450 Marlin recently. I do check Ammo-seek regularly.