338 Marlin Express

I'd love to get my hands on one of these rifles at some point but finding ammo is pretty difficult. Anyone know if they can use brass from another cartridge, and if any other bullets will work in the tubular magazine besides round nose stuff and the Hornady FTX?

I'd ask the experts here... www.handloadersbench.com or www.reloadersnest.com or the Marlin forum at www.go2gbo.com (CAUTION--over 70 outdoors forums !!)

Bud's Gun Shop has all you will ever need, I just ran a sale cart thru and you can have 400 rounds delivered for $497 + shipping. +/- $1.25 a round which is cheap for the power of this cartridge [it would be hard to reload and save any $$$$$$$$$$$$ at this price].
I have a few rifles and if I can buy factory ammo for these prices, I buy it.
I will buy a few single boxes of different brands, shoot them and whichever brand shoots the best, I just order a case of that brand of ammo {lifetime supply of hunting ammo and quick n easy}.
If I do want to reload after that I have plenty of fresh factory brass that is already fireformed in MY rifle. Just get a LEE collet neck size die set and load'em.
And no, no other cartridge brass will work since the factory brass has a very thick web to aid in pressure control, according to Wikipedia.

You might want to PM DRS here on the forum. He reloads for it and really likes it.

Ammo for the .338 Marlin Express is relatively easy to find. I order most of mine online, but I have found plenty in some stores. My suggestion is to buy several cases of ammo, then you have plenty for a while and can use the brass later to reload. I have a stock of factory ammo, once shot brass, Hornady bullets, powder and plenty of primers. I have found a good load using Hodgdon Leverevolution and AA 2520 is suppose to be go to powder. I have acquired some AA 2520 but have not worked up a load with it yet.

No other brass will work. The brass for the .338 MX is loosely based on the .376 Steyr. When they say loosely that's what they mean, brass from the Steyr cannot be used to form brass for the .338 MX. As far as bullets there are some cast molds, there is one company working on a bullet ( small company) who knows when or if it will be available, some guys modify spitzer bullets to have flat noses other than that it is just the FTX. The FTX is a fine bullet by the way. Oh, I forgot about Hawk bullets.

All of this said with factory ammo and reloading components readily available, I don't think you can go wrong with purchasing a .338MX. Finding a .338 MX will be the challenge, then it's not going to be cheap. The blued model regularly sells upward toward $1000 on GB and the MXLR (stainless) model who knows, $1500 would be a good starting point.

Beware of a few of these had barrels not square to the receiver. It is known as "barrel droop". Most are in the serial series starting with 91. Many have been fixed by Remington and have MR serial numbers. One thing about the MR marked ones is it don't hold the JM stamped guns value with Marlin collectors, so you can pick up one relatively cheaper. Lots of info on the .338 MX on Marlin Owners.

I love mine and don't plan on getting rid of them. I have shot my best groups with the blued model, less than 0.5 MOA. That thing is a tack driver. I have killed hogs, deer and coyotes with mine. It is truly an awesome performer, out of a conventional lever action.

https://ammoseek.com is a good place to start an ammo search.