[Rapier]

I shoot cast in micro grooved rifled guns and the inaccurate myth is just bunk, period. The only two Marlin guns I own are the 94C in 357 mag and the 444 in its namesake. I do shoot 357s in several guns including a couple of Martini Cadets and a Merrill or XL, a Mauser, an 1885 High Wall and a couple of Contenders. All in cast bullets. Revolvers are left out as we are into rifles and cast.

The very best cast bullet in 357-358 is the 200 gr RCBS, the close second is the 180 gr RCBS. If you want a rifle to shoot you must get a good bullet to bore fit and unlike Paul, I always size my bullets to bore size or no more than .0005 over. Just my preference.

I shoot cast in the 357 Harrett which is pretty close to the 35 Remington, but my action is stronger, a Contender, so the loads I use are very hot for a 35 Rem Marlin. No neeed to even start there. Do you have an older Lyman book, like the #43, I believe that is the #. The last book that had the accuracy loads and cast bullets in it? You should be able to duplicate any cast load for the 35 Rem in the Lyman book.

What I suggest to you is that 10 gr of Unique will shoot in your Marlin with the 180 or 200 and you can play with the load to tweek it. Also H-4227 shoots with most cast bullets in the 35's case capacity. 4227 is a funny powder in that it works at a wide range of charges and a wide range of bullet weights within the same case.

You mentioned a 30-30, I also shoot several guns in 30-30, all cast and shoot three bullets, the 150gr, 165 gr and 180gr RCBS and all with Unique at 10 grains or 4227. The 150 is suited to the tube mag as it is a big flat point. The 165 has a small flat point and the 180 is a spirepoint.

Paul, That 358 might have the wrong twist if you can not get it to shoot. I like the old Python twist of 1-14 myself for 357 cast, but I bet your 358 Win is different. If the 358 Win will not shoot with the 200 RCBS and 10 gr of Unique, it will not shoot at all. Then it gets dow to you ar the gun and you have been in the game to long, so I go with the gun being set up wrong.
Best,
Ed

PS The first thing to do before you shoot cast is to slug the bore. You know about Assume don't you? Never assume anything about a bore diameter. Also, shooting "as cast" does not allow you to shoot a concentric bullet. I gurantee you that your "as cast" are not round. Get a larger mould and a larger sizer.