Hi Gerry, Ginger shoots a Marlin in .357 /.38 and I shoot one in .45LC the accuracy on both is great, (5 shot cloverleaf at 30 m out of the box.. from a benchrest on the .45) and no problem hitting a 12 in gong at 75 m with the 357. They both feed flawlesley with the mechanical lifter ( as oposed to the Winchesters spring loaded lifter.) ( I have shot many and in many cal. and they all had lifter problems with heavier bullets.)
Ginger's .357 feeds excelent with .38 rounds.
She is shooting a Marlin Cowboy Limited ballard with a 20 in bbl and it is quite heavy. and has a 10 shot capacity.
If you plan to shoot competition you will need the 10 shots to save a reload "on the clock".
Both Ginger's .357 and my .45 are great rifles, and many of the competitors at the CAS Canadian National finals at Ft. Kusk Ab. were using Marlin rifles to compete and three of the prizes given out were Marlin rifles (.357 &.45)
As for cal, it depends on what you want to do with it and your club policy on hits vrs knockdowns on targets. If you just have to ring a gong , go with the .357 cowboy , if you have to knock down a steel plate, (or want to take it bear hunting in your spare time) go with a heavier cal. And remember that you want the 10 shots to stay competitive.
I am sure you will receve as many opinions as there are members here and most of it will be good advise.
I suggest you try to get to a CAS shoot and look at the firearms they have.
Most of them are more than happy to let someone try out one of their firearms if even just to show off how proud they are of it.
I hope you can get some usefull info out of all this. Feel free to pm or email me for any info I can provide.
Doc Thompson SASS # 72011,
Prince Albert, Sk.