Dry paper patches to reduce copper fouling?

[Huvius]

A .358” cast boolit will paper patch right up to .366” which will be perfect for your 9.3x74.
Go ahead and wrap some cast unlubed gg boolits and give them a try.

[country gent]

Paper is mildly abrasive ( probably around 2000-2500 grit) it will polish slowly. A few well wrapped bullets may help smooth the bore, but to see the effects may take 50-100 rds. I have done a barrel break in with paper patched bullets and it seemed to polish the bore up a little quicker. I simply fired 1 round cleaned the bore and repeated. I did this for 25 rounds. Then 2 rounds and clean for 10 rds. Bore showed noticeable improvement after this. The draw back to this is you cant use solvents to check like using jacketed bullets since there is no color change. But a good bore scope will show the differences. as you progress. The plus to using PP bullets for this is in cleaning you don't have to remove any hard fouling like jacket fouling. I wet the bush gave the bore 2-3 strokes to remove powder fouling and then a dry patch. Fired next set of rounds and repeated.

I would be cautious with the following, but paper is a good Carrier for abrasives also. A light coat of flitz, JB Bore cleaner, Iosso applied to the wrapped bullet very lightly. Here wrap the bullets and with a very small coat on fingers coat patch, then remove any excess with a patch. I would load these lighter and work slowly.

The last option is to literally lapp the barrel lightly with a lead lap. It is more work and set up to do. A solid vise is required ( with stops to keep lapp in the bore not letting it out until rotating is needed. Pluses to this is you can clean the bores up with out firing, If desired you can work a taper into the bore rifling, feed lines are parallel to the bore when done. Draw bcs are the need to make lead lapps, the fixture required, and the time energy involved.

[JSnover]

Thanks for the input. This post started in this section because it didn't really fit anywhere else and my intent was to load BP, figured this was the best place to start looking for info.
Since no one near me stocks JB (ordered some over the weekend) I dug some cast .357 and some jacketed .351 bullets out and wrapped them. Results are encouraging and groups are tightening up a bit, one of these days I may even start patching The Right Way.
Thanks again!