I have a 336 30-30 made in 1951, non micro. I have a chance to get one in 35 that is micro, will they shoot good with lead. I'm not at all interested in jacketed with these. My 30 with the RCBS 150 gr. lead will put 5 all touching at 50 and 7.5gr. Unique. Love that load.
Thanks,
David

There are claims that the micro-groove is not accurate with lead --that's nonsense !!
However the micro-groove is much more sensitive to bullet diameter and bullet hardness. Hard enough and proper diameter and it's fine .But that means that it probably is not a good thing to use purchased bullets but rather use home made ones and experiment with hardness and diameter.

I've got a Marlin .45/70 that I bought new about 5 years ago. All that's been shot through it is Garrett super hardcast lead and it shoots great with those loads.

Whether that answers your question or not? I don't know...

i use a microgroove 1894 in 44mag for cowboy action shooting. It shoots very well with soft lead bullets at slow speeds. I've not shot cast hard or soft in it at max loads though.

I have an older 1894 44mag. Bought it in 1975.
It has the micro groove rifling. It shoots Lyman's 429421 Keith bullets cast of Ww and water dropped. It shoots them to 1800+fps, and about twoinches at 50 yards. If I load them to 1600 fps I get about 1 1/2 inches at 50 yards.
I have shot several jacketed bullets that don't shoot any better.
I have tried Lee's 429-200-RF bullet. Loaded so the case crimps in the front groove, and it's to short to feed well. Crimped in the second groove it feeds better but shoots worse. 6-8 inches at 50 yards.
I think I'll get a mould for a simular bullet but at 240 grs. It should feed and shoot better.