My 40X's were never 1/4 minute rifles in stock form. My 6x47 was a 3/8 agg shooter on good days. It would, of course, produce the occasional sub 1/4 group. This was stock, except for bedding. Later on, restocked and re-barreled, it would agg in the low 2's under match conditions. On calm days, in practice, I could stay in the ones. In the late seventies, this wasn't bad shooting.
One of my better 40X's was a 10 1/2 pound 308. I could never agg under 1/4 with it but I did come close and once had a low-2's agg going then blew it with one shot in the last group. The recoil always got to me sooner or later with this one.
When I bought my first 40X, it cost me about 400 bucks which, at that time, was about ten days pay for a sawmill worker. About 2800 of todays dollars, I reckon. The new 24 Leupold scope was 125.00. WH