Were those 38 special?
A -4 wouldn't be 1985. The 586 "no dash" ran from 1981 to 1986. The -4 was introduced in 1993. I think most, if not all, were originally square butt, changing to round butt in 1995-96 when S&W went to the RB grip frame for all the revolver models. The -4 was replaced by the -6 in 1997 (the -5 was a special run for Brazil, and was chambered in .38 Special).
3" and under were always round butt.......
....38 Special and the barrel is actually 4.2". This was the second Brazil Contract.... -4's but were shipped in 1997, while the other contract was made up of -5's but shipped in 1993.
Rechecked serial on mine. It's BSP putting it between 94-95.
JR.
I've personally seen 3 different 586-5 357s round butts. All had 4" barrels and came with hogue square butt grips. Sku was 103534.