In my pre-mil 99s, I sometimes had good luck reducing trigger pull weight a slight bit by adding one or more small, thin, flat washers under the trigger return spring. This trigger pull weight hack is reversible so if it is not to your liking, just remove the added washer(s).

Credit where credit is due. The hack did not originate with me. IIRC, I read about it in one of John Barsness's magazine articles.