My son and I both own and use 12 Ga. H&R Ultra Slug guns. As far as which sabot slug to use . . . all I can say is that you should shoot every type in every length you can afford to try. Yes, this will be a bit expensive but if you really want to know which sabot slug your gun likes best, there is no other way. My son and I split the cost of sabots with his brother-in-law who also recently purchased a 12 Ga. H&R Ultra Slug. The three of us went to our local range to sight-in. All three of us ended-up with guns that preferred different sabots. My gun preferred the 3" Federal Hydra Shok, my son's gun preferred the 3" Winchester Partitioned Gold, and his brother-in-laws gun preferred the 3" Brenneke KO sabots. All three guns were shooting clover leafs at 50 yds with their favorite slugs. All three guns were shooting 2.5" to 3" 3-shot groups at 100 yds with their favorite sabots. Now keep in mind that this was from a sandbagged benchrest. Since our local range only goes out to 100 yds, we were unable to test any of the three guns at 150 or 200 yds. I can't say that we tried every type and length of sabot available but between the three of us, we went through about $150.00 worth of ammo that day. It may well be that there are other sabots available that will shoot better from our guns but you have to ask yourself, how good is good enough. Most of the shots in our neck of the woods are at 75 yds or less (usually much less). We are happy with our Ultra Slug guns and all three of us managed to take deer last year this season with our Ultra Slug guns. Not one of the deer traveled more than a few feet after being hit. To me, the H&R Ultra Slug is the single most undervalued deer gun on the market today. Now if I had one of the faulty ones I've been reading about, I might not feel that way but I don't. Maybe they found the guy who wasn't doing his job correctly and canned him.