So I picked up 3 boxes of them, 12ga, 2¾, max (1330fps), 1¼oz, #5. I hoped to use them for squirrel and rabbit.

From my 26" mossberg, with F, M, and IC, they failed to produce quality patterns at 30, 35, and 40 yards. Maybe at 30 with the IC, they were tight enough for birds, but would likely only place one or two pellets on a squirrel.

I noticed the wad is a special 2 piece design, which on the tighter chokes, separates and breaks up, causing worse patterns than the IC.

We tested them against clays as well, and found with the IC they did, in practice, breaks clays at longer distances than my go-to walmart bulk pack winchester #7½. We left the pattern board up at 50 yards, and tried to throw the clays low and straight out to make actually hitting them easy, so we could wait and get them to fly out further. The hi-birds did seem to break to about 35-40 yards, where the winchesters would only make it to about 30, despite their pattern on paper suggesting them being a 40yard load.

I found the federal game-shok #5, 1¼oz, 1220fps to pattern better with a full choke, being a traditional cup wad. They put far more pellets, nearly double the density on the board. We had much greater success grenading clays with them than the two previously mentioned loads. They either grenaded it, or it landed unscathed (obviously the skill of the shooter caused the clean-miss) due to the tight patterns.

Yes I switched chokes up, but I wanted to compare the tightest possible pattern of my gun and shell combo. Quite frankly I don't care which choke I hunt with, so long as it provides the necessary pattern to bag the game. Normally I have good success with the federal and winchester high brass, regular wad, #4s or heavy dove loads in 7½ using a mod choke for squirrel and dove respectively.

To conclude the ramblings of a madman, has anyone had success with the hi-bird shells? What is producing the best patterns for you in #4 or 5 shot without moving to turkey loads (which is wholly inappropriate for squirrel)? Anyone tried prairie-storm (flightcontrol birdshot)? I have a hard time ponying up the money for prairie-storm which might actually be too tight for closer shots.

I have used them at pigeon shoots, both box birds and columbaire.  7.5 shot, though, which is the largest legal pellet in that game.

They pattern fine in the Mod/Full combination that I shoot.  I do like RST pigeon loads better, though.

I've been happy and successful with #4 on small game, but was willing to go down to #5 with them expecting much tighter patterns and the extra 100fps.

Seems like an excellent combo on paper, higher pattern density, velocity makes up for lack of mass, etc...

Do you get pass through with #5 and 6? That's the number one reason I've been using them (in 410, 20 and 12). It actually drops them, and for some odd reason the pellets are still small enough that *most* pellets which gutshot, seem to wiggle their way around not pierce the guts, or make a small enough hole to not leak too bad for when the critter sits in my game bag for 3 hours.

I still despise using shot for sport hunting squirrel, but am required to by the nearest convenient hunting area.

Yes I would consider it stout as well. Not quite punishing, but a bit much.

However if it holds the pattern, and the extra velocity ensures a pass-through, then it's all good.

I think the closest I've taken squirrel with a shotgun is 10 yards, and with #4s didn't feel as if the pellets did undue damage. This was with a 410 3" though. I think all of my shots with 12 have been over 15 yards. A 1¼oz (dare I say magnum?) load out of the 12ga at 10 yards might not leave much animal left to eat.

Most of my shots are longer in the shotgun zone, ironically. I can usually get 10-15yd shots in the private property I also hunt. That can also be very challenging to get a hit with a rifle on them that close.

Of course the main reason I enjoy squirrel hunting so much is because it doesn't have to be super serious like turkey or deer. Nonetheless I am constantly in search of the best shells for such uses, as when I do get to pull the trigger, I want to have one in the bag, or know it escaped unscathed. Nothing pisses me off like knowing I wounded game and couldn't finish it.

I do generally snatch up all the #4s I can find. Sometimes I think I'm the only one that buys them.

I've yet to meet anyone in the real world that uses 4/5/6 for squirrel. They all use 7½. I shot a squirrel at about 25yds with 7½ once. Not moving. Gun/shells busted clay and drop dove in problem. Big cloud of dust kicked up. Squirrel did a flip and ran off. I felt horrible for wounding the little guy.

ETA: same shot with a load of wwb 2¾ 1¼oz. 1220fps #4 would have rolled that bushytail into next week, and likely had zero shot stuck in it. That incident is why I have a handful of #4 in my pocket and a box of them in my gear when dove hunting.

Yes they are tree rats. Scurridae family, rodents. They're fun to hunt and tasty to eat.