Thought I'd post this back here...no one is going to really believe it anyway, so posting along with editiorial opinions seemed about right.
Freind gave me an old Benjamin 310 (how old...don't know..serial number is an H23XXX) smooth bore that wasn't working. Finish worn off to a bright brass, wood not cracked or dented, just gray with age and dryness (it came back just fine). He'd bought the little gun used in the middle 1950's. Swore he's killed a pile of squirrels with it in Oregon during that time, taking them out to 25-30yards.
Resealed it, made new pins, tapped the end cap for new screws and got her running again. Figured the main seals were still good, if I pumped really-really fast it would get some air and hold it for a day...was the pump-seal that was keeping air from compressing. Kept the old intake and exaust seals in place, changed only the pump seal, cleaned it (wow...50+ years of use can collect enough crud to grow cabbages).
Tried "perfect rounds". They ain't perfect, finging everthing from .175" to .181" in the mix. Sorted them...resorted them...and ended up with groups of pretty exact diameters.
The best of the best would average 1 2/3" at 20yards...which kind of sucks and made me doubt his tales of the past. Not bad accuracy, might be good enough to shoot squirrels at 15 yards at best. Figured it was a case of an old guy letting distance grow with the passing years.
So, with nothing to lose, tried pellets.
First pellets tried, the modern type with a nearly soild base and short length, suck about as bad as round ball. Kept trying different pellets. PRobably have 13 or 14 differnt types on hand, but it didn't take long to find the trends.
Trends was that accuracy was getting better as the pellets (1) grew longer (2) had more and more of a hollow base and (3) used a pinted or round nose shape.
The limit of this came with Beeman's Kodiacs...long pellet, hollow base, round nose. First 3 shot group fired at 20yards went 3/4". had to be a fluke, so fired six more goups. OF those 7 3-shot groups, the largest was 1" and the smallest were 3/4". Call it 7/8" average.
Which IS good enough to shoot game at 25yards...so the old man wasn't disremembering, a smooth bore can do the job at that range.
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Guess the moral is that if you find a good deal on a smoothbore Benjamin (or other good make) might consider it if most of your shooting is done at short range. I'd have though pellets would have tumbled, but evidently they don't...that weight to the nose balance =eveidnetly keeps them point on out to 20-25yards at least. the target holes are round, not oblong or keyholed, and recovered pellets show they stayed point on in the target backing.