I've read that most 32BP rifles twist rate are a little slow for accuracy with lower charges needed to preserve the meat is this as big a concern as im meant to believe?
NO, it isn't a concern at all.
It's likely coming from a modern rifle shooter who may (or may not) own a small caliber muzzleloader, or couldn't get his one example to shoot well (perhaps he's not such a good shot with iron sights) or perhaps doesn't own any muzzleloaders, and the assessment is based on what he's learned about modern projectiles, NOT patched round ball. The twist rate to stabilize a 45 grain .22 LR bullet is very different from what one needs to stabilize a 45 grain .310 sphere....
Further, one should be going for
head shots with a .32 in my opinion, NOT body shots.
So this may be the origin of the idea that there is a twist rate problem. (I've taken both squirrel and rabbit with a .54 caliber and a deer load.... a head shot is a head shot.)
The smallest current barrel offered by Colerain is .36 with a 1:48 twist rate. Their .40 caliber rifles also offer a 1:48 twist rate.
The Traditions
Crockett rifle in .32 is a 1:48 twist rate
The Pedersoli
Alamo, Pennsylvania, Scout,when made in .32 are all 1:48 twist rate
Now these three companies have a vested interest in making these small game rifles accurate, and can have barrels made in any twist rate, so I think if the twist rate was any sort of problem then somebody would've made a change.
The rule-of-thumb is that one tries a starting load of grains equal to caliber, rounded to the nearest 5..., so one should start with 30 grains of 3Fg in a .32 and adjust up or down five grains at a time to see what's the most accurate. I figure one should use from 20-35 grains for hunting.
LD