The plastic does seem to build up to make loading a little more difficult, factory UBC treatment and all. Only time will tell if the FPB guilding metal jacket will foul at all.
The people I know that use saboted shotgun slugs tell me that plastic build-up is a problem for them, with accuracy falling off after relatively few rounds. It's really only a factor at the range unless you get in a running gunfight with your deer.
When I used to shoot 777 I got my best accuracy between rounds 3 and 13. After that accuracy would start to fall off. No problems with BH209 up to 17 rounds though (the most I've shot). I do notice slightly increased loading effort until about round 5 then it stays the same.
I can't say for sure if the loading effort is increased by plastic or powder fouling. If it was plastic then it should get harder to load with each shot but it doesn't seem to do that.
One thing worth noting is I'm shooting a TC Omega with very shallow rifling, a polished bore, and UBC.
I'm not disagreeing with you Pappy it's just I don't
think I'm running into plastic fouling issues
with my ML and the load/sabot that I've been using.
A different rifle (or shotgun), non-polished bore, no UBC, different sabot/projectile, and I'm sure the results would vary.
