After losing a deer that I hit square in the shoulder with a powerbelt, I went back to the shockwave. I have killed a dozen deer with them in the past. But as Giles said, PIA loading them. I lube all the jackets with vaseline now and it helps some
You are defeating the purpose of the sabot when you lubricate it, or at least one of the purposes that leads to accuracy.
A sabot is used to seal the gasses and provide friction and contact with the rifling in the barrel. Lubricating a sabot can cause some significant accuracy issues.
A tighter fitting sabot bullet combination will typically provide better accuracy than a loose fitting combination. That said all barrels vary slightly and some of the standard sabots bullet combo's are damn near impossible to load, certainly not any fun. Sabot manufacturers have tried to address that problem in a couple of ways. One is to make a crush rib sabot that compresses more easily on tight fitting barrels and they work OK. Another way is to make the sabots in slightly different sizes to address barrel differences. A friend of mine was really unhappy and ready to get rid of his Thompson Omega a few years ago for a couple of reasons. The primary reason was that it so difficult to get the bullet down the barrel. I sent him some MPP HPF 24 sabots that are .002 smaller and they work like a charm and he shots sub MOA with them at 100 yds all day long. The only other problem was he had to quit shoot that nasty Tripe 7 to get rid of that terrible crud ring that made reloading and cleaning difficult. He shoots BH209 now and all is good.
MZ's are no different that any other gun in that you need to find what works best in your gun, trying to cheat the system never allows you to fully appreciate the potential of the gun.
I would suggest you order some crush rib sabots and some MPP HPF 24 sabots, shoot BH 209 if you can find it, and have a gun that will shoot little bitty groups downrange. It is really easy to get great accuracy out of any MZ, the low cost and the high end, they all shoot about the same out to 100 yds, you just need to understand what you need and where to get it.
This will help with some of the sabot explanation and availability. Harvester makes good sabots, but so does MMP, in fact at smokeless pressure Harvester isn't always the best choice. I shoot the MMP sabot's they work well for me
http://mmpsabots.com/store/hph-sabot-series/
Just say NO to Powerbelts!!!