I can recommend but can't predict the results.
Right now Midway has a sale on 20 packs of .430 XTP bullets with sabots, and boxes of 100 of the same XTP bullets.
The 20 packs on sale may end up being cheaper than the bulk pack and sabots by a few bucks.
The only difference by buying the packs of 20 on sale is that the sabot is not ribbed and you still get to try them out.
Perhaps you want to buy 100 of each, but I can't promise how they will shoot.
Also, these are ,44 magnum .430 pistol bullets that mate in a .50 sabot instead of being .451 [.45] bullets that mate in a .50 sabot.
I shoot the .44's myself.
Normally I'd say to buy bulk lead bullets, XTP's or Gold Dots.
But you're not sure what will work best right now.
So you just want to try some out to see how that bullet weight range shoots.
240 - 250 grain bullets are the most popular weight on the market, and they kill deer dead.
If they shoot well, then you can buy similar weight bullets and sabots in bulk, either lead, jacketed or plated.
I was going to recommend TC Cheap Shots, which are a 240 grain an all lead HP plinking bullet.
But they cost as much as the XTP's that are on sale.
And Gold Dots are hard to find right now because Speer recently had a rebate.
This is one of the safest recommendations that I can make at the moment.
You can start with a reduced powder charge of say 80 grains of powder instead of 90 grains.
And then try them with 85 - 90 grains, just to test them out at full strength.
Some folks buy 500 lead or plated bullets, but not just to test out.
Others will buy boxes of 100.
And still others buy premium bullets that cost nearly $1.00 each.
Hornady XTP 20 pack $8.99 --->>>
https://www.midwayusa.com/product/1002234214?pid=539065
XTP .430 240 gr, 100 pack on sale $29.99: --->>>
https://www.midwayusa.com/product/1010865576
Harvester .50 ribbed sabots for .430 bullets. pack of 50 $8.99 : --->>>
https://www.midwayusa.com/product/1002231268?pid=884314
TC sabots .50 unribbed sabots for .430 bullets pack of 50 $8.99 : --->>>
https://www.midwayusa.com/product/1002281140?pid=562630
TC Cheap Shot bullets with sabot 20 pack $8.99: --->>>
https://www.midwayusa.com/product/1002274911#:~:text=Thompson Center Cheap Shot Sabots,who prefers a lead projectile.
I saw these TC Cheap Shot bullets somewhere online for sale on clearance for $3.99, but I can't find them now.
But when you can find them cheap, you buy them.
Or buy a box of generic 240 - 250 grain lead or plated bullets for plinking, and then buy the sabots that work the best and are designed for that size bullet.
Using .451 bullets in a sabot is more common.
But ,430 bullets aren't bad, they're just a tad longer with a tad less diameter.
At this point, you're just trying to climb the learning curve to find what works with your gun and to form a basis for future comparison.
For future reference, here's the websites for the 2 major sabot makers.
Try to become familiar with their different sabots and the different size bullets that they will fit, some have differences.
MMP has 2 product pages. --->>>
https://mmpsabots.com
When I went to the Harvester Sabots website, they have 2 different Hornady XTP bullets on clearance.
240 grain XTP MAG bullets 100 pack, .451 $22.99 plus tax. --->>>
https://www.harvestermuzzleloading....item/271-45-cal-240-gr-hornady-xtp-mag-bullet
XTP MAG bullets do not expand as well as regular XTP bullets.
They often pass right through deer without expanding, but would be fine for target shooting and accuracy testing.
300 grain .430 diameter XTP bullets 100 pack $25.99 plus tax: --->>>
https://www.harvestermuzzleloading....item/272-44-cal-300-gr-hornady-xtp-mag-bullet
These require buying the Harvester sabot indicated.
The longer 300 grain bullets don't always stabilize as well in every gun, in some guns they shoot great, and some guns they won't.
They may need to be pushed at a faster velocity with more RPM's for best accuracy.
They may shoot okay, they may shoot fine, but they are a little more risky to test out.
But the price is really good.
Here's the Hervester sabots page: --->>>
https://www.harvestermuzzleloading.com/index.php/products/sabots
And the Harvester sabots home page: --->>>
https://www.harvestermuzzleloading.com
Harvester makes crushed rib sabots which are supposed to be a little easier loading.
They also make sabots under different labels that are not crush rib.
Many people prefer the crush ribbed sabots.
Some prefer MMP's.
You'll try them both eventually, so maybe buy some bullets and give them a try in your gun.