BT-99s were guns that went thru a couple of POI changes, due to different stock styles. Somebody posted on here a list of high shooters. Maybe they can do it again if they are reading this post. My guess is yours is among them. You can trade it or look for another stock. Both are options.
How about having an adjustable comb added - with a wide saw kerf - to lower the comb top? The cost in our area is around $250 which "might" be a better avenue than shaving the present stock or buying a new stock.
WHOA...hold on before altering your comb. We need a lot more info from you to determine if it is your comb.
The first thing we need to know is the gun shooting high or are YOU shooting the gun high. If the gun is shooting high while the sight picture has the beads in a figured 8, lowering the comb will not help you. Lowering the comb will put your eye behind the top lever and not over the gun.
You need to take the gun out to the patterning board, put it on sandbags, line the beads as a figure 8, shoot it at 25 or 40 yds, and then measure from your aiming point to the CENTER OF THE PATTERN.
Now, if you cannot get your eye low enough to see a figure 8, and have space between the beads, a comb alteration then could be needed. Seeing as you are relatively new to this site, I'll go out on a limb and assume you might also be somewhat new to shooting. If this is the case, I would have you see an experience shooting instructor to ensure your SHOTGUN mounting skills are correct, before making changes.
Suggest not to shave the stock as you will really devalue your gun. Some Bt's no matter if you even bury the front bead it still shots to high. If you really bear down on the stock will the gun appear to shoot as low as you want it to?
If so, have an adjustable stock made where they take extra wood out from underneath. I had a BT 99 that shot to high and I took a piece of rib from another barrel and drilled a hole a bit larger that the BT99 front bead and placed the extra piece of metal over the original bead and had a new bead installed on the added rib. That made the gun shoot where I looked. In my opinion it's easier to make a BT99 trap gun shoot higher than make it shoot lower.
To get your gun to shoot a lower POI!!! All you have to do is lower your EYE!!! Your eye is your rear sight. Lower that and you lower your POI. Now!!! what do you need to do!!! To lower your EYE!!! If your head is firmly on the stock and you can not lower it any further, than you must lower the stock. You can try to raise the End bead as well. But you "may" still need to lower your eye to get your gun shooting a lower POI. Best of Luck and break em all. Jeff
PS As Mentioned, Are you currently making a perfect figure 8 with the two beads. End bead is on top and the mid bead is at the bottom and they should like just like a figure 8. The two should just touch each other!!! Can you get your eye low enough for this to happen??? Or is there a gap between the two beads??? If there is a gap between the beads!!! How big is the space???
What you say makes a lot of sense. Problem I had was with a high shooting BT 99 where the rib was a lot higher from the breach end no matter how low I set the stock it still shot to high for me. I love BT's but that gun has been modified and redesigned more by Browning than other gun I have ever seen over the years.
Steve, Did that BT-99 have a factory Rib??? Or was it a aftermarket job??? I have heard that Browning made the 99's with a factory high POI back in the early 70's, but am unaware of any other time frame that shot real high. I'm with you on a low POI gun. Its just a more natural breaking point. Its also a must if you shoot Sporting Clays and skeet as well. Break em all. Jeff