Magic Bullet Stacking Formula
This is essentially a clean detailing of my findings as little as I can explain it without having extra confusion so bare with me as I try to explain how I found out how Magic Bullet properly stacks.
So currently I have MB at lvl 2 which is a 25% stack per critical hit. When I run a build with just magic bullet I along with many others noticed we get a different number per shot. In MB lvl 2’s case its 40%. Mind you this is without the precision rifle damage card. Were just only using Magic Bullet. So where are we getting this number from?
Sniper Passive?
Turns out theirs a hidden number we never knew about with snipers. I strongly believe snipers have an innate 15% damage bonus with snipers. Why you may ask? because when you do the math it starts to add up but not in the way you think.
The Math behind it
If we were to take the 15% and times it by 25% we end up getting 18.75. Obviously that is no where close to the 40% we see in game.
So after looking at the equation for a while I had this random idea of putting a decimal turning the 25% into 2.5 instead. When we run the calculations with this new number 15 x 2.5 = 37.5. Were close, very close to that 40%. What I then did was start rounding and came to the conclusion that you need to round 2 different times. You must first round the 37.5 into a 38. Then from there we round 38 to 40.
If we follow this method with each level of magic bullet, every version will calculate perfectly to the numbers we see on screen (again without using damage boosting cards, just magic bullet.)
Heres a quick sheet if just the first shot of each level of magic bullet and the calculations:

MB lvl 1 15% stack: 15 x 1.5 = 22.5, Rounds to 23, then rounds to 25% on the first shot

MB lvl 2 25% stack: 15 x 2.5 = 37.5, Rounds to 38, then rounds to 40% on the first shot

MB lvl 3 35% stack: 15 x 3.5 = 52.5, Rounds to 53, then rounds to 55% on the first shot

MB lvl 4 45% stack: 15 x 4.5 = 67.5, Rounds to 68, then rounds to 70% on the first shot

MB lvl 5 55% stack: 15 x 5.5 = 82.5, Rounds to 83, then rounds to 85% on the first shot

MB lvl 6 65% stack: 15 x 6.5 = 97.5, Rounds to 98, then rounds to 100% on the first shot
(also if you notice the end results, each level was increased by 15% respectively)
Why 2 step rounding?
Look at MB lvl 2, if we just took the 37.5 and just simply rounded up without, rounding out the decimal first. That formula wont work for MB lvl 1, 3, and 5 as they would all be rounded down and would give us a different number than what the game shows us. So its important you round up with the decimal then round up again on the whole number to give us the accurate result.
Adding Precision Rifle Damage cards
If you want to throw in your precision rifle damage card into the mix too its very easy to calculate. Just add the additional number on top of the first shot calculated.
Example: You have a 60% Precision rifle damage and a lvl 3 magic bullet. The first shot wouldove been 55% alone but when you add the 60 it becomes 115% on the first shot. Try it out and see if im correct.
The Stacks
When it comes to the stacks, the magic bullet card alone is whats doing the stacking before your precision rifle damage card. No matter what my Lvl 2 MB card will only give me an additional 40% per stack. It doesnt take my precision rifle damage card and stack along side it but instead additvily at the end. That is why my first shot with this particular set will put me at 80% total on the first shot.
Labeling Error?
However with this new set of numbers (the 25% per stack becoming 2.5 instead) that would suggest we would get a 250% stack if it were reworded but as you may already know that would further confuse people as they wouldnt see this massive number being stacked. And even if they made the card say x2.5 again people would be really confused believing that MB lvl 2 is doubling each shot.
Hidden 15% number
The main component to the confusion is this hidden 15% Magic Bullet is calculating and stacking from. This 15% isnt apparent to the player nor is it mentioned in any post on any official gears forums and such. Passives arnt a new concept as currently the scout has a passive with the double energy pickup during combat. I did find one guy mentioning the possibility of this innate 15% sniper buff but cannot find the post anymore but remember people questioning the whole thing and not drawing any clear conclusion to such a thing. But I think with the introduction of Magic Bullet and this formula it very well possible snipers DO have a passive. Of course we wont truly know until either its data mined or confirmed by the devs.
Is this the formula?
Its entirely possible its a different formula all together at play but I happen to find an alternate one that just so happened to accurately predict each calculation. Hopefully I explained it as well as I could. If you still doubt the formula I urge you to give me the current levels of your magic bullet and precision rifle damage cards and I can accurately predict your first, second, and third shot with this formula. I need to know if I figured out how Magic Bullet works and put my formula under tests and peer review.
The formula goes as follows:
15 x (MB percentage increase but with a decimal between the numbers) = xx.5, Round the decimal out to get a whole number, then round up once more to get your true number per stack.
Questions?
Feel free to ask any questions. I did make a video detailing everything, it long but it shows you how the hell I figured out this whole thing as it was a wild goose chase but in the end payed off. Dont wanna post it here tho as i dont know teh rules for these forums exactly so ill play it safe for now. As much as it made me bang my head against the wall trying to figure it out, the game itself gave me clues as to how it calutlates its numbers and was really fun discovering this previously unknown entity called Magic Bullet Stacking. I already posted this in the gears reddit so dont be surprised to see it here as i wanna get this topic some exposure and find out if we finally figured out Magic Bullet’s Calculations and possibly if snipers have a damage passive we never knew about… Any feedback is appreciated.