hey guys this is rich and today on what the tech  we're gonna take a look at alignment what it is  

how do you go about checking it alignment one of  those bug buzzwords anybody that's been around  

HPA for any length of time is heard but a lot  of people don't really understand it or don't  

really feel comfortable with checking it and  adjusting it so we're going to take a look at  

how we check alignment and some ideas on how  you go about fixing it so let's jump right in

alright so the way people have been checking  alignment for quite a while and this is the  

way we suggested quite a while ago is basically  this is your barrel this is your hop-up basically  

shining a light up the feed tube and then visually  looking down the barrel and you can see generally  

when you're looking down there where you're gonna  be able to see is you're gonna be able to see the  

barrel you're gonna be able to see the nozzle as  well and then now the nozzle will either look nice  

and centered like it should or well look off to  one side or high above something like that and  

you can see where you need to adjust it so let's  talk about why that method is not wrong per se  

but I'm not always completely accurate what ends  up happening sometimes is the hop-up fits into  

the front of the gearbox you can actually get into  situations where if if that fit between the hop-up  

and the gearbox is tight for instance again here's  our barrel it will be held in place by the gearbox  

here's our gearbox over here and it'll it'll  need to line up with the gearbox over here but  

that line is not straight with the barrel so but  it gets forced into that position then what you  

end up with is one of two things either you bend  the barrel a little bit to make it fit in position  

or the parts within the hop-up themselves shift  a little bit with respect to each other so that  

it can line up but either way the end result is  when you're looking down because it's still held  

Center the hop-up itself is held centered on the  gearbox real closely it'll still look like it's  

centered it'll still look good in your eye isn't  gonna pick up on the slight curve in the barrel  

or the parts being being shifted a little bit  sometimes it'll it'll look good and then you'll  

take it apart and you'll find that the nozzle  maybe has some marks like it's rubbing on the  

hop-up or or something along those lines or it's  still not shooting real well but it looks good so  

we're gonna talk about an alternative method for  how to how to check the alignment that works a lot  

better so what you're gonna need is your gun and  a donor barrel and that's about it you need those  

two things and maybe you're gonna want to do it  in a pretty well lit area so you can see clearly  

but other than that don't need a flashlight  don't need anything like that so let's talk  

about how to do this okay so what we're gonna do  is going to take our barrel as you can see we've  

got the system installed in the gearbox and we  have removed the hop-up and barrel from the gun  

you want a barrel with the hop-up off and I'm  gonna do is I'm going to slide the barrel down  

the inner barrel if you watch be able to see it  come out right there and all I'm gonna do is this  

lets me visually check whether it's lined up you  can see if the nozzle actually lines up correctly  

from the side and you can look from the bottom and  see it lines up well from the bottom now there may  

be some guns that this is doesn't work real well  on but for the most part especially any stage  

damn for this is by far the best way to go about  checking and you can see where you need to adjust  

it if you need to adjust it alright so you found  that you've checked your alignment and you found  

that it's off for some reason we can't cover every  single gun and how you would go about fixing it  

we can't even really cover every single variant  because there's a lot of them but give you some  

general ideas specifically for m4 style platforms  as far as how you might go about adjusting it put  

the receiver apart here there's basically two ways  that the that the alignment can be off it can be  

off vertically it can be off so side to side of  the two generally side to side is a little easier  

and more reliable to fix generally basically what  you're gonna do is you need to space the gearbox  

on the two sides here between the receiver and the  gearbox generally we put just a drill and put in  

some set screws on each side and that allows you  to adjust it so right down in this location I put  

a screw in on that side I'm gonna screw down in  on that side and then you can adjust it back and  

forth and you can get it centered right where you  want and once you get it you can lock tight those  

screws in place and they'll never move and  it reliably goes back together the same way  

every time vertically is a little more a little  more tricky if that's off sometimes because in  

theory this shouldn't this gearbox shouldn't be  able to move vertically in theory it's held in  

place by these two pins however sometimes those  pins either are not in the right location or  

they are loose so the gearbox has some slop in  it one way or the other if it's off vertically  

generally what we will do is we'll remove this  front pin for just remove that guy and and just  

try to adjust the vertical with the back pin in  place the the back body pin there in place on a  

lot of guns the reason that most most often when  we see the alignment off vertically what we see  

is it's too high the nozzle is sitting up too high  in the receiver usually this is because the buffer  

tube is going into the back of the gearbox this  one's been modified you can see so that's not an  

issue on on this this platform at this point but  it's going into the back of the gearbox with the  

buffer tube adapter and that's getting tightened  down and that's pivoting the gearbox around at  

this point and it's pulling it rotating the  gearbox backwards or counterclockwise which  

pulls the nozzle up if that's what you're finding  what you're going to want to do is loosen the  

buffer tube up and tighten down the grip screws  first because those grips screws are pulling on  

an angle like this and if we remove this pin now  when they're pulling they're pulling the front of  

the gearbox down lower so you're gonna if it's  too high which is by far the most common thing  

we see with alignment on em fours just go ahead  and tighten the grip down first maybe tighten  

it down a little bit at a time and you can go  back and check the alignment as you go put the  

top back upper receiver back on and check it a  couple times and then then Snug down your your  

buffer tube screw and don't just go nuts on that  Snug it down as much as it needs to be but don't  

don't crank it down super tight because you might  might pull it back up usually that those methods  

will will get you lined up sometimes in more  extreme cases you may find that it just the  

gearbox can't sit in the right position in the  lower receiver this usually is because people are  

using a mismatched gearbox and receiver they're  using a different brand gearbox than the receiver  

they're using we don't really have time to go into  how to fix that issue right now but generally we  

just recommend use the same brand preferably the  same gearbox that came with the gun but at least  

the same brand gearbox so that you don't run into  that type of a situation that's generally how we  

go about fixing basic alignment alignment issues  I highly recommend using this method running the  

barrel down visually check how it lines up with  the nozzle because it's going to make it makes  

it much easier to pick up on misalignment then  the way it's been done in the past thanks for  

watching guys I hope this was helpful to you  if you have any questions or comments be sure  

to leave them in the comment section below and we  look forward to seeing you guys out on the field