[Blain]

I am going to swap out the flash hider on my M14 for one with a bayonet lug. My only question is, am I liable to notice a change in zero for elevation? I imagine, since the front sight has to come off, that there might be a slight change in windage, but how would elevation be affected?

Also, I have never swapped out a flash hider before, though I do have the pliers. Anyone want to dumb it down for me and give me a quick tutorial? If there is minimal change in zero for elevation, I'll swap it out right now!

 

[steve12]

I did on mine when I swaped out USGI flash hiders. Both were reamed to NM specs.

 

[jameslawson71]

The only way to find out is to do it. Make sure the new flash hider goes on straight. If the edge of the bullet touches it you can be sure of a change in something (Thats why they are reamed, but they still need to be straight). Be careful with the little castle nut screw. Dont torque it down too tight. Its easy to strip. Ultimately there could be a change is so-called "barrel harmonics" regardless of everything else and that could lead to a change in zero...

 

[ripsaw]

Flash

Oil and remove set screw in front of sight that holds castle nut in place, unscrew castle nut counterclockwise, tap lightly on back of flash suppressor with rubber or rawhide mallet, best place is lug, unscrew castle nut as you go, move nut a little move suppressor, repeat until clear of barrel, gently as not to mess up threads on barrel. Reinstall new one in reverse order. There might be some change in POI but negligible if sight is same size.

 

[Eagle 1]

I didn't see any elevation change when I swapped FS, only windage. YMMV.

Eagle 1

 

[dwight55]

Because the front sight on the new flash hider is not on the absolute "exact" same place (we're talking 1,000ths of an inch)
you should expect some "windage" movement, either left or right on your point of impact.

Look real hard at the one you are taking off, . . . try to make the one you are putting on be in the same position, . . . and you should be fairly close.

I did a 25 meter battle sight zero on mine when I did what you are doing, . . . my new setup was shooting 3 inches to the left. All you can do is re-zero your sights, . . . which I did. I started my moving the front sight verrrrrrrrrrrrrrrrrrry slightly to the left, and moved it within 1/2 inch, . . . then I just adjusted my rear sight, . . . all is cool.

Your height should not change, all things considered.

May God bless,
Dwight

 

[Blain]

Hmmm, I removed the set screw, but the front sight still won't budge. And I have no idea of how to use the castle nut pliers. I don't know how they are supposed to grab on to whatever they are supposed to grab on to. Pics or more detailed description might help!

 

[82nd ABN]

The little claws on the end of the plier goes into the section of the nut that is cut out. Hence the name castle nut. Looks lime the top of a castle wall. That's how the plier grabs the nut. Did I just say that? Anyway one claw goes into the opposing side of the nut and that is how torque is applied to turn the nut. As the other gent mentioned turn it and then tap the fh towards the muzzle it will move until you need to loosen the nut again until it comes completely off. Be sure to remove the small set screw holding it in place before you start. A word of advice. Don't get frustrated if it won't budge. If it's a sai rifle, for some reason many members have expressed that they don't move! I don't know if loc tite was applied to the threads or what but some of them can be a PITA to get off. If yiu need a pic of the plier in action let me know via pm and I'll lost one here on your thread.

 

[Blain]

How do you get that tiny set screw out that goes diagonally through the flash hider?

 

[dwight55]

That one is up front, over the barrel, . . . and takes a 1/16th allen wrench. I've been told there are metric ones too, just make sure you get the right wrench.

May God bless,
Dwight

 

[Blain]

I took that one off, the one in the front sight. But it looks like there is another tiny screw that is on the top going in diagonal when you're looking from the rear of the flash hider.

 

[Night Stalker]

The only way I can see a problem is if there is a dif. in the high th of the flash hider.

 

[dwight55]

Blain,

Look at the picture below. The little wrench to the right is the one that you have to take almost completely out (I take it all the way out and lay it aside, carefully so as to not lose it).

Then you can loosen the castle nut, . . . tap the back of the bayo lug, . . . loosen the nut, . . . tap the lug, . . . till it comes off.

The wrench to the left is the one that removes the front sight.

May God bless,
Dwight

 

[Blain]

That helps a LOT!!! Thanks so much. How do the wrench clamp on?

Thanks again!!

 

[Al Mack]

I didn't see it mentioned, but you need a gas cylinder wrench to make sure you don't twist any thing when you are torquing the castle nut. You'll get it done! Then take it to the range and re-zero.

 

[Blain]

I didn't see it mentioned, but you need a gas cylinder wrench to make sure you don't twist any thing when you are torquing the castle nut. You'll get it done! Then take it to the range and re-zero.

Thanks for the tip, I do have that wrench.... what I DON'T have is an allan wrench for that tiny hex screw! I have one for the larger one on the front sight post, but with all of my allen wrenches (and I have a fair selection) I can't find ONE that will fit the tiny hex properly. All are either slightly too large or slightly too small! Grrr... What size is supposed to fit it again? 1/32?

....guess a trip to Home Depot is in order then...

 

[Blain]

Update!!!!!!

Well, thanks to the generous help on this forum, I swapped flash hiders....only there's one problem...

The rounds seem to be skimming the top of the flash hider (it's a non NM). I can see where it looks like the rounds have stripped the finish, or left copper streaks. In addition, the flash hider is a little loose now, and has some play / wiggle when gripped where as before there was none and it was tight.

In conjunction to all of that, when I took it out to check my 25/250 meter zero I was hitting 14 MOA LOWER than before, where as before I was DEAD on for my 250 meter zero at 25 meters....

Could the rounds clipping the flash hider be causing that? How can the flash hider be installed crooked? The splines line up directly with the grooves in the barrel, they lock right in, you can't really adjust them!!

Any help would be GREATLY appreciated, as before my rifle was perfectly zeroed in and now it's a mess.

Thank you.

 

[High Hat]

I'm going through the same problem with a Bush rifle I just purchased. The solution I'm going with is a hooded gas lock front sight and a Vortex direct connect flash suppressor from Smith Enterprises. The front sight is well protected and the Vortex flash suppressor wants to turn tighter from muzzle blast. It looks like the rifle will end up 11/2" shorter overall. The only downside I'm aware of is a shorter sight radius. I expect most of my shooting to be 300 yards or less, sight radius shouldn't be a problem. I hope this helps you.

 

[Blain]

Well, I appreciate your input, but I know there MUST be a way to install this flash hider so that there are no issues!

 

[M1AallTheWay]

...I swapped flash hiders....only there's one problem...

The rounds seem to be skimming the top of the flash hider (it's a non NM). I can see where it looks like the rounds have stripped the finish, or left copper streaks. In addition, the flash hider is a little loose now, and has some play / wiggle when gripped where as before there was none and it was tight...

How can the flash hider be installed crooked? The splines line up directly with the grooves in the barrel, they lock right in, you can't really adjust them!!

Any help would be GREATLY appreciated, as before my rifle was perfectly zeroed in and now it's a mess.

Thank you.

Apart from violating the old rule "if it works, leave it alone", how about the FS being a little loose now. When you installed it, did you have to use some force, such as a rubber mallet, to get it on, or did it slide on easily? Was it tight before because you tightened the castle nut, or was it already tight before that? The alignment of the FS will generally be determined by the splines if they're all tight in the barrel's grooves. If they're not tight, any wobble will have the FS shifting position from shot to shot. And even if it feels tight when you grip it, forces applied by the expanding gas are considerably more.

Moreover, consider where the FS contacts the barrel. The splines in the grooves contact at the back end of the FS assembly, but the muzzle passes through that and the space the castle nut fits into and presses against the rear of the FS itself. Inside that is a recess which receives and encloses the face of the muzzle. If the back and front ends of the FS are not perfectly aligned, that recess will push the front of the FS in some direction away from dead center. I had that happen with an SAI muzzle brake; you could see the brake slide on straight but when the muzzle reached all the way in, the brake would be forced to tip up. An SAI FS alignment gauge just barely made it through without contacting the mouth of the brake (which was thus still within spec according to SAI). But the mouth of the SAI brake is the same size as a NM reamed FS; if it was the size of a standard FS, I'm not sure I could even have gotten the alignment gauge in without damaging the barrel. And in any case, the bullets would have clipped the brake on the way out, just like you're experiencing.

The Reader's Digest version is that your new FS may be defective, causing an alignment problem and bullet contact.

...but I know there MUST be a way to install this flash hider so that there are no issues!

Well, maybe not that FS. GI4 With my SAI brake, I eventually gave up and switched to an SEI USCG brake.