My BIY Muzzle Brake!

**hcpookie** · 10-09-2008, 11:45 AM

I built mine and it didn't turn out too bad. Paint should make it look better.

How I did it -

Started out with 1 1/8" steel rod.
Drill out center to 13/16"
Thread to M22x0.75 (nice to have a lathe!)
Measure outside diameter
Compute distance for notches
Cut notches with dovetail
Finish notches with 3/16" end mill
Cut parallel wrench slots
Clean up with wire wheel

I'm not entirely satisfied with the vents. The mill walked on a few of them and I think it was due to my dull cutter. I had to finish off the errors with a dremel cutter, so it isn't as PRETTY as I'd like it to be. I'm sure it will work fine. Its length adds 1.75" past the muzzle.

I also found that my 60 degree dovetail cuts just deep enough that I could not cut all the way through without enlarging the hole too much. In fact the first two grooves are a bit larger than the others, but I doubt you would notice unless you gave it a really close inspection! I wanted the edge to be beveled, so that is why I chose the dovetail. I could have done it with a ball end mill directly into the groove, but I don't have any ball end mills to play with... yes let the jokes fly!

I ran into a problem when cutting the notches. I wanted to go smaller but the smallest I had was 3/16" and it was dull. I've tweaked most of the play out of my mill so it is very difficult to turn the dials, but it shouldn't walk any more like that. I may open up the slots to make them more straight. We'll see.

Has anyone used these and can say for certain if they work? I'm real interested to get a feel for it with- and without the brake so I can say with certainty that they actually do something.

**sjohnson** · 10-09-2008, 12:57 PM

I once worked with a master machinist. We got to talking one lunch, he told me that his apprenticeship lasted almost 8 years - his proctor wouldn't pass him on until he could quickly and properly sharpen every cutting tool in the shop. Some of those endmills are tricky to set up and sharpen.

Gunter · 10-09-2008, 03:07 PM

The two wider slots should be on to to help with muzzle rise....yeah...that's the ticket....I meant to do that.

Brake looks good!

**7.62x39** · 10-09-2008, 03:37 PM

Pook, That's slicker 'n snot on a doorknob.

Nice job bud.

Sid_Vicious · 10-09-2008, 03:37 PM

Looking real good!

**hcpookie** · 10-10-2008, 12:04 AM

Thanks! I noticed that this thing will rust up REALLY fast. Not sure if that means a sign of higher iron content? Don't really know. I do know that the metal came from an old car axle, and was surface hardened and was almost glass-hard. So I believe it will be a durable part, once I park and paint it. That new 4-jaw lathe chuck really works well!

While digging through my scrap metal, I discoverd a forgotten piece - a 6-sided 1 1/8" metal bar! I remember getting this hexagonal bar and wondering what to do with it. I realize now that the flat sides will make it much more easier to cut the notches for an M60 style flash hider! I may have to do that for my 45 Win Mag build

**DPH arms** · 10-10-2008, 01:47 AM

Looks very nice!!!

We got our samples in today for our new brakes and we used the M22x0.75 thread as well. We did find that the brakes would not fit ALL the guns we had in stock. Some went on fine and other would "lock up" after about 4 turns. Did you have any trouble with the threads?

Scott

**7.62x39** · 10-10-2008, 08:08 AM

They sure are one of the finest threads I've ever seen on anything of that diameter.
Maybe they are threading some of them to 22x1.0?

**hcpookie** · 10-10-2008, 10:10 AM

Quote:

Originally Posted by DPH arms

Looks very nice!!!

We got our samples in today for our new brakes and we used the M22x0.75 thread as well. We did find that the brakes would not fit ALL the guns we had in stock. Some went on fine and other would "lock up" after about 4 turns. Did you have any trouble with the threads?

Scott

I'll take a guess that the lock-up you describe is due to the internal diameter being too small. Note the threads aren't all the way to the end of the muzzle, and the very tip of the muzzle needs to sit "inside" the internal diameter of the brake, not "behind" the brake I.D. if you get my meaning.

Therefore, if my guess is correct, the I.D. of the brake needs to be opened up just enough so the barrel tip can fit inside.

If you mark the area with a sharpie magic marker (degrease first!) you should be able to see a rub mark where it rubs off the sharpie ink. That will tell you for certain.

Now, if my first guess isn't correct, then the threads could be too shallow or tapered, with the large end of the taper toward the rear, causing the threads to work for only a few turns. I've done that before while threading things on my lathe...

ETA - I just looked at my threads and I cut mine pretty long, so the unthreaded tip is not touching the I.D. of the brake until about 10 turns. I just thought that while using a sharpie can help, you may be able to measure the point where it stops on the outside, mark it, and use something as a probe that fits inside (toothpick, allen wrench, anything) to see where that point is on the inside of the brake.

AudiHenry · 10-21-2008, 04:20 PM

can't buy that here!