Bm 62 Muzzle Cap To Brake

[John Ryan]

Have any BM 62 owners ever considered porting their muzzle cap to make it a brake.

 

I was comparing the BM 62 cap and BM 59 E brake and other than the ports and placement of the Gas cyl hole, it seems like the pieces were of the same construction.

 

Type E brake TOP. BM62 cap BOTTOM

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http://i9.photobucket.com/albums/a51/Rotor_/M1/Type%20E%20Garand/Muzzle%20Brake/DSCF3168.jpg

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BM62 cap LEFT, Type E brake RIGHT

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http://i9.photobucket.com/albums/a51/Rotor_/M1/Type%20E%20Garand/Muzzle%20Brake/DSCF3172.jpg

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Type E brake LEFT. BM62 cap RIGHT

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http://i9.photobucket.com/albums/a51/Rotor_/M1/Type%20E%20Garand/Muzzle%20Brake/DSCF3174.jpg

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JR

[mikebaker1129]

I would think that a good machinest could make it happen . I do not know how difficult that 62 cap would be to mill ,the steel could be heat treated and be pretty hard .

[John Ryan]

Well, I went ahead and did it. I found a machinst on the FAL files who takes custom work. Mountainman the mad machinist.

 

I sent him the brake from the BM59 E and a BM 62 muzzle cap and explained I wanted the same pattern on the blank BM62 cap.

We set terms and this is what I got a few months later.

 

I'm not sure when I will get to test it. If works as well as the BM 59 E brake I will be very happy.

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Type E brake TOP. Converted BM62 muzzle cap MIDDLE, Std BM62 muzzle cap BOTTOM

 

http://i9.photobucket.com/albums/a51/Rotor_/M1/BM%2062/Brake/DSCF4129.jpg

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Type E brake LEFT. Converted BM62 muzzle cap RIGHT

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http://i9.photobucket.com/albums/a51/Rotor_/M1/BM%2062/Brake/DSCF4132.jpg

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Type E brake TOP. Converted BM62 muzzle cap BOTTOM

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http://i9.photobucket.com/albums/a51/Rotor_/M1/BM%2062/Brake/DSCF4137.jpg

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Whole shebang

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http://i9.photobucket.com/albums/a51/Rotor_/M1/BM%2062/Brake/DSCF3876.jpg

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JR

[mikebaker1129]

John stay tuned, this 62 type E break is soon to be a item that will be available.It is in the works as we speak.

 

[John Ryan]

Jeez Mike. You could have told me and saved me the trouble.

 

I also followed the edict "Why buy one one when you can have two at twice the price".

 

Its available for "interesting trades".

 

JR

[mikebaker1129]

Jeez Mike. You could have told me and saved me the trouble.

 

I also followed the edict "Why buy one one when you can have two at twice the price".

 

Its available for "interesting trades".

 

JR

 

I did not know that you were going to have one machined or I would have let you know.

Please let us all know how effective the break you had made is ?

 

 

[John Ryan]

This is a Lazarus post. I finaly got around to testing the new E style brake on my BM62 last fall. The recoil reduction was there but it was short stroking on every shot. I supected I may have had the gas port misaligned and could not check that day. I just got back around to it couple weeks ago. This time I made absolutley sure the gas port in the gas cyl was perfectly lined up.

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http://i9.photobucket.com/albums/a51/Rotor_/M1/BM%2059%20Alpini/DSCF4699.jpg

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http://i9.photobucket.com/albums/a51/Rotor_/M1/BM%2059%20Alpini/DSCF4706.jpg

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Sure enough. Short stroking again. South African surplus would occasionaly string two together. The bolt was not coming back far enough to eject or reset the hammer.

 

I switched to the mid sized brake from Reese.

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http://i9.photobucket.com/albums/a51/Rotor_/M1/BM%2059%20Alpini/DSCF4717.jpg

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Back in action. It ran like top.

 

This got me thinking about the "booster chamber" in the tricomp and what else it does. I always thought that the BM-62 had an unported muzzle cap for asthetic ( read PC) reasons. Now I think it might have had something to do with the unported muzzle cap creating needed back pressure for cycling. ( FYI the Springfield SOCOM will not run with a standard M14 flash hider because there is not enough pressure)

 

The mid sized tri comp ran great and it also has a "booster chamber" backing up a little of the gas. What if by porting this muzzle cap exactly like the BM59 E brake I am letting out too much gas too fast.

 

I might have screwed myself her by not thnking this through enough.

 

Ideas are welcome.

 

JR

[Punch the Clown]

Hi John. Myself and Tim Shufflin did a lot of fooling around with this one. It seems that Beretta must have customized the gas port according to the muzzle device. Here is what we found. If you use the "E" pattern repro device the rifle will run fine with a standard 7.62 size gas port. Put on a tri-comp and the rifle cycles so fast and violently it fails to strip the next round and kicks like a mule. Same goes for the 5" compensator and the 62/69 muzzle cap. My BM69 clone ran fine with the muzzle cap but the recoil was punishing. What Tim ended up doing in my particular case and for those that wanted the long tri-compensator was to mod a standard BM59 gas lock screw by drilling a vent hole in it to relieve some gas pressure. That works like a charm and gives you the flexibility to change muzzle devices. Another solution is to use a Shuster adjustable plug. Unfortunately the Shuster will not fit with the 9" tri-comp. On your rifle it seems you would have to open up the gas port to use the 59E clone device and use a vented plug with the tri-comp. You can have your cake and eat it too. Stu

[John Ryan]

Thanks for the observations Stu.

 

I am getting myself confused a little here so I should restate.

 

My rifle is a BM62 in 59 dress

• Runs fine with stock 62 cap ( unported) Kicks hard.
  
• Runs fine with 5" triComp
  
• Wont run with Stock cap ported in E pattern
  

My assumption was that my BM62 gas port was too big to operate without the "booster chamber" ( in form of the 62 unported cap or 5" triComp) backing up a little of the gas for operation.

 

Are you saying Beretta had a smaller gas port on 62's because it sold them with the unported cap and they knew it would create enough backpressure to run it?

 

If so, I am having a hard time undersanding how a Schuster or vented plug would help if not enough gas is getting in in the first place. It seems to me I need to increase my gas pressure not lower it.

 

I will meausre to see if it has a 30-06 or 7.62 size port.

 

JR

[Punch the Clown]

John, it seems the design relies on back-pressure created by the muzzle device. The 59E type just doesn't create enough back pressure. You can open up the gas port but then you will have too much pressure with the 5", 9" and the '62-'69 device. That's why I suggested drilling out the gas port to use the "E" brake, using a vented gas plug for the others. You'll also find the vented plug calms the recoil down quite a bit.