(Tentative) BHO jumping spring fix

[Parson Julabee Jones 32]

I've been shooting some hot reloads in my converted S12, and was surprised, when I tried to bring the bolt into battery today, to find it locked back. A quick look about the receiver showed the BHO tab was missing. And of course, the BHO had risen in the receiver and action, and was locking everything back.

 

That was easily enough fixed, and I soon had the bolt loose and closed...but the question remained, how to keep the spring from jumping out again and again?

 

A careful examination of the spring and BHO showed that the little triangular cut-out I had filed in the BHO for the short end of the spring to rest in, was "V" shaped, with sloping sides and too little depth (which is to be expected since I used a triangular file).

 

So, as a fix, I used a hack saw and sawed a square/rectangular kerf in the former "V" shaped cut-out. I cut deeply enough that the top of the spring, when installed, actually sits lower than the top of the kerf edges. The Spring diameter and the width of the hacksaw kerf are a perfect match, in fact, one needs to check and make certain the spring is resting in and bottomed out in the kerf during installation.

 

It's a silly simple fix, and time will tell of course, but I believe this will prove to hold the spring much better than my formerly filed cut-out. I do not like my guns failing, even over BHO springs.

[JunyardDog 2]

I notched mine too as shown in one of the CSS videos...did it a bit deeper and put a bend in the spring. Mine's a new gun with less than 200rds but no indication of any problem so far.

[ewoketeer 35]

It's merely conjecture on my part, as I don't have a BHO on my S12--might it be better to drill a hole where the notch would be, so as to virtually eliminate a chance of the spring coming off due to recoil?

Edited July 19, 2011 by EWOKETEER

[glennhmd 23]

Confucius said... "a picture paints a thousand words". OK. i'm officially confused. it wasn't him.

 

but a picture would surely be most helpful.

[evlblkwpnz 3,418]

PJJ,

What type of hammer do you have and has any work been done to it?

[BitBasher 11]

I have had this issue, and after a lot of research on my gun I found that the spring alone wont solve the problem. I will explain my observations, but as the tolerences for saigas change I cannot mage guarantees for other folks. I am not a professional gunsmith.

 

The BHO resides under the rail on which the bold carrier rides. Normally, when pressing the BHO the upward travel is stopped by the top of the BHO meeting the rail. However, in my case, as a result of slightly too much metal being removed from the right side of the hammer during the conversion process the BHO could tilt about 15 degress side to side when pressed.

 

This play meant that when pressing the BHO up, if you pulled outward when you did it, which is a fairly natural motion, the top of the BHO inside the gun would tilt to the left and could clear the rail allowing it to slip entirely up into the gun. As far as I can tell this is the only way the BHO can clear the rail and end up entirely in the gun.

 

This can happen whether or not the spring is still in the proper place on the BHO.

 

I fixed this by using JB Weld to affix a 3/16" stainless steel washer to the left side of the BHO as a spacer to reduce the amount of play, or extra space, along the hammer axis pin. I then polished down the washer and used a jewllers file to fit the part to my hammer axis pin so that it did not cause any extra friction, and reassembled.

 

The end result is that the BHO does not tilt nearly as much and now cannot physically be pressed up into the reciever because the rail acts as a stop. I still recommend notching the BHO to keep the spring captured, but I do not feel the two issues are directly related. The BHO cannot do this unless too much material is shaved off the right side of the hammer.

 

Or, you know, ignore me, I may be insane.

[Parson Julabee Jones 32]

My hammer is a G2, and hasn't been altered save for slight reprofiling and polishing of the top. In fact, I've wondered when reading that TAPCO G2's need to be ground in answer to folks just starting or planning their conversion. Mine was a part of the S12 conversion kit from CSS, bought about 4 months ago.

 

And yeah, when repairing my 'outed' spring yesterday, I did note that it seemed to fall outside the bolt carrier rail just a bit. I think I'll go with the JB Weld(ed) washer as well.

 

Thanks!