312 bolt leak and seal solution question

[Relentless Holiday]

Hey all, been away fsihing in upstste NY.  Lake George and Champlain.  Great fishing up there.

Down to it,  I decided to break out the newer to me 312 as the first shooter getting back.  I notices a lot of blow back in my face so I took a dunkin napkin 2"x2" double layer piece and layed it over the breech and took a five pump shot.

The napkin piece actually flew several feet up and tore almost in half.

OKaaaay.....

So where do ya think I should start.

I had a notion of maybe removing the bolt and cleaning the neck down area real good then putting a bead of 100% silicon caulk around it then carefully carving away everything that wasn't a small bevel triangle of the silicon that could press seal onto the breech when fully inserted.  What do ya think.  My searches haven't turned up much here today.

Another though was to freeze an O-ring and sand to a very flat profile on both sides and slipping it on the bolt. 

Yeah I have no more AG money for the foreseeable future so this is gonna be a quickie DIY improvised fix.  ...Even leaking as it is it's an amazingly accurate shooter and has stolen my heart as my oldest gun (1961)...

I have no machining equipment BTW.  So making a new bolt isn't gonna happen. Obviously, neither is retooling the breech to accept an actual O-ring.

As always any help is appreciated and a donation will be made to GTA depending on the cost and effectiveness of any assistance offered by you all.

Thx

[Habanero69er]

Simple fix. With the bolt in the up position, loosen the screws & adjust the cam plate on the left side of the receiver. You want it to be snug when you put the bolt in the down position. It may take a couple attempts to get it just right, but it’s easily doable.

[Relentless Holiday]

Simple fix. With the bolt in the up position, loosen the screws & adjust the cam plate on the left side of the receiver. You want it to be snug when you put the bolt in the down position. It may take a couple attempts to get it just right, but it’s easily doable.

I don't have the gun in front of me but I can picture the plate and how it could be slid forward to keep the bolt in there tighter.  I'll be taking a look tomorrow afternoon.

Thanks a ton Habernero!

[Relentless Holiday]

Had a min to look.

Yeah I did this to myself when I removed the plate to install a peep sight.

To help anyone else who may find this by searching I found a very easy adjustment technique.

The plate is taper cut on the end to tighten up the bolt as it is locked in place.  After two attempts to guess the amount of change I just put the bolt into a bit less than half cocked position, slid the plate tight to the removable screw/pin and tightened the plate down.  Finishing the lock down on the bolt snugged it into the receiver just right.

Because the taper end of the plate is actually bent inward there is now a springy feel to locking it down and when I first start to lift the bolt handle to unlock it the handle springs open up just the smallest hair.

Perfect, tissue test shows no leaking.  :-)

Hope it helps whoever.