Dear Members
I want to straighten and lenghten a CZ 550 bolt handle. Ive got replacement bolt handles, need to cut and weld these onto the original bolt handle. I am in Zambia and dont have access to a gunsmith who has a heat sink for this bolt. Please can you advice how i can proceed without a heat sink if possible, or where can i get one. Can a machinist turn a copper rod and make one. What else can one use to replace heat absorbing paste. Thanx in advance

I have found powdered limestone to be a great heat protection, put inside and around the bolt when welding.

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I turn them on the lathe out of 1018 or some other buzzard grade of steel suitable for high pressure hand railing or high performance pig fences. Then I wrap the bolt body with toilet paper, wet and weld. I re-wet the toilet paper every 5 minutes or so. The color seldom moves more than 1/2 inch up the body.

Thanks daune. As always a great help. The welding will be in distal third of the bolt. Will just filling the bolt cavity with heat control paste and applying the same on surface be enough to prevent softening of the rear recoil lug and prevent scaling of the threads.

Just hold the darn thing in the vice and do the job. The bolt won't get hot enough to do any harm unless you put the torch on it and go for coffee.
I have a set of aluminum (aluminium for our British friends)jaws with a "U" milled in them just for holding bolts. The aluminum is an effective heat sink and it is unlikely that even the cocking cam with get hot enough to soften any.
Once you are finished welding, just run water over the bolt body, near the handle, to cool it down.
Holding the bolt in aluminum jaws like this, I have welded handles with oxy-acetylene with no significant issues except for annealing the cocking cam. This is easily re-hardened anyway. Regards, Bill.