Hahn welded receivers can be a risky proposition. I’ve seen them work fine and I’ve seen them not work at all. Jack Martiinez built a couple of AR-10’s with them-one worked flawlessly, the other kinda worked but the bolt carrier would drag inside the buffer tube a bit. For example when Lloyd Hahn was still welding/manufacturing AR-10 lowers a buddy and I bought two. When they finally arrived at my dealer I let my buddy get first pick because I owed him a favor. The lower he selected appeared to be the nicer of the two but unfortunately when my buddy dropped in the fire control parts he discovered the tolerances were off. Turns out when the two halves were welded together the distance between the trigger and hammer pins was too short. The hammer would cock and catch with the sear but would not release. Hahn had stopped making lowers by this time and that was that. I lucked out and the lower I chose worked just fine.
By the way, gun people have been using that term “reweld” WRT to fastening two receiver halves together for decades and it’s technically an incorrect term. Unless the receiver was welded, and the welded AGAIN its not a “reweld”. I used the term forever myself until Ron Smith once asked me, “What do you mean “reweld”? Unless its been welded more than once its a weld, NOT a reweld!” I had to admit he was right.