I got a few drill rifle barreled recievers which did not have the chambers welded. They just had a rod hammered into the chambers. Some came out with taps of a rod, others had to be drilled out. Most were shootable. A couple were slightly damage in the chamber neck when they were drilled out. I did'nt know it till I barreled and fired them. They had hard ejection and the cases were swollen around the neck. Other wise the bullet when down the bore and hit pretty much where it was pointed.

Unless you make a casting of the chamber, you may not know how usable it is untill you fire a round in it.