That may be true of the current models, but as stonecreek says, all the L & A series rifles I have rebarelled were 1"x16tpi. Any limitations are strictly confined to what the smith's lathe will do regardless of thread.
The gunsmith was probably thrown off by the L57 which was metric (25mm) as well as having an oddball thread pitch of approximately 17 TPI that I understand is tedious to duplicate. Some references also show the L57 as using a thread that was a bit flattened on top.
I had two L57s rebarreled by Pac-Nor. They never even blinked. I always tell people the most expensive & slowest way to have a barrel installed is to have "your" gunsmith do it. Just send the dang gun to the barrel maker. They will properly install it with a warrantee, faster & cheaper. Just sayin'.
I’ve only had one AII rebarreled, I had Douglas Barrels do it. No question ever arose on thread size issues…None
Nice pics of what very few people ever see. The squared off tips on the barrel thread are part of the specs they were cut to. Threads come with "sloppy" fit (like the bolts you buy at the hardware store) on up to a Grade 5 Interference Fit (where the threads actually "crush" together with the male & female threads becoming the exact same dimension). Most rifle makers specify what is called a 2B Fit (what is pictured) with a runout of no more than .0002". This allows for the barrel to be screwed to the action without distorting either thread & letting the "crush" occur between the barrel shoulder & the action face. This is what keeps the barrel tight to the action & it takes very little actual force to accomplish that. I have seen BR shooters install a barrel @ the range & tighten it with only their hands. Most rifle makers today overtighten & even use thread locker on the barrel threads. I hate them for that!!
ARRRRGH! Thread locking compounds have absolutely no place anywhere around a firearm. If a guy uses thread locker on his guns he deserves to have someone use thread locker on his safe dial.
