just bought a trw bolt from auction arms unissued, new condition. the last one i bought was trw also and dropped right in my polytech. gauged out like new and has remained so for about 2000 rounds. will see if this one will drop in when i get it. my other poly will not accept the trw bolt nor an hr bolt. my hr reweld will not accept the trw bolt. i have heard of some being just right and guess i got one. paid 70.00 freight and all for this new one. kept the old poly bolt and use it for a paper weight on my computer table. will let you know if this new one fits the other poly. i might even start looking for a good hr barrel now as my old one is shot out. has to be hr as the complete rifle is all hr and this will be passed down to my grandson someday.