02-04-2014, 07:58 PM
While this is wondering slightly off the intended topic of this thread I bought one of the 18" barrels from brownells while I quickly threw it together ran a patch down the bore and tried to chamber a round and it stuck a little, I had to hit the charging handle on the under side of my bench to extract the round and there were some marks on the case mouth my first thought was out of spec since that seemed to be going around... I scrubbed the chamber with a bronze brush an sprayed it out with brake cleaner and rounds then chambered and extracted better but it still didn't feed very well, so I did a bolt polish up and polished the feed ramps and now everything is gravy
Other than a thuroghly cleaning I did not do anything to the chamber or throat
I think one thing people forget when they are putting these guns together is that we are assembling components and not dealing with a finished and test fired product, when these barrels get made the chamber gets cut blown out with air and a go/no go test gets done most likely with a bolt with extractor and ejector removed and if it passes the barrel is good to go and gets an assembled bolt put in it and goes out of the shop
It is out job as home gunsmiths to make things work from there, one thing I would recomend I order to cheek the throat/chamber of these new barrels is to load up a dummy round and cheek it with a case guage to ensure it should chamber then with the bullet seated quite long and the ejector and extractor removed from your bolt chamber said round jamming it into the lands and let the bolt push the bullet into the case then remove bolt and tap round out from the muzzle with a cleaning rod this should give you a rough estimate of your throat profile, or you could do a chamber cast and take your measurements that way
In the end it's very difficult for even the best mind to diagnose and or solve a problem with a tangible item sight unseen through a computer screen
Other than a thuroghly cleaning I did not do anything to the chamber or throat
I think one thing people forget when they are putting these guns together is that we are assembling components and not dealing with a finished and test fired product, when these barrels get made the chamber gets cut blown out with air and a go/no go test gets done most likely with a bolt with extractor and ejector removed and if it passes the barrel is good to go and gets an assembled bolt put in it and goes out of the shop
It is out job as home gunsmiths to make things work from there, one thing I would recomend I order to cheek the throat/chamber of these new barrels is to load up a dummy round and cheek it with a case guage to ensure it should chamber then with the bullet seated quite long and the ejector and extractor removed from your bolt chamber said round jamming it into the lands and let the bolt push the bullet into the case then remove bolt and tap round out from the muzzle with a cleaning rod this should give you a rough estimate of your throat profile, or you could do a chamber cast and take your measurements that way
In the end it's very difficult for even the best mind to diagnose and or solve a problem with a tangible item sight unseen through a computer screen
Punctuation is for the weak....