garyb Posted March 22, 2010 Report Share Posted March 22, 2010 Chaps.. This weekend I took my old 22lr to see a good friend of mine, who has a shed full of lathes and other metal work gear. I wanted him to a-cut the barrel down to 16" and b-screwcut it for a moderator. Ok.. he managed to cut it down and crown it... but - He said it couldn't be screwcut because the rifle bore is offset from the actual barrel.... To demonstrate this, he spun the barrel in the lathe - and sure enough if you compare the outside edge of the barrel (as it spins) with the inside edge or the actual bore, there does seem to be a bit of a jump, like a bent bicycle wheel! Has anyone in the know, managed to resolve this problem? FYI... This rifle shoots same POI @ 65yards, so I'm very happy with it's performance.. Quote Link to comment Share on other sites More sharing options...
MC Posted March 22, 2010 Report Share Posted March 22, 2010 If he turns it "Between centres" then it can only be concentric with the bore. How did he manage to crown it if it isn't central? Quote Link to comment Share on other sites More sharing options...
garyb Posted March 22, 2010 Author Report Share Posted March 22, 2010 No idea Martin... All I know is, it's pretty damn accurate after his work... the dozen rabbits currently sat in my fridge would tend to agree... He seemed to think that the mod would sit tighter on one side, and therefore clip ? Quote Link to comment Share on other sites More sharing options...
bennyblanco Posted March 22, 2010 Report Share Posted March 22, 2010 (edited) Is the barrel a fat varmint one or nice and skinny? The guy I bought my lathe off used to mount in the chuck as normal but as far back to the chamber as possible and then put a rotating centre in the crown at the far end of the bed, this would cut concentric to the bore as long as the barrel could flex a touch. He said it was comon for marlins to be very off centre. Hope this makes sense ben Is the machinist Dave Lilly? Edited March 22, 2010 by bennyblanco Quote Link to comment Share on other sites More sharing options...
garyb Posted March 22, 2010 Author Report Share Posted March 22, 2010 It's a skinny / normal one I guess! Quote Link to comment Share on other sites More sharing options...
Dunkield Posted March 22, 2010 Report Share Posted March 22, 2010 I am sure (but haven't done it) the correct way is to centre the bore the outside of the barrel, he will know how to do this but essentially you need a four jaw chuck a DTI and some patience/skill to get it running true. Unless the mod is over barrel it shouldn't be afffected. Or you can use a centre as MC said, but my understanding is if you us a centre you can damage the crown if you are not careful? Quote Link to comment Share on other sites More sharing options...
Dekers Posted March 22, 2010 Report Share Posted March 22, 2010 This is not that uncommon, the thread should always be cut to the bore and not the barrel. Tools/Lathes are available to do this, so it's not an issue then! Quote Link to comment Share on other sites More sharing options...
bennyblanco Posted March 22, 2010 Report Share Posted March 22, 2010 I am sure (but haven't done it) the correct way is to either get it running true, he will know how to do this but essentially you need a four jaw chuck a DTI and some patience/skill to get it running true to the bore not the outside of the barrel. Its a ****** to centre using a rifled hole although possible if you take your time, thats why my man started doing it the way I described. Its certanly not impossible to do either way. Quote Link to comment Share on other sites More sharing options...
Dunkield Posted March 22, 2010 Report Share Posted March 22, 2010 Yes I can imagine it is,I don't think I ever tried it but I have done other offest turning years ago. But as we know, it's all easy when you are sat behind a keyboard telling people what they should be doing Quote Link to comment Share on other sites More sharing options...
webber Posted March 22, 2010 Report Share Posted March 22, 2010 I once tought this subject, and have screw cut many barells. The turning and screw cutting should be done between centres. Not a difficult task, but does require skill and care. webber Quote Link to comment Share on other sites More sharing options...
garyb Posted March 22, 2010 Author Report Share Posted March 22, 2010 Looks like I'd better take it to the gunsmith to do then... I'm not sure my friend has all the tools required! Thanks chaps Quote Link to comment Share on other sites More sharing options...
al4x Posted March 22, 2010 Report Share Posted March 22, 2010 this isn't the same .22lr you were using on our outing Gary that would have been more effective had you thrown it at the bunnies Quote Link to comment Share on other sites More sharing options...
Beardo Posted March 22, 2010 Report Share Posted March 22, 2010 SS did say to me the other day "come back Beardo all is forgiven" in relation to hitting rabbits (and in the head not the guts!) Quote Link to comment Share on other sites More sharing options...
garyb Posted March 22, 2010 Author Report Share Posted March 22, 2010 Indeed... but I was right... there was something wrong with it It's now back to shooting like a dream! Quote Link to comment Share on other sites More sharing options...
al4x Posted March 22, 2010 Report Share Posted March 22, 2010 yup there had to be either that or the barrel was bent the couple I had were all front end shot NB thank SS for the pressies he left in the back my hound found them yesterday in front of the other halfs mum who couldn't understand what rabbit foetuses were doing in the back must have reeked she picked the scent up from quite a way away and made it into the pickup withput the tail gate down to get to them Quote Link to comment Share on other sites More sharing options...
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