Screwcutting Annie Barrels

[onehole]

I know I joined in a topic or started one some time ago but once again after shortening and screwcutting  my Annie {20mm barrel]  it shot quite poorly with nearly all ammo. I hadn,t checked before going out to try the rifle to see if there was some relaxing of bore dimension at the point of the screw cut but indeed there was!!   A pretty basic test i know but it was plain to feel as i gently pushed a .22 bisley magnum up through and almost as soon as the pellet entered into the screw cut area the pellet loosened and before it had started to exit the pellet actually dropped out of the barrel!! I had noticed this quite a few times when cutting 1/2 unf but on this occasion I cut 5/8x18 and still the bore opened up. I will probably now sweat on a sleeve and screw cut that as i have done before but what a faf!!

Anyone know of ways around this,,,,I know Anschutz back bore their barrels but i don,t feel confident in doing this and to effect a decent crown,,,,,,,,In addition could this happen to CZ Sako Browning etc etc....thanks,,,,O

[Dellboy]

Funny enough i asked a couple of people about screwcuttin my old target rifle (22) and all three said they would but it may well shoot badly afterwards .. so it hasnt got a mod on it ...

[baldie]

Anschutz barrels are choked at the muzzle.

I've shortened plenty, and see no ill effects however.

The .22 pellet is hardly an engineered test Dave. Borrow, or by some pin gauges.

on a 20mm barrel, you would have been better with an 18mm thread.

Have never had a barrel come back that shot worse after shortening, most usually report a marked increase in accuracy. usually because the barrel is shorter, therefore stiffer, and obviously a freshly cut crown.

[onehole]

Thanks for coming on Dave,,,,,,,,,,,,,I went with 5/8x18 Dave as Lathe is basically imperial and although all the gears are in a box  to convert to metric guess I took the easy option ,,,however thought this would be chunky enough not to give the metal reason to breathe? Dave the pellet test was done several times and felt in good contact all the way up to the cut and as i said it fell out on its own from a pellets depth inside. I,m really just trying to get to whats actually happening to the metal as i have seen this quite a few times now. I,m only an amateur and bow to your professional experience but tell me this why do Anschutz back bore there screw cut barrels. I know the Match barrels are choked but not sure about all their sporter barrels?,,,,My 1710 isn,t "sorry pellet test again" but it does grip the pellet uniformly all the way by feel.Dave can you add anymore or anyone else please,,,,,,,,,,,,,,O

[D Johnson]

3 hours ago, baldie said:

Anschutz barrels are choked at the muzzle.

I've shortened plenty, and see no ill effects however.

The .22 pellet is hardly an engineered test Dave. Borrow, or by some pin gauges.

on a 20mm barrel, you would have been better with an 18mm thread.

Have never had a barrel come back that shot worse after shortening, most usually report a marked increase in accuracy. usually because the barrel is shorter, therefore stiffer, and obviously a freshly cut crown.

Agreed 

I managed to pick up an old 1427 biathlon rifle that had only ever done a little bit of indoor target work, I had it cut down by 4 inches and fitted a moderator and scope and have used it for the past 19 years for vermin control. The shortening and screw cutting had no effect at all on the accuracy of the rifle. 

[Ballistol]

 

[onehole]

Wow,! not seen this before,,,,thanks,,,,so I rest my case .. My Annie barrels defo opened up and accuracy decreased. When i say decreased it would still shoot inside 1 1/4/1/2 at 60 yards with most ammo and match ammo a little tighter but no way good enough and  a fair representation for the ammo that was used . Do not wish to be rude but some would probably think this sort of grouping is ok and fit for purpose ,,,ok I can accept that for those that can live with it ,,,I cant. Knowing this problem does exist,s I can get round it and benefit from the much improved grouping or rather I should say retaining accuracy the barrel was originally blessed with. For some this may raise many questions about threading implications,,,whose barrels may be affected in this way or perhaps not.It might not affect barrels that are made/formed by different methods,,,cut,cold hammer forged,,buttoned etc etc,,,dunno? My centerfire rifles have heavy profiles, cut rifling and are all threaded and fitted by well respected smithys on here that shoot silly tight groups and would not dare or need to bring in any questioning regarding their performance ,,,,its just my experience with the rimfire got my attention,,,,,,,,,,,,thanks for some comments guys perhaps its best left as interesting????