Author Topic: gamo barrel question?  (Read 2756 times)

Offline shady816

  • Sr. Member
  • ****
  • Posts: 327
    • http://thehowellnet.com:82
gamo barrel question?
« on: April 08, 2010, 03:14:40 AM »
i recently was completing my cfx barrel cut and recrown number and again was disapointed to see something with the barrel that did not look good. the barrel was bored way off center from breech to crown. the bore was centered perfectly at the breech end but at the muzzle end the bore is way off center now this would lead me to believe the gun would shoot off the center of bore and would cause excessive scope correction at longer distances. now i am no expert but this does not seem correcet or am i just to picky or is this common with cheap air guns. i will post a picture tonight to better explain the issue.

Offline Magnum

  • Hero Member
  • *****
  • Posts: 1530
    • http://
Re: gamo barrel question?
« Reply #1 on: April 08, 2010, 04:17:30 AM »
That does seem weird to me, I had not see that before. Makes me wonder how they make the barrel and then rifling without twisting the barrel!

Offline RedFeather

  • Hero Member
  • *****
  • Posts: 2308
    • http://
RE: gamo barrel question?
« Reply #2 on: April 08, 2010, 05:05:52 AM »
Barrels are many times drilled out and then rifled, so a bore can be straight but off-center. You see this in some black powder barrels. The recommendation is to align the bore up/down. How did the gun shoot before shortening? If OK, then it's not a problem.

Offline shady816

  • Sr. Member
  • ****
  • Posts: 327
    • http://thehowellnet.com:82
Re: gamo barrel question?
« Reply #3 on: April 08, 2010, 05:06:30 AM »
wait till you see the photo. i think if the barrel were 5 inches longer the bore would have come out the side of the barrel, it is that bad. the only reason i would have ever know was the rifle never shot good at all the groupings were horrible and started looking for answers and saw the factory muzzle break machining was showing sign of pellets riding and digging in the inside of the break and after cutting and revieling the true end of the barrel did i notice this.

Offline shady816

  • Sr. Member
  • ****
  • Posts: 327
    • http://thehowellnet.com:82
RE: gamo barrel question?
« Reply #4 on: April 08, 2010, 05:16:37 AM »
hi red the gun never shot at all good and if you remember my post before cutting the machined end of the barrel was showing signs of pellet hitting it upon the exit of the muzzle and i think mine is to the right side not up or down and now that i think about it with every scope i mounted it always had to be adjusted way to the left to get it on the paper. not a little but alot to the left.i think this will be my last gamo for sure, everything that could be wrong has went wrong with this from piston seal all mangled up to spring cant so bad it was horrible but i will say that with new seal honed, deburred and gas ram the firing and cocking cycle is apsolutely sweet and her crony speeds are in the low 900's with no more than 12 fps deviation so i would think this rifle should be doing much better but it is not.

Offline Magnum

  • Hero Member
  • *****
  • Posts: 1530
    • http://
RE: gamo barrel question?
« Reply #5 on: April 08, 2010, 07:00:13 AM »
Low 900's and 12fps deviation is fantastic all that good work you did!:o  It would be nice if you could get a replacement  or different barrel to fit maybe  nice lothar walther if it would work?  
 http://www.lothar-walther.com/455.php ?

I also thought this was an interesting on how barrels are made   http://answers.yahoo.com/question/index?qid=20080912144531AAeNLZk

Offline shady816

  • Sr. Member
  • ****
  • Posts: 327
    • http://thehowellnet.com:82
RE: gamo barrel question?
« Reply #6 on: April 08, 2010, 07:08:25 AM »
yes sir i spent alot of time fixing and tuning this rifle and i have looked at the lothar walther barrels and in fact the .591 x 23.8 would be a almost perfect match and would work but i will have to practice threading a piece of round stock on the lathe first before i attempt a 100$ barrel replacement