Page 1 of 3 123 LastLast
Results 1 to 15 of 44

Thread: Bam bolt unlocking

  1. #1
    Inactive Member

    User Info Menu

    Default Bam bolt unlocking

    I have only had my Bam 50 for 2 weeks or so, I have noticed everthime I pull the trigger the bolt would turn anticlock wise by about 5 degrees. Is it normal? Also, the thing is less accurate is than expected (8mm CTC with most pellets from 10 m), worst than my R800 CO2 rifle. IS something wrong with my gun? I don't really have much experience in it and the internal stuff is hasn't been touchede at all.
    Sign Up To Air Rifle SA Forums

  2. #2
    Inactive Member

    User Info Menu

    Default

    Stopper,
    tighten the screw at the side of the bolt, but check first to make sure the spring and little ball is still in place.
    If there's a mussle break on the rifle, or has a silencer fitted, you've got to make more than 100 % sure it doesn't interfere with the exiting pellets. Sometime it doesn't even touch but still throughs the pellet off course.
    Good luck
    Sign Up To Air Rifle SA Forums

  3. #3
    Inactive Member

    User Info Menu

    Default

    "Stopper,
    tighten the screw at the side of the bolt, but check first to make sure the spring and little ball is still in place. "

    As in Parts 8a 9 11 and 12?

    I will try taking the suppressor off (doesn't really work anyway). I know the high pressure gas can interfer with the pellets in a supressor (free bore boast), worrth a try....

    Can it also be that the gun is shooting too close to sonic speed (I understand the BAm is rather fast out of the box)? I don't have any heavy pellets on hand (I have TS10 but Gamo pellets suck), Tried RWS GECO, AA field, Crosman Powapel, CZ LUX and most are on the light side anyway...... [br][img:width=200&height=322]../../Deadlinks/public/1156145193_357_FT23362_untitled_.jpg[/img][br]
    Sign Up To Air Rifle SA Forums

  4. #4
    Sharp Shooter

    User Info Menu

    Default

    Hi Stopper,

    The BAM's have a choked barrel causing inaccuracy with most pellets that are tight fitting. I have tested most pellets with my BAM and the best fit are the Crosman Premier 10.5 grain heavies which are available most anywhere. I shoot one hole groups consistanly up to 20m and 1/4inch groups at 30m+. You will be amazed at the difference. If you need more help you can also speak to Warrick.
    Sign Up To Air Rifle SA Forums

  5. #5
    Sharp Shooter
    Doctor BAM

    User Info Menu

    Default

    Stopper
    Swannie is right in identifying the possible cause of the problem, and this is all contributing to the inaccuracies.....
    What you must do as a first priority, is to get good quality JSB's or AA Field of at least 10gr and heavier.....
    What is even more important, is to shoot the pellets over a chrony to at least know what your power levels are.....!!!
    No use fighting a monster if you do not know what size it is.....
    My suggestion would then be to down-power the rifle to at least 15ft.pounds to give it a chance to settle in before you condemn it to accuracies lower than you CO2 rifle......!!!! The down-powering is done by releasing all the air out of the system, opening the receiver from the back.........and, ........and......., and finally adjusting part 38 to as little as possible striking length...... Swannie is an expert at this and he will guide you to much better consistency through improvements..... I suspect the rifle is shooting at least 1100 ft/second with the pellets you are describing....
    The thumb-hole twin-sister of your rifle took a starling at 27m firing from the shoulder with a Tasco 3 to 9 X 32 scope, which is proving to be a deadly combination.....

    Malan :smokin :drool :jump3
    Sign Up To Air Rifle SA Forums

  6. #6
    Inactive Member

    User Info Menu

    Default


    a few things may help.

    clean ur barrel
    use chrony to check the consistency .
    use quality pellets .
    adjust the trigger pull .
    Sign Up To Air Rifle SA Forums

  7. #7
    Inactive Member

    User Info Menu

    Default

    Oh yes, I need a Chronograph that picks up pellet speeds (my ChronoTech gets the velocity from 1 out of 10 pellets, rims fire and center fire OK), HWich chrono should I buy?
    Sign Up To Air Rifle SA Forums

  8. #8
    Inactive Member

    User Info Menu

    Default

    Stopper, Not 8a. Only 9, 11, 12

    8a must always be tight. Good idea is to use a half drop of lock-tite on 8a.
    Sign Up To Air Rifle SA Forums

  9. #9
    Sharp Shooter
    Doctor BAM

    User Info Menu

    Default

    Stopper
    Be sure to only use the BLUE Loctite product for the application....., since you will have to undo the screw at some stage later..... The RED is only used under special conditions and where you can heat up the part to release it... When tightening parts 9, 11 and 12 you only want the ball-bearing to engage slightly on the shaft, which has a notch in it to prevent the bolt from turning....

    Malan
    Sign Up To Air Rifle SA Forums

  10. #10
    Protea FT Team '07/'08/'09/'10/'11/'12/'13
    National FT Champ '09/'13

    User Info Menu

    Default

    Stopper, try the little chrony that you attach to te muzzle with a elastic band, called "Combro MK4".They are specially designed for airrifles and gives you ft / sec and energy in ft.lbs or m/ sec and energy in joules / gms.

    They work wonderfully, and I got mine from Target Specialists.
    Sign Up To Air Rifle SA Forums

  11. #11
    Inactive Member

    User Info Menu

    Default

    Morning Piet. Nice to see you surfaced again.
    Sign Up To Air Rifle SA Forums

  12. #12
    Inactive Member

    User Info Menu

    Default

    I went thome and tried to sort out the problem and here is the feed back.

    THe bolt unlocking: turns out the bolt is actually slightly off center when the little ball clicks home (bad workmanship?) so if I turn the bolt all the way clockwise, it will turn slightly to click home upon firing everytime, doesn't seem to affect accuracy......

    Suppressor: I took it off and it seemed to help slightly and hell, maybe the tiny stock supressor doesn't work that well but it did kept the noise to acceptable level, Now my ears hurt (I shoot indoor)!

    Pellet weight: I eventually tried the TS-10 and the accuracy improved a greatdeal. I think it is just that with normal pellets at about 8-8,5gr, the velcoity is about the speed of sound and accuracy suffers. WIth TS-10, the group is now 3mm CTC instead of 8mm. The group will probably improve further if I get better heavy pellets like JSB and H&B but I think I need to down tune it and make it my HFT rig anyway (yeah right, who is shooting HFT).

    I also found the loading of certain pellets (flat ones) is no very smooth, part of the pellet would get caught on be the rough part on it way to the chamber (you can see its nose tipping up), maybe deformation is a problem?

    How much is a "Combro MK4" anyway?

    Thanks guys!

    Sign Up To Air Rifle SA Forums

  13. #13
    Inactive Member

    User Info Menu

    Default

    Stopper,
    I've made an insert in the chamber using very thin copper shimming material which I glued in. Now the pellets slide very smoothly.
    Sign Up To Air Rifle SA Forums

  14. #14
    Sharp Shooter
    Doctor BAM

    User Info Menu

    Default

    Stopper
    Do not worry about the slight misalignment of the bolt not being vertical when firing.... The point is it must be clicked in by the ball bearing and spring when firing.... It seems as if you turn it too much clockwise when pushing it home....
    As far as noise is concerned, please get yourself a good noise suppressor before the neighbours remove you and the rifle from the premises.....!!!! I can only imagine the noise if you are shooting (most probably faster than the 1100ft/sec) indoors......!!! The answer is to downtune the rifle as per my previous thread..... At that rate of speed you will probably only get some 25 decent shots to be fired....!!! No wonder accuracy is up the pole..... Read Enzace's thread on accuracy with the BAM to see what can be achieved....... You will find that under the PCP Forum.....!!!!!!

    Malan :awais :claphead at
    Sign Up To Air Rifle SA Forums

  15. #15
    Inactive Member

    User Info Menu

    Default

    My 2 cents worth, clean the barrel, pull through a string from a mop.

    I had great accuracy from Crosman Premier Heavies, but better accuracy from JSB Exact and Air Arms Fields. Word is too that CPH lead foul the barrel quickly.

    With domed pellets I also had problems feeding the pellet, I had to use 2 hands when feeding pellets in, one finger on the pellet skirt to stop it tipping up when the dome hits the rough part, and the other hand to open and close the bolt.

    If you adjust the hammer striker screw out to reduce the distance between it and the valve stem, don't expect to be able to fill up to 200bar again, there will not be enough power in the hammer blow to open the valve and you will get valve lock.

    I'm not saying its the safest method, but I used to release air from the cylinder by slowly loosening the fill nipple with a No 16 spanner, to allow the excess air out.

    Then you need a chrony and find out your sweet spot (a region in which you have a nice flat shot-to-shot velocity curve) and then determine the fill pressure at the beginning of the sweet spot and don't bother filling abve this pressure.

    Don't be surprised if the fill pressure is only 170bar or less, just think of all the air you'll be saving and how many more fills you'll get from a SCUBA tank.

    Lose the muzzle brake thingy, its not well aligned, you're better off replacing it with one of Caspers silencers or just putting up with the noise.

    cheers
    Martin
    Sign Up To Air Rifle SA Forums


Similar Threads

  1. Hot Bam MZE BAM B22
    By mze in forum Airgun Discussions
    Replies: 52
    Last Post: 25-10-13, 08:22
  2. Better cocking bolt for BAM B51
    By malan128 in forum Airgun Discussions
    Replies: 6
    Last Post: 02-06-08, 15:36
  3. Bolt on S4x0
    By JTK in forum Airgun Discussions
    Replies: 5
    Last Post: 06-04-08, 14:10
  4. S400 bolt
    By avion in forum Airgun Discussions
    Replies: 7
    Last Post: 07-04-05, 22:26

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Friends of Air Rifle SA