Is it a Bent Barrel?

Discussion in 'Gunsmithing' started by CTcaleb, Dec 12, 2014.

  1. CTcaleb

    CTcaleb New Member

    Hello all, I am new to this forum and look forward to hearing feedback and learning from other Marlin enthusiasts. I consider myself a rifle enthusiast with a basic knowledge of firearms and an above average shooting ability. Even though I'm a fairly avid shooter with great appreciation and respect for firearms, by no means am I an expert or scholar in the subject.
    Three years ago my father gave me a Marlin 336 for Christmas to use as my primary hunting rifle. It's a beautiful gun that dates back to the 1950's and doesn't appear to have seen much use in it's lifetime. The only imperfections in the rifle are a couple screws on the receiver are very slightly scored/stripped, other than that the rifle is pristine. It really is a beautiful rifle.
    Unfortunately, the rifle is quite innaccurate and I am not comfortable using it to hunt. After spending several weekends with the rifle that year I was unable to zero my shots on target. All rounds were a few inches high and equally left. Not wanting to alter the original condition of the rifle, I chose to add a Williams peep sight to improve accuracy. Cranked all the way down, the Williams doesn't seat flat on the top of the 336 receiver, so I ground out the inside edge of the peep so it sits flat on top of the receiver in its lowest possibe position (I'm far from a gunsmith or metal worker, but I was quite pleased with my modification to the sight, I looks like it was made to fit the reciever). I replaced the front pin a couple times increasing the height with each pin. Despite these changes the rifle continues to shoot high and left.
    I'm not sure if there's a possibility of a bent barrel. But the other thought/possibility that's been on my mind is an improper seating of the barrel into the receiver. As mentioned earlier, the only imperfections in the rifle are a couple screws on the receiver that are very slightly scored/stripped. I'm wondering if someone took the rifle appart and did not reseat the barrel correctly. Any thoughts on this possibilty?
    Resolving this problem has been on my mind for the last two years and I'm ready to tackle it. I expect that I'll have to send the rifle out to be serviced and fixed by a reputable gunsmith and was hoping someone might be able to recommend someone in the vicinity of southwestern CT. I also suspect that might be wishful thinking and am perfectly willing to send the rifle further away. Although, I am quite handy and would be willing to further inspect on my own with guidance.
    I look forward to reading any feedback on this issue. Any recommendations would be greatly appreciated.


  2. MattNH

    MattNH Well-Known Member

    I'm interested in following this, to see if you can get it straightened out. But I'll ask the obvious (to me) questions.

    So with the original sight, high and left, but consistent?
    Changed to a peep, same high and left, but consistant?
    Adjusting sights to move to zero, always high and left?

    Are you using the same ammo all the time?

  3. greyhawk50

    greyhawk50 Well-Known Member

    First off; Welcome to the Marlin Forum.

    I'm curious about your answers to MattNH's questions.
    Although possible, it's not likely that the barrel is bent w/o there being some external mark or indication of a traumatic incident.
    I'm not a gunsmith nor have I ever seen a 336 barrel removed from the receiver. Most center fire rifles have the barrel screwed into the receiver and set in place to create the proper head space. Maybe someone on here has the answer.
    I've owned numerous 336s over the years, however there was one 1986 model that had a problem with the barrel. The sights on the barrel were not at top dead center. They were cw by a few degrees. Almost like the barrel wasn't screwed in far enough. Didn't notice any head space problems. Didn't notice the barrel being canted until I mounted a set of Ghost Ring Sights on the receiver and they wouldn't dial in. With the factory sights both being on the barrel, it wasn't a problem. Also no problem when I mounted a scope on it.
    If you find the answer, please inform us. Curious minds need to know.
  4. CTcaleb

    CTcaleb New Member

    Thanks for the responses, I really appreciate the questions and interest. I haven't shot the rifle since I gave up on sighting it in a couple years ago. There definitely aren't any obvious marks or indications of trauma to the barrel or any other part of the rifle. I'm going to shoot it this weekend to give an accurate response to your questions.
    As for how the rifle shot with the original sight; it was high and left, but not consistent. It remained high and left with the peep sight and with taller front pins. I don't recall ever having any tight groups, with the original sight or peep. It also seemed as if the accuracy wandered further as the barrel heated up, but I couldn't fully convince myself that was the case.
    I will shoot it again this weekend and get back to you.
  5. hombre243

    hombre243 Well-Known Member

    Caleb, not to doubt your ability in any way...I wondered if you may be resting the barrel on a hard surface, instead of resting the wood forend on the rest. (providing you are using a rest.) Laying the forend on a soft rest, halfway back to the receiver will help eliminate jump.

    By your description, after replacing the sights and getting almost the same pattern/groups I can't see the problem as being mechanical. But, it was just something that popped into my head and I thought I should ask.

    Good luck.

    PS Can you ask your Dad about it? Is the barrel leaded up or fouled in any way? Very strange problem.
    Last edited: Dec 16, 2014
  6. CTcaleb

    CTcaleb New Member

    I apologize for the delay, I didn't get a chance to shoot until this past weekend. Thanks again for the questions and shooting tips.
    One important thing I did realize while shooting: I was out of practice, especially with iron sights. Since putting the 336 away, for the first time in my life I've been using a scope, mounted on an X-bolt, which I also have not shot this year. It took a few rounds before I was able to get a tight group, high and left.
    Shooting from a soft rest at exactly 50yds, I was high 5", and left 4". With the Williams peep sight, I zeroed the windage (which does not line up over the notch in the rear iron sight). I was also able to lower the elevation a hair. After going through the 35 rounds I had, I am still hitting 3+" high at 50yds (my groups were also loosening up a bit).
    At this point, the first thing I need to do is shoot the rifle quite a bit more. I was very disappointed with my shooting and need to improve that before I can accurately assess the rifle. Although, I am sure of the problem I had before putting it away a couple years ago.
    A friend of mine who is an Army veteran is going to shoot with me at some point in the next few weeks. At that time I hope to have an accurate assessment of the rifle to report. Thanks again for the input and suggestions.
  7. Gumpy

    Gumpy AKA Richard Prestage

    It's good to hear from you again, CT! I thought we had lost you! For sure let us know what you discover. This has been a headshaker.