Talley one piece- My lapping experience

Discussion in 'Long Range Scopes and Other Optics' started by 260nut, Jan 27, 2013.

  1. 260nut

    260nut Well-Known Member

    Messages:
    77
    Joined:
    Jan 17, 2012
    I bought these Talley mounts for my .260 build on a Remington 700 action. I searched for information about lapping and got differing opinions on everything I read. Ultimately, I chose to lap mine for piece of mind and I didn't want to chance ring marks on my new Vortex. From the pictures, you can see that this was the correct decision. This is not a knock on Talley but just an example of what can happen when you mate mass produced items that are not custom matched to one another. Being a machinist by trade, I can say that just because the Talleys are CNC machined doesn't guarantee perfection. You still have the human element involved in tool and part setup. It is also well known that 700 actions have their share of imperfections. For these reasons, I recommend lapping regardless of the make or style of mounts you choose. I think the Talley mounts are an excellent choice for a solid, affordable mounting option and lapping will ensure that they are the best they can be.
     

    Attached Files:

  2. 260nut

    260nut Well-Known Member

    Messages:
    77
    Joined:
    Jan 17, 2012
    A little more
     

    Attached Files:


  3. 260nut

    260nut Well-Known Member

    Messages:
    77
    Joined:
    Jan 17, 2012
    Good enough for me
     

    Attached Files:

  4. dieseldoc

    dieseldoc Well-Known Member

    Messages:
    170
    Joined:
    Jan 12, 2010
    Mounts will not any truer that the action, check the top of the receiver and you will find problem.
     
  5. 260nut

    260nut Well-Known Member

    Messages:
    77
    Joined:
    Jan 17, 2012
    Yes, I am aware of the problems with the action as mentioned in the original post but you can't fix that unless you redrill the holes. The easier option is lapping.
     
  6. Sully2

    Sully2 Well-Known Member

    Messages:
    2,480
    Joined:
    Feb 28, 2011
    For a 40 lb Bench gun shooting Bugholes at 100 yd...a must. For a hunting rifle shooting less than 1" groups at a hundred yards...all in your mind.
     
  7. 260nut

    260nut Well-Known Member

    Messages:
    77
    Joined:
    Jan 17, 2012
    From an accuracy standpoint, you are probably correct. However those ring marks on your $600 scope are very real.
     
  8. Sully2

    Sully2 Well-Known Member

    Messages:
    2,480
    Joined:
    Feb 28, 2011
    You got to be kidding me? Ive only got one scope that cost less than $600 and bolted down tight...what am i going to do...take it with me in a bikini on vacation??? Bolt it down...zero it in and LEAVE IT there.

    At worst your only scraping finish...not gouging the aluminum.....nothing a can of spray paint cant fix if ever need be.

    If you were using 2 piece bases they have a tendency to self align anyway....
     
  9. bruce_ventura

    bruce_ventura Well-Known Member

    Messages:
    1,106
    Joined:
    May 22, 2011
    260nut,

    That's an extreme case of poor ring alignment. I expect a poor base fit on Rem 700 actions, but that's really bad. You did the right thing by lapping.

    If you hadn't lapped the rings you would have had problems later. Either the scope tube would have had severe stress when you torqued the ring screws down, or the scope would have had less than 10% surface contact with the Tally base, or both. Its likely you would have seen a shifting point of aim with temperature changes, and the scope would have slipped under recoil, making the ring marks even worse. .

    One alternative was to bed the bases, but that's not easy with two piece bases. You have to mount both bases on a tube to keep them aligned during epoxy set. You still would have needed to lap the rings.

    FYI, Tally integral bases are machined from extruded bar stock. The cylindrical ring surfaces are extruded, not machined. You can see the extrusion marks on the ring surfaces. I always lap Tally integral bases, even when they are aligned well. It's pretty obvious when lapping that the ring surfaces were not machined.
     
  10. 260nut

    260nut Well-Known Member

    Messages:
    77
    Joined:
    Jan 17, 2012
    Thanks for the info on their manufacturing process. I didn't have any first hand knowledge on their process and was just going on things I read in other posts. Others spoke of CNC machining as if it guaranteed perfection and that simply is not the case. I am glad that I lapped the rings and felt that it only made sense to have a precision mounting platform on a precision rifle.
     
  11. 260nut

    260nut Well-Known Member

    Messages:
    77
    Joined:
    Jan 17, 2012
    I am not understanding you argument. If you choose to not lap, that is your prerogative. I don't like ring marks, so if I can take 45 minutes and a little elbow grease to eliminate a misalignment, I am gonna do it. I may decide to upgrade scopes in the future and will need to sell this one so I would like it to still be in good condition. If I damage it during a hunt then so be it, but I generally take very good care of my equipment. I see no reason to knowingly induce cosmetic damage when it can be avoided. Is it going to affect accuracy or function? Maybe, maybe not, but it is a FACT that my scope is more precisely mounted, with no stress, and more clamping surface than it would have been without lapping. The proof is in the pictures.
     
  12. 8andbait

    8andbait Well-Known Member

    Messages:
    594
    Joined:
    Jan 14, 2012
    I lap all my talleys also, it makes me feel better.

    gary
     
  13. Sako7STW

    Sako7STW Well-Known Member

    Messages:
    433
    Joined:
    Feb 12, 2004
    So you showed you lapped your rings. O.K.. What would have been useful to us is showing how and what you used to do so. I am a very big of Talley rings and I have never seen that much material needing removed from them. I hope the inside of that action is far better then the outside!
     
  14. 260nut

    260nut Well-Known Member

    Messages:
    77
    Joined:
    Jan 17, 2012
    The inside of the action is fine because I trued it and I could have reworked the mounting holes but didn't see the need when lapping serves the same purpose. In all reality, the actual amount of material removed is probably far less than it appears in the pictures. Just guessing, maybe .005-.007". I was using 800 grit compound so it's not like I was going at it with 60 grit sandpaper or something. My main objective was to show that they were not perfectly aligned. As far as what I used and the procedure, Brownells 30mm lap bar and 800 grit lapping compound. I installed the bottom halves torqued to 25 in/lbs. I let them self align to the radii. Apply compound to the rings and place the bar in them. Then apply compound to the uppers and install them only snugging them so that the bar still moves. I used a combination of side to side, front to back motion and as the bar moved more freely, I would snug the uppers a little. From time to time, I would remove the bar to check my progress and repeat as needed. It was an easy process and well worth it IMO. I did it to eliminate scope damage and for more uniform clamping pressure.