1 piece vs 2 piece bases

Discussion in 'The Basics, Starting Out' started by Idahoan, Feb 28, 2011.

  1. Idahoan

    Idahoan Member

    Dec 18, 2010
    Is there any practical advantage of a 1 piece base over a 2 piece base?

    I understand that the 1 piece (if machined properly) pretty much guarantees the rings will be aligned properly and minimize stress on the scope, but does it do anything to the rifle itself?

    I imagine that by attaching a 1 piece base it could theoretically add stress to the barrel if it expands or contracts differently from the barrel it's attached to.
  2. SBruce

    SBruce Well-Known Member

    Oct 31, 2009
    They used to say that a properly machined 1 piece base would actually help "stiffen" the action, or help keep it from flexing, and thereby increase precision........? Don't know if that's true or not.

    One advantage of a two piece is more room to see into the action and easier to get in from the top for cleaning sometimes.

  3. Outlaw6.0

    Outlaw6.0 Well-Known Member

    Feb 18, 2010
    You both make good arguements, I think the OP hit it on the head when stating (when machined properly), if not, the fit could be uneven & when torqued, theoretically could cause undue stress/torque on the receiver. Even when using 1 piece it's still a good idea to at least check ring alignment to determine if lapping is necessary (if you aren't using the Burris rings w/inserts). Call me overprotective but 2 piece bases scare the heck out of me on big, hard recoiling uber magnums, just seems weaker in my mind, I guess a guy could pin them to the receiver, that would make me feel better.

    I am in no way trying to say 2pc bases are inferior, just posting my thoughts!
  4. VarmintGuy

    VarmintGuy Well-Known Member

    Jan 24, 2008
    Idahoan: I use both types of ring bases - the one piece type and the two piece types.
    I have never had a problem with either "coming loose" or failing in some fashion.
    Now to "correct" some perceptions YOU may have about the one piece base, fist of all - the ONLY "alignment" that the one piece base can "guarantee" like you suggest is the rings SHOULD be at the SAME LEVEL in a one piece base.
    The actual openings of the rings can still be out of LINEAR alignment!
    How YOU correct this is when you are setting up your rings on the one piece base you get out your heavy steel rod lapping tool and use IT to align the rings to EACH OTHER!
    How you do this is to take the top half of the rings off the bottoms after the rings are set in the one piece base.
    Lay the heavy rod into the bottoms halves of the rings and physically align them and tighten them down IN ALIGNMENT with each other.
    Then lap the rings - THIS guarantees them being in alignment - not the one piece base.
    And another point - the one piece base is NOT attached to the barrel - it is attached to the action and the barrel and action should remain pretty much in alignment even when they cool or heat at different rates.
    I have never traced an accuracy problem to the action and barrel expanding at different rates.
    This could be so - but a heated barrel compared to when its cool is often cause for MINOR changes in bullet impact not significant loss of accuracy just slightly different points of impact as barrel temperatures change.
    This has nothing to do with ring bases.
    To minimize "torque" on a scope one must precisely align the rings to each other this is done NOT with the type of ring bases used but by aligning, locking down and then lapping the rings.
    Lapped rings impart no twisting torque to the scope.
    And this, when I set my rings into the bases (both types) I use a large carpenters square to SQUARE the rear ring to the exact axis of the rifles bore.
    If you can visualize the rear ring place a carpenters square on the front edge of the rear ring and use it thusly to exactly make this surface perpindicular to the Rifle bore.
    This is a little tough to describe in print but is easily done with your Rifle held in a Rifle cradle (gun vise) and placing the carpenter square onto the front of the rear ring. Once the rear ring is set in and aligned THEN install the front ring and place the heavy lapping rod into the rings and lock the front ring down - then lap them.
    If you have any questions regarding my humble attempt to illustrate this last please do not hesitate to ask me to try again explaining myself.
    I have been mounting scopes on Rifles for nearly 50 years now and about 25 years ago I started "aligning and lapping my rings" - this put an end, immediately, to all manner of strange accuracy problems!
    I highly recommend lapping your rings or try some of the "insert" type rings for your scope mounting.
    Hold into the wind
  5. RDM416

    RDM416 Well-Known Member

    Jan 31, 2005
    Good info from "VarmintGuy". I like using one piece rail type bases. You may only have one or two rifles now, but that may change in the future. If you start out using rails on everything it will enable you to quickly and easily swap scopes from one rifle to the other without having remove the scope from the rings. Just remove the rings from the rail and re-install on another rifle. Windage will typically be close and unless you mix tapered rails with non tapered rails, elevation will be close as well. One shot to get on the target..... one shot to adjust to "0", one shot to confirm......

    I used to just cringe at the idea of removing a "zeroed" scope. Now, with rails and using the "3 shot" zero method, I think nothing of swapping scopes around.
  6. kcebcj

    kcebcj Well-Known Member

    Jan 28, 2008

    My smith mounted a Near Mfg. Picatinny rail on a rifle he is finishing for me. The receiver was found to not be perfect so the Picatinny was beded. Once done the rifle was jigged up and the rail was checked with a dial indicator to be perfect in both directions.

    I like the rails for reasons already mentioned and the Near has a lug that rest against the receiver to help prevent movement under recoil. Both Seekins and Near Mfg. make quality rails and rings. I have both.

    Picatinny rails are mounted to the receiver not the barrel as you stated. When properly mounted they would add to the integrity of the receiver. When mounting the scope the rings should be checked for alignment but with a properly fitted rail the rings should line.