Scope base measurement question

Discussion in 'Long Range Scopes and Other Optics' started by MachV, Aug 17, 2003.

  1. MachV

    MachV Well-Known Member

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    Just checkt the NF 20MOA 1 piece base on the SSRem action.Kinda tuff to get an exact measurement with it all mounted up but looks like your good to go.
    It apears they are .3 in hieght also and the slots are .4 apart,.2 gap and .2 spacer
    CJ
     
  2. chris matthews

    chris matthews Well-Known Member

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    Brent
    Badger bases are 1913 Picatinny spec- NOT Weaver. Farrell's aren't to any spec. Stick with Badger then Nightforce but I would stay away from Farrell.
    Just my opinion...
     
  3. Brent

    Brent Well-Known Member

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    Need a measurment from a BO and a NF 1 piece base (20 MOA) from anyone able. I need to know the hight from the top of the crosslots, the very top the rings set on to the point where the top of the reciever contacts... This measurement must be on the frontend of the base and not the rearend of it.

    I've got a set of Ultra High (AR15) MKIV rings and need a base that measures .250" thick or better to get the NF 5.5-22x56 to clear the barrel block on the new 30.

    My brothers 2 piece NF base measure .300" tall and just wanted to make sure the 1 piece up front did too, .300" thick would be even better than .250". I know the Ken Farrell base is .400" tall and would work perfect, I just want one with a recoil lug on it and the NF is what I'm looking at for this right now.

    Another question...

    What's the spacing specs for the cross slots on the Weaver style bases like the BO and NF use vs. the what Ken Farrell uses?

    My dads Farrell base has .400" spacing and square cut slots for his 700LA.

    Thanks a bunch in advance. [​IMG]
     
  4. Brent

    Brent Well-Known Member

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    Thanks CJ, and Chris. [​IMG]

    Anyone know exactly what the 1913 Picatinny specs are?

    Thanks a bunch. Off hunting this afternoon...
     
  5. Brent

    Brent Well-Known Member

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    Thanks Dave. [​IMG]

    Looks like .394" CTC.

    FWIW, the NF 2pc. base was not .394", it was .4" +- .001" "maybe", but definitely not .394".

    Anyone have a Badger base to check and see what it's spacing and height in front is?
     
  6. J Schulze

    J Schulze Well-Known Member

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    spacing dont really matter as long as the groove is the same dimension to fit the rings properly. INteresting no tolerance givin on the center to center dimension
     
  7. Brent

    Brent Well-Known Member

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    For me, spacing is most critical, as I want to switch a scope between two rifles and they must fit perfectly on both.
     
  8. J Schulze

    J Schulze Well-Known Member

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    ok I see what you are getting at.
     
  9. Guest

    Guest Guest

    Brent,
    I just went out and attempted to measure the BO rail on my REM700 PSS in 308. It is approx..220" tall at the front receiver ring and the spacing is about .394", best that I can measure with the dial caliper I have.
    Hope this helps some,
    Wayne
     
  10. chris matthews

    chris matthews Well-Known Member

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    Brent,
    If you have both rifles set up with Badger the scope will switch fine, even if it's a short to long action switch.
    Chris
     
  11. Ian M

    Ian M Well-Known Member

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    Brent,
    Ring height is as significant as base height for getting big scopes up off the barrel, particularly if the barrel contour is straight. Unfortunately this means you cannot always have scope clearance uniform if the barrel contours are not the same.

    Like Chris says, you can switch scopes on Badger bases regardless of what rifle and action length are involved. Makes it handy if you want to use a particular scope for various shooting tests or hunts.

    Best to get a 65 in-lb torque wrench if you wish to do this. We covered that other times but the one to get is also from Badger and it is set for 65 tightening and 80 un-tightening (is there such a term, maybe releasing makes more sense), otherwise you can't take rings off with the torque wrench. The ones sold by Leupold are 65/65. Of course any 1/2 inch socket or wrench will take the suckers off quick.

    I do this a lot, matter of fact have several Near bases also and they let me switch back and forth with Badger bases with perfect uniformity.

    What are you hunting? Moosa? Good luck, hope you get into a monster.
     
  12. Brent

    Brent Well-Known Member

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    Thanks for all the help guys. [​IMG]

    It doesn't sound like the BO base is tall enough for this 1.350" dia. barrel in the block, was hoping they were in the .300" high range as well...

    NF has a nice base that will fit the bill, have to do some interchangability tests on the NF and Farrel's when I get it mounted up.

    I mounted the MKIV rings on the NF that's on the 300 Ultra the night before I left hunting, bore sighted it in camp with the eyeball boresighter [​IMG] and fired 7 or 8 rounds to verify my zero. Ended up being 2" rt. and .25" high at 100yds is all, was pretty quick.

    Chronoed a few loads I figured should be safe enough on the first go seated much deaper to fit in the mag (they were 3.835" 1 or 2gr under max) with the 200gr Accubond 90gr Retumbo at 3.660" turned 3045 fps ave. over five rds.

    Shot the same charge/bullet combo in the new 30/338 Lapua Imp to form a couple cases and they went 3075 fps in the 30" tube. Pretty comparable I thought but, the primer was still "nice" and round in the Lapua tho, not so with the Ultra, but who knows yet, time'll tell...

    I loaded that 3045 fps into the Exbal program and the factory "unverified" BC of .588 and figured I keep the range down to 500yds or not much more with this totally unproven load. The two groups I shot after my bore sighter shot were both under an inch while adjusting the scope too, and if overlayed they would likely all have held under .7" if no adjustments had been made... I was delighted, and confident in it to maybe 600yds without a known drop chart, considering the mooses kill zone size, beyond that I'd have to work in closer or it'd just be luck hittin one I figure, and that ain't what I'm out there for...

    They jumped right out of the alders into the swamp as I was moving from one area to another. It's a small fork horn bull but, meat's meat, and that's what I'm still in the mode for at this stage. Gettin skunked last fall removed any doubt as to weather this one was coming home with me...

    I raised up, he's 187 yards away, bipod just hangin there for balance I guess [​IMG], fired and he kept walkin and stuffed his nose to the cows hind end?????? Well, like the one I shot the year before last, this one took the second shot and finished life with a happy face too. The second shot dropped him instantly!

    I didn't recover the any bullets, yet, but the meat's hangin so I may find something in there when it gets cut up. Two bullet holes in the hide and chest but, I only found one that went "into" the chest cavity?????? The one either had to take a freaking detour some place, or it blew up on the rib it hit????? I'm totally 100% perplexed and didn't have the time to investigate, as rain was coming in fast and I was by myself. The other bullet wrecked havok on both lungs and off side shoulder bones with b-b-b-big chunks of bone and bruising... I need to work on my offhand shooting a bit more than I have been, quite a bit more... I hate hittin'em in the shoulders.

    Oh well, here's the pics I took today. Had fun while the weather was good, the shirt came flyin off immediatly after the pix, man it was too hot for my blood today.
    [​IMG]

    [​IMG]

    [​IMG]

    [ 08-22-2003: Message edited by: Brent ]