Using a Boresighting Device

Discussion in 'Technical Questions & Information' started by Cliff, Dec 6, 2004.

  1. Cliff

    Cliff New Member

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    Old Glory,Gloryland, Texas
    I picked up a decent buy, I hope on eBay, $20 for a Savage 3-7x30 scope with full length, I guess that is what you would call it, rail which measures 4-1/2 inches but only has one inch clips/bars that you tighten the scope down in the rails. I used a BSA Boresight device which is fairly new and when I had used it on some large rifle scopes/rifles elevation/windage was close, windage was always closer than elevation on all of them though. (Not thinking to measure the CenterScope/CenterBore). Bear this in mind.

    When putting the boresight device on the Romanian, elevation and windage was dead-on center. I mean it was there. The Savage has real thin reticles so it was sorta hard to make certain that was what I saw.

    I was accepted into a range club in Graham Saturday and took the Romanian out to shoot it. Well, some deputies had the 25yd range taken, all members have to let the LEO's have priority on the pistol range and on the 500 yard range. Others are come first, you get on the line. Well, I put up only one target instead of the usual 2x2 matrix that i normally do when sighting in a firearm for the first time. You never know where the sucker is a going. I had no idea that they would let me in the range that day so I did not take my spotting scope. Usually have it in the pickup but had been going to school ball games and it best not to even have spotting scopes/ammo setting out where it can be seen (Texas - zero tolerance 100 ft/yd?). Anyways, if they see shooting paraphenalia in your vehicle that gives them the right to search. Better safe than sorry though.... (Range rules also no one goes down range to set/check targets until everyone clears...LEO's there, they had set up a potful of targets I guess because they never called to go down range during the time I shot 36 rounds. I could not see any bullet holes but could not see where the bullet was hitting either. Anyways, I hit the target 2 times out of 36 tries but the windage was danged near right on. After 2 magazines I raised my point of aim to the 3/4 of the target and still couldn't see squat. On the last target I aimed at the very top of the target and I guess that is when I hit it close to the 10 ring. I wished I'd had my spotting scope.

    Okay, now that I remember that the BSA boresighting device is for a 1.5 inch C-C how do I go about boresighting when the measurement is not that magical 1.5 inch size? I measure on the Romanian/Savage 3-7x30 scope measurement to be approximately 1.238 inches or so. I imagine that it is 1.25 inch but using 1.23 or 1.24 will work as well.

    The X,Y factor both +/- X, +/-Y can go to 10. Each single mark is equal to 4". How does one go about changing the clicks on elevation considering 4" rise or drop when the C-to-C equals X. The booklet that came with the device did not mention how to do it. Shame, shame on them!
  2. CountryGunsmith

    CountryGunsmith New Member

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    At this point you should not adjust anything because you really have no idea where your bullets are striking.

    I'm not familiar with your boresighter - I use the old-fashioned grid collimators with the multiple spuds for different calibers. Works pretty well even with slight differences in scope height (I use an adapter for boresighting rifles with see-through ringsets).

    Anyway, get on the 25yd range. Set the rifle up on bags and remove the bolt. Sight through the bore and center the bull, then bring the crosshairs to the bull. You are now boresighted and ready to fine tune.

    Of course, this is all based on a good scope mount. The Romanians have a smaller groove width than the typical 3/8" dovetail - you have to modify your mounts, generally, to get a solid fit.
  3. Cliff

    Cliff New Member

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    Location:
    Old Glory,Gloryland, Texas
    Did not have to modify the grooves on the rifle nor the mounts either. The problem that I am trying to findout about is the BSA boresighter is set up for a center of bore to center of scope to be 1.5 inches. The measurement of the Weaver/Romanian is 1.22 inches ++a tad. How many lines below the 0 elevation line should I put the Weaver's elevation reticle on. The BSA is the collimator type also.
  4. CountryGunsmith

    CountryGunsmith New Member

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    Not going to be that big a deal. Try one or two lines underneath and see how that does.

    You really need to start at the 25yd range, though.
  5. Cliff

    Cliff New Member

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    Location:
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    As I had said, I 'couldn't use the 25yd range'. I know that 20-25yds 'is the best' when starting out even when using a boresighter. I am asking the question because sometimes you cannot do as you intended to do.

    There has got to be a formula or a 'base' to start out from when something like this occurs. That is what I am looking for.
  6. stash247

    stash247 New Member

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    Use the collimator, if that's what you want to do, take your scope, and look.50 yds is 2X 25yds, in error, 100 is 4X. Count the clicks, and dial 'er in!
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