View Full Version : Question, how does one measure a dovetail?

March 26, 2001, 02:54 PM
I need to get a riser block for my front sight on a lever action rifle that I installed a peep sight on.

Question #1. Does anybody have a formula to calculate the amount of height I need to add? The rifle now shoots approx 15" high at 100.

Question #2. How does one measure a dovetail? Is it across the top (widest dimension of the slot) or across the bottom?

TIA to the knowledgable folks on this board.

March 27, 2001, 12:31 AM
I think if it is shooting high you need a lower front sight.

The dovetail has to dimensions width at the bottom and angle ,i.e. .375x60 degrees.

George Stringer
March 27, 2001, 08:27 AM
Rezman, to lower the point of impact you need to either raise the front or lower the rear. The measurement of the dovetail is at the widest or bottom, point. George

March 27, 2001, 09:54 AM
I had a similar problem when I rebuilt an old Marlin a while back. The folks at http://www.marblearms.com were very helpfull in determining what parts I needed to order. I'm not sure if the "formula" is on the web site, but it's in their catalog.

Good Luck...


March 27, 2001, 10:29 AM
Thanks for the replies.
Cmc, I think you are mistaken, as George has posted, to lower POI, I need to raise the front sight, or lower the rear. The new rear peep sight is already at the lowest setting possible, hence the need to get a taller front post.

Joe, thanks, I'll check the website

March 27, 2001, 10:45 AM
OK, I checked the Marble website, and the formula described fitting a new sight with the rear being a barrel mount. I've put a Williams peep on a BLR. How do I determine the height above barrel centerline on the rear, so I can determine needed front sight dimensions?

I've seen a calculation that used POI in relation to POA to determine needed height dimensions. You needed to input sight distances and range to target. Seems like it was used to sight in fixed sight revelvers. Anybody remember this formula or have a link? Thanks.

March 27, 2001, 04:27 PM
Found the answer to my own question. Gawd ain't the internet great. For anyone in the same situation, go to http://www.realguns.com, and use the sight adjustment calculator