Correcting for Elevation Error of the M-1 Sight
Use first detent for 100 yd. If you want to you can use the same detent and set up for 50yds or 150 yds. I chose to use first detent for 100 yds.
Full fwd the peep will rest on the stop. Do not use the stop
, use the first detent. Under recoil the peep will slide off stop, and seek nearest detent. It will cause a flier.
You have noticed that the range scale on the M-1 sight doesn't match your actual range. To adjust we will have to take some off the top of the front sight blade. Again the Dremel comes in handy.
Use 3 shot groups and use center of triangle to measure distance to center of bull. This is the amount of Elevation error we will correct for.
The M-1 carbine sight is a combat sight with rough 50 yd increments. The scale was laid out for the 30-cal rnd. don’t expect the elevation graduations to be accurate on your 5.62 or 7.62x39 mini. What we are doing is correcting for the “sight-in range” i.e. at 100 yds at sight’s 100 yd setting, for your favorite ammo. It will be up to you to know how much hold over to use at different ranges vs sight setting. If you switch ammo or POA
the POI will change.
If you haven't found your Mini's favorite ammo yet, then do not proceed until you have. Once you've ground your sight, you can't add back on.
Amount of Error X Sight Radius divided by Distance to Target in inches = Sight Correction Needed
For sight error you must figure the difference between your initial POI and where you want the POI to be. "Not POA". Your POA will be consistent. My POA will be 3 inches lower than POI at 100 yds with my 63 grn Serria handloads. This allows me a large field of view. Shooting at a 6" bull I will aim at the bottom, but impact will be dead center (hopefully
). Hunting it will allow better view for varmints. Yours may be different. Main point is keeping your POA consistent and only figure your POI.
POA = Point of Aim
POI = Point of Impact
With the M-1 sight you will be shooting low. You will have to shorten your front sight. If you were shooting high, then you would replace your front sight with a taller sight. Add or subtract the number of thousandths needed to the actual height of your sight and this is the amount of material you will remove.
Example with sight set at 100-yd setting:
At 100 yards, mine shot is 5.5" low and the distance between the front and rear sight is 21.375"
(5.5" X 21.375")/3600" = .032"
Since in this example we are shooting low, we would need to lower our front sight by .032".
If you want your first detent to be set at 50 yds, then substitute 1800" in the Formula for the "Distance to Target". For 150 yds use 5400", and the corresponding amount of "error" at that range. (Or aprox .006" of material removed will raise POI - 1" at 100 yds. This is only aproximate!)
I will adjust my front sight to compensate for 5.5" of error with the 63 grn Serria. The lighter 45-grn Winchester had an error of 9". By correcting for the heavier bullet which has less error, my POA will be 6:00 to a 6" bull for the POI to be dead center. The POA for the 45 grn will be same as POI. This allows me to correct major error for 2 different bullet weights. Simply stated, my 63 grn will shoot 3" higher than my aim point, and the 45 grn will shoot dead on.
I cut a small piece of aluminum tape and attached to my front sight at .032". I then fired a second group using the top of the tape as the new top of blade. It raised POI 6" as you can see in the attached pic. I suggest you do the same to verify your calculations before grinding the sight. Once material is removed it is difficult to put it back!