The following is another generous contribution by Brad, one of my fine Jews Don’t Shoot Guns informational contributors. Please note that his Mosin Nagant Rifle, named Lyudmila, is unmodified other than minor adjustments, as outlined here:
I went to the range yesterday w/ the lovely and deadly Miss Lyudmila with two goals in mind . . .
1) to pattern the rifle and determine the variance between point of aim and point of impact.
2) adjust the front sight to reduce the variance found in #1.
My first finding was that from a resting position, at 50 yards, rounds were hitting 4 to 5 inches right and about 7 inches high. I was shooting light ball 148 grain steel core surplus ammo. It’s nasty dirty stuff that stinks to high heaven . . . . . but put a round in the chamber, close the bolt, pull the trigger and the rifle goes BOOOOOOOM. Every time. Can’t argue with that.
Adjusting for windage. There’s a fairly simple formula for calculating sight adjustment . . . . found it at Robert Farago’s place.
a=(b*c)/d where . . .
a = amount to drift the front sight
b = sight radius (distance between front post & rear notch. My rifle measured at 24.5 inches)
c = variance between impact and aim point (I used 4 inches as that was the average of a 5 round group from a cold bore)
d = distance to target
After doing the math, I had to drift my front sight about 0.05444 inches, or just over 1/20 of an inch. I did this with a small nail set and a hammer. Not quite BANG BANG BANG BANG but more than tap tap tap tap. Crude to be sure, but effective, and no need for special tools that cost a lot of scratch and only get used once every 10 years. As an aside . . . I did buy one special mosin-nagant tool — a broken case extractor. I’ve been seeing about one or maybe two split cases (cracks in the metal) about every 50 rounds or so. I figure now that I have this $11 tool, I’ll never have a broken case which will jam the gun.
On yesterday’s outing, I didn’t adjust for vertical. I’ll do that on another trip.
The result? If I do my part and hold true, I can make 2-3 inch groups at 50 yards with junk ammo. Mosin Nagant rifles are shooters . . . they are not precision tools. And I’m fine with that. Besides . . . shooting stuff is FUN.
One other thing . . . . my next two rifle improvements will be as follows:
1) I’m going to enhance the front sight so the rifle doesn’t hit quite so high at 50 yards. This is done by slipping an ‘extension’ over the front post. By raising the front post, one lowers the muzzle, thereby lowering the point of impact. We’re not talking much . . . maybe a 1/16 of an inch. By my math, that should drop the point of impact about 4 or 5 inches.
2) Trigger job. The trigger on Miss Lyudmila is a giant ball of suck and fail. It is long, heavy, and gritty with no take-up and no indication when the pull will break. I’ll wait until late Fall because I do very little outdoor shooting in the winter.
Once again, Brad. Thank you for your informative additions!
These Jews Shoot Guns. Boooom.