A liitle confused about POI with my Mosin. And Mauser.

[BigAlofPa.]

I took my Mosin and Argentine Mauser out today. I was shooting the Mosin with the irons at 25 yards. My loads with speer .150 grain 311 bullets and 14.5 grains of green dot were very accurate. I was getting groups touching each other on the target. It's the best that rifle ever shot. They were hitting where i aimed but a little left. I also loaded some berrys 123 grain .311 with 20.21 and 22 grains of 2400. The key hole issue i had solved. But they were hitting low.

I had to move the rear sight up a notch. They were close to where i was aiming height wise. Some spread out though. Im just trying to figure out why they would be hitting low. I wish i had bought my targets home and took some pics. The Mauser is the same way. I only loaded 2 rounds with the 123 grain and 22 grains of 2400. I had 2 casings mixed in my 762.54R casings. So figured i would load them since the powder drop was set up already.

[Noah Zark]

If I understand the situation, IMO it's a lighter boolit with the same charge of the same powder, and fizziks and rule of thumb state that the lighter boolit will have higher velocity which means a flatter trajectory which means they will hit the paper or bad guy lower.

But I ain't no expert.

Noah

[Rickf1985]

If I understand the situation, IMO it's a lighter boolit with the same charge of the same powder, and fizziks and rule of thumb state that the lighter boolit will have higher velocity which means a flatter trajectory which means they will hit the paper or bad guy lower.

But I ain't no expert.

Noah

At 25 yards?!

[TurnipEaterDown]

Most likely you are seeing a couple effects, to some varying degree as to how much of each, or what predominates. Also: when you say that the bullet 'strikes low', as compared to what? The heavier bullet load mentioned, I would guess. Do you know velocity of both loads?
1) Sightline (siteline?) (line drawn through site alignment features) is not bore centerline. This is more pronounced w/ scopes, and people forget that the bullet hits low near muzzle as the sight (scope) sits above the bore, and for all practical purposes there is no drop within a few feet of muzzle. The bullet makes an effectively straight line over horter distance, and the line of sight through the sites IS straight. You see & measure drop significantly over longer ranges, but the practical effect can be lost in dispersion at very close ranges. Something to remember when shooting the racoon in your driveway w/ scope sighted 22rf at 20 feet...The bullet will be ~ 1.5 inches low...
2) Recoil & barrel residence time. All cartridges being fired generate recoil. Lighter bullet loads generally make less recoil force. Faster bullet loads create less barrel residence time (the gun's muzzle moves less by the time the bullet leaves because there is less time for the bullet to be in the barrel as the gun is moving). This is why heavy bullet loads in a revolver shoot high at short range compared to light bullet loads. The heavy bullet doesn't get out as quick, and the recoil is higher. The muzzle climbs more before the bullet leaves. You have likely seen the opposite: lighter bullet got out quicker and the total motion generated by recoil was probably less too.

[BigAlofPa.]

Yes the lighter bullet loads did have less recoil. I used 2400 because it's slower burning than Red or Green dot. They keyhole with them for some reason. I chose 25 yards because i can see where i was hitting without needing a spotting scope. I did not chrono the loads. But the 2400 loads were faster based on loading data. Im happy im finally getting my loads to group. Before it would only group well with Tula 147 grain ammo. I was going to sell my rifle at one point. I did some extensive bore cleaning. What i thought were pits from corrosive ammo. Turned out to be fouling. Before the deep cleaning. When you looked through the bore with a light it looked like a sewer pipe. I would get blue/green patches. Then black ones. Then back to blue/green. Then black again. It was interesting seeing how the layers were coming off. Now it's smooth and shines.

Im doing the same to my buddy's Mosin now. His is worse than mine was. Im getting there slowly. I can see bare steel finally. It still has what i call high spots of fouling.

The lower strike is about 4 inches lower than the 150 grain bullets hit.

Great reply Turnip Eater. Thanks.

[TurnipEaterDown]

Glad it was of some help Al.

Funny aside: I started shooting cast bullets seriously in rifles only about 12 years ago. Used them in pistols for almost 30 years, but the irrational part of me was always skeptical of using very many of them in rifles before we had Old Bummer and costs shot up. I "knew" there would be some leading, and I hated the thought of that in a 24 inch barrel. I "knew" that from the occasional lead bullet in a Marlin 1894 44 Rem Mag I had at one time. So I bought a beater -- a Yugo 24-47 (well, really a few...but hey, they were $120). Then I said, I have a beater for this, lets try cast bullets in rifles full time. Guess, what?
I applied what I learned from handgun success, and learned some more, and my Yugo Mauser didn't lead. Hmmmm... Then a few years later I found that I never really had to clean that 24-47 more than once or twice a year (400-1000 rounds between cleanings), it shot the same clean or not. No guess, back to back 25 shot groups. Didn't take longer to clean really if it was so filthy before cleaning that I had smudges on case heads from accumulated combustion blow by. Throw in a few more years and I finally got a borescope. Looked at that bore in my cast bullet 24-47. I would have thrown the gun down on the floor years ago had I seen that. More craters and pits than a 40 Buick frame in a salvage yard in the 80s... Hmmmm...
What I learned was a lot that I heard from others might not be so absolute, and 50-50 beeswax - Alox w/ a little Lithium chassis grease added, along with incompletely combusted powder actually probably helps that old rough cob not to foul. It's a funny thing. At least to me.
I wouldn't treat another gun of mine like I do that Yugo, but it seems to not care at all. Seems like there is always something to learn, and that 100+ yr old 8x57 is a pretty forgiving test subject...

[725]

Here's a thought. If your heavy bullet takes a few nano-seconds (whatever they really are) longer to get up & go down the barrel than the lighter bullet does, that means the gun is in a fuller state of recoil by the time the bullet exists the muzzle. Because recoil has redirected your gun more for the heavy bullet (that took longer to get out of the barrel) than the lighter bullet (faster to squirt out) did, it's aimed higher at the target (because of recoil) , hence, at 25 yards, it prints higher.

[samari46]

I shoot lyman's 314299 at about 1700FPS. This in a Finnish model 27. Set up two targets one with the target reversed on the bottom of the frame at 100 yds. And the target I used to sight in at 100yds. With my small spotting scope easy to see bullet impact at that distance. So worked on the elevation 1st. Then fine tuned it and then the windage. Change only one variable at a time otherwise you never get sighted in. The sights on both the mauser and moisin will get you where you want to be. Just one step at a time. Frank

[waksupi]

The higher you raise a rear sight, the more critical bench technique becomes.

[BigAlofPa.]

I loaded more rounds yesterday for both rifles. Ready for the next decent day. Im going to take a hammer and drift along. And correct the slight to the left impacts. I'll take my splatter bust targets and work it 50 yards with them. I did smooth the trigger some. It's less gritty. Sanded the rough machining off the sear spring and trigger.
https://www.thetruthaboutguns.com/a-bubba-gunsmiths-guide-to-the-mosin-nagant-trigger/

[303Guy]

Here's a thought. If your heavy bullet takes a few nano-seconds (whatever they really are) longer to get up & go down the barrel than the lighter bullet does, that means the gun is in a fuller state of recoil by the time the bullet exists the muzzle. Because recoil has redirected your gun more for the heavy bullet (that took longer to get out of the barrel) than the lighter bullet (faster to squirt out) did, it's aimed higher at the target (because of recoil) , hence, at 25 yards, it prints higher.

This has been my understanding. This effect seems to be consistent. One sees it in revolvers in which barrel flex would not be able to account for it.

[Tokarev]

Long Mosin was designed to be shot with the bayonet attached. W/o it the POI will shift. To the left is par for the game. Drive your front sight ways to the right.

[BigAlofPa.]

Yeah i'll have to try it with the bayonet on.

[jetinteriorguy]

Long Mosin was designed to be shot with the bayonet attached. W/o it the POI will shift. To the left is par for the game. Drive your front sight ways to the right.
Moving the front sight to the right will move the POI to the left even more.

[Tokarev]

Moving the front sight to the right will move the POI to the left even more.
Ah, you mean that left? Right. It's the other left.