Finnish M39 high shooter

[Kyle S.]

Got my M39 from classic firearms about a year ago and was saddened by how high it shot. Its been in the safe for awhile without getting shot because of it. My mom was asking for Christmas ideas and I've been thinking about getting a new front sight for it but was going to ask what you guys think. It shoots 203 gr SP Silver Bear(preferred load) about 6.5 inches high at 50 yards and 147 gr Tulammo about 5 inches high at 50. Reloading D166 ammo is probably out of the equation. Is there a way to manipulate the rifle to shoot lower without modification because i want to keep it in its genuine configuration, or should i go ahead and buy a new front sight. Im not sure how tall the current sight is and was wondering if anyone knew how tall of a sight i should get. 8.6mm sights on ebay for $19. Thanks in advance.

 

[Jackal]

6 o'clock hold? A 400 yard zero is sort of odd for a Finn.

 

[boom boom]

Shoot this guy an email and ask him. BTW, he sells them as well for pretty reasonable or redoes your sights. He did post on THR as Joshua Smith
http://www.smith-sights.com/

Here is an old THR forum posting on exactly this problem.
https://www.thehighroad.org/index.php?threads/mosin-nagant-shooting-high.681711/#post-8464515

 

[illinoisburt]

** edit - applies to 91/30, Finns are apparently different

Super simple fix that works well without any modification. You need small amount of hot melt glue, a heat source, and a black plastic coffee stir. Cut a piece of the coffee stir just slightly taller than the current front post. Heat the front sight until it will melt a small dab of the glue, slide stir over the post. The glue will ancor it in place and fill in the small air space at the top. Allow to cool, it is done. Makes the post a tad thicker but generally has no practical effect on accuracy especially since you're now on target. If by chance you made it too high or low, just heat off the old piece of stir and redo. The end of the barrel generally doesn't get hot enough while firing to affect the plastic or glue so there is no worries about it falling off or breaking. Totally red neck, but aint bubba and it works.

 

[boom boom]

Super simple fix that works well without any modification. You need small amount of hot melt glue, a heat source, and a black plastic coffee stir. Cut a piece of the coffee stir just slightly taller than the current front post. Heat the front sight until it will melt a small dab of the glue, slide stir over the post. The glue will ancor it in place and fill in the small air space at the top. Allow to cool, it is done. Makes the post a tad thicker but generally has no practical effect on accuracy especially since you're now on target. If by chance you made it too high or low, just heat off the old piece of stir and redo. The end of the barrel generally doesn't get hot enough while firing to affect the plastic or glue so there is no worries about it falling off or breaking. Totally red neck, but aint bubba and it works.

Nice simple modification. Thanks for posting.

 

[caribou]

M-39 Finn Mosin's have blade type front sights, not the posts of the M-91/30, M-38/M-44's.

Look atop your front sight blade.

There will be a number there, 8.8 or 8.9, etc, and such is to indicate height of the front blade.

Just behind the front sight, atop the barrel , there will be (hopefully) the same little tiny number.

Its very possible someone has changed your front sight blade, sometime in the past. If the numbers are not the same, you can buy a front sight blade with the proper height. If the number is the same, you can replace it with a taller one, and save the original.

M-39s left the factory combat set for 150 meters. They were set in a gun cradle and shot 5 into a 50mm group at 100 meters, or were tweeked untill they did, before being crated up and sent to the military.

They will generally shoot high at 50 yards, by a couple three inches. Wehen I was using an M-39 to make a living it shot dead center at 150, any thing closer I simply held a bit lower; ie; instead of dead center on a Caribou head, the top of the front blade with 1/2 a Caribou head in sight, Id place the top my sight just at the line of the lower jaw, and that was that.

The Finns aimed at the belt buckle, so hitting a bit high was not a problem for them.

 

[WelshShooter]

50 yards is awfully short range to be shooting at with this rifle. I have a Finn M24 which shoots around 4" high at 100m when I was doing load development. The minimum sight setting is 300m on my rifle so I was not surprised it was shooting high at 100m. What is the lowest sight setting on your M39? Have you tried shooting it out to 100m or further? I would try this before making any changes to your front sight.

However, if you are only ever going to shoot this rifle at 50 yards and want to correct your zero, then go ahead and make the necessary adjustments to your front sight.

 

[Kyle S.]

M-39 Finn Mosin's have blade type front sights, not the posts of the M-91/30, M-38/M-44's.

Look atop your front sight blade.

There will be a number there, 8.8 or 8.9, etc, and such is to indicate height of the front blade.

Just behind the front sight, atop the barrel , there will be (hopefully) the same little tiny number.

Its very possible someone has changed your front sight blade, sometime in the past. If the numbers are not the same, you can buy a front sight blade with the proper height. If the number is the same, you can replace it with a taller one, and save the original.

M-39s left the factory combat set for 150 meters. They were set in a gun cradle and shot 5 into a 50mm group at 100 meters, or were tweeked untill they did, before being crated up and sent to the military.

They will generally shoot high at 50 yards, by a couple three inches. Wehen I was using an M-39 to make a living it shot dead center at 150, any thing closer I simply held a bit lower; ie; instead of dead center on a Caribou head, the top of the front blade with 1/2 a Caribou head in sight, Id place the top my sight just at the line of the lower jaw, and that was that.

The Finns aimed at the belt buckle, so hitting a bit high was not a problem for them.

The sight and barrel are both marked at 74. You mentioned how the Finns aimed at the belt buckle so hitting a foot high at 100 meters sounds about right. I would feel bad replacing the sight but if that means hitting at POA then so be it.

Edit: Is there a way to calculate how high of a sight i need?

 

[illinoisburt]

The standard formula for front sight movement on any firearm is the ratio of sight radius to target distance divided into the amount of correction needed. I think the math is going to put 0.1 mm sight adjustments around 5/8" of movement at 100 yards based on 22.75" sight radius. This should be a good ballpark if the measurement is close.

** I used the standard sight radius specs listed on 7.62x54r.net so your actual numbers may be different. Math looks like 100 yards = 3600 inches. Divided by 22.75 is 158.24 to 1 ratio. 1 inch = 25.4 mm, or 254 of the 0.1mm adjustments. Divide 158.24 by 254 gives us 0.623 inches of movement. That is roughly 5/8 inches.

 

[Kyle S.]

The standard formula for front sight movement on any firearm is the ratio of sight radius to target distance divided into the amount of correction needed. I think the math is going to put 0.1 mm sight adjustments around 5/8" of movement at 100 yards based on 22.75" sight radius. This should be a good ballpark if the measurement is close.

** I used the standard sight radius specs listed on 7.62x54r.net so your actual numbers may be different. Math looks like 100 yards = 3600 inches. Divided by 22.75 is 158.24 to 1 ratio. 1 inch = 25.4 mm, or 254 of the 0.1mm adjustments. Divide 158.24 by 254 gives us 0.623 inches of movement. That is roughly 5/8 inches.

So let me check if i understand correctly. If I add 2mm on top of my front sight that will lower my point of impact around 12 and 1/2 inches? .623 × 20 = 12.46 inches correct?

 

[caribou]

If the math is correct you would need a 94 marked Front blade. They are out there.

Some guys get a high sight and ''fine tune' it with a passing shave of the file, untill its ''perfect''.

Once you 'know'' your rifle and shoot good, consistent ammo, 2'' groups at 100 yards should be normal.

The minimum rear sight setting is 150 meters for an M-39.

A belt buckle on a Soviet was just about over the bellybutton...

 

[illinoisburt]

Sounds about right assuming you want to come up that far. But i would get some measurements to confirm sight radius and carefully shoot a 100 yard group to be sure how much movement is needed. Also as sight radius increases the amount of movement per 0.1mm will go up.

 

[caribou]

The M-39's built by SAKO and Valmet (with Tikka barrels) have a standard, very specific sight radius length.
Thats not an easy question on these excellent boards, but at a more Mosin specific Forum, you would probably do well asking for such on the general discussion forums at Gunboards, where Mosin is fluently spoken.

Make your groups, get a mesurement and work the math

Wish I were there... ( I have Mosinitus)

.

 

[Kyle S.]

The M-39's built by SAKO and Valmet (with Tikka barrels) have a standard, very specific sight radius length.
Thats not an easy question on these excellent boards, but at a more Mosin specific Forum, you would probably do well asking for such on the general discussion forums at Gunboards, where Mosin is fluently spoken.

Make your groups, get a mesurement and work the math

Wish I were there... ( I have Mosinitus)

.

Did some calculations and figured out that 2mm is about 5/64 of an inch which i rounded to 1/16 inch and found a piece of copper that big and electric taped it to the front sight. Pretty impressive i know haha. Just something to test before i put money into it. Will be testing it once the rain clears.

 

[caribou]

A bit of a test before buying.........Awesome.

 

[illinoisburt]

Makes sense to me. Please post your results!

 

[entropy]

** edit - applies to 91/30, Finns are apparently different

Super simple fix that works well without any modification. You need small amount of hot melt glue, a heat source, and a black plastic coffee stir. Cut a piece of the coffee stir just slightly taller than the current front post. Heat the front sight until it will melt a small dab of the glue, slide stir over the post. The glue will ancor it in place and fill in the small air space at the top. Allow to cool, it is done. Makes the post a tad thicker but generally has no practical effect on accuracy especially since you're now on target. If by chance you made it too high or low, just heat off the old piece of stir and redo. The end of the barrel generally doesn't get hot enough while firing to affect the plastic or glue so there is no worries about it falling off or breaking. Totally red neck, but aint bubba and it works.

Use a roll pin, a little sturdier.

 

[Kyle S.]

Bottom left group was at 50 yards. I couldnt really see the target even with my glasses on so i moved up a couple yards. And this was my result. I think if i was shooting at 100 it would be a little high but that is okay and its better than 12 inches high! Accuracy is probably my lack of marksmanship. Thanks for the help!

 

[illinoisburt]

That isnt bad at all for irons at 50 yards. Glad to see the measurements worked. Assuming we can operate off ballistics charts, there won't be much if any noticable change in point of impact at 100 yards. Think you are good to go.

 

[caribou]

Looks like it shoots fine after a warm up

 

[_N4Z_]

That's damn fine shooting considering the less than match fresh ammunition you're using.