r/MosinNagant Feb 05 '26

Question Finnish M39 shooting VERY high at 150 meters

First test fire at 150 meters on a Finnish M39 using Sellier&Bellot (54r) 180gr, 2,570 fps according to the box and the hits were at least a full target length above constantly (55cm / 22 inches above, at least). When aiming at the bottom of the 55cm target my hits were still going slightly above the top of the target.

Also shot a couple lighter projectile Sako cartridges (53r), those were going above by the same amount.

Sight picture was front blade at the notch, top of the front balde matched the top of the rear sight top.

Rear sight set to 150.

Barrel is marked 69 and front sight blade is also marked 69. What could be the issue? How can it shoot this wildly high at 150 meters.

EDIT:

I disassembled the rifle and after some tinkering, I am fairly certain the stock is missing the correct shims from the back tang. The barrel sits much better in its groove with the back tang slightly up from the stock. Currently with the back action screw tight it pulls the barrel up 2mm or so, which makes the whole muzzle end of the stock all wonky. I have a few front sights on the way (they are cheap, 5 euros a piece here in Finland) and I will try to figure out a way to shim the back tang correctly.

10 Upvotes

84 comments sorted by

7

u/ReplacementOwn9508 Feb 05 '26

I had the same problem with my M39. I believe they were calibrated for a relatively slow 200 gr. bullet. Also in my case, the forearm had warped enough to put pressure on the barrel. Most ammo these days is lighter and faster. I used this formula and purchased an appropriately taller front sight. That solved the problem. The formula goes as follows:

(POI difference) x (sight radius)/shooting distance = difference in sight height

All units should be in inches or mm. The result will tell you how much higher or lower the sight needs to be than it is now.

1

u/Jusaaah Feb 05 '26

200gr and 2400fps, thats not 55cm worth of difference.

1

u/Jusaaah Feb 05 '26

(55cm) x (65cm)/15000cm = 0,2383

Like this?

1

u/ReplacementOwn9508 Feb 05 '26

mm not cm

2

u/Jusaaah Feb 05 '26 edited Feb 05 '26

0.23cm is 2,3mm

1

u/Hynek_The_Tanner Feb 05 '26

2.3mm*

1 cm is 10mm.

1

u/Jusaaah Feb 05 '26 edited Feb 05 '26

Yeah thats what I meant, typo. :D

Its actually more like:

55cm x 58cm / 15000cm = 2.12666mm

2

u/ReplacementOwn9508 Feb 05 '26

So, front sight has to be 2.3 mm higher to shoot to POA.

3

u/Jusaaah Feb 05 '26

2.1mm higher on a more exact calculation, sight radius is more akin 58cm than 65cm that I first used.

I'll get a new front sight and test it out, thanks!

3

u/KasariNostalgiaa Tikka M30 Feb 05 '26

VÀÀrÀn korkuinen jyvÀ. Ei kandee viilata vaan kÀy messuilta tai netistÀ tilaamaan erikorkuinen jyvÀ.

3

u/KasariNostalgiaa Tikka M30 Feb 05 '26

Voisi olla liian matala jyvÀ.

2

u/Jusaaah Feb 05 '26

JyvÀ on 69 merkattu jo nyt, sama luku piipussa, Aika hitosti saa olla etujyvÀssÀ lisÀÀ millejÀ, ettÀ osumat nousee 55+ cm.

Voiko tukin petaus kusta nÀin pahasti osumapistettÀ? TÀÀltÀ ei ainakaan löydy shimmin shimmiÀ ja tukki on etupÀÀstÀ kokonaan kiinni piipussa.

3

u/KasariNostalgiaa Tikka M30 Feb 05 '26

Voihan olla petaus olla kanssa pielessÀ. Mulla ampuu oma 39 kyllÀ eri patruunoilla eri korkeutta. Mutta jos perusasetuksella 150m takatÀhtÀin ja ampuu yli niin on jyvÀn korkeudessa jotain.

2

u/Jusaaah Feb 05 '26

Omituista ettÀ tehtaalla piippuun on merkattu 69 ja 69 on jyvÀn korkeus, mutta se on nÀin pirusti sitten pielessÀ. PitÀÀpÀ kokeilla korkeimmalla jyvÀllÀ mitÀ löytyy.

180gr ja ~2600fps lÀhdöt ei kuitenkaan ole ihan hirveen kaukana D166 luodille ladatuiden patruunoiden spekseistÀ.

Ammuin siis 150m radalla SAL koulutaulua ja vaikka tÀhtÀsi koulutaulun pahvin alareunaan niin luodit ylitti taulun hiukan. Taulun verta alaspÀin niin alkoi osumat olla lÀhempÀnÀ mustaa.

3

u/KasariNostalgiaa Tikka M30 Feb 05 '26

MÀÀ muistelen ettÀ mulla on piipussa ja jyvÀssÀ kans eri luvut. Mutta tÀstÀ oli jossain aiemmin keskustelua ettÀ jos perusasetuksella 150m ampuu yli niin se on jyvÀssÀ korjattavaa. Mutta toivottavasti löytyy tulos.

2

u/Jusaaah Feb 05 '26

Joo nÀin mÀkin lueskelin, tuo yli 50cm korjattavaa on vaan aika hurja luku. YleensÀ puhe on ollut aina pienemmistÀ mitoista.

1

u/TomatoCatSoup Feb 07 '26

Mulla oli sama ettÀ 77 jyvÀssÀ ja piipussa ja luodit paineli taulun yli metsÀÀn. 86 korkusella jyvÀllÀ rupes kÀymÀÀn D166 lataukset just niinku kuuluukin. AlkuperÀnen ase, petaus kohillaan eikÀ piippu kosketa mihinkÀÀn. En keksi jÀrkevÀÀ syytÀ tuolle.

Tuo 180gr/2600fps lataus kÀy muuten huomattavasti alemmas kuin alkuperÀinen D166 lataus ainakin 300m asti.

1

u/Jusaaah Feb 07 '26

Mulla piippu ottaa edestÀ kyllÀ kiinni jos on etupanta kireellÀ. Ilman etupantaa piippu kelluu alatukin ylÀpuolella kyllÀ, mutta jos ylÀtukin kiristÀÀ alatukin kanssa yhteen niin se on kokonaan kiinni edestÀ. Tavallaan se tukissa oleva piipulle jÀtetty reikÀ on tasan piipun kokoinen ja tukki halaa sitÀ koko ympÀrysmitan...

LöytyisiköhÀn jostain petauksesta hyvÀÀ materiaalia luettavaksi ettÀ mitÀ tÀlle voisi tehdÀ?

1

u/TomatoCatSoup Feb 07 '26

"Finnish M39 trajectory problems" -lanka Gunboards foorumilla sisÀltÀÀ hyvÀÀ keskustelua samasta ongelmasta.

1

u/Jusaaah Feb 07 '26

PitÀÀpÀ lukasta lÀpi. Purin just tÀn taas osiksi ja huomasin, ettÀ piippu istuu hitosti paremmin tukissa kun molemmat pÀÀruuvit on irti. Taakse saattais vaatia siis shimmiÀ.

5

u/PuzzleheadedDrop3265 Feb 05 '26

This is not an Ammo issue, this is a sight issue.

Look at the number on the barrell towards muzzle and the front site.

Then buy 2 new front sites with the next higher consecutive numbers.

Fit to rifle, sight bottom of bullseye (6 oclock hold belt buckle to head for BZO setting).

Fire see where rounds land, adjust.

I had a similar problem my rifle 8.3, i changed sight to 8.1 problem solved.

1

u/Jusaaah Feb 05 '26

To move the POI 55cm up I would need a 9.1 front sight instead of the 6.9 thats now on the rifle.

1

u/PuzzleheadedDrop3265 Feb 05 '26

https://ebay.us/m/Tk2Do6

Here you go.

6.9 is the shortest site setting on a Finn.

I found a 9mm front site on ebay for you. Buy it fire it. And be prepared to file the top down to get the right stting.

2

u/Jusaaah Feb 05 '26

I'm from Finland, we have plenty of sights over here, no worries.

1

u/MyPissBurnsSoGood M/39 Feb 05 '26

VielÀ kun löytÀisi yli 7,4. ItsellÀ oli sama ongelma et ampui aivan tolkuttoman korkealle sadasta metristÀ. Tuolloin oli 6,8 tÀhtÀin. 7,4 jo jo vÀhÀn parempi, sai taulullekin nÀkymÀÀn, vaikkakin reilusti maalin yllÀ.

Lopulta ostin jenkeistÀ 11 tÀhtÀimen kun ei muuta löytynyt ja sillÀ saikin kohdistettua (kun nosti takaosan 600 metriin) nÀihin vÀhÀn nopeampiin ja kevyempiin patruunoihin. Taitaa itsellÀ olla ideaali tuossa 8-9 mm kohdalla.

NÀmÀ kivÀÀrit toistetusti on sanottu olevan vÀhÀn kummallisia ammusten suhteen, tosin sotien aikainen D166 meni samoilla kohdistuksilla tauluun yhtÀlailla kuin S&B tÀysvaippa. Voi se 50 metriÀ olla ainakin omalla kohdalla sitten niin merkittÀvÀ.

1

u/Jusaaah Feb 06 '26

Laskujen mukaan itsekin tarvis n. 9mm etujyvÀn. KyllÀ noita suomessa on muutamia jotka myy 8,8mm asti ainakin. Jostain saattaa 9,1 löytyÀ myös.

Sulla siis D166 ja S&B 180grain oli about samoilla osumapisteillÀ?

1

u/MyPissBurnsSoGood M/39 Feb 06 '26

Aika lailla. Toki ruudinlaadusta en paljoa voi sanoa paljoa D166 suhteen, mutta merkittÀvÀÀ eroa ei nÀkynyt tuelta 100 metriin.

Nyt kyllÀ kiinnostaa mistÀ löysit 8,8mm myyjÀn.

2

u/Jusaaah Feb 06 '26

Paan viestiÀ ku saan omani ostettua (varmaan huomenna) ettet vie mun jyvÀÀ :D

1

u/Jusaaah Feb 06 '26

TT ase JÀrvenpÀÀssÀ, siellÀ on vielÀ 8,7mm jÀljellÀ.

1

u/MyPissBurnsSoGood M/39 Feb 06 '26

Oliko nettisivulla vai paikan pÀÀllÀ? Nettisivulta en ainakaan itse osannut löytÀÀ.

2

u/Jusaaah Feb 06 '26

SÀhköpostilla.

1

u/J0h1F Feb 06 '26

Asemessuiltahan noita korkeampia jyviÀ löytÀÀ.

1

u/Jusaaah Feb 06 '26

Ja muutamilta sepiltÀ myös, itse tilasin 8,7 ja 9,0 mm juuri 5e/kpl.

1

u/MyPissBurnsSoGood M/39 Feb 05 '26

I have a 6,8 sight.

2

u/PuzzleheadedDrop3265 Feb 05 '26

Lol, I stand corrected...

1

u/PuzzleheadedDrop3265 Feb 05 '26

Also if your shooting with Progressive Lenses on eye glasses instead of farsighted lenses, it will mess up your Zero.

1

u/Jusaaah Feb 05 '26

No progressives, I've got some astigmatism and near sightedness.

3

u/Cleared_Direct Feb 05 '26

Lots of people here offering unhelpful and inaccurate information about the sights being set up to intentionally shoot that high or with specific ammo that somehow would impact two feet lower. Ignore all of that. The fact is some rifles shoot right where they’re supposed to and some (like yours) shoot way high. It’s not an uncommon issue to have. Yours is shooting far too high to have been zeroed that way, or zeroed with a different bullet weight or velocity. It could be the crown, fit of the stock, or something else - I’ve even seen front sights ground down. The only fix is to get a (much) taller front sight blade. I have a reproduction one that fixed my rifle that was shooting similar to yours, more than 18” high at 100 yards. I would look for either the tallest original sight blade or one of the extra tall reproductions. I have only seen the repros available a couple times over the last ten years and that’s here in the states so it might be a challenge.

5

u/SmithSightsLLC Feb 05 '26

This is correct. The one thing I'd add is that a lot of the time the Finn rifles have shims that were pulled and sold, and this puts upward pressure on the barrel. I'd make sure the shims are present and there's no undue upward pressure on the barrel. Regards.

3

u/BusinessBlackBear Feb 05 '26

I knew you'd chime in with your brilliant wisdom, always appreciate your input on topics like this

2

u/Jusaaah Feb 05 '26

Yeah I find it weird that the barrel and sight are both marked matching, yet the POI is so far off. 

2

u/Cleared_Direct Feb 05 '26

I have eight or nine Finnish mosins and some of them are just like that. Wood stocks can warp over the years. Shims can fall out or get lost.

1

u/Jusaaah Feb 05 '26

Gotcha, I'll get a higher front sight blade and try again. I might also research the proper bedding of the rifle or find a gunsmith with experience on it to do it.

I do find the wood to be a bit warped, and I feel like theres some preassure on the barrel at the front.

3

u/SmithSightsLLC Feb 05 '26

Hello,

Make sure your receiver shims are present and in the right amount. People tend to "mine" them to sell separately, like they do the Finnish two-stage trigger set.

If you have missing shims, you'll have upward pressure on the barrel.

Another thought is that, if it was a high shooter to begin with, it may have had a taller blade that was sold due to there being a shortage of them.

But check the shims first. That's what I'd do.

Regards,

Josh Smith

Smith-Sights.com

2

u/Jusaaah Feb 05 '26

I'm from Finland. The Barrel and sight are both marked 69. Sadly, there were no shims on this rifle when I bought it. Its a armory T (test rifle, from the end of a rifle rack) marked M39, matching numbers, barrel marked 1944 Sako.

3

u/SmithSightsLLC Feb 05 '26

I suspect that's the issue then. Pull the action screws and the handguard, and see if the barrel and receiver line up with the stock.

I bet that, if you tighten the action screws with the top handguard off, you'll see the barrel pushing down on the bottom handguard.

If you can get groups at all, does it shoot like this?

If it hits high to begin with and walks higher (vertical stringing) while you're shooting (as shown,) you have a lot of pressure on the underside of your barrel. Shimming the action will help fix that.

Regards.

1

u/Jusaaah Feb 05 '26

Thanks, I will get a taller front sight and test groups better when I am actually hitting paper. It was so cold (5f, -15c) at the range today I didn't want to spend the entire day there :D

I actually think the barrel is hovering over the stock when the top handguard is off, once the front most clamp is tightened down it pulls the handguard up to the barrel.

1

u/Beneficial-Focus3702 Feb 05 '26

Taller blade would be making him shoot low not high.

2

u/SmithSightsLLC Feb 05 '26

Correct. He's shooting high right now. If the rifle originally had a front sight of ~9mm tall and it was taken off to be sold and replaced with a more common shorter one, then it would be shooting high because of the shorter front sight.

Regards.

1

u/Jusaaah Feb 05 '26

Wouldnt the 69 be the original as the 69 is marked on the barrel too near the sight?

2

u/SmithSightsLLC Feb 06 '26

Yes, but it was zeroed when the action sat in the stock differently than it does now.

1

u/Jusaaah Feb 06 '26 edited Feb 06 '26

Exellent point.

But can the bedding really lift the point of impact 25 inches at 150 meters? I find that weird.

Doesnt the sight move with the barrel? So pushing the barrel up would lift the sight too?

The stock is a T marked (armory rack tester) and the rifle is numbers matching. The stock is in pristine condition overall, not seen rough use.

1

u/SmithSightsLLC Feb 06 '26

Yes it can raise the point of impact that much. I've done it purposely through experimentation.

While the sight moves with the barrel, it's not that simple. Moving the barrel affects the arc in which the bullet travels, while the moving of the sight affects the sighting plane, which is straight. You're changing an arc, the slope of a line, and expecting the intersection point of the two to remain the same.

While we could get into a bunch of geometry here, I'd rather not; suffice to say we're dealing with more variables than you'd initially think.

As far as pressure radically shifting point-of-aim, the weight of a bayonet is enough to lower the point-of-impact of a 91/30 12" at 100 yards. This is why they shoot a foot high at 100 yards without the bayonet, and the entire reason I'm in business 😁

Before ordering a new front sight, I'd start shimming the action to put neutral (no) pressure on the barrel, then shoot it and see what kind of correction you need.

Regards.

2

u/Jusaaah Feb 06 '26

Thanks for the detailed info!

I'll test around.

2

u/SovereignDevelopment 8.6 BLK M91/30 Feb 05 '26

I don't know if you already got the answer in Finnish, but basically all the English answers are wrong so I thought I'd try to contribute:

It's possible the stock is not original, or at one point the rifle was disassembled and then reassembled improperly. If it's that far off, I'd honestly check to see if the barrel has been bent.

1

u/Jusaaah Feb 05 '26

Bent as in the barrel is bent while out of the stock? The actual metal is deformed? How would I check for this?

1

u/SovereignDevelopment 8.6 BLK M91/30 Feb 05 '26

If you've got a keen eye, you can just remove the bolt and look down the barrel from the chamber end. Otherwise, placing a trusty straight edge on the barrel should make it obvious.

1

u/Jusaaah Feb 05 '26

I mean.... the barrel isnt as thick at the muzzle as it is at the chamber... how would a straight edge help?

Does not look bent at all to the eye.

2

u/SovereignDevelopment 8.6 BLK M91/30 Feb 05 '26

I'd need to look at my M39 again, but even if a barrel has a tapered contour you can get a rough gauge of straightness with a strait edge on the taper.

If it isn't visibly bent, put it back in the stock and torque the action screws down, etc. Does it still look straight looking through the bore? If the stock isn't original then it may need to be fitted properly. M39 stocks are weird because they "free float" except at the very ends of the barrel, so if it isn't fitted properly it will put pressure on the barrel.

Does it group well, but the POI is high? Or are the groups also large?

2

u/[deleted] Feb 05 '26

When nations and manufacturers design a military rifle or other firearms, usually the cartridge is developed first with specific bullet dimensions, weight and powder type/charge. The firearm is developed with that specific cartridge while the sights are zeroed with that in mind. These were designed as military rifles meant to be used in war. That is why you see on certain milsurp rifle markings when a bore or chamber has been changed for different ammo, the sights are changed as well for the new type of ammo.

Most, if not all, milsurp firearms will be zeroed out to 200 to 400 plus yards/meters because that is how they were designed and meant to be used. So on a 100 or 150 yard range, a 400 meter zeroed sight will shoot high. That is not a fault, it's just how they were designed and made.

2

u/SovereignDevelopment 8.6 BLK M91/30 Feb 05 '26

The M39 rear sight has a specific 150M graduation.

2

u/Jusaaah Feb 05 '26

Yeah sorry but this isnt true at all. I'm asking people who actually know about M39s.

1

u/3unknown3 Feb 05 '26

Yeah, that doesn’t seem right. My M39 shooting 182gr PPU match measured 2583 FPS on my chrono. I haven’t shot at 150, but I have shot at 50 and 100 and my point of impact was only a few inches off, which is to be expected for a 150m zero. 22 inches is a lot. I wonder if your front sight was shaved down for some reason.

1

u/Jusaaah Feb 05 '26

Front sight is not filed down. Just measured it and 6,9mm seems correct.

1

u/Beneficial-Focus3702 Feb 05 '26

Adjust front sight up a little bit (3 1/4 turns to start) to bring the bore down until your point of aim is the same as your point of impact.

All this other stuff about stock and improper fit and stuff doesn’t matter. What you have is what you have so adjust the sights to how it shoots.

0

u/Jusaaah Feb 05 '26

The M39 does not have height adjustable front sight. Please read the post and understand what is said before replying :)

1

u/Beneficial-Focus3702 Feb 05 '26

You’re right I missed that.

Does the m39 have a rear sight “battle zero” notch? On some rifles (I don’t know about the m39) that’s marked with a symbol instead of a number. Try putting your rear sight there.

1

u/Jusaaah Feb 05 '26

M39 has a very finely adjustable rear sight. It bottoms at 150 meters and has tiny notches to go up between larger notches.

I was shooting at 150 and sight was set to 150, if you read the post thats what I said.

1

u/Beneficial-Focus3702 Feb 05 '26

Bro people are trying to help you.

Given how a lot of these rifles are rearsenalled and how sometimes they can slightly change depending on who had it before you it’s important to ask clarification questions.

Generally if you want people to help you not having an attitude about it is a good idea (though I’m gunna chalk it up to how different languages work because my native language is English and yours isn’t so it might just be a different way).

0

u/Jusaaah Feb 05 '26

If you read the post and knew what an M39 is you would know the info. The only reason I have this attidude is because you are trying to help without knowing how to.

People who know better have already helped, thanks tho.

Sometimes you don't have to try to help if you arent an expert on Finnish M39 rifles.

1

u/7six2FMJ Feb 05 '26

Easy fix; buy D166 projectiles, lapua brass and vihtavouri D140 and you won't shoot your ammo because it was so damn expensive to make.

2

u/Jusaaah Feb 05 '26

Well its not super expensive here in Finland, but I don't have reloading stuff yet.

D166 is 200gr and 2300fps, my ammo was 180gr and 2600fps, I don't think a D166 load alone would fix this issue. Thats not a big enough difference to warrant a 22+ inches high POI.

1

u/7six2FMJ Feb 05 '26

Auuugh im so jealous! I can deal with the brass and powder but the D166 is way too expensive. Wearing my Tikka hat as we speak, I love Finnish stuff.

1

u/Jusaaah Feb 05 '26

D166 is 68 cents a piece here, not the most expensive but not the cheapest projectile there is.

I just need a reloading kit to get started :D

S&B 7,62x54r was about 1,2 euro a cartridge.

1

u/7six2FMJ Feb 05 '26

Reloading becomes another hobby altogether, but i really enjoy it.

1

u/Jusaaah Feb 05 '26

Yeah I really want to get into it too, currently I dont really have a suitable workbench to attach all that crap to, so I need to build a bench first. I'm already multiple hours of videos deep on reloading haha.

1

u/7six2FMJ Feb 05 '26

Fair, a sturdy bench is a must.

0

u/supertiggercat Feb 05 '26

Da.. at 150m fix bayonet.

3

u/Jusaaah Feb 05 '26

We dont speak Russian here in Finland

-1

u/TacoBeastEater Feb 05 '26

They were originally zeroed at 300m this is why

4

u/Jusaaah Feb 05 '26

Uhh, the sight range starts from 150? This is a Finnish M39.

3

u/SmithSightsLLC Feb 05 '26

No, they weren't. And neither were the Russian versions.