MOSIN 90/31

[DMark]

now I am missing something? harmonics?

All barrels vibrate when fired.

The bayonet doesn't stop the barrel from vibrating but it does adjusts the Sine Wave*** traveling along the vibrating barrel to be at the same point which result in better grouping.

*** The sine wave or sinusoid is a mathematical function that describes a smooth repetitive oscillation. It occurs often in pure mathematics, as well as physics, signal processing, electrical engineering, and many other fields.

The attachment of the bayonet gives a Sine Wave for a single dimension, thus the generalized equation gives the amplitude of the wave at a position x at time t along a single line. This could, for example, be considered the value of a wave along the entire barrel.

In other words...., hanging that long-ass bayonet and its added weight on a Mosin 90/31 will change how the barrel shakes when fired.

[NRA]

man thats some heavy sh#t and I will have to take your word for it. BTW was that english you just wrote?

[Garufa]

In other words...., hanging that long-ass bayonet and its added weight on a Mosin 90/31 will change how the barrel shakes when fired.

Exactly.

[Moped]

All barrels vibrate when fired.

In other words...., hanging that long-ass bayonet and its added weight on a Mosin 90/31 will change how the barrel shakes when fired.

Well put! And the rest of the quote is right on too!

[DMark]

...... BTW was that english you just wrote?

Its your tax dollars at work. For whatever reason and known only to the Army, this MTSU Liberal Arts major was sent for more schooling and therefore educated beyond my means to understand on several topics. I learned all about sine wave and harmonics while doing Flight Test on early Longbow Apaches. Aircraft that shake when they shouldn't is a bad thing.

Getting back on topic.....

The Russians knew something about all of this. The bayonet was to be mounted at all times on the Mosin. There are NO scabbards for its bayonet.

[DaveS]

OK, this just got even more complicated. Soviet Female snipers in WW2 shot thoasands upon thousands of enemy soldiers, some of those shot at hundreds of yards. I've researched hundreds of pictures of those snipers "in action", and only a handful had a bayonet. The great Red Army Firearms Instructor must have forgot to tell these snipers about the bayonet thing.

That math lesson was too heavy for me!

[Garufa]

OK, this just got even more complicated. Soviet Female snipers in WW2 shot thoasands upon thousands of enemy soldiers, some of those shot at hundreds of yards. I've researched hundreds of pictures of those snipers "in action", and only a handful had a bayonet. The great Red Army Firearms Instructor must have forgot to tell these snipers about the bayonet thing.

They used scopes and the front sight can be adjusted to compensate for not having the bayonet attached.

[DaveS]

the front sight can be adjusted to compensate for not having the bayonet attached.

Since I'm new to Nagants, could you please elaberate?

[Garufa]

Since I'm new to Nagants, could you please elaberate?

The front sight can be adjusted for windage. With hammer and punch beat the thing over to wherever the bullet is going without the bayonet attached.

I just shoot with the bayonet on. It's much easier.

[Will H]

^^^ That would be my suggestion. I don't think they all behave exactly the same with the bayo on or off. Most, but not all were used in combat, and some may have been sighted without bayos. I do not think we can have a hard rule for all Mosins. The few I have seen seem to have some individuality to them.

[DaveS]

I'm not arguing here, but drifting a "front sight" is an old age way of adjusting the windage of many firearms. With that done, i'm still curious about the bayonet usage. Some "shockwave" may be fine for "labatory testing", but albeit every rifle out there has it. I think this subject needs more research. I smell a rat in the grain bin here!

[Mike.357]

i dunno about rats in the grain bin.

From experience I know that my 91-30 hits one spot on a target without a bayonet and another with the bayonet. I don't need any more proof than that.

[Tempest455]

While the debate of the bayo changing the harmonics may have merit and move the POI. Just sight it for use without if you do not like it. It's just a barrel, a long metal tube with a rifle hole down the center just like any other rifle. Plenty of Mausers, K31's, Garands etc. that shoot just fine without a bayo. Also keep in mind there were numerous Mosin variation that were not designed to have a bayo at all.

[DaveS]

I find this topic very interesting. What a better way to spend the day, than to research Mosin Nagants, it's varients and issued equipment. Comrade Ivan will be proud!

[Guest pfries]

If you watch, you can see the pressure wave distort the barrel as the bullet travel up and out,
Below represents the wave pattern.




If you change the mass of the barrel, length of the barrel including any attachments it will change the sweet spot if you will.

Variations in the loads, bullet weight, and chamber pressure ECT will cause the top of the wave to be inconsistent, the node or resting point will not be influenced by these things. So hanging the bayonet on the end of the barrel changes the time it takes the wave to travel up and down the barrel , this changes the timing of the wave in relation to the round exiting the barrel.

[DaveS]

Very interesting video. I'm surprised a pellet gun would have such barrel movement. I have a "break action" pellet gun that looks just like that...that's crazy! How in the world? Eye opening for sure!

[DMark]

..... there were numerous Mosin variation that were not designed to have a bayo at all.

Outstanding point!

The Finnish Model 1939 Service Rifle is the best example of how good a Mosin can be, and you still can bayonet somebody if you want to (but a real Finn Bayonet isn't cheap).

Shooting a M39 is a totally different experience. I really enjoy shooting mine and would suggest that anyone who likes the 91/30 must, Must, MUST have a M39.

[Guest pfries]

Very interesting video. I'm surprised a pellet gun would have such barrel movement. I have a "break action" pellet gun that looks just like that...that's crazy! How in the world? Eye opening for sure!

They use the term Harmonics but it is really the pressure wave. Powder burn rate, time to max pressure, the barrel swelling changing the bore diameter, temperature, and many other factors play a role but barrels move and a lot more than one might think.

If you like, some of the technical jargon this is a link to an interesting and informative read:

Optimal Barrel Time Paper

[Moped]

Outstanding point!

The Finnish Model 1939 Service Rifle is the best example of how good a Mosin can be, and you still can bayonet somebody if you want to (but a real Finn Bayonet isn't cheap).

Shooting a M39 is a totally different experience. I really enjoy shooting mine and would suggest that anyone who likes the 91/30 must, Must, MUST have a M39.

My understanding is comparing a 91/30 to a M-39 is on par to comparing a Chevette to a Cadallic. They are supposed to be that much better. The Finnish Mosins were used in the 1920s and 30's in the Olyimpics and they brought home Gold, I do believe. I would love to have one of those, but they aren't cheap to come by. Some do not require an FFL, because their receivers were built before the turn of the 20th century.

Edited December 17, 2011 by Moped

[DaveS]

Very, very educational. Ya'll forced me to learn something. However, I am sadened by all my "Comrades of the Mother Land" whom had to go without a bayonet in 1942 and beyond, due to a shortage of steel. Apparentely, tanks, bullets and aiplanes was more important than bayonets. Wow! Them poor Red Army Infantrymen on the battlefield without a "harmonic balancer"!

I admit, ya'll was right!

[Guest pfries]

Very, very educational. Ya'll forced me to learn something. However, I am sadened by all my "Comrades of the Mother Land" whom had to go without a bayonet in 1942 and beyond, due to a shortage of steel. Apparentely, tanks, bullets and aiplanes was more important than bayonets. Wow! Them poor Red Army Infantrymen on the battlefield without a "harmonic balancer"!

I admit, ya'll was right!

Better watch it you'll be an SME in multiple fields for to long....

[DaveS]

Not me brother! I'm a retired Taxidermist. I do however do a little WW2 re-enacting on the side. No expert on the subject here! Ya'll teaching me this time! lol!

[Will H]

Given that this seems to have become the "Mosin Thread" LOL I have a question. Has anyone used stripper clips to load? If so, do you like them? I am thinking of pickling up some el-cheapos from Egay to try out.

[NRA]

I have and I am not very impressed. It may just be my technique. If I was in battle I would worry about it but I enjoy loading one at a time.

A guy on youtube made it seem easy though.

[Guest pfries]

I have a few and load them up but once we are out at the range I can just load the gun faster than making it a two step operation.