Bayonets and Point of Impact

[Bigslug]

I am in the process of returning to the French Chassepot ammo experimentation on which we have a thread cooking in the Black Powder Cartridge section.

When last we had this rifle out, grouping was a bit to the left. The bayonet (which we have, but have not shot mounted yet) mounts on the right side of the muzzle.

We're going to find out for sure when we load it up and pull the trigger, but it seems to me that the bayonet so mounted would push rounds even FURTHER to the left.

Seeing as this rifle has no apparent mode of adjustment for windage, we're curious as to what the noted effects of mounted steel on shot placement are with various platforms.

Let the enlightenment begin!

[725]

The barrel harmonics will be affected in some manner. Just have to light off a few and see.

[samari46]

The Russian model 44 carbine in 7.62x54r has a side mounted bayonet that releases to slip over the muzzle. I left mine in the dismounted position along side the stock when firing Yugo NNY head stamped heavy ball. Outside of tweaking the front sight with the bayonet along side the stock never shot it with the bayonet attached to the muzzle. Frank

[Bigslug]

The barrel harmonics will be affected in some manner. Just have to light off a few and see.

Indeed we will. . .

If indeed this rifle zeros with the blade attached, one has to wonder what rattles around in the hive mind of a governmental think tank that would calibrate a breechloading rifle to shoot to the sights with the bayonet mounted, AND yet equip it with sights that give sufficient elevation for some hundreds of meters, AND not give the operator any means of adjusting the rifle for whether the bayonet is on or off.

Giving the order to "FIX BARREL-TUNING WEIGHTS!" when the enemy is still 800 yards out just doesn't have the same machismo. . .

[Earlwb]

The powers that be may have still been thinking of the old massed troops in formation doing volley fire. The old military techniques and strategy wasn't that old when these early breechloading rifles came out. Thus individual accuracy may not have been all that important yet.

My other thought is that the rifle may be regulated for a particular loading. A certain powder charge and a certain bullet weight may be needed.

[HABCAN]

Years ago I had a little brown 'Soldier's Manual of Small Arms' (which I gave away to a museum) describing in detail the many weapons they might encounter in the field that was issued to British troops early in WW2. I distinctly remember an instructional passage in it advising different points of aim for the L/E #1 Mk III with and without bayonet attached. Wish I had it now so I could quote directly for those interested.

[Multigunner]

The old long barrel Mosin Nagant 91 was sighted in with bayonet mounted and soldiers instructed to always mount the bayonet when in combat.

The Enfield No.4 rifle had a definite shift in POI with bayonet mounted and instructions were to mount the bayonet to lower the POI at closer ranges.

Some European rifles had a secondary front sight dovetailed into the bayonet muzzle ring. These allowed pin point accuracy at close range with bayonet mounted. Don't remember which country used these.

[Bigslug]

The Enfield No.4 rifle had a definite shift in POI with bayonet mounted and instructions were to mount the bayonet to lower the POI at closer ranges.

Ok. . .that's at least a possible indication that the point of impact may get pulled toward the bayonet, which would be desirable in this case.

[Dan Cash]

Don't have a Chassepot but my 1911 Schmidt Rubin prints abut 3 inches vertical string centered for deflection without bayonette. Add the bayonette and the string changes to 3 inch horizontal but centered for elevation, these groups at 100 yards. This is the only gun I have paid any attention to performance with bayonette.

[turtlezx]

sks poi is considerably diffent with the bayonette on or off
Any thing touching the barrel is going to change POI

[Ballistics in Scotland]

The old long barrel Mosin Nagant 91 was sighted in with bayonet mounted and soldiers instructed to always mount the bayonet when in combat.

The Enfield No.4 rifle had a definite shift in POI with bayonet mounted and instructions were to mount the bayonet to lower the POI at closer ranges.

Some European rifles had a secondary front sight dovetailed into the bayonet muzzle ring. These allowed pin point accuracy at close range with bayonet mounted. Don't remember which country used these.

That sight on the bayonet (solid I think, rather than dovetailed) was Austro-Hungarian. I don't remember which rifle in a time when Europe was so full of empires that couldn't afford to turn their backs on each other, that successive rearmaments followed in ruinously expensive succession. But I believe (work this out if you can) it was only the NCO's model.

It is true about the bayonet being used to adjust the zeroing on the model of the No.4 Lee-Enfield which had the simplified two-leaf rear sight. But the bayonet by that time was a piffling little spike, too light to produce great effect. The Martini-Henry was said to shoot some fifteen inches to one side at a hundred yards with its large sword-bayonet fixed, which was unhelpful when you consider how quickly uncivilised persons with large choppers of native make could cover that distance.

I'm in no doubt that a large side-mounted bayonet would make a rifle shoot to one side. I just can't completely convince myself which side it would be. As human beings in 19th century tactics were a higher target than they were wide, the bayonet underneath was a better object. I suppose people hadn't quite got rid of the idea that rifles needed a ramrod - a bit like most of the world's railways having the when spacing of George Stevenson's horsedrawn road carriage.

Here is my favourite pictures of an even larger side-mounted sword-bayonet, introduced for the muzzle-loading Enfield and occasionally used with a bushing for the Martini-Henry. Here it is used by Lord Roberts's Gurkhas storming the Peiwar Kotal, which is the back door into Afghanistan. I've got mine, but never a rifle to fit it.

[Artful]

Mosin 91/30 with and w/o bayonet fixed
https://www.youtube.com/watch?v=6elWsvQzNrY

Mosin M44 and T53 tested with and without
https://www.youtube.com/watch?v=cWGB9AjdXyY

Baker Rifle w/ Sword Bayonet
https://www.youtube.com/watch?v=J5ux-kBZIyM

[Mr_Sheesh]

Just touching a car antenna gently with a barrel will deflect POI sideways noticeably.

[Larry Gibson]

My MN poi changes low and left with the bayonet attached. Accuracy remains the same. Target shows 2 ten shot groups. Top group w/o bayonet. Lower left group is with bayonet mounted as per the Russian manual. The rifle's sights obviously were "zeroed" without the bayonet attached. Other "L" ammunition from various countries including mother Russia hit pretty much to the same poi. Zeroing the front sight windage with bayonet attached would result in the front sight being way off to the left side of the front sight base, hanging about 1/3 of the way out.

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Note; the service load hits high because the front sight was filed for a zero with the 314299 at 1900 fps. That load hits just above poa at 100 yards.

[Bigslug]

Well OK then. . .

I've been concurrently obsessed with the British mad minute and as such studying the Lee-Enfield family. It seems that the 6:00 mounted tent-stake bayonet on the No.4 was good for about 9 MOA of downward shift. The No.4 has a muzzle that's pressure bedded at 6:00 and not in contact at 12:00.

Gibson's Moist Nugget is shifting down and left with a bayonet at 3:00, and as I recall, the MN handguards and bands are full contact all the way around the barrel, so this is constructed much like the Chassepot I'm trying to sort out. The downward shift would be welcome, but the rifle's already shooting left by about 8-10 MOA.

Hmmmm. . .the best course of action at this point may be to surrender and cede Alsace-Lorraine.[smilie=b:

[shooterg]

No experience myself but we have frequent vintagr rifle matches - one guy did shoot his Krag with bay mounted and couldn't tell any difference(200 yards). Now we may have to create 2 classes - one rifle only, one with fixed bayonets !

[Mauser 98K]

yes the POI will change. it is the same as when using a suppressor. what happens is that A:the harmonics are effected slightly, and B: the extra weight on the end on the barrel will cause the barrel to ever so slightly droop if it is a long skinny barrel. varying pressures on a barrel are never a good thing if you want accuracy to stay the same. this is why you never mount a bipod on the barrel. you never allow the barrel to touch a wall like i have seen some schmucks do and then complain the POI is off the map. and if you have a rifle that you run a suppressor on you dedicate it to suppression as the POI will change with the added weight on the end of the barrel. this was never really a problem with the old rifles when fixing bayonets, as when you put the bayonet on the rifle it usually meant you was going to be within spitting distance of the target and the change at this range was not enough to make you miss the target.. bayonets require physical contact with the target, so POI changes was never a problem..

[Shiloh]

My '03 shoots better with no bayonet.

SHiloh

[am44mag]

I tested this with my M91/30 Mosin Nagant, I tried shooting with the bayonet on and off. There was a substantial difference in the point of impact. With the bayonet on, the rifle shot true to it's sights. With it off, it shot much higher. I don't remember exactly how much higher, but I think it was around 6-8" at 100 yards.

[derek45]

I tried it several years ago with my M1A and M1 Garand

it did change the 100yard zero on both

the muzzle blast fouling painted a sunrise pattern on the M14 bayonet ring


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