Bayonet moves point of impact

[Gil Boyd]

Thats close and personal, and as I said, and it often happens in built up areas and high grassed fields where "first come first serves" is the only motto for survival

[Charlie303]

Have you checked your barrel dampening?

Thank you Jesse, but no not yet. I know that the Lee Enfield No.4 has defined movement / damping at the barrel tip, but no idea if the M1 should have. I'll look into it.

[Charlie303]

At the local range today, 100 yards with the M1. And another bayonet experiment. I remembered that when I got the M1 I’d tried it with a a standard WW2 M1 bayonet and it made no difference to the POI. So I tried it again today and same result, POA = POI. Put the M1905E1 on and POI up by 14”. Weird! Something about the harmonics of the M1905E1 blade, the metal and/or the shape, is having a hell of an effect on the barrel when fired. I have 2 more bayonets, another M1905E1 (Bowie tip to the blade) and a Korea era M5 which has a different mount which I will try to see what they do.
Attachment 118051

[Ovidio]

14” is a lot…

[Gil Boyd]

Sadly that sort of spread is not uncommon.
Bayonets are like bipods, any additional weight at the front end stops a "floating" barrel from doing its job, and one has to expect these types of performance.
Thats why it is a CQB (Close Quarter Battle) option to be fitted, when you are close in or low or out of ammo!

[CalTex]

Charlie303, thanks very much for sharing that. I agree that is very odd that between two bayonets that look very similar and were issued interchangeably, one does not move the point of impact and the other moves it 14 minutes! You could have probably won a few bets on that.

I have never shot with a bayonet on or out and I am not 100% sure it would fly at my local range. I would also be interested to know: 1. Did your group size change with either bayonet vs. with none? 2. Did the group center only move up with the cut-down bayonet, or was there any side-to-side movement as well? 3. Did either bayonet feel looser in attachment than the other one?

[Charlie303]

Hi CalTex,

The POI movement was in the vertical plane, I didn't notice any lateral movement nor a change in the group size.

Yesterday out at the range again and more trials with different Garand bayonets.

The standard WW2 M1 by AF&H made no difference to the POI as before.

I then tried a different M1905E1 bayonet, this one with the 'Bowie' blade tip, a cut down 1942 OL (Oneida Limited) blade. This lifted the POI by about 8".

Then a post-WW2 M5 Bayonet. As you probaby all know, the M5 mounting was different on the rifle. It made no difference to the POI at all, but did fall off twice when firing , a result of the bayonet's catches not engaging properly with the M1's lugs. Oiling the mechanism of the bayonet helped but didn't eradicate the problem entirely, the internal spring seems a bit weak.

[Charlie303]

Sorry CalTex, I didn't address your last question. The M1 and M1905E1 bayonets lock on the rifle using the same system and all appear to be exactly the same when mounted, a bit loose and wobbly.

As to why both the M1905E1 bayonets raise the POI, it may be the steel used. I'm no metal expert but both M1905E1 blades appear to be made of better quality steel and the finish is much better than the standard M1. The quality of the steel may be superior possibly due to them being cut down from a longer original bayonet which required a better steel. This may be having an affect on the harmonics of the barrel/bayonet when fired.

[baltimoreed]

I’ve mounted bayonets on several rifles during my cas clubs BAM shoots. 1866 and 1873 Winchester muskets and my Krags. Of course we are shooting steel at close ranges. Never tried doing a comparison of with and without. Even fired my ‘97 and M12 trench guns with the looong bayonet. It’s a hoot.

Attachment 118334Attachment 118335

[CalTex]

Thanks Charlie, very interesting tests, and no doubt fun to try. Re: looseness, I was thinking that one that was looser might dampen the harmonic effects, though it might also amplify them. Since no difference among them, no mileage on that theory.

Beyond any differences in steel density, the M1905E1s definitely have different sections along their length than the M1 and vs. each other, and so different density along their lengths that might explain the differences. It’s interesting that the M1 and the M5 showed the least difference. If this is consistent across different bayonets and different rifles, I wonder if this might have been due to any tweaking of their sections in final design to minimize the difference. Of course, not a lot could be done with the cut down versions if they were going to be the same length.