Carbine bayonet band - how tight and where?

I have a carbine with which I have won a couple of competitions and been well placed in others. Everything is OK except the barrel band, on which I had to fix the screw with a twist of wire in the slot, to stop it gradually shifting and the zero wandering.

In the article "Carbine shooting with accuracy" (available online) it says:

"... a bayonet lug barrel band outshoots the other kinds with the least fooling around. The rebuilds with a bayonet band are accurate ... The tight fit of the bayonet lug barrel band covers up and cures many other problems with carbines."

So I bought a bayonet barrel band (maybe repro, but that doesn't matter). But it does NOT have a "tight fit". In fact, it is a loose fit! :thdown:

So how tight should the band be? I guess it should be a rubbing fit, like the original band. And where should it be tight? All the way along, or just front and rear?

Any advice will be welcome!

Patrick

Quote:

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Originally Posted by Patrick Chadwick

I have a carbine with which I have won a couple of competitions and been well placed in others. Everything is OK except the barrel band, on which I had to fix the screw with a twist of wire in the slot, to stop it gradually shifting and the zero wandering.

In the article "Carbine shooting with accuracy" (available online) it says:

"... a bayonet lug barrel band outshoots the other kinds with the least fooling around. The rebuilds with a bayonet band are accurate ... The tight fit of the bayonet lug barrel band covers up and cures many other problems with carbines."

So I bought a bayonet barrel band (maybe repro, but that doesn't matter). But it does NOT have a "tight fit". In fact, it is a loose fit! :thdown:

So how tight should the band be? I guess it should be a rubbing fit, like the original band. And where should it be tight? All the way along, or just front and rear?

Any advice will be welcome!

Patrick

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How tight is a subjective matter. It should not move once installed at all. Normally, the screw will not bottom-out against the band-nut once snugged and should lock the hand guard in place. If you run the screw down to the point it bottoms and the band is still lose, I’d suggest you have an issue with the nose of the stock. The specification often used for the torque of the band-screw is “snug”.

I remember the discussions here some time back about the accuracy being at the back end where the receiver was "Hung" being the key to accuracy. If they didn't hang correctly they'd never shoot???

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Originally Posted by browningautorifle

I remember the discussions here some time back about the accuracy being at the back end where the receiver was "Hung" being the key to accuracy. If they didn't hang correctly they'd never shoot???

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Agreed, I've always thought as long as the barrel floated a little bit above its channel after "hanging" the action in The recoil plate, that it should be fairly accurate. And the front band screws were designed to be tightened with an empty brass casing so I would guess they're not really meant to be torqued really tight

Hello Patrick,
According to Jim Mock-
" the bayonet lug provides a far more secure method of holding the barrel band to the barrel, stock and handguard without shifting and therefore provides far more reliable and better accuracy than the narrower barrel bands."

Found at the bottom of this link:
The U.S. Caliber .30 Carbines - Barrel Manufacturers

I have a IBM I shoot a lot that began to wander off center. I assumed the bore was getting worn as I had made no changes in ammo or the recoil plate set.
I found that the barrel band when tight had some side to side and teeter totter movement.
While tearing down to clean the Bayonet band slid very easily off the wood work and up the barrel. Normally I oil or lightly grease ahead of it on the barrel to limit scratches... but didn't need to this time. Later I took it off along with the front sight and compared it to a NOS Bayonet band. The 3 inner pads on the front end of my old Bayonet band showed a lot of wear, they looked like worn out brake pads. They stood proud on the NOS one. When I put the new one on I had to oil/grease the barrel again to limit scratches to the barrel.
After getting things back together it was accurate again. So just note those 3 inner pads that put finish wear on 3 spots on your barrel do in time wear down and don't get the bite on the barrel, stock and hand guard.

Maybe yours is doing the same thing?

On another I was getting a little forward and rearward movement of the barrel band (as much as the barrel band spring would allow).
The Band being as tight as I could get it also allowed movement between the stock and hand guard.

I used a thin strip of leather over the top lip of the hand guard (cut boot lace) as a shim.
The strip of leather snugged it up and has worked well. I've read about guys using that 2 sided tape the same way.

Guess we have to expect some wood crush after all these years... So we intervene as lightly as we can.

Good Luck, Keep in touch how things go for you.

Quote:

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Originally Posted by flydthecat

How tight is a subjective matter. It should not move once installed at all. Normally, the screw will not bottom-out against the band-nut once snugged and should lock the hand guard in place. If you run the screw down to the point it bottoms and the band is still lose, I’d suggest you have an issue with the nose of the stock. The specification often used for the torque of the band-screw is “snug”.

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A couple of years back I had difficulties with a CMP "High-wood" stock where the band wouldn't tighten enough and it would move forward during firing and the upper hand guard would fly off when firing. I contacted the CMP and explained the problem (and I had tried three different barrel bands to see if that was the issue and all three were the same) and was asked for a copy of the original receipt. I couldn't find it at the time so I couldn't send it back, which I'd explained in subsequent emails. He suggested gluing a small strip of leather at the front of the hand guard to take up some space as without that receipt the CMP couldn't exchange it. I've not done that yet as I've been trying other methods, but I think I'll be epoxying a thin strip of pigs leather to that little ledge soon to see how that works as it's far less difficult than trying to do so with glass bed. Trying to coat necessary parts with release agent and get it right the first time is far harder. Yes there might be a moisture problem as leather soaks up water, but it's worth a try as I've two carbines with the same issue. An alternative is to lay some glass bed on that ledge, let it set, and file it to shape. I'll try the leather first.

---------- Post added at 10:40 AM ---------- Previous post was at 10:36 AM ----------

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Originally Posted by painter777

Hello Patrick,
According to Jim Mock-
" the bayonet lug provides a far more secure method of holding the barrel band to the barrel, stock and handguard without shifting and therefore provides far more reliable and better accuracy than the narrower barrel bands."

Found at the bottom of this link:
The U.S. Caliber .30 Carbines - Barrel Manufacturers

I have a IBM I shoot a lot that began to wander off center. I assumed the bore was getting worn as I had made no changes in ammo or the recoil plate set.
I found that the barrel band when tight had some side to side and teeter totter movement.
While tearing down to clean the Bayonet band slid very easily off the wood work and up the barrel. Normally I oil or lightly grease ahead of it on the barrel to limit scratches... but didn't need to this time. Later I took it off along with the front sight and compared it to a NOS Bayonet band. The 3 inner pads on the front end of my old Bayonet band showed a lot of wear, they looked like worn out brake pads. They stood proud on the NOS one. When I put the new one on I had to oil/grease the barrel again to limit scratches to the barrel.
After getting things back together it was accurate again. So just note those 3 inner pads that put finish wear on 3 spots on your barrel do in time wear down and don't get the bite on the barrel, stock and hand guard.

Maybe yours is doing the same thing?

On another I was getting a little forward and rearward movement of the barrel band (as much as the barrel band spring would allow).
The Band being as tight as I could get it also allowed movement between the stock and hand guard.

I used a thin strip of leather over the top lip of the hand guard (cut boot lace) as a shim.
The strip of leather snugged it up and has worked well. I've read about guys using that 2 sided tape the same way.

Guess we have to expect some wood crush after all these years... So we intervene as lightly as we can.

Good Luck, Keep in touch how things go for you.

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Exactly my thinking.

I have deformed the lip on commercial bands and even commercials with post war T3 bands to tighten things up. Just lightly bend the top lip edge inward to make better contact with the nose of the hand guard similar to what one might do with the rear tab and it’s not noticeable.

NO….I would not suggest that on a rare or original band, only for shooters. You can’t very well make dead wood grow and I never have been fond of gluing anything on a gun. But, various solutions are available.

Quote:

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Originally Posted by flydthecat

I have deformed the lip on commercial bands and even commercials with post war T3 bands to tighten things up. Just lightly bend the top lip edge inward to make better contact with the nose of the hand guard similar to what one might do with the rear tab and it’s not noticeable.

NO….I would not suggest that on a rare or original band, only for shooters. You can’t very well make dead wood grow and I never have been fond of gluing anything on a gun. But, various solutions are available.

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Ah, a solution I had not considered but will.

"So just note those 3 inner pads that put finish wear on 3 spots on your barrel do in time wear down and don't get the bite on the barrel, stock and hand guard.
Maybe yours is doing the same thing?"

I think you got it Charlie! This bayonet band seems to be an original Quality Products band that, judging by the abrasion, was removed from another carbine. The slop was only 0.002", so maybe it was removed in a brutal manner. So I pragmatically tightened the lips front and back until it became a push fit on the barrel.

BTW, this is a shooting carbine, not a collector's item. Probably used postwar by some non-US authority - seems to have had an arsenal makeover in 1961.

https://www.milsurps.com/showthread....hlight=carbine

Warped stock, loose recoil plate, tatty extractor, etc. etc. The stock was so badly warped that I had to file a bit off one side to shift the band over and stop the barrel binding on that side. The type 2 band could easily twist and loosen the screw, hence my binding it with wire to keep the screw in position. But it still shot better than most, thanks to an AI bore!

Thanks to all who commented - I've been through the book on carbine adjustment, and this was the last aspect.

If this fix works, by stopping the band twisting, I shall post a couple of photos. If it does not work, then you may judge by my silence that it was a failure!

Here's hoping! And now I have to go and make up some really good ammo...

Patrick

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Originally Posted by Patrick Chadwick

Probably used postwar by some non-US authority - seems to have had an arsenal makeover in 1961.

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Patrick,
I have a feeling your barrel may have been inspected by the Dutch. AI was the mark used by the artillerie inrichtingen Dutch arsenal. Other carbine barrels have been reported with this marking and 60's dates.
The Dutch were also supplied thru the MAP Program / Lend-Lease.

Here is a link to Patrickduis from the Netherlands, reporting this marking on his carbine:

Inland s/n 373872 - The Carbine Collector's Club

Here are more examples of Carbines found by Patrickduis from the Netherlands:

Looking for info n the U.S. 104th I.D. - The Carbine Collector's Club - Page 1

The AI Logo Stamp-

https://static.wikia.nocookie.net/gu...20190311062554

I hope you find this helpful :thup:

Brilliant Charlie! Many thanks!

Unfortunately, the 2nd link doesn‘t produce anything.

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Originally Posted by Patrick Chadwick

2nd link doesn‘t produce anything

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I don't know why?
Here is the homepage: The Carbine Collector's Club

When open try the first search box on the upper left with this:
Looking for info on the U.S. 104th I.D.

:dunno:

Maybe this ?

Looking for info on the U.S. 104th I.D. site:www.uscarbinecal30.com - Google Search

Thanks Charlie, got the Carbine Collector‘s Club now!

And now, of course, I‘m wondering whether my carbine came from the same source as Patrick Duis‘ example.:confused:

Anyway, I just made up enough ammo to be able to try it out again.

BTW, a couple of years ago (i.e. pre-Covid) I had the recoil plate perfectly set up so that the barrel floated about 1/8“ high in the channel before tightening the band. When I reassembled it with the bayonet band this float had disappeared. The recoil plate screw was not completely loose, but by no means tight. So I tightened it up to what I felt was a wood-compressing - but not wood-crushing - torque (i.e. remaining within elastic limits) and - hey presto! - the 1/8“ float was back again.

It obviously needs some kind of fixing. I don‘t want to have to re-torque it before every competition. I‘m thinking of a dab of contact adhesive over the end of the screw and the inset nut. Any other suggestions?

Patrick

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Originally Posted by Patrick Chadwick

. I‘m thinking of a dab of contact adhesive

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Maybe blue loctite? That can be broken by hand. Make sure you get a new tube and when done discard the rest. This advise was given me here after years of holding onto stuff...and it goes to pot. New tube...

Thanks Jim, it is indeed important that it can be broken by hand.