The recoil and reciprocating buffering action

[Peter Laidler]

GOOD question L-E. The friction collar - or as I prefer to call it, the brake ring - does actually work. It does spread and does grip the side walls of the buffer housing. If you were so minded and had a class of students to set a series of tasks for you could set up a small trial with a cut-open, cut down butt slide buffer housing and measure the poundage WITH and withOUT the nut and collar. Interestingly, when you visually inspect a well worn buffer housing you can actually see the witness marking made by the collar.

Another good part of your Q is that it has prompted me to re-read the student notes again. It mentions that the 3 small recesses in the rear end of the friction collar are there to ensure that the ring opens up equally around its circumference so as to friction equally around its circumference. I found it interesting precising (?-is that a word?) the old Shrivenham course notes for this. Makes you think...... Just ONE small part of the gun can be so mechanically interesting and important. Or just nerdy for the engineers amongst us!

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[Joe H]

GOOD question L-E. The friction collar - or as I prefer to call it, the brake ring - does actually work. It does spread and does grip the side walls of the buffer housing. If you were so minded and had a class of students to set a series of tasks for you could set up a small trial with a cut-open, cut down butt slide buffer housing and measure the poundage WITH and withOUT the nut and collar. Interestingly, when you visually inspect a well worn buffer housing you can actually see the witness marking made by the collar.

Peter,

I'm currently working on a semi BAR. I just got a copy of "Rock in a Hard Place" about the BAR. They give a detailed description of how the BAR buffer works. Same design as the Bren and same description as noted above.

Just as you said a small mechanically interesting part to us nerdy engineers

Joe

[TactAdv]

.....Just as an aside to this.......I've had the "pleasure" of repairing a few fullauto M1918A2 BAR's over the years and one of the more common issues is that the steel portions of the "cups-and-cones" buffer (all FOUR) inside the buffer stack are VERY hard to keep free of rust, the buffer tubes being inside the stock more often than you'd want to think get heavy accumulations of not just dust and lube, but also a lot of moisture gets trapped in there and that is one area that is invariably overlooked when cleaning the guns. Many guns start to have trouble, especially when set to "semi-auto" setting as the sliding actuator plug stops moving freely as required, and the buffer stack can get either very sluggish or possibly even just jam solid from years of rusting inside the tube. That buffer assembly is almost never completely cleaned, except when the gun stops working and the whole thing is torn down to find out why. Usually, it appears people just try and keep dumping more applications of some kind of spray lube in there which quite happily accumulates and combines with whatever amount of dust and grit that finds its' way inside too.

Same would hold true with the Bren.......therein laying a measure of advice. ;-)))

-TomH

[Joe H]

.....Just as an aside to this.......I've had the "pleasure" of repairing a few fullauto M1918A2 BAR's over the years and one of the more common issues is that the steel portions of the "cups-and-cones" buffer (all FOUR) inside the buffer stack are VERY hard to keep free of rust, the buffer tubes being inside the stock more often than you'd want to think get heavy accumulations of not just dust and lube, but also a lot of moisture gets trapped in there and that is one area that is invariably overlooked when cleaning the guns.

Thanks Tom for the insight.

The fire control on the semi will be hammer fired so the actuator will serve no purpose but I still want that buffer to work. I guess I'd better pull it apart and give it a good cleaning. I think the gun was in WWII rebuilt after the war with a new barrel, put in storage and then de-milled.

Joe

[MGMike]

......I've had the "pleasure" of repairing a few fullauto M1918A2 BAR's over the years and one of the more common issues is that the steel portions of the "cups-and-cones" buffer (all FOUR) inside the buffer stack are VERY hard to keep free of rust, the buffer tubes being inside the stock more often than you'd want to think get heavy accumulations of not just dust and lube, but also a lot of moisture gets trapped in there and that is one area that is invariably overlooked when cleaning the guns. Many guns start to have trouble, especially when set to "semi-auto" setting as the sliding actuator plug stops moving freely as required, and the buffer stack can get either very sluggish or possibly even just jam solid from years of rusting inside the tube. That buffer assembly is almost never completely cleaned, except when the gun stops working and the whole thing is torn down to find out why. Usually, it appears people just try and keep dumping more applications of some kind of spray lube in there which quite happily accumulates and combines with whatever amount of dust and grit that finds its' way inside too.

...

-TomH

The late Roy Dunlap had "been there and done that" in WWII, and his comments on the frailties of the BAR rate-of-fire/buffer assembly are instructive. Bellville washers are great in theory, less so under combat conditions. See his classic memoir, Ordnance Went up Front, p. 304-307.

M

[forti-cinis]

Here's my recoil and reciprocating action

[tr63]

Here's my recoil and reciprocating action

So with your system the buffer still operates on the Bren Gun ?

[browningautorifle]

the frailties of the BAR rate-of-fire/buffer assembly

Apparently water would freeing accumulate from the field and this was known. Two rates wasn't necessary anyway.