To most, this is going to be a real yawn fest. But, if you're a detail nerd like me, you might enjoy it. I received a small parcel from France today containing some NOS nylon knobs with their fastening pins for the MAS 49/49-56 rifles and it got me to pondering. You'd think something as simple as a synthetic cocking knob that slips over a steel charging handle to give you a better grip would be a no brainer thing. Design something simple, test it to make sure the design is sound and BLAMMO, you're good to go for the life of the design's service life. Yeah, welllll, they're French. Besides, when you think about it, the changes, most of them anyway, do make sense. Lets take a look. Now, for the most part, my thoughts below are not based on any "official" documents I've encountered, but rather observations made over time and experience so, take them for what you will. Also, the way I'm presenting them is also a bit convoluted but should be clear enough so that a careful reader will be able to follow along just fine. In other words, don't just look at the pictures Francis; read the words too!
When the MAS 44 was introduced, polymers were really still a pretty new thing if you think about it. Installing a plastic knob over a steel handle made sense. It enlarges the grasping surface enabling a better purchase by the user for a more robust charging of the rifle while also saving steel, fabrication time, and weight. It was also more durable than a wooden knob which may easily crack. Well, it turns out that the plastic used, shrinks over time and becomes brittle. Eventually, with enough time and use, those knobs cracked and fell to pieces. To the left in the picture below, you see a severely cracked MAS 44 knob (ignore the other knob for now):
I don't even pull back on this knob unless I've removed the receiver cover and recoil spring for fear of it shattering in my hand.
It appears there were other problems too. Use the following picture as a reference when reading the text following it:
As far as I can tell, the MAS 44 knobs were not molded. Instead, they seem to have taken a long plastic rod and knurled it along its entire length. Then, it was cut up into cocking knob sized pieces. Next, each knob was drilled to accommodate the steel charging handle on the bolt carrier. A further hole was drilled across its axis for the affixing pin and then, finally, to each outside face of that pin hole was added a larger diameter blind hole. To affix the knob to the bolt carrier, the knob was placed over the charging handle and rotated until the pin hole in the knob aligned with the one on the carrier. Next, a rondel was placed into both blind holes and the affixing pin pushed into position until it was flush with both sides of the cocking knob. Finally, a pointed punch was placed on either side of the affixing pin (most likely by a machine dedicated to this purpose) and pressure was applied, expanding the diameter of the affixing pin and locking it to the rondels, thus locking everything together into a solid unit on the bolt carrier. Notice two pictures above, the divot in the affixing pin from it being squeezed. Is that complicated enough for you for a knob that ends up cracking to pieces?? Back to the drawing board.....
Next, they came up with a nylon knob that was attached in the same way as the plastic knob. This was used on the MAS 49. Like the MAS 44 knob, it was knurled but it was larger. However, each knob was now molded, reducing necessary machining to boring the charging handle hole, the affixing pin hole and the two rondel recesses. Changing the material seems to have done the trick as I have a MAS 49 dating from 1953 with its original knob still in place and, other than the knurling wearing down some from use, it appears to be still going strong (this time, ignore the knob on the left)
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So, the polymer problem was solved. The next challenge was to simplify the outlandishly crazy affixing method.
The next knob was the one used on the MAS 49-56. It was nylon and it was knurled as before, but it's a finer knurling. They were also molded individually and the charging handle and affixing pin holes needed to be bored but they eliminated the rondels and went with a smaller pin, not a roll pin, but a solid pin driven in. This pin was then, as before squeezed on either end creating a divot that is often mistaken for the end of a roll pin.
In both the first edition and the 1974 2nd edition of the parts catalog for the 49-56, knurled knobs are illustrated and only one part number is used, telling me that the knurled knob was the only knob used while the rifle was still being manufactured.
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MAS 49 and 49-56 knurling compared:
I have just a few more pictures and thoughts to finish up in the next post.