Early B-17 Ammo Boxes
Early B-17 Ammo Boxes
The .50 cal. M2 BAM guns, aircraft model, on the first production B-17 aircraft were equipped with AAF Type O-1 ammo-boxes, holding only 33 rounds each; this was inadequate, and Boeing designed their own ammo-boxes from the B-17C onward, for the non-electric-turret guns. Turret manufacturers provided their own ammunition handling systems.
The first three boxes were designed for the B-17C; a top-gun box, bottom-gun box and a side-gun box. Of these three, only the side-gun box is seen in the majority of old B-17 photos, due to the photogenic side-gun position.
I've acquired from Smithsonian NASM full-scale prints from microfilm of the original Boeing drawings for these 3 boxes, as well as the 500-round dorsal-gun box used on the B-17F “radio-room†gun after the side and dorsal-guns were upgraded to bulk-feed with Hughes Aircraft flex-tube feed (not yet sure, but I believe the tail-gun may have been given bulk, 500-round feed before the other guns, starting with the B-17E). I will try to give a good description here.
Full-scale prints from microfilm, with 47% replicas of E-8 mounted M2 and Side-Gun box
15-6999 BOX ASSEMBLY CAL .50 AMMUNITION. This box is tall and rectangular, and looks as if it was based on the AAF O-1 box, but holds 100 rounds of link-belt ammo. Dimensions are 17†tall (exclusive of top handle), 5.56†inside dimension W, and 5.20â€W at bottom, and 5.60†top-length. The box loads from the top, which is secured with an ordinary cupboard latch and slides to the rear. The box originally attached to an “L†shaped bracket fastened to the E-5A dual adaptor in place of the outside trunion-bracket pair.
This box has a “C†shaped bracket riveted to the sides just under the feed-opening, with “U†clips bent at the right and left ends of the front. The feed-opening on this box is at the top, very similar to the O-1.
This top-gun box was used on the B-17C, D & F models.
15-7453 BOX ASSEMBLY (BOTTOM-GUN) .50 CAL. AMM. (Rev E,F). This box is also basically tall and rectangular, except for a bulge on the rear from the top down about 6â€. This box also holds 100 rounds, routed over an internal feed-roller, feeding a baffle that puts the feed-mouth about 5.70†down from the top, so that the box hangs about equally above and below the bottom-guns, which were also twin M2's on an E-5A ring-mount. It has the same height and bottom-dimensions as the 15-6999 box, and the same arrangement for the mounting clip.
This box shows 10 sheet-metal reinforcements in the form of “sausage shaped†embossing spaced at 2†intervals, 3 on front, 2 on the bottom, and 5 on the rear. A window 2-11/16â€W drops down the upper front from the horizontal axis to the feedway, showing the ammuntion belt when loaded.
Both the previous boxes were assembled with spot-welding; construction was basically two flanged sides and a front/bottom/back bent from a single piece of sheet metal.
15-7469 BOX ASSY SIDE GUN AMM. This is the best-known of the Boeing ammo-boxes, as the side-gunners were considered the most photogenic, and these boxes appear in good number on the WWW when googling “B-17 side-gunner†or B-17 waist-gunner.†This box has what I would describe as an “Art Deco†design. 12-1/8†tall overall, and 5.67†W across the front, and a Depth of about 8.20†from rear-edge to line-of feed-mouth. There is a roller, on a 1/4†axle-assembly with 1/4-28 thread-ends, and the handle is attached on this axis with washers and a lock-nut.
47% scale-replica of the Boeing Side-Gun Box
The rear-panel is 10.03†high, and the top slopes upwards about 16 degrees toward the front radius of 2.02â€; the top-cover ends at 45 degrees from the axis, and has a simple latch sliding front-to-back at the top rear. A window 2-11/16â€W drops down the upper front from the horizontal axis to the feedway, showing the ammuntion belt when loaded. This box also has two flanged sides, and a bent-sheet forming the lower front, bottom and rear-panel; unlike the other boxes, this one uses riveted construction to fasten the sides to the other pieces.
This was introduced on the B-17C, and used (with some changes) through the B-17F. It appears (from boxes seen in Destination Tokyo (1944) and Air Force (1943)) that this box was originally made to clip directly onto the flat side-bars of the E-8 flexible adaptor, with two individual clips riveted on the lower front edge of the box; however, by the B-17E it appears to have been harmonized with the other boxes by replacing this with the side-riveted “C†clip located, as the others, just below the feed-mouth.
By the B-17E, all the 100-round boxes were slung from the guns themselves, by placing a bracket on the feed-side pawl-bracket of the M2; this bracket also was used to attach the Hughes flex tubes, and made the boxes compatible with same for backup (those 500 round boxes did run out of ammo, and it took much too long to reload them during combat).
The only revision available from Smithsonian NASM is the last rev, I,J, and this version deleted the embossing seen on bottom and rear of this box in the many photos and motion-pictures, apparently as an economy measure, but no photos of this particular rev have shown up; all those I have seen photos of have the embossing, the same as on the 15-7435 box.
HTH, Regards, John
Reply With Quote
Originally Posted by Guamsst
