Test Gun: S&W M442
Barrel length: 1 7/8 inches.
Ammunition: Remington .38 Spl 158gr +P LHP (Part # 22297)
Test media: 10% Vyse Ballistics Gel
Distance: 10 feet.
Chronograph: Caldwell Ballistic Precision Chronograph G2.
Five shot velocity average: 763fps
BB Calibration: 3.75 at 585fps, 3.73 at 577fps
This is something that people have been asking for a long time. As it has become known, the “FBI” load. The one made by Remington is basically the same as Federal and Winchesters ones. At this point, someone is going to comment that one or the other is different in some way, whether it be the lead is softer or harder.
This is the one I have, so it’s the one getting tested. Let’s get started.
I achieved a five-shot average of 763fps with a high of 777fps and a low of 754fps with an extreme spread of 23fps at 10 feet. Unfortunately, no velocity was recorded with the gel shots. The first two shots were a bit high and exited the block. This is what can happen when you have aging eyes, small sights, and dim lighting.
The first shot in the bare gel penetrated to 13.5 inches and expanded to .59 by .58 inches. The recovered weight was 156.5 grains.
Round two expanded 12.5 inches in the block and expanded .58 inches all around. The recovered weight was 158.7 grains.
Neither round expanded through the heavy clothing covered gel. Both showed deformation and ended up with a shape similar to a wadcutter. Both penetrated the 16 inch Vyse gel block and into the clear gel catch block at 17 and 19.5 inches.The weights were 156.1 grains each.
General Cartridge 
Barrel-cylinder gap can influence velocity as much as barrel length. S&W these days considers a gap of up to 0.010″ as being “within spec.” In my time (1980s) max. was 0.008″ in the “pass” dimension [in which a “front gage” could be inserted completely through the frame window and the cylinder triggered through a full revolution in DA]. The max “hold” dimension was 0.009″ in which the front gage could be inserted through the frame window, but would bind cylinder rotation in DA with the “rear gage” in place. Not having Go and NoGo headspace gages insert sized, fired brass in the chambers when gaging. A gun having an 0.010″ pass dimension would have been rejected as “open front gage.” The factory fix back in the day was to refit a “+” cylinder which was 0.005″ longer to correct a large gap without having to set back the barrel. This is necessary because barrels cannot be swapped on airweight guns without damaging the frame.
The expected Delta-V in .38 Special firing lead-bullet ammunition is 10 fps per 0.001″ change in cylinder gap from Mean Assembly Tolerance. It is therefore possible that a 2-inch gun at min. spec could produce velocity higher than a 4-inch gun at max. spec.
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Not even breaking 800 ft/sec? No wonder they failed to expand after clothing. It’s a minor miracle they deformed in bare gelatin. I wonder if they might do better 150 or so ft/sec faster, like the box says they’re supposed to.
Also, S&W pushed their max acceptable barrel/cylinder gap up to .012″. I would have thought a gap that big would cause lead splinters to fly out the sides on every shot, unless they really hogged out the forcing cone too.
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