In Part I and Part II of the TFB Weight Omnibus, we published the weights of 58 rifles and submachine guns, and their magazines. Now, we’re going to take a look at that data, and do a little analysis to them to see what we can learn. First, my methodology when doing the weighings was somewhat flawed, and so we’ll have to compensate for that. Chiefly, I was inconsistent in whether I weighed rifles with or without their slings. In some cases, the slings of some of the rifles were old and delicate, and I did not want to remove them, but time constraints and a certain absentmindedness on my part were the larger reason behind this. To compensate, I’ve created four categories of slings which, while they won’t exactly match the weights of the slings actually mounted to the rifles, will be a close enough approximation. They are:

M1907 Leather Sling – Weight, 0.320 kg. For weapons mounting actual M1907 slings or reproductions.

Foreign Leather Sling – Weight, 0.160 kg. For weapons mounting any leather sling other than an M1907, as they are much lighter.

Cotton Web Sling – Weight 0.126 kg. For weapons mounting any cotton web sling, with one exception.

M1 Carbine Sling – Weight 0.100 kg. For the M1 Carbine, which has a considerably smaller sling than normal.

For the analysis, these values will be subtracted from the measured weight for any weapon weighed with an applicable sling. While this does introduce error, it makes the data more meaningful than if raw data was analyzed for all weapons, regardless of whether they were weighed with a sling or not. Further, even major percentage errors in sling weight estimates are a very minor percentage of the overall weight of most weapons.

The weapon weight data will be organized into 10 categories, those are:

1. All Weapons

2. Intermediate Caliber Rifles

3. 5.56mm and 5.45mm Rifles

4. Other Intermediate Caliber Rifles

5. Full-Power Semiautomatic Rifles

6. Full-Power Detachable Magazine Semiautomatic Rifles

7. Full-Power Fixed Magazine Semiautomatic Rifles

8. Bolt-Action Rifles

9. Bullpup Rifles

10. Submachine Guns

For each category, there will be produced charts of all the data in that category graphed on axes of the weapons and their weights, with one graph showing weapons with no magazine (if detachable), and weapons with affixed empty magazines. For the major categories, graphs of rifle weights on an axis of year of introduction will be created.

Values for the lowest weight, highest weight, difference between highest and lowest, mean weight, median weight, and standard deviation will be produced.

With all that out of the way, let’s begin:

1. All Weapons

 

Lowest Weight: 1.980 kg, M1 Carbine

Highest Weight: 4.798 kg, M1A1 Thompson

Difference: 2.818 kg

Mean Weight: 3.675 kg

Median Weight: 3.704 kg

Standard Deviation: 0.584 kg

 

Lowest Weight: 2.058 kg, M1 Carbine

Highest Weight: 5.036 kg, M1A1 Thompson

Difference: 2.978 kg

Mean Weight: 3.820 kg

Median Weight: 3.862 kg

Standard Deviation: 0.590 kg

 

2. Intermediate Caliber Rifles

 

 

Lowest Weight: 1.980 kg, M1 Carbine

Highest Weight: 4.478 kg, RPK-74

Difference: 2.498 kg

Mean Weight: 3.498 kg

Median Weight: 3.600 kg

Standard Deviation: 0.522 kg

Lowest Weight: 2.058 kg, M1 Carbine

Highest Weight: 4.786 kg, MP.43

Difference: 2.728 kg

Mean Weight: 3.659 kg

Median Weight: 3.714 kg

Standard Deviation: 0.552 kg

 

3. 5.56mm and 5.45mm Rifles

Lowest Weight: 2.828 kg, MR556 SBR

Highest Weight: 4.478 kg, RPK-74

Difference: 1.650 kg

Mean Weight: 3.558 kg

Median Weight: 3.604 kg

Standard Deviation: 0.418 kg

Lowest Weight: 2.950 kg, LE6920

Highest Weight: 4.696 kg, RPK-74

Difference: 1.746 kg

Mean Weight: 3.722 kg

Median Weight: 3.743 kg

Standard Deviation: 0.435 kg

 

4. Other Intermediate Caliber Rifles

Lowest Weight: 1.980 kg, M1 Carbine

Highest Weight: 4.394 kg, MP. 43

Difference: 2.414 kg

Mean Weight: 3.278 kg

Median Weight: 3.298 kg

Standard Deviation: 0.756 kg

Lowest Weight: 2.058 kg, M1 Carbine

Highest Weight: 4.786 kg, MP.43

Difference: 2.728 kg

Mean Weight: 3.426 kg

Median Weight: 3.298 kg

Standard Deviation: 0.817 kg

 

5. Full-Power Semiautomatic Rifles

Lowest Weight: 3.616 kg, SCAR 17S

Highest Weight: 4.756 kg, G.41(M)

Difference: 1.140 kg

Mean Weight: 4.224 kg

Median Weight: 4.282 kg

Standard Deviation: 0.291 kg

Lowest Weight: 3.858 kg, SCAR 17S

Highest Weight: 4.770 kg, SIG AMT

Difference: 0.912 kg

Mean Weight: 4.364 kg

Median Weight: 4.470 kg

Standard Deviation: 0.267 kg

 

6. Full-Power Detachable Magazine Semiauto Rifles

Lowest Weight: 3.616 kg, SCAR 17S

Highest Weight: 4.474 kg, SIG AMT

Difference: 0.858 kg

Mean Weight: 4.107 kg

Median Weight: 4.143 kg

Standard Deviation: 0.256 kg

Lowest Weight: 3.858 kg, SCAR 17S

Highest Weight: 4.770 kg, SIG AMT

Difference: 0.912 kg

Mean Weight: 4.334 kg

Median Weight: 4.339 kg

Standard Deviation: 0.278 kg

 

7. Full-Power Fixed Magazine Semiautomatic Rifles

(Note that for this category, any rifle is included that was designed to be loaded with the magazine fixed, regardless of whether the magazine is readily removable or not)

Lowest Weight: 4.018, Pedersen PB

Highest Weight: 4.756, G.41(M)

Difference: 0.738

Mean Weight: 4.359 kg

Median Weight: 4.399 kg

Standard Deviation: 0.226 kg

 

8. Bolt-Action Rifles

Lowest Weight: 3.624 kg, M1903A3

Highest Weight: 4.030 kg, M1917 Enfield

Difference: 0.406 kg

Mean Weight: 3.858 kg

Median Weight: 3.856 kg

Standard Deviation: 0.146 kg

 

9. Bullpup Rifles

Lowest Weight: 3.600 kg, Steyr AUG A3 and Tavor

Highest Weight: 3.694 kg, FS2000

Difference: 0.094 kg

Mean Weight: 3.640 kg

Median Weight: 3.633 kg

Standard Deviation: 0.041 kg

Lowest Weight: 3.706 kg, Tavor

Highest Weight: 3.800 kg, FS2000

Difference: 0.094 kg

Mean Weight: 3.751 kg

Median Weight: 3.748 kg

Standard Deviation: 0.041 kg

 

10. Submachine Guns

Lowest Weight: 2.618, MP5

Highest Weight: 4.798 kg, M1A1 Thompson

Difference: 2.180 kg

Mean Weight: 3.274 kg

Median Weight: 2.983 kg

Standard Deviation: 0.762 kg

Lowest Weight: 2.740, MP5K-PDW

Highest Weight: 5.036 kg, M1A1 Thompson

Difference: 2.296 kg

Mean Weight: 3.489

Median Weight: 3.231

Standard Deviation: 0.789 kg

 

Finally, The Thrilling Conclusion:

So what did we learn here? Well, most obviously, the Thompson submachine gun is incredibly overweight, and it’s difficult to justify in retrospect the fielding of such a weapon during the latter part of World War II, when obviously better options were available. In contrast, the early model M1 Carbine is absolutely jaw-droppingly light, handily beating the next-lightest gun (the MP5) by almost three-quarters of a kilogram (almost a pound and a half)! We discovered that bullpups and early full-power selfloaders all pretty much weigh the same as their stablemates, but that there is rather a lot of variation within the 5.56mm/5.45mm camp. Surprisingly, plotting weights versus the year of introduction of the design didn’t yield any immediately obvious trends. It seems as though the lightness of the rifle probably depends more on the talent of its designer than the materials available to him.

Of course, 60 rifles was a lot for one guy to weigh in just a day and a half, but even so the sample sizes were pretty small for many of the subcategories, and it would be further enlightening if those were expanded.