Mexican War to Civil War – The Model 1841 6-pdr Field Gun

In the discussion of the 6-pdr field guns, I’ve built up to the Model 1841 with much justification.  The type represented the ultimate reversion from iron to bronze for field pieces, the findings of a series of tests, and the affirmation of the proper length to weight proportions for field pieces.  The type provided the Army with a weapon equal to any of those in Europe.  In service, the Model 1841 served well (nay… outstandingly!) in Mexico.  But of course by 1861, was eclipsed by heavier caliber field pieces and rifled guns, but still served in large numbers through the war.

Again looking at the comparison of previous 6-pdr bronze guns, the Model 1841 returned to the full 57.5 inch bore of the Model 1835 and added more metal around the breech with the 10.3 inch diameter of the Model 1840.

At 880 pounds, the Model 1841 registered as the heaviest field piece since the old iron guns.  The final form followed the same basic pattern of the earlier bronze guns with base ring, reinforce shoulder, chase ring, and muzzle swell – seen here in a diagram from the 1864 Instruction for Field Artillery (plate 6).

The same manual offered a diagram of the carriage also standardized in 1841 for use by field artillery (Plate 8).

And the carriage worked with a new limber, which carried the ready ammunition chest (Plate 11).

This established the familiar carriage and limber arrangements used in both the Mexican War and Civil War (and well beyond for what it is worth).

The 6-pdr ammunition chest contents, by regulation, varied a bit over the years.  The 1850 Ordnance Manual instructed contents to include 35 shot, 5 spherical case, and 10 canister.  The 1862 Ordnance Manual modified that load-out to 25 shot, 20 spherical case (A.K.A. case shot or shrapnel) , and 5 canister.  This change to the mix perhaps noted the growing importance of case shot rounds in the tactical implementation of the guns.  It also brings up a question regarding the use of canister, which I will save for another day.  As noted in my earlier discussion of Field Artillery mobility, with one chest on the limber and two chests on the caisson, a 6-pdr gun going into action had 150 ready rounds for use.

A standard solid shot for a 6-pdr measured 3.58 inches in diameter and weighed 6.1 pounds.  This afforded a very narrow windage under a tenth of an inch from the standard bore size of 3.67 inches.  A 1.25 pound powder charge in the 6-pdr propelled that solid shot to a range of 1523 yards at 5 degrees elevation.  By regulation, packing boxes for solid shot had an olive coat of paint for easy identification.

A spherical case for the 6-pdr contained 37 musket balls and a half ounce bursting charge.  The filled spherical case weighed 5.5 pounds.  As noted in the table above, the 6-pdr ranged 1200 yards at 4 degrees elevation with a spherical case shot.  Case shot boxes were painted red.

A standard 6-pdr canister contained 48 cast iron, 1.15-inch diameter, 0.21 pound balls.  The loaded canister weighed just over seven pounds without charge or sabot.  Shipping boxes for canister were painted a drab color when prepared for use.

Notice the 6-pdrs did not have a shell projectile designated for use.  In the mixed gun-howitzer batteries of the day, the 12-pdr field howitzers would provide the shells where needed.

Both the 1850 and 1862 Ordnance Instructions offered particulars of European guns for reference.  While these are the “known” dimensions and weights, and are not specific to other nation’s model years, the particulars allow for at least some comparison of the American guns to their contemporaries.

While offering the same length as the “late” British 6-pdr, the American gun was heavier by over 200 pounds.  The French calibers straddled the 6-pdr size, and were generally longer and heavier.  The American gun fell well within the European range for weight and length for bronze guns.  And recall the Army tested some Sweedish 6-pdr guns in 1841 for side-by-side comparisons.  What the chart does not provide are two more important measures – range and durability – which would perhaps confirm or refute the wisdom of the American design.

Since the Model 1841 represented a significant point in both the evolution of the 6-pdr type and overall in the study of American field artillery, I’ll break out the next posts with more details on production and variants, along with a “walk around.”

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