The Union was not capable of producing 15,500 terms because 1860 numbers include the 11 States of the Confederacy; obviously their secession dropped American production and it took until 1866 to recover as documented by the charts provided.
How did you miss that I was using Union production from 1861, the lowest point of US production, not US production from 1860?
Here it is again, with emphasis.
Even at
the 1860 low, the Union was producing over 14,000 tons of lead, which would be 28 million pounds of lead. Official records show that in the first year of the Civil War, t
he Union purchased about 23 million pounds of lead or lead bullets and issued or expended about 19 million pounds. That means the Union,
at the lowest production point and without expanding production due to the cut off of imports, could produce 10 million pounds of lead beyond what was needed for the army. A blockade would result in major problems for the Union, but running out of bullets would not be one of those problems.
On hand in 1861: 1,302,000 lbs
Purchased to 30 June 1862: 23,057,000 lbs
Expended to 30 June 1862: 18,920,000 lbs
Purchased to 30 June 1863: 48,720,000 lbs
Expended to 30 June 1863: 31,139,000 lbs
Purchased to 30 June 1864: 12,740,000 lbs
Expended to 30 June 1864: 7,624,000 lbs
Thanks for the numbers, but they show the amount of lead "
issued or expended", not just expended. That would include the 40 rounds per man carried by the troops in the field and probably regimental stores as well. The figures show that from mid 1862-63 the Union army issued or expended about 2 million more pounds of lead than
the country produced that year, but the Union army started that period with a surplus of over 5 million pounds of lead.
The numbers show that from mid-1863-64 the Union army only "issued or expended" 7.6 million pounds of lead. Considering that this time period included the Gettysburg, Chickamauga, Chattanooga, East Tennessee, Knoxville, Red River, Atlanta, Bristoe Station, Mine Run, Valley, Bermuda Hundred, and Overland Campaigns; it seems obvious that major portions of the 31 million pounds of lead issued from mid-1862-63 had not been expended.
Lead imports from Britain by year
1861: 1,679,000 lbs
1862: 28,926,000 lbs
1863 5,777,000 lbs
1864 25,929,000 lbs
The numbers show that little lead was imported for 1861, thus suggesting much of the purchasing occurred after the Trent Affair IOTL.
After the Trent Incident, the Union Army made sure it had a 2 year supply of gunpowder on hand, so it is no surprise that they massively increased their on hand stores of lead as well.
That is important, as the on hand figures and knowledge of American production show the Union has no reserve upon which to rely on. Given annual production for both 1861 and 1862 was ~14,000 lbs, this means that British imports for 1862 alone was equal to the entirety of American production.
The figures show that save for the mid-1862-63 buildup of a multiyear reserve of of lead, US lead production exceeded the needs of the army. From mid 1861-62, the US produced 20% more lead than the army purchased and almost 50% more than the army issued. From mid 1863-64, the US produced 135% more lead than the army purchased and over 290% more than the army issued.
A British blockade would definitely prevent the Union from building up a multi-years reserve of lead and would result in major problems for the Union, but running out of bullets would not be one of those problems.