The 6-pounder was the smallest caliber cannon used in the War Between the States. Although of Mexican War vintage this smoothbore was still being used by many Confederate batteries especially at Antietam and Gettysburg. This gun is supposed to be a 12-pounder Napoleon. and both of these altered 6-pounders represent the artillery used by this battery while at this location on July 3, 1863. The altered 6-pounders are easily identified as "false" Napoleons as the muzzle is flared and real Napoleons did not have a flare at the end, but the 6-pounder field guns do have a flare. The modification included removing exterior features to present a smooth appearance. The modification were done in the 1890s by the Gettysburg National Battlefield Commission to overcome a shortage of guns for displays. Another example of this exact type of gun @ Gettysburg is an Alger produced 6-pounder, registry #144 which can be found 
HERE.
Through my investigations, I learned the man who made the tablets which accompany the cannons also had a hand in restoring these cannons as well. Gettysburg National Military Park has hundreds of these historic artillery pieces on its field of battle. Their carriages, sights, limbers and on rare occasion (should you find them), the caissons have all been restored. Much of the restorative work came from Major Calvin Gilbert who owned the Gettysburg foundry.
Calvin Gilbert owned a Foundry which bore his name in Gettysburg. This man was responsible for creating all of the cast iron battery tablets. His work did not end there as his foundry created many of the carriages for the historic cannons at Gettysburg. Although almost all of the cannons are from the Civil War, their carriages, sights, limbers, wheels and caissons have been restored at his foundry in the early part of the 20th century. Gilbert was in his 70s when he did this work and completed work at other battlefields as well.
The two altered 6-pounders and the Battery G, 1st New York Artillery Position Marker are located at the southern part of Hancock Avenue (RD310), just past the intersection where Sedgwick Road changes its name to Hancock. United States Avenue also runs perpendicular at this intersection, 237 feet to the south. This position marker is accompanied by two altered six-pound bronze cannons. All of this is located on the left or west side of the road if traveling north along the avenue. It seems most of the monuments here have artillery pieces on both flanks like this monument. There is a long string of these set up on both sides of the road kind of terminating at the Pennsylvania Monument (MN260); this is the first in that long line along Hancock Avenue. The cannons face due west, in the direction where the Union position was defending on July 3, 1863. This area is an absolute beehive of activity as this site represents the best of what Gettysburg has to offer, both historically and monumentally. Parking is plentiful and is available road-side at intermittently enlarged shoulder cut-outs, usually marked with white striping. Be sure to keep vehicles off the grass or you will be ticketed by park police. I visited the monument on Thursday, July 5, 2012 @ 5:34 PM, EDT & @ an altitude of 566 feet, ASL. I used a Canon PowerShot 14.1 Megapixel, SX210 IS digital camera for the photos.
Initially, I could not identify this gun. I learned from the HMDB site these two guns were originally 6-pounder altered to resemble the 12-pounder Napoleons. A thorough inspection of the trunnions yielded more information which eventually helped me cement a definite registry number. The proper left trunnion bears the date 184? (Last number battered) and the right proper trunnion reads N.P. Ames Founder Springfield Mass. I next was able to make out the initials J.W.R. at the 12 o'clock position and referred to the Robinson's Battery site. From there I discovered J.W.R. or james Wolfe Riley inspected 4 of these 6-pounders at Gettysburg BUT only one of those is along Hancock Avenue, so by process of elimination and a little detective work, I was able to figure out this gun's registry number was No. 182. My aforementioned SOURCE for all things weapons at Gettysburg provided me with the rest of the manufacturing information no longer readable on the battered muzzle. I am presenting the data as the site presented it, not knowing the arrangement or order of the information as it appears on the muzzle. Again, all I know for sure is the inspector's initials are at the 12 o'clock position.
J.W.R. ......Ames ......1847 ......884
J.W.R.. are the initials of the inspector who gave the gun a once over before it was shipped out to the Federal army. The initials stand for the very famous Union Army Brigadier general James Wolfe Ripley. A.M.C. refers to the foundry, Ames Manufacturing Company out of Chicopee Massachusetts. The foundry is on the National Register of Historic Places. 1847 refers to the date of manufacture even though this is an 1841 model. 884 lbs refers to the weight of the firing tube. Each gun is usually very unique and has its own weight which distinguishes it from every other gun, like a fingerprint.
About the Foundry
Ames Manufacturing Company has its origins in blacksmith and founder, Captain John Ames, who in 1774, made some of the first manufactured shovels in what would emerge as the new, United States of America. The company was founded in 1791 at their factory in Chelmsford, Massachusetts. It was continued by the founder's son by Nathan Peabody Ames (1803-1847) and produced its first swords for the US Government in 1832. A foundry was added, to cast cannon and bells. The historic sword and armament factory, located at 5-7 Springfield Street in Chicopee, Massachusetts, was built in 1847. The structure was added to the National Historic Register in 1983.
SOURCE
About the Inspector
James Wolfe Ripley (December 10, 1794 – March 16, 1870) was an American soldier, serving as a brigadier general in the Union Army during the Civil War. 
He was instrumental in the early days of the war in modernizing the artillery's ordnance. However, Ripley also delayed the introduction of repeating rifles into U.S. arsenals, an act that has been widely criticized by later historians. With the outbreak of the Civil War in early 1861, Ripley was promoted to colonel (April) and brigadier general (August) and appointed chief of ordnance of the army. As the Federal forces then had no heavy rifled cannon, he immediately ordered the conversion of old smoothbores and the manufacture of Parrott guns.
At the same time, Ripley refused to authorize the purchase of additional stocks of rifle-muskets for infantry use. The decision was based on the large existing stocks of smoothbore muskets in U.S. arsenals, which he argued could be re-rifled in the same manner as the Parrott guns (an assertion which proved incorrect). He also adamantly opposed the introduction of breech-loading repeating rifles, on the basis that they would encourage poor fire discipline and waste ammunition. James Wolfe Ripley died on March 16, 1870 in Hartford, Connecticut. He is buried in Springfield, Massachusetts.
About the Gun
The Model 1841 6-pounder gun was one of a “family of weapons” designed by the U.S. Army Ordnance Department in 1841 (companion pieces were the Model 1841 12-Pdr., 24-Pdr. and 32-Pdr field Howitzers; the Model 1841 12-Pdr Gun and the 12-Pdr Mountain Howitzer). The effectiveness of the 1841 series was proven in the Mexican War, during which U.S. Ordnance gained an outstanding reputation for maneuverability and reliability. Most 1841 6-pounders were cast in bronze but in August and September 1841. at West Point Foundry, Captain William Maynadier inspected two cast iron 6-Pdr guns identified in the record as Model of 1841. Of essentially the same length and weight as those of bronze for the same model year, their base rings were 0.7 inches larger, or eleven inches in diameter, further supporting the tradition of broader taper for cast iron than for bronze weapons. The 6-Pdr was common to both armies in the early war years. The piece gradually fell into disfavor at the introduction of the Model 1857 Napoleon because of the bigger bore and hitting power. However, in the western theater the 6-Pdr soldiered on until the end of the war.
SOURCE.
About the Battery
The 1st New York Artillery, Battery G served as a member of Fitzhugh’s Brigade in the Artillery Reserve, Army of the Potomac. Battery G, First New York Light Artillery was recruited at Mexico, Oswego County, New York, by Marshall H. Rundell and Nelson Ames, in September, 1861. It joined the regiment at the general rendezvous at Elmira, and was there mustered into the United States service for three years, September 24, 1861, by Captain Tidball, United States army mustering officer, with the following officers: Capt. J. D. Frank, First Lieut. Nelson Ames, Second Lieut. Marshall H. Rundell. The battery was engaged with the enemy in every battle the Second Army Corps participated in during the war, as shown by the company records. They had 11 officers and men killed, 31 men wounded, and 15 died of disease, a total loss of 57 officers and men. Capt. Nelson Ames and Lieut. S. A. Mc-Clellan were also wounded during the terms of their service. Battery G was never driven by the enemy's fire from a position it was ordered to hold, never fell back until ordered, and never lost a gun or carriage of any kind during its term of service.
This battery was commanded by Capt. Nelson Ames (1836-1907), a native of Mexico, New York. He was wounded during the Overland Campaign of 1864 and was the post-war mayor of Marshalltown, Iowa. For Gettysburg, Ames reported, "During the night of the 2d we refilled our ammunition chests and refitted the battery ready for action. July 3d we were in position with the Second Corps on the front line of battle, and took part in the terrible artillery duel, also in repelling Pickett's charge, and thus ending one of the most fearful battles of the war." Ames also wrote a book, published in 1900 entitled, History of Battery G, First regiment, New York light artillery. Ames' obituary found in the New York Times, published March 9, 1907 can be found HERE.
The position monument marks the positions of this Battery on July 3, 1863 and has a brief inscription incised on the slanted front face, which reads:
Battery G
(Ames)
1st N.Y.L.A.
July 3rd 1863.
This area is crazy-stupid with all types of cannons and guns and monuments as far as the eyes (or binoculars) can see, a veritable outside museum. I would suggest allowing up to an hour and a half to walk around Hancock Avenue to fully inspect all the tablets, monuments and weapons in this area.