(M2 AP bullet, shown alongside actual AP core)
Some time back we examined some Lake City armor piercing ammunition here on Carteach0. By 'examined', I mean tore it down and looked inside the insides, just to see what made it tick. As part of the article, yours truly mentioned not having a rifle to test the ammunition at that time.
Well now.... It seems that might have been akin to waving a red flag in the faces of the fine folks who read this blog (that would be YOU people). Not only did offers of rifle loans come in, but one unmatchable gentleman even gifted the author with one (Story to come). In addition, another reader took up the cause and did his own range testing, writing up his findings to share here with the family. Digging ever farther into the subject, reader 'Hartley' forwarded a bleeding great big bag of 30-06 AP pulled bullets here to the 'Ol Fat Man for testing and examination. Of these, a small portion were held back for our prying eyes, while the majority were sent on to the official AP 30-06 ammunition testing guy down South, where they will be loaded up and accuracy tested one day when time and weather permit.
What you are reading here today.... given the idea that a picture is worth 1000 words.... should give some idea what Carteach found when he got inquisitive with these bullets.
First, let me say I have no sure provenance on these bullets. There are very clear differences amongst the batch, with four distinct bullets being present. While all are clearly pulled bullets from M2 AP ammunition, who made that ammunition and when is not clear. About half the pile look exactly like the bullets pulled from the '54 Lake City. The others have differences in their cannelures or bases.
Bullet weight varied across the lot about one grain from low to high. There didn't seem to be any leaning there, just all over the place within 162 to 163 grains. As for dimensions, I gave that a pass. These are pulled bullets, and the method of pulling, as well as their treatment after, will make any measurements a mostly useless guess.
Hartley reports a few thoughts on the AP ammunition in question:
"I did a bit of sniffing around and discovered the story on the AYR (Norwegian) AP ammo - it seems that Uncle Sam stopped making 30-06 AP in '54, so they contracted with AYR to produce it for our allies who were still using the caliber. Therefore, I would assume it is fully "mil-spec", though that may account for the slightly different cannelures visible on those bullets - or they may just be from different US arsenals.
Btw, I've shot a number of those at some mild steel plates I have (railroad tie plates - .4" - .75" thick) and I've found that they don't penetrate a whole lot better than plain ol' ball, at least on suspended plates. They do go just a smidge deeper, and I have seen at least two where the steel "penetrator" lodged in the plate - though NOT straight into the "crater". On an AR500 plate, I notice they make a slight "dimple" in the surface, which pretty much matches the dimple I get with M855 5.56 rounds (all shot at about 80 yards). Ball 30-06 (and M193) does not dimple the suspended plate at all, just leaves a surface mark. "
One of the questions regarding surplus M2 ball is accuracy. On this subject, the following images may shed some light. What I found as I sectioned bullets with both hand file and diamond lapidary wheel..... well.... the pictures show. Diagrams from a 1961 US Army manual on small arms ammunition show the lead filling the nose of the M2 AP bullet is something called 'Lead T shot'. It appears the bullet jacket had some fine lead shot deposited in the nose, and then the AP core was pressed in before the base of the jacket was rolled over (Just my guess).
What was found in the bullets examined here was the lead deteriorating significantly. 75% of the bullets sectioned had some sort of void in the lead portion, and several were quite dramatic. There is not the slightest doubt in my mind that such voids cause inaccuracy proportional to the size and placement of the void.
On the other hand, excellent accuracy has been reported from Lake City AP ammunition.
More info will follow eventually!