The original A and A2 are forged steel, not cast iron or even mehanite. They are probably the strongest presses ever made. Somewhere toward the end of the A2 run into the A3 run RCBS quit installing a removable nut in the top that would allow the 7/8 x14 dies and then when removed the larger dies for British calibers (don't know the thread pitch). Most of the A3's come without the removable nut but are threaded straight into the press itself in 7/8 x 14". The use of forged steel also was stopped somewhere into the A3 production. RCBS also made a press called a B which was also made of forged steel. It was smaller than the A series more the size of a rockchucker and is very rare. Press collectors spend big bucks to get a B. I have use an original A2 for years. I acquired it from a friend without any parts for the base around 1980 and have used it as my single stage ever since. I was able to get the base from the original RCBS company in Oroville, along with the two bolts. One of the features that the A, A2 and A3 have is the ability to change positions on the base and tilt it at a slight angle for reloading.

Another feature of the A series that is seldom noticed is that the spent primers drop down into a hollow ram and exit out a hole in the lower rear of the ram. I've found sometimes they don't come out and the ram won't go all the way up because a primer may be sticking out of the hole slightly and catch on the press body.

I have had a lot of presses over the years including Rockchuckers, an A, and an A2, along with a variety of "steel" Hollywoods and Hollywood turrets. I think the A2 is the best of the bunch. It has served me well and I think it will served my son for most of his life too. For none single stage work, I still prefer my Dillon 550.

The A4 seems Ok, but it is mehanite which is a version of cast iron, not steel as the A and A2 were. The A3 is cast iron although some at the transition may be forged steel. The forged steel presses are the very strongest and best. The early A, A and A3 command top premium prices way out of range of most reloaders, although they can be found at gunshows much cheaper than Ebay prices.