Why 16 + 18 lb Recoil Springs?
Generally, the distance of ejection of empty shell casings, gives us feedback about function and slide velocity. And generally, we look for this distance to be in the 4’ – 8’ range. This is where “All 1911s are not created equal”, applies. During our testing with 230 gr standard pressure ammunition, we found distance of empty case ejection to be in the 4’ – 6’ range with our standard 16 lb recoil spring and our Heavy Main Spring. When we changed over to our Light Main Spring, distance of empty shell case ejection was an additional 1½’ – 2 ½’ further, depending on the ammunition being tested….giving us empty case ejection in the 6’ – 8’ range. With the lighter main spring, we could then go to our heavier 18 lb recoil spring, and tame the recoil a bit, and reduced the empty shell case ejection distance and increased the authority of the slide’s return to battery. Our 18 lb Recoil Spring also nicely controlled +P .45ACP ammunition, particularly with the heavier main spring. These results were in our 1911 used for testing which is a recent production Remington R1. The owner of a Colt GI 1911, made in 1930, may find a slightly different combination to be optimal, and the owner of a Springfield 1911 may find yet a different combination to work best.
Many manufacturers go to great efforts to make quality 1911s, with consistency of build quality that, given today’s technology and modern machinery, is better than it’s ever been in history. Unfortunately, many 1911 owners (and manufacturers) are missing the best possible 1911 performance by not finding the best possible combination of Recoil and Main Spring. The importance of these two springs, working together like gears in a well-oiled machine, cannot be overstated with respect to the 1911.