Do you know the history of this pistol? If not, it's possible that someone was attempting to fit a part that does not fit. That little washer is definitely not a standard part on a 1911. Could it have been hiding in your parts washer from a previous project? I've never run across it, and I've taken apart a 1911 or two. Neither Kunhausen's, nor Brown's, nor Wilson's books on the 1911 show it, nor do anyone's parts diagrams.
As far as that Series 80 firing pin block, it was the proverbial "answer to the question nobody asked". The 1911 has what is known as an "inertial firing pin". Essentially, it's too short. With the hammer at rest, the nose of the firing pin rests just below flush in the breach face. In other words, it does not protrude to make contact with the primer. So how in the hell can it fire if the firing pin doesn't reach?
Simple -
inertia. The hammer smacks it hard enough to propel it forward against the firing pin spring's pressure so it can hit the primer. It works great. This way, with the hammer at rest, you can smack the hammer all you want and the gun will not fire, so it's safe to carry with a chambered round. Unlike the old Single Action Army revolver, whose firing pin, with the hammer at rest, rests on the primer. That's why we carry those with the chamber empty that lines up with the hammer.
There is only one problem with this inertia idea. What happens if we drop our 1911 and it lands on the muzzle? The firing pin will move forward - it has no idea what invoked its movement, a blow from the hammer or the fact that the rest of the gun got dropped and suddenly stopped. Its
inertia will carry it forward either way.
Now I will defy anyone to drop a 1911 and have it actually land on its muzzle. Impossible. Their balance is such that they simply will not do that. But, well, someone thought it
could, and was suitably horrified at the thought. Hence the Series 80 firing pin block which positively locks the firing pin against any forward movement unless the trigger is pulled. Whew - we're all much safer now...
The 1911 actually has three safeties. The grip safety, which has to be depressed by gripping the pistol in a firing position before the trigger can be pulled. The thumb safety, which has to be lowered from its "safe" position before the trigger can be pulled. And, finally, the guy who is carrying it.
So, I can't tell you to just put it back together and forget about it. I can, however, tell you that I know some people who know some people who do this regularly. Reckless and irresponsible, I know. But I'm told it does improve the trigger pull pretty dramatically in many cases. Maybe I'll try it myself some day...
