Bolt Safety Lug ?

[umwminer]

I have several 03's & A3's . There are vast differences in the in the "space" (gap) between the safety lug and upper reciever right side wall when the bolts are cammed down into the locked/cocked position. None of which actually contact the side wall (rear reciever bridge ?) but one is so close that I had to hold it up to a light to see the gap and at the other extreme another has a gap of approx . 1/16 of a inch.

Can any of you knowledgeable brothers comment on this condition and how this safety lug was orginally engineered ?

[JimF]

The "book" says there is to be a .004" MINIMUM gap at this point!
Sounds like you have no problem on that score. --Jim

[Allen Humphrey]

The engineering was a little before my time :) so I can't comment first hand on the criteria that was used to determine the correct gap. However, based on manufacturing drawings the gap is supposed to be a minimum of .004". My rifles show gaps ranging from the afore mentioned .004 up to about .050". Since the main purpose of the lug is to prevent the reward projection of the bolt in the event of a catastrophic failure, I think the only thing to worry about is to make sure it isn't touching the rear bridge in normal operation with the bolt in battery. FYI, a piece of cheap printer paper is about .004" thick.

A safety lug that IS touching shouldn't be fired (in my opinion) until the cause is determined. The cause could be the result of excessive bolt wear, excessive receiver wear, out of spec bolt dims, out of spec receiver dims, damaged bolt, or damaged receiver.


***looks like Jim types faster than me.....what he said!

[umwminer]

Always valuable , informative info from the CSP folks. Thanks again......Bob