Razorhunter
05-23-08, 20:23
I recently received an AR10A4 stripped upper, in which I had to install the ejection port cover door, spring, and rod myself.
This is the first time I've done this. Of course, like all other armorer work, none of this is rocket science. Mostly just roll pins, and proper torquing of a few nuts. Anyhow, I immediately noticed that there are TWO ways that the ejection port door spring can be installed. First off, you will notice there is a SHORT STUB end of the spring, and also a LONG STUB end of the spring.
You can either put the short stub end of the spring to the FRONT (which results in OPENING/SPREADING of the spring when you close the ejection port door), OR you can put this short stub end of the spring to the REAR of the rifle, (which results in the COMPRESSING of the spring when you close the ejection port door).
The second method, which COMPRESSES the spring, with the short stub end to the REAR of the rifle, seems to offer the most tension, and results in a more "crisp" opening of the ejection port door.
I have noticed that my LMT MRP upper has the LEAST amount of tension applied, with the short stub end of the spring to the FRONT of the rifle, which OPENS/SPREADS the spring.
I installed my AR10 spring in the opposite manner, which COMPRESSES the spring, and provides a good bit more tension to the door when it opens.
I would like to know if anyone has ever seen this mentioned in an armorers book, and which method is recommended to use, OR better yet, how are your AR rifle ejection port door springs installed? Short stub end to the rear (compressing spring), or short stub end to the FRONT of the rifle (spreading of spring?)
My Blackwater armorers manual is not here right now, so I cannot refer to it, to see what it recommends.
This is the first time I've done this. Of course, like all other armorer work, none of this is rocket science. Mostly just roll pins, and proper torquing of a few nuts. Anyhow, I immediately noticed that there are TWO ways that the ejection port door spring can be installed. First off, you will notice there is a SHORT STUB end of the spring, and also a LONG STUB end of the spring.
You can either put the short stub end of the spring to the FRONT (which results in OPENING/SPREADING of the spring when you close the ejection port door), OR you can put this short stub end of the spring to the REAR of the rifle, (which results in the COMPRESSING of the spring when you close the ejection port door).
The second method, which COMPRESSES the spring, with the short stub end to the REAR of the rifle, seems to offer the most tension, and results in a more "crisp" opening of the ejection port door.
I have noticed that my LMT MRP upper has the LEAST amount of tension applied, with the short stub end of the spring to the FRONT of the rifle, which OPENS/SPREADS the spring.
I installed my AR10 spring in the opposite manner, which COMPRESSES the spring, and provides a good bit more tension to the door when it opens.
I would like to know if anyone has ever seen this mentioned in an armorers book, and which method is recommended to use, OR better yet, how are your AR rifle ejection port door springs installed? Short stub end to the rear (compressing spring), or short stub end to the FRONT of the rifle (spreading of spring?)
My Blackwater armorers manual is not here right now, so I cannot refer to it, to see what it recommends.