1911 Main Spring Replacement

[rockhopper46038]

Ok, had some light primer strikes last night at FNS, did some diagnosis with help from my group-mates, and this morning performed the mainspring "pencil test" with the pencil clearing the muzzle by about 6 inches - less than I am led to expect a strong mainspring would generate.

So, I'm going to replace the firing pin spring (because it needs it - I swapped out the recoil spring when it lost about 3/4" of original length, and knew I should swap the firing pin spring at the same time, but didn't ), and the mainspring.

Firing pin spring replacement is easy, but mainspring replacement looks a little more daunting...anyone have some hints from experience? I've already printed off some instructions and watched some videos on the interwebz (BTW, for 1911 fans http://www.sightm1911.com and http://forums.1911forum.com are two (among many) good sites for reference) but would still welcome some advice from someone who may have done the MSH dis-assembly a few times...

 

[drgnrobo]

Make sure you have a punch the right size for the plunger retaining pin,depress the plunger & the retaining pin should drift out easily then slowly release pressure from the mainspring/plunger or you will be scouring the floor for it ,you almost need a third hand but it can be done .Good Luck

 

[rockhopper46038]

Well, it proved easy enough to do. Using a magnet to pull the plunger retaining pin, while I kept pressure on the plunger worked pretty good. I guess I'll need to hit the range tomorrow to see if I've solved my light primer strike issue. The heavier mainspring does seem to slow the slide down some as it comes into battery and pushes down the disconnector... am I imagining this, or does it make sense to any of you 1911 mechanics? I don't see how the mainspring influences the disconnector, but maybe it does through the hammer strut?

 

[Aszerigan]

I would imagine that a heavier mainspring would do just the opposite, it would bring it back into battery with a bit more force. That's just what my instincts would tell me. Make sure its not rubbing on the disconnector. Check for metal filings on the rails or marks on your guide rod.

 

[ghitch75]

sounds as if your leaf spring is out or stuck behind the sear.....

 

[rockhopper46038]

sounds as if your leaf spring is out or stuck behind the sear.....

That was my first concern, even though I had taken great care to secure the grip safety prior to pulling the MSH. Turns out the new bushing I installed is a pretty hard fit to the barrel, and is dragging a bit just before the slide hits battery. Locks up awfully darn tight, but I may have to polish them just a touch...