Jump to content

M4 Aluminum Hammer Spring Cap


smeck

Recommended Posts

AHA.

The old magnet trick works again.

All the trigger group components are steel except the carrier which is a light weight non-ferrous alloy.

 

I was studying your photo.....it almost appears that the action lever tab that engages the hammer spring cap, is bent to less than 90 degrees ? parallax, or is it really turned inward ?

Edited by benelliwerkes
Link to comment
Share on other sites

Don't think the tab has any influence on the damage to the cap - it is stationary and just hold the cap in place. Can you push the cap down easily? No binding etc when it moves down? If it moves freely, I would suspect a defective cap. The gouge in the center appears to coincide with the impact point of the hammer - high load point. The hole area would be a bit weaker having less surface area to handle the load - if the cap "tube" would have too much grease in it, maybe it could not move fast enough or had too much resistance - I think the hole is a vent hole similar to the screw on the back of an AR stock letting air move when the buffer moves - if the "tube" the cap moves in has too much grease/oil, maybe it does not retract properly and has too much resistance to the hammer and therefore the gouging of the metal.

Link to comment
Share on other sites

tactical1 has a good point about the grease. I would definitely *NOT* use grease in the hammer plunger/ spring area, as it is incompressible and too viscous to rapidly expunge out the vent hole.

 

In fact, it's a common automotive technique to pull clutch bearings by packing the recess with grease and hammering in a plunger (e.g. solid steel rod) with interference fit to the inner bearing: the force of the plunger is transmitted through the grease to the bearing outer race, thus driving it out of its recess.

 

Point being: if there is captive grease below the plunger when the hammer strikes it, the plunger will be prevented from

fully depressing into its recess. Something has to give way, and given how hard the hammer is, it's going to be the plunger cap.

 

I just run a very light lubricant (e.g. machinegunner's lube from LaRue) throughout my trigger group, *except* for the sear contact/ engagement points, where a small amount of grease is appropriate.

Link to comment
Share on other sites

  • 1 month later...
  • 3 weeks later...
tactical1 has a good point about the grease. I would definitely *NOT* use grease in the hammer plunger/ spring area, as it is incompressible and too viscous to rapidly expunge out the vent hole.

 

In fact, it's a common automotive technique to pull clutch bearings by packing the recess with grease and hammering in a plunger (e.g. solid steel rod) with interference fit to the inner bearing: the force of the plunger is transmitted through the grease to the bearing outer race, thus driving it out of its recess.

 

Point being: if there is captive grease below the plunger when the hammer strikes it, the plunger will be prevented from

fully depressing into its recess. Something has to give way, and given how hard the hammer is, it's going to be the plunger cap.

 

I just run a very light lubricant (e.g. machinegunner's lube from LaRue) throughout my trigger group, *except* for the sear contact/ engagement points, where a small amount of grease is appropriate.

 

The cap is hollow and there is ample space inside of it not occupied by the spring for this to not be a concern. If it were a concern, the shotgun would have a very hard time cycling, as the hammer must be cocked during the rearward passage of the BCG. I am a fan of grease on sliding metal parts, which this cap is.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...