Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
AR Sponsor
12/4/2004 7:01:15 AM EDT
I have been working out the minor bugs on the AR I built from a model 1 sales kit, and a 0% lower. I am having a problem with the hammer pin walking out during firing. After a little research here I found out that J pin is supposed to prevent this. I removed my hammer and checked, and the J Pin is missing. I did not have any parts left after assembly so apparently my hammer came without one. Anyone have a picture of one or know where I can order just the J Pin??
12/4/2004 2:18:12 PM EDT
[#1]
best solution is to get a new hammer.  From what I understand it is a bit of a problem to install the j-spring. easiest thing to do is get a new hammer.
12/4/2004 3:53:23 PM EDT
[#2]
i have never seen a j pin outside of the hammer. try calling model 1 and tell them your kit is missing the j pin, then cross your fingers and hope they help.


if not just find a new hammer
12/4/2004 4:14:07 PM EDT
[#3]
J pin is a cakewalk to install.

Press the spring in until the J’s side bottoms out in the bottom hammer groove.  Then using two punches in the hammer witness/stake hole on the side of the hammer (one on each side), back the bottom punch up on an anvil, and then make a blow to the top punch.  This will stake/crimp the spring into the hammer (at the stake hole location) and prevent the pin from falling/walking back out.

Most of the time on the cheaper kits, the pin is not staked in correctly from the start, and you are forced to correct it anyway (will walk out and bind up the hammer stroke on the front of the receiver).  Sound like your hammer J pin was not staked, and fell out either at their shop, or in shipping.  Like said, just have them send you another pin, and stake it in correctly.

Note: It helps to give the spring a slight middle bend (towards the inside of the hammer pin channel).  This puts more tension on the spring/pin and prevents the hammer pin from walking out of the hammer as the center annual grove begins to wear.
12/4/2004 4:32:32 PM EDT
[#4]
I would  try to get a new hammer from them. The j pin is hardened and is difficult to deform with normal punches. It takes a lot of pounding if you have a spec pin. Bending the pin can make it difficult to install the hammer pin. The hammer pin is only slightly rounded/angled at the end and if the j pin is bent out past this portion of the hammer pin if will cause problems putting it in.
12/5/2004 5:14:15 AM EDT
[#5]
they are also very easily made, get a peice of stainless steel welding rod of same diameter, using a needle nose pliers, bend the "J" then trim to size with grinder, install & stake,  i have made two "J" springs this way & no problems........
12/7/2004 5:33:09 AM EDT
[#6]
Hey, thanks for all the replys. I have had this kit for almost a year while finishing my lower so model 1 might not be to helpful now. I thought of trying to make my own pin but not sure of the size or shape. I'll probably just get a new hammer. Adco is pretty close and it will give me a chance to check out all the other goodies Thanks again, TOBG
AR Sponsor