I upgraded the trigger in my 180b to a Timney AR competition 3 lb. My gun loves MFS 55 gr but the spring on the Timney is too light to ignite the MFS primers. I called Timney and they sent me a heavier spring but it is way too wide to fit the housing, same as a standard AR spring. Called again and they want me to send the whole unit to them in Arizona. This is turning into a huge pain! I could just shoot reloads again but I have a case of MFS that is very accurate in my gun and don't have to search through grass and snow finding brass anymore. Anyone else been through this?... Ideas?
Timney in 180-B
- Thread starter Black Cloud
- Start date
Black Cloud
I've felt your pain, here's how I got rid of it...
The problem is that the 180-B has a firing pin return spring and the timney's hammer (as you found out) doesn't provide enough inertia to overcome the return spring pressure and have the pin strike the primer with the needed force to reliably fire the round.
The Fix: I went to Princess Auto and bought a package of various different springs. I found a few that were the same outside diameter as the stock Firing Pin spring, (but with less tension) and cut the length down on one and kept trying it until I got reliable ignition. You don't need to fire live rounds to test this, primed cases will work just fine for this.
As a side note, I had to mill two slots in the bottom sides of the Timney base to clear the stiffening ribs on the floor of the receiver. Did you have to do the same?
Hope this helps.
I've felt your pain, here's how I got rid of it...
The problem is that the 180-B has a firing pin return spring and the timney's hammer (as you found out) doesn't provide enough inertia to overcome the return spring pressure and have the pin strike the primer with the needed force to reliably fire the round.
The Fix: I went to Princess Auto and bought a package of various different springs. I found a few that were the same outside diameter as the stock Firing Pin spring, (but with less tension) and cut the length down on one and kept trying it until I got reliable ignition. You don't need to fire live rounds to test this, primed cases will work just fine for this.
As a side note, I had to mill two slots in the bottom sides of the Timney base to clear the stiffening ribs on the floor of the receiver. Did you have to do the same?
Hope this helps.
Jakester, thanks for the reply. I hadn't thought about weakening the firing pin return spring, I will see what I can do there. As for getting the Timney to fit the receiver I used a wood chisel to scrape a small amount from the ribs on the floor. Kind of bubba but there is lots of material left and isn't noticeable.
