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Post by lkrbuilder13 on Jul 7, 2013 16:57:29 GMT -8
I have done some trigger smoothing up And I have changed the springs to lighten the pull up. I was wondering instead of spending $150+ on a trigger if there is a way to shorten up the lop of the trigger and what to use to do so. Thank you for your help.
Brian
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Post by GLSHOOTER on Jul 9, 2013 8:52:12 GMT -8
Never have seen a way to shorten it. 99% of what I see wants to lengthen it. Surely someone has done it in the match shooting world. I'll keep my eyes open as I meander the net in those circles.
Greg
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Post by lkrbuilder13 on Jul 9, 2013 12:06:53 GMT -8
Never have seen a way to shorten it. 99% of what I see wants to lengthen it. Surely someone has done it in the match shooting world. I'll keep my eyes open as I meander the net in those circles. Greg This is a site I found. What do you think about doing this??? www.junkyardgenius.com/firearms/ar-15/ar08.html |
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Post by GLSHOOTER on Jul 9, 2013 13:35:46 GMT -8
ARFCOM has the 15 Minute Trigger Job. I have done some with that. I have not done the screw through the pistol grip thing. Nothing wrong with dropping $15.00 on spare parts if you screw up or it wears out too soon. I would do most of my testing away from other so that if you do get a bit doubling etc. no one will know but you and the trash can.
The one I have clipped and bent gave me a nice 4 pound pull. I have not gone in and done much polishing. The RRA is a god trigger for cheap (under $150.00) if you wnatto buy one. I have a pair of Timneys and a Geissele High Speed ($280.00) they all work well. I also have four 'smith 2 pounders that will bump fire in a heart beat if you aren't paying attention. Not doubling just bumping.
Greg
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Post by lkrbuilder13 on Jul 9, 2013 17:31:01 GMT -8
I am going to try it and see how everything goes. Worst case I have to buy a trigger
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Post by bravo5two on Aug 27, 2013 4:06:05 GMT -8
I have done some trigger smoothing up And I have changed the springs to lighten the pull up. I was wondering instead of spending $150+ on a trigger if there is a way to shorten up the lop of the trigger and what to use to do so. Thank you for your help. Brian The AR trigger in its original form is a single stage, but the so called mil-spec trigger unit is very "creepy" and gritty. You can smooth out the engagement surfaces to remove the gritty feel but be careful not to get too aggressive with the stone. Best way to remove the creep is to lift the trigger tail up by inserting a screw through the grip. You can buy a 1/4 long hex head set screw (not sure of the exact size but you can bring the grip screw to the hardware store and match it up), or you can make one up by cutting 1/4 in off the old grip screw, cut a slot in one end for use with a flat blade screw driver. Set up - With just the lower, put a hammer block in the mag well to prevent damage to the lower receiver. Cock the hammer. Slowly turn the adjustment screw in until the hammer falls off the trigger sear surface, that would be the maximum lift. Back off one full turn and cock the trigger, it should engage the disconnector and trigger sear after, if not, back off the screw a little until the hammer releases off the disconnector but stays on the sear. this should be the optimal point for your trigger. You can do a safety check after by re-assembling the rifle, be sure it is not loaded. Run the charging handle to cock the hammer, pull the trigger but don't release it. Run the charging handle a few times and let the bolt/carrier slam into battery. The hammer should not follow. If it does follow, then back out the adjustment screw another 1/8 turn or so. This will for sure allow enough overtravel for the disconnector to catch the hammer. |
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Post by lkrbuilder13 on Aug 27, 2013 13:11:27 GMT -8
I have done some trigger smoothing up And I have changed the springs to lighten the pull up. I was wondering instead of spending $150+ on a trigger if there is a way to shorten up the lop of the trigger and what to use to do so. Thank you for your help. Brian The AR trigger in its original form is a single stage, but the so called mil-spec trigger unit is very "creepy" and gritty. You can smooth out the engagement surfaces to remove the gritty feel but be careful not to get too aggressive with the stone. Best way to remove the creep is to lift the trigger tail up by inserting a screw through the grip. You can buy a 1/4 long hex head set screw (not sure of the exact size but you can bring the grip screw to the hardware store and match it up), or you can make one up by cutting 1/4 in off the old grip screw, cut a slot in one end for use with a flat blade screw driver. Set up - With just the lower, put a hammer block in the mag well to prevent damage to the lower receiver. Cock the hammer. Slowly turn the adjustment screw in until the hammer falls off the trigger sear surface, that would be the maximum lift. Back off one full turn and cock the trigger, it should engage the disconnector and trigger sear after, if not, back off the screw a little until the hammer releases off the disconnector but stays on the sear. this should be the optimal point for your trigger. You can do a safety check after by re-assembling the rifle, be sure it is not loaded. Run the charging handle to cock the hammer, pull the trigger but don't release it. Run the charging handle a few times and let the bolt/carrier slam into battery. The hammer should not follow. If it does follow, then back out the adjustment screw another 1/8 turn or so. This will for sure allow enough overtravel for the disconnector to catch the hammer. I found this trick online while in my searches and I also added a JP 3.5 lb spring kit and it gives a respectable 2 lb 15oz avg on one rifle and 3# 3oz on the other. With just the spring kit it was up around 5 3/4# |
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Post by varminterror on Jan 22, 2015 8:36:19 GMT -8
I know that this thread has been dead for about 18mos, but front page threads are always fair game, right?
In my experience, trigger "creep" is about excessive sear engagement length, and nothing else. If you block the rear of the trigger such that it only contacts the last few thousandths of the sear, you get the same effect on travel length, but it's better, in my opinion, to let the trigger remain at its designed rest position, and create an earlier break. Blocking the trigger tail "advances" the trigger slightly by stopping it from reaching it's fully forward reset position. "Trimming" the sear engagement is done on the hammer, and should only be done by someone experienced with the proper tooling to accomplish this task. I also polish my engaging faces with a hardbacked leather strop rubbed with jewelers rouge, but any ultrafine diamond lap will suffice (not a stone, way too easy to get confused and tear off way too much material).
So that takes care of "take-up," "creep," and "grit" in a single stage trigger.
Pull weight is purely a spring weight issue (pressure is about leverage, we don't change any of the geometry, so we can only change the applied force. The poor man's trigger job, in my opinion, is a polished and minimum sear engagement mil-spec trigger with a $10 set of JP springs. In my past builds, I've hit a cozy 3.5-4.25lb trigger break with these springs in over a dozen rifles. I do the "15min Trigger job" style bend even on the JP trigger spring, basically by bending it until it misses the reset (overpowered by friction of the disconnector), then either bending it back slightly (really works the spring), or by shimming under the leg of the spring - that basically dictates that I have the lowest possible trigger spring pressure for reliable function. Of course, this has to be done with a "broken in" spring, otherwise you'll have to readjust it again later.
Over-travel is something I'm particularly sensitive to in any firearm, so I tend to look for remedies for it at every opportunity. My EDC revolver even has an overtravel stop! The AR-15's overtravel stop is actually quite simple. D&T a plug screw into the forward end of the trigger, then adjust such that it bottoms out on the receiver exactly at the moment of break.
If a guy is rather handy, they can use the same overtravel stop to become a "creep eliminator" as well. Again, I modify my HAMMERS to minimize sear engagement, rather than by blocking the trigger advancement, but a guy can insert a pin or screw in the forward end of the trigger that bottoms out at the TOP on the hammer when the trigger is at rest, such that it limits the sear engagement, and bottoms out on the receiver at the end of the trigger pull to limit the over travel. Pretty exacting work, and I've always been concerned with fouling build up on the top of the trigger that would cause a slipped sear from insufficient engagement, but it does work for a mil-spec creep AND overtravel stop.
With these adjustments, even done to a mil-spec trigger, it's very easy to get somewhere between a "candy cane break" and a "glass rod" trigger with a 3.5-4.5lb break weight, and a travel length that's almost imperceptible to my finger.
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