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View Full Version : My experience with the JARD trigger on an LR-308


captbilly
10-15-2010, 12:22 AM
I got and installed the JARD AR-10 trigger on my CMMG lower LR-308 about a week or so ago, and I thought someone might be interested in hearing about my experience with it. My background is in competitive target shooting with almost no hunting, so keep that in mind when considering what I write.

I have a Rock River trigger in my heavy barrel Rock River upper AR-15, and it is a huge improvement over the standard AR trigger but not quite what I was looking for on my long distance LR-308 project. First off the Rock River is a two stage and I just can't quite get used to a two stage for target shooting. Secondly the Rock River is about 5+ lbs pull and that is just too much for me if it isn't required by the rules (some competitions require 4.5 lbs if I remember correctly, it's been a while since I shot any event where trigger pull was measured). I picked the JARD because it had the lightest pull of any trigger that I could get my hands on in a reasonable length of time. The Geiselle can be had with similar pull but they are on back order at many places and they don't seem to make one specifically for the LR-308 platform. I have heard nothing but good things about the Geiselle, and will probably try one soon.

First off: Don't even think about installing the JARD trigger if you aren't pretty familiar with how triggers work. The trigger isn't hard to install but it requires 4 separate adjustments, and if you don't do these correctly you could end up with either a crappy trigger or a very dangerous gun. You will also likely have to tap the pistol grip screw hole because one of the adjustment screws goes all the way in that screw hole until it actually extends into the lower receiver. Many (maybe all) lower receivers do not tap this hole all the way through, because it isn't necessary for the grip screw) so you will have to do it yourself. The adjustments aren't particularly tricky, but the instructions don't seem to have been written with a complete newb in mind so you may not quite understand what they are trying to describe, I know it took me some time to figure a few things out.

Once you get the trigger installed it is very light and crisp with essentially no take up, creep or over travel, (all of which exist in abundance with stock AR triggers). Pull is not exactly adjustable but rather you can pick anywhere from 1.5 to 4 in 1/2 pound increments by changing a single spring (although changing that spring requires the removal of both the hammer and trigger). There is no comparison between the JARD and the stock trigger. If you have only shot with the stock trigger then don't try a JARD or even a Rock River unless you plan on buying a new trigger, because you will never be willing to put up with the stock trigger once you try pretty much any of the decent upgraded triggers.

Interestingly JP recommends that you don't use anything less than 4 lbs. pull with their trigger when used in an LR-308 due to concerns of doubling (two, or more, shots for one trigger pull), but JARD says you can go down to 1.5 lbs. (the lightest spring they make). I got scared when installing the 2 lb spring in my JARD so I first loaded only a single cartridge in the magazine, then two and then all 10, to be sure I didn't empty a 10 round mag on my first pull (I don't think the range officer would like that one bit). But the trigger functions flawlessly with a single cartridge fired on each pull.

I would recommend the JARD AR-10 trigger to anyone who is disciplined enough to not accidentally pull such a light weight trigger. If you are the jumpy type and you look at your AR as a self defense weapon than no 2 lb. trigger is a good idea for you, but if you are a disciplined hunter, target shooter or even a sniper (do those guys get to pick their own equipment?) I would highly recommend the JARD single stage adjustable trigger. Of course with the caveat that you get it installed by a qualified gunsmith if you aren't sure you know what you are doing.

By the way, I used the JARD AR-10 trigger, not the heavy hammer AR-15 trigger as recommended by JARD for the LR-308. The AR-10 trigger has a special narrow hammer, that I assume is necessary for proper fit in a genuine AR-10, but is not require on the AR-15 or LR-308 due to their bolt carrier design. I did it sort of by accident (ordered the wrong trigger) but I think I will stick with the AR-10 trigger because it works and it has a lighter hammer. A lighter hammer should have a shorter lock time and should disturb the rifle less during the time between trigger pull and igniting the primer, both things that a precision shooter appreciates. If I find that I am having any problems with the AR-10 trigger I will switch to the AR-15 with heavy hammer as JARD suggests, but so far the AR-10 trigger seems fine. There is no issue with interference, in fact the bolt cycles a bit easier with the AR-10 trigger than it does with the standard trigger, so I must assume that the reason for JARD recommending the heavy hammer is that they have some trouble igniting certain .308 ammo with the lighter hammer (although I do not actually know this, anyone know where I can get a titanium firing pin for the LR-308?).

Deadon
10-15-2010, 9:29 AM
This video really helped me. I installed mine a couple hours ago.
http://www.youtube.com/watch?v=HmxYGhJUhXk

captbilly
10-17-2010, 8:46 PM
That video would have been great for my peace of mind. I saw nothing in the instructions about setting the sear engagement, but the video makes it pretty clear that Jard recommends you back off 7/8ths turn from hammer release. I will probably tighten that up a bit since I think I have too much sear engagement.

Thanks for the link.