JP Enterprises AR Captured Spring buffer

[fkleinbu]

I ordered 3 of these, and after nearly a month wait they finally came in..

It is simple to install.. Remove original buffer spring and buffer.. If using an A2 stock install the white spacer in the receiver extension first, then the spring/buffer assembly.. If you have a carbine stock, the white extension is not needed.. That is it..

There are technical reasons why one should consider ordering one of these.. Go to JP's web site (http://www.jprifles.com/1.4.7.2_os.php

[burnsome]

I got 2 in last week and have run about 100 rounds thru my 6.5G upper. I installed one on a carbine length buttstock and a full sized buttstock. it works great in the full length buttstock as was mentioned above. the gun runs smoother and no spprrrooooonnnngggg when the gun goes bang so i think its a good product. really couldnt tell any difference in the carbine length stock but time will tell i suppose. i had one instance where the bolt failed to lock back on the last shot whereas that never happend with the regular set up. could have been a fluke so i need to do some more testing. am running a 12 inch suppressed upper on my Grendel config so perhaps mine is a little more finicky on how it functions. i left the buffer retaining pin in my lower as the instructions say its not necessary to remove it but it says you can if you want to. i noticed that the spring sits exactly like it should on the full sized stock with the front of the spring touching the buffer retaining pin. however, on the carbine set up, there is about a 1/8th inch + gap between the spring and the retaining pin so i dont think thats quite right. perhaps my buffer tube is out of tolerance as i would think it should fit where the front of the spring touches the retaining pin, thereby providing some forward force on the bolt carrier. probably not a good situation to have no forward force touching the bolt carrier and that 1/8th inch gap might contribute to it not locking back on the last shot. when (if) he cheaper wolf steel case stuff hits the market i'll try it on full auto, but i think JP states their new springs arent designed to work in full auto guns but they are going to come out with a version in the future that will. overall, i'd say its a nice upgrade and I am going to get some trigger time in on my 5.56 uppers with it soon and see how they do.

[fkleinbu]

Good to hear the JP spring works with the Grendel.. I don't have my Grendel upper yet so I was only able to test the new spring in a couple of uppers chambered for 5.56 NATO..

My buddy did test the spring in his lower (also with an A2 stock).. Worked without any problems with his 5.56 upper.. However he put 3 rounds in an 6.8 upper, and it did cycle the action, but didn't hold open the bolt after the last round.. Of course this was the first three rounds through this new upper, so there could be a host of reasons not related to the JP spring.. More shooting and testing to follow..

I wish JP offered different spring and buffer weights.. Still as it comes, to me it is one of the best upgrades I ever installed in an AR..

Flk k