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Juggernaut JT10 80% review

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hi all, so I came on here a couple months back when I ordered everything for my 308 build & got way to busy to start on it until today, so today I started on the Juggernaut JT10 80% lower & came in to a few speed bumps I will call them with it.

#1: their video & instructions they provide via youtube & some very basic instructions that take all of about 1 minute to read on paper were actually set for their AR15 lower & not the 308, while they are for the most part the same in principle they just dont work out real well without a little extra work, with their jig if you follow the instructions it will end up with quite a bit of bowing in it, they should have provided shims for the bolts "no problem my pop made a set"

#2: the billet aluminum their using gave me a little bit of trouble "maybe this is common & I'm just a newbie" while drilling out the 1/8" holes in the top I ran in to an area where all of the sudden the aluminum got so hard I had to put an immense amount of pressure on it to get another 1/4" of hole drilled out " I was keeping an average of a 1/4" at a time between cleaning & lubricating" this continued with a group of holes all in one area of the receiver, biggest issue with this is that I had a bit snap off in one of the holes, I left it & will deal with that tomorrow.

so I finished off the rest of the 1/8" holes & decided to call it a day, images are the shims that pop made fore the jig & pop at the lathe, I'll add an update after working on it tomorrow



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I recently completed a Juggernaut 308 80% lower.  I ended up making spacers similar to what you did in order to avoid the bowing of the jig.  I didn't have any issues with the hardness of their material, but I did run into a few other problems with their lower.

First off, the buffer retainer hole (which is already drilled by Juggernaut) is too far to the rear of the lower.  This results in the buffer sitting perfectly flush with the lower, instead of protruding a bit like it is supposed to.  This led to the buffer slamming into the retainer during firing and may have contributed to some of the malfunctions I was experiencing.  My solution was to fill the hole with JB Weld and mill a new hole slightly forward of the original.  Your lower may or may not have this issue.

Second, when using their jig to locate the trigger and hammer pin holes, I ended up with my Wilson Combat TTU hammer making contact with the bolt catch at the same time that it would contact the firing pin.  If I dry fired the weapon, the bolt catch would be impact and bind up. This was taking away from the strength of the hammer strike. I have since found that the shape of the hammer plays a big part in this.  While my Wilson had the issue, my Geissele does not. Just something to look out for.  BTW, I'm using the Juggernaut upper as well.

You can find more info about my saga here, or you can PM me if you have any specific questions.

Edited by kazuaki

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from reading the topic on yours it sounds like you had your hands full with trouble shooting, I hope I dont run in to the same issues, I have a JP upper & almost everything I got for the build from JP as well, trigger/ carrier/ bolt, I got their silent capture buffer which from what I have read doesn't require the use of the retainer pin, we'll see how it all works out.

I finished the lower today & am going to test fit everything tomorrow, after a test fit I'm going to dura coat the lower, upper receiver & hand guard, I'm still waiting on the scope from Optics Planet "back ordered" I plan on painting it as well, hopefully I'll be resting this rifle out in a couple weeks

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I did my 80% .308 with a lower and jig from 80percentarms.com.  For the record, all the holes ended up in the right place; I goofed a bit on the first one, which they replaced at half price.  Second one came out superb.  That said, I also didn't like the bowing from having no spacers for the bottom two bolts.  I also had to have them replace the bolt set twice, as they had a bad bunch of bolts for a while.  They were very good about that, and as a result, I ended up with extra spacers, which I used to make shims for the bottom bolts.  Also, I was able to repair my first error, so ended up with two good lowers.  And my 80% lower fits perfectly with my Aero Precision upper.

Hang in there.  You will end up with a super rifle in the end.  

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