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LPK recommendations for SI HK receiver???


2336

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Folks, I've got one of SI's HK format upper/lower receiver sets on the way and would like to pick your brains as far as Lower Parts Kit recommendations for this particular format.  It's my understanding that SI's .308 receivers all use DPMS format stuff, ie 16 tpi on barrel threads and so on.  Hopefully there is one of our membership here that has dealt with this and has some pearls of wisdom.

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Well gents, I should be able to make a better informed report to youse guys soon. My upper/lower receiver set is due to arrive at my FFL tomorrow and I was able to snag a DPMS lower parts kit which I should get this weekend or early next week. I'll go ahead and "attempt" to install the LPK and see what I get. I'll let you guys know and post some photos. Hopefully it all works out. If nothing else I can at least give someone else the straight scoop on these SI Defense HK format receiver sets. BTW, they should have 14 sets left, if anyone's interested LMK and I can PM you the info so you can get ahold of John there. They come in black anodized, NiB or bare.

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<lmao>  All other posting people should take note of his actions...  That's how it's supposed to be done, right there. 

 

When you find something that nobody else has right now, it's your responsibility to buy one and evaluate it for the rest of us.  You must take that plunge.  If you ask a question about a certain product, and nobody has any details yet, you're just obligated to do your part for the good of the herd, fall on your sword, and shell out bucks.  <thumbsup> <laughs>

 

Well done, 2336, very well done.  :hail: :hethan:

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<lmao>  All other posting people should take note of his actions...  That's how it's supposed to be done, right there. 

 

When you find something that nobody else has right now, it's your responsibility to buy one and evaluate it for the rest of us.  You must take that plunge.  If you ask a question about a certain product, and nobody has any details yet, you're just obligated to do your part for the good of the herd, fall on your sword, and shell out bucks.  <thumbsup> <laughs>

 

Well done, 2336, very well done.  :hail: :hethan:

 

You have two weeks to post pictures of your new Barrett MRAD before I call you on this one!  <munch>

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Well gang, to go along with what 98Z5V said, here's my new SI HK format upper and lower receiver set. I must say, my initial impression is very good. The two seem to fit together pretty good, and the anodizing is smooth, even and so black it looks evil! The upper is serialized and matched to the lower. I went ahead and installed the forward assist tonight, which is included, just no retaining pin. Luckily I have several extras. I've got several G3 mags and tried one out. The fit is on par with what you usually see from most AR-15s and GI aluminum mags. I should get the lower parts kit in the next couple of days, then we can see just how tightly these two fit.

SIrec2_zpsf580f307.jpg

SIrec1_zpsb765aa61.jpg

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Kicked In The Nuts! :(

That's usually the kind of feeling you get when you realize something has gone terribly wrong with a project that you really want to go smoothly. I received my DPMS LPK today and got started installing it this evening. Everything seemed to be going along pretty good. I was initially concerned about the front pivot/take-down pin being long enough - it was. I think the other member here that had problems with an SI lower receiver was trying to use an Armalite LPK. Anyway, front pin - good. Magazine release - good. I even tried it with a 20rd G3 mag and release was very smooth and positive. Hammer, trigger and disconnector all went in fine - just like an overgrown AR-15. Rear take-down pin needed work on the "well" for the detent and spring. The spring included with the DPMS LPK for the rear take-down pin was slightly larger in diameter than the spring for the front pin. I ended up having to ream out the detent hole in the receiver about 7/8 of the way down so the spring would go in, the detent itself fit fine. One minor gripe, and I'll talk to SI about getting a pin from them, the slot in the rear take-down pin doesn't extend close enough to the "head" so the head of the rear pin ends up sticking out a bit on the right side when closed and requires another pin to push it out from the left. These are all minor gripes as far as I'm concerned. Now for the acid test, mate the receivers together. They went together okay, closed them and they're a little loose. Might just be the take down pins, nothing that one of those little orange wedge dealies won't fix. Now for the big test. Insert and release a magazine with the receivers together - oops! No Go!!! Magazine stops about 3/4 inch from complete insertion - doesn't engage the magazine catch! WTF! Look inside the upper receiver and the magazine lips are hitting on the inside of the receiver. I take a deep breath, set everything down on the work bench so as to avoid "slinging the crap around" syndrome!

SIHKdontfit_zps9446945d.jpg

I looked at the photo of the receiver set that SI sent me before I ordered my set. Look at and compare the bottom forward edge of the upper right above the magazine well, then look above at the upper they actually sent me.

SI-HKreceivers_zps91b1e7b0.jpg

Looks like they sent me a standard upper. Plus, since it was serialized to match the lower, whoever did that wasn't paying attention. I'll be sending John at SI an e-mail tonight and then making a phone call Monday morning. Crap, this sucks. Oh well, like 98Z5V said someone's gotta evaluate a new product, and folks, I'm evaluating my butt off! :P

Edited by 2336
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I couldn't help but notice you have the same issue I had.

Screenshots_2013-11-22-20-35-30_zps37f86

To prevent this from getting worse, you'll have to relieve the inside of the safety lever. Find my .308 build thread in the "SI Defense" section.

Didn't the bolt catch cutout raise any red flags? Amazing that it made it through so many hands and passed inspection each time. I look forward to SI-D's response to this.

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 Rear take-down pin needed work on the "well" for the detent and spring. The spring included with the DPMS LPK for the rear take-down pin was slightly larger in diameter than the spring for the front pin. I ended up having to ream out the detent hole in the receiver about 7/8 of the way down so the spring would go in, the detent itself fit fine.

I'm wondering if that was a safety detent spring, and not a takedown/pivot pin spring.  Takedown and pivot pin springs are identical.  The safety detent spring is slightly larger in diameter, larger wire coil diameter, and a little bit shorter than takedown and pivot pin springs. 

 

EDIT - Matt, I wasn't the first person to mention the MRAD, brother...  <dontknow> >:D

Edited by 98Z5V
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I couldn't help but notice you have the same issue I had.

Screenshots_2013-11-22-20-35-30_zps37f86

To prevent this from getting worse, you'll have to relieve the inside of the safety lever. Find my .308 build thread in the "SI Defense" section.

Didn't the bolt catch cutout raise any red flags? Amazing that it made it through so many hands and passed inspection each time. I look forward to SI-D's response to this.

Robocop1051, yes, I noticed the bolt catch cutout earlier, but thought that they had tried to consolidate their line-up by combining those different features. I just pretty much figured, "hey, they designed and built the thing - they know what they're doing." Boy, was I wrong! I take it you actually meant the take-down pin, right? There's no problem at all with the safety lever. Now on the rear take-down pin, without the detent in the receiver the take-down pin goes all the way in to where the head is flush on the right side and the small end of the pin is protruding very slightly on the left side - just enough to start pushing it through to open it. That's why I inspected the "slot" in the underside where the detent pin slides and verified it was the culprit.

98Z5V, on the spring issue, I think the problem lies with the DPMS LPK that I received. The detent pin springs were different size, both length and diameter, but just very slightly. All the rest of the springs were of the "usual" sizes and instantly recognizable.

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I just may have to "fess up" about this. Though I'm not sure if I was the first person to mention it (I think).

YEP. I just might have enabled myself when it comes to this particular item...........................

I can't shunt the blame to Tom on this one (though I'm trying to think of a way). But I did throw out that I was considering either the Remington or the MRAD.

 

I throw myself on the mercy of the court..............................WAIT.......what the FCUK am I doing? <lmao>

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I just may have to "fess up" about this. Though I'm not sure if I was the first person to mention it (I think).

YEP. I just might have enabled myself when it comes to this particular item...........................

I can't shunt the blame to Tom on this one (though I'm trying to think of a way). But I did throw out that I was considering either the Remington or the MRAD.

 

I throw myself on the mercy of the court..............................WAIT.......what the FCUK am I doing? <lmao>

 

Damn, reminds me of many a "kangaroo court" convened when I was still active duty. Didn't matter how eloquently you pleaded your case, how innocent you really were, someone was gonna buy the beer! ;)

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