AR-308 Part 5

Previous posts in the series:
Part 1
Part 2
Part 3
Part 4

OK…the rifle is together. If I’d bought one off the shelf, that’s pretty much what I would have gotten. There are still a few odds and ends to add, like a magazine, a scope, a bipod, etc…but those wouldn’t have come with an off the shelf rifle and I’d still have to buy them anyway…so for an apples to apples comparison, what’s the tally so far?

$565. Excellent.

But we still have some loose ends to tie up. There are two components that, although not technically necessary for shooting the rifle, they really make it work better: A magazine, and some sort of sighting system.

I ordered a 10 round Magpul LR-308 Pmag from Midway USA for $18.

The sighting system was a little more complicated. I knew I wanted a scope because I want this rifle to be a tack driver at range. I’d love to be able to shoot it well at 500 or 1000 yards so I wanted something that would work for long range…variable power and a high zoom level.

Another thing I like is Mil-dot reticles. I like the fact that a mil-dot reticle can be used to estimate range. The down-side of that with a variable power scope, however, is that if the reticle is in the second focal plane, you have to adjust your calculations by the zoom level of the scope at the time…that really complicates the math. With a first focal plane scope, the reticle zooms along with the background, so the perspective stays the same, regardless of the zoom level of the scope. That makes the math (relatively) easy.

Adjustable Objective is a must for me. I don’t like having to worry about compensating for parallax. And a large diameter objective means more light, better view.

But, I didn’t want to spend $1000 or $2000 either. After reading review after review and finding scopes that were close, but was missing one or another feature I was looking for, I ended up finding a Vector Optics Counterpunch at Optics Planet for $200. Vector Optics gets mixed reviews, but, again, for the price, I figured it would do for now and I can upgrade in a year or so if needed.

Finally, just a couple of optional accoutrements I ordered from Amazon.

Bipod $38
2 point Sling $10
GrovTec QD bases $8 (needed to add QD sling swivels to the Luth-AR stock)
M-loc QD sling base $12
QD Sling Swivels $9

And that completed the build. I now have a fully operational rifle, customized exactly how I wanted it.

Total cost: $852

A little over my original budget, but very good nonetheless.

I have to admit that I did splurge and break the bank a bit. On the first range trip, the cheap-o FCG I had in there left, um, a lot to be desired. Very gritty, heavy pull and the pins walked loose, causing the rifle to malfunction. This won’t do at all. I could clean up the trigger, reduce the pull and make it smoother, but I’d still have to worry about the pins walking.

Considering I’m hoping this rifle will be a tack driver, I decided that skimping on the trigger isn’t a good idea. I decided I wanted a good match style 2 stage trigger. I was going to buy a Jewell like I had on my National Match AR-15, but alas, they don’t appear to make them anymore.

That’s a right shame…I loved that trigger. Completely adjustable and smooth as glass. I was really disappointed when I checked their web site and they don’t list them any more.

I settled on a Geissele G2S. Not adjustable, but pre-set for a 2.5lb takeup and a 2lb release for a total pull weight of 4.5 lbs. I prefer more on the takeup and less on the release, but that’s the closest I could get to what I want. I had my Jewell adjusted for a 4lb takeup and a 1lb release to meet the minimum 5lb pull needed for matches.

I could have gone cheaper…Rock River makes a similar 2 stage match trigger for half the price, but from what I’ve heard, it’s half the quality as well. The Geissele was $165 at Optics Planet, but after shooting it, I’d have to say, worth the price.

So I ended up at a little over $1000 all in. Sigh. It’s only money, I can make more…

Anyway…I took it back to the range with the upgraded trigger today. It ran like a clock, everything was perfect.

So, what’s the verdict?

I think it’ll do.

100 yards on a standard sight-in target with 1″ squares. That’s a 3 shot group right at 1″.

This was from the bipod with cheap Remington Core-Lokt 150 grain ammo. I got 1″ groups or close to it consistently after dialing the scope in with cheap ammo and a not entirely stable rest. I really can’t wait to see what it’ll do with some match grade ammo. I’m pretty confident that it will do sub-moa.

Mission accomplished. The only question is: how long will the cheap scope hold up? Time will tell.

Final Post in the series.

AR-308 Part 4

Previous posts in the series:
Part 1
Part 2
Part 3

So, we’ve got all the parts for the basic rifle, now we just need to put it together.

I’m not going to go through the whole assembly process as it’s no different than the standard AR-15 assembly I’ve covered that at least twice here on this blog; also, you can find the process everywhere on the internet and youtube.

What I do want to talk about, however, are the oddities I discovered while assembling. This is related to the weird configuration of the Diamondback lower. As I mentioned in previous posts in the series, the Diamondback DB-10 upper receiver was configured to take DPMS parts, so I assumed I needed DPMS parts for the lower as well. Silly me.

The first clue that something strange was going on was the magazine release. I installed the spring and release, started screwing the button onto the shaft, pressed the button and screwed the shaft into the button until the top of the shaft was flush with the face of the button, released it and…the button wasn’t seated in the receiver. Hmm. Looked like the shaft just wasn’t screwed in far enough.

I pushed the button back in (after lining it up with the hole in the receiver) and screwed the shaft in as far as I could get it to go. that did the trick, the mag release fit now and seemed to operate just fine, but the shaft was sticking out past the face of the button by about 1/8″. It was painful to press the magazine release because the protruding shaft would dig into my finger.

Long story short, I ended up using my dremel tool to cut the extra 1/8″ off of the shaft.

The next thing that hinted something wasn’t right was the bolt catch pin. On AR-15’s and Armalite AR-10’s, the bolt catch is held in place with a roll pin. In my DPMS lower parts kit, the bolt catch pin was threaded on the end. Hmm. Can’t screw a threaded pin into a receiver without a threaded receptacle.

I dug into my spare parts bin and used a standard AR-15 roll pin to install the bolt catch. It seemed to fit fine.

Everything else went uneventfully…but after it was all together, the bolt catch wouldn’t catch the bolt.

After getting a magazine and trying it, the bolt would lock open on an empty magazine, but no matter what I tried or how I manipulated the bolt catch, I could not get the bolt to lock back without a magazine inserted.

In trying to figure this out, I e-mailed Diamondback and explained my issue. They replied very quickly, but told me that a DPMS parts kit should work.

I did some more research and ended up stumbling across a comment from a person who said they used an Armalite A series LPK with their Diamondback DB-10 lower and it worked fine.

I decided to take a chance and ordered a bolt catch from Armalite for $23. It took a week or so to get it, but after installing the Armalite catch, everything worked as it should. I’m guessing that had I also purchased an Armalite magazine release and Armalite takedown/pivot pins, they would have worked as well.

At any rate, with a little trial and error, it went together.

So, if by some chance you ever purchase a Diamondback DB-10 upper and lower set, just know that the upper takes DPMS parts and the lower takes Armalite A series parts…just to keep things interesting.

Still some finishing touches…more to come…

Next post in the series.

AR-308 Part 3

Previous posts in the series:
Part 1
Part 2

So, now that we’ve figured out what types of parts we need, the next step is to figure out exactly what to order.

The goal was to make a custom rifle, as accurate as possible…preferably sub-moa, but also keep it under $800 all-in. A lofty goal.

I had an idea of what I wanted, but I didn’t want to rush because I was planning on getting things as I found sales and deals. The best laid plans…

The first thing I found was a 20″ Socom profile barrel made by ELD for $105. I didn’t know anything about ELD but I looked up some reviews and didn’t find anything bad. They guarantee sub-MOA performance with match ammo so I took the chance. For that price, I figured even if I have to buy a new barrel in a year or so, at least it would get me started.

I bought it from Omega Manufacturing. I did find some bad reviews about Omega manufacturing and apparently it’s owned by a parent company that also runs a couple of other online gun parts retailers. Basically, the reviews weren’t about the parts they sell, but about their customer service…so again, not a show stopper as I was more concerned about getting quality parts than excellent service. Turns out, they actually were pretty good. Got my parts out quickly and resolved the one issue I had.

While I was there ordering the barrel, I looked around at what else they had. They actually had really good prices on quite a few parts, so I ordered several things from them in addition to the barrel:

Omega Manufacturing M-lok 15″ free float handguard – $53
Omega Manufacturing muzzle break – $35
ADK Defense Bolt Carrier Group and charging handle – $110
Ejection Port Door assembly – $9
Rifle Length gas tube – $10
AR-15 Forward Assist Assembly – $10

I ordered a cheap low profile gas block for $6 from Cheaper Than Dirt; I ordered some other stuff at the same time, so call it $1 for shipping.

OK…so I pretty much had everything for the upper on order in one fell swoop…so much for taking my time and buying stuff as I found it…but I still needed the lower parts. I really wanted a Luth-AR MBA-1 stock because of how adjustable they are, but they aren’t cheap. Usually around $160. I finally found one at Schuyler Arms for $120 + $7 shipping and as a bonus, it came with the LR-308 buffer kit and a DPMS LR-308 Lower Parts Kit minus the fire control group.

So the final piece was a fire control group from a cheap $29 LPK I already had.

So, that’s where we are: One AR-308…some assembly required (click to make bigger).

Note: There is a vital component missing from this picture. 100,000 internet points to anyone who can figure out what it is. (hint: It’s a fairly small part, but it’s not a spring or pin or anything like that),

More to come…

Next post in the series.

AR-308 Part 2

Previous posts in the series:
Part 1

So, after getting a great deal on the upper and lower, I needed to start getting the rest of the parts. This is where it got complicated.

It seems there is no “mil-spec” for the AR-10 style rifle because they were never made for the military. Apparently there are two primary styles with different variants and even more “one-off” types from various manufacturers.

The two primary styles are the Armalite style (this is the only style, by the way, that can really be called the “AR-10” since AR stands for “Armalite Rifle”).

Armalite style AR-10’s come in two variants: A series and B series. They are not interchangeable as the receivers are milled differently. The most obvious difference between the two are the magazines. The A series uses magazines that look much like a scaled up AR-15 magazine. This magazine style became the “standard”; it’s used in DPMS lowers and is produced by many aftermarket manufacturers including Magpul. The B series uses an aluminum magazine based on the M-14. The magazine release and bolt catch are also different.

The other primary style is the DPMS pattern. There are a few different variations and many manufacturers that produce receivers ostensibly in the DPMS pattern do so in non-standard ways. Basically, there is no guarantee that uppers and lowers from different manufacturers will work together even if they describe themselves as DPMS pattern or Armalite pattern, and DPMS and Armalite definitely won’t work with each other. It seems to be the best bet to buy the upper and lower from the same manufacturer to ensure they’ll work correctly with each other.

In addition to the uppers and lowers being different, many of the other parts are specific. One of the big differences between Armalite and DPMS style rifles is the barrel nut threads. Armalite uppers take a 1 7/16″ barrel nut threaded at 18 teeth per inch (TPI). “Traditional” DPMS uppers take a 1 7/16″ barrel nut but threaded at 17 TPI. More recently, DPMS has introduced a generation 2 upper that takes a 1 5/16″ barrel nut threaded at 18 TPI.

There are also three variations of DPMS upper height. The two main ones are high and low. The third one is apparently rare and is called “high rise” or “slick side”. This becomes important with railed handguards. If you get the wrong handguard for the upper height, the rails won’t line up.

Whew! Talk about confusing.

One thing that helps is that some of the parts are interchangeable with AR-15 components. I found this handy website that goes through all the parts and what is interchangeable.

Just in case that isn’t confusing enough, it turns out that my Diamondback receivers are sort of a combination of DPMS and Armalite.

The rear of the upper and lower where they fit together (the area between the takedown pin and the buttstock threads) are shaped like an Armalite (DPMS is more rounded there), but the upper takes a “traditional” DPMS barrel nut and matches the DPMS high rail profile.

The lower apparently works best with Armalite series A parts (I figured this out through trial and error). I read in the reviews that only Diamondback proprietary pivot and takedown pins will work, so I ordered them, but then I read later that Armalite A series pins work…I didn’t try those, but based on other discoveries I made, I’d guess it’s probably accurate.

At any rate, here’s what I ended up using:

Upper and Lower: Diamondback

Upper parts:
Barrel, extension and barrel nut: DPMS (traditional) style
Gas block and gas tube: AR-15
Bolt and bolt carrier: DPMS style
Charging handle: AR-15
Handguard: DPMS high
Ejection port cover: DPMS
Forward assist: AR-15

Lower Parts:
Takedown and pivot pins: Diamondback*
Takedown and pivot pin springs and detents: AR-15
Safety, safety spring and detent: AR-15
Grip: AR-15
Fire control group: AR-15
Buffer and buffer spring: DPMS (these are interchangeable with Armalite)
Buffer retainer and retainer spring: AR-15
Magazine release: DPMS (modified**)
Bolt catch, spring, detent and roll pin: Armalite series A
Stock: AR-15

*As I previously mentioned, I bought proprietary takedown and pivot pins from Diamondback, but I read elsewhere that Armalite A series pins would work. My guess is that’s accurate based on the fact that I needed an Armalite A series bolt catch.

**The DPMS magazine release “almost” worked. I’ll go into more detail later, but I had to “make” it fit.

More to come…

Next post in the series.

Latest Project: AR-308

Actually, one project among several this summer, but this is the only one that’s gun related.

I love the AR style platform, but I’ve always been interested in something bigger than a varmint cartridge. I know you can make an AR work with 7.62×39, .300 AAC Blackout, 6.8 SPC etc, but I wanted a true “battle rifle” loading.

So, I’ve been interested in getting an “AR-10” style AR platform rifle in .308/7.62x51mm.

The problem is that they’re kind of pricey, typically somewhere between $1000-$2000 (or more…just for the rifle, not including accessories or scope).

I just happened to run across a sale on a blemished Diamondback DB10 upper/lower set. I got them both for $129…about half what I’d expect to pay. The “blemish” involved a lack of anodizing inside the mag well on the front and rear surfaces.

On the rear surface, there was also a flaw in the machining, you can see it on the left edge of the groove about 3/4 of the way down (as always, click to make bigger).

I doubt that it would have affected the magazine fit, but I didn’t like it so I cleaned up the groove with a jeweler’s file and then hit it with Alumi-Black. This is what it looks like now.

I think it cleaned up nicely. That was the only real issue. The fit between the upper and lower is perfect. The only other very minor issue is that the finishes don’t match perfectly, the lower is just slightly shinier than the upper, but that’s not even noticeable with the rifle assembled.

Here’s the upper and lower mated together, along with a standard AR-15 upper and lower for comparison.

More to come…

Next Post in the series

It’s a good thing…

…Japan has such strict gun control. Because that makes mass murders impossible or something.

A man screaming “You die!” burst into an animation studio in Kyoto, doused it with a flammable liquid and set it on fire Thursday, killing 33 people in an attack that shocked the country and brought an outpouring of grief from anime fans.

Everything you wanted to know about suppressors but were afraid to ask

Hi guys.  Long time no post.  I recently received a request from our friends at Ammo To Go to publicize a blog post they recently put up.

I had actually already seen the post and enjoyed it immensely, but when they specifically requested that I spread the word…well…here I am, spreading the word.

They basically cover everything you ever wanted to know about suppressors (aka silencers), from how they work, where they come from and why they are sometimes called suppressors and sometimes silencers; then they test several different calibers and types of ammunition with and without suppression to see how much difference it makes.

It’s a great article and well worth your time if you’re interested in the subject at all:

Silencer Guide with Decibel Level Testing

I’ve actually been interested in silencers for a long time. After being a shooter all my life and 21 years working up close and personal with jet aircraft, I’ve got a pretty severe case of Tinnitus. I’ve lost about 30% of my hearing and I have a constant ringing in my head. Sometimes the ringing changes pitches just to keep it fresh, but it never goes away. You get used to it after 20 years or so, so there’s that.

Anyway, I have a serious concern that if I ever do have to use a firearm in self-defense…especially in the close confines of my home…that firing multiple shots without hearing protection in those conditions could render me completely deaf, or nearly so.

I’ve been interested in getting a suppressor for a home defense gun for a long time. I’ve never done it because the price gives me pause, as well as the whole “pay the non-refundable tax, beg for permission, wait up to a year, and hope for the best” thing.

I’ve really been rooting for a legislative fix to get this common sense safety equipment taken off the NFA list so I could buy one like a free, law abiding citizen should be able to…pay your money and take it home.

The recent shooting in Virginia Beach dashed that hope (in spite of the fact that the incident should have proven beyond a doubt that suppressors don’t make gunshots silent or more deadly). My only hope is that more people become educated about what suppressors are and what they are really capable of (rather than what they see in hollywood movies).

And so…to that end…please click the link, read the article and share it with all of your friends.