Tuesday, December 2, 2014

AR-15 follow-up #3

This is the third update on my request for information w.r.t. refurbishing AR-15 rifles for disabled and handicapped shooters.  The original post is here;  the first update is here;  and the second update is here.

I've been learning a lot about fixing problem AR-15's, and working with a couple of people more knowledgeable than I in the field.  It turns out that most problems are caused by people 'tinkering', particularly by using mismatched components.  I thought the firearms enthusiasts among my readers might like to learn more.

I've managed to fix two of the 'problem' rifles without too much difficulty.  The process began with a really thorough cleaning.  The upper and lower receivers were partly disassembled to expose major parts, which were coated with Slip2000 Carbon Killer inside and out and left to stand for 10 to 15 minutes.  They were then brushed to remove the loosened carbon, and cleaned again using Frog Lube solvent.  Following that, the gas key was checked to make sure it was correctly staked;  the extractor was checked for correct functioning;  and any suspect springs, O-rings, etc. were replaced, with new parts where possible, otherwise with used-but-still-good components.  The lower receiver parts were cleaned in the same way, then checked for function.  The buffer springs were replaced as a matter of principle, but in both cases the existing buffers looked to be in acceptable condition and were retained.  All metal parts, still largely disassembled, were warmed in the oven, then generously coated with Frog Lube CLP paste and allowed to stand for an hour to let it 'soak in', after which the paste was wiped off and the weapon reassembled.  (Frog Lube seems to make a noticeable difference to the smoothness of the action and trigger let-off, BTW.)

The same process has revealed some potentially serious issues with four more rifles.  In each case, individual components (e.g. the bolt carrier group, or the extractor, or something else) had been replaced with third-party components or - even worse - 'tweaked' by an over-enthusiastic amateur gunsmith.  In the worst of the four, the BCG is from one vendor, the extractor from another, the gas system appears to have been cobbled together with a blunt hacksaw, and the railed fore-end won't go on straight even with the help of a sledgehammer!  In that particular case, I think the cure's going to be a new upper receiver, complete with all parts, from a reputable manufacturer.  It would take far too long to tinker with each suspect component while trying to balance its fit and function with all the other suspect components.  As far as the other three are concerned, money's tight for the disabled shooters who own the rifles, so I guess we'll tackle them slowly and steadily over the next few months, fixing bits and pieces as we can afford them or find used parts that other shooters are prepared to donate.

I've learned many valuable lessons in the process.  In particular, I now understand how important it is to make sure that all the major sub-assemblies work well together.  For example, putting a new, heavier buffer into an old, well-used buffer spring may not work very well.  (On that subject, mention was made on an e-mail list to which I belong of a JP Enterprises extra-strength carbine buffer spring coupled with a Spikes Tactical T2 heavy buffer.  I tried the combination, and was astonished at how well it tames the sharper recoil of carbine-length gas systems.  It makes them feel like a softer-shooting mid-length gas system.  I'm sold on the combo, and will be retrofitting it to other carbines as and when money can be found to do so.)

Of course, the proof of the pudding is in the eating, and the proof of whether or not one's fixed the problems with a firearm is to shoot it.  I've called in the help of a few friends, because I certainly don't have time to do all that myself.  We're testing the rifles with five different rounds:

  • Lake City 5.56x45mm M855 62-grain military ball;
  • Federal 5.56x45mm XM193 55-grain military ball;
  • Winchester White Box .223 Remington 45-grain JHP (a varmint load);
  • Wolf .223 steel-case Remington 62-grain FMJ (polymer coated rather than lacquered);
  • Tula .223 steel-case Remington 55gr. FMJ (ghastly stuff, smoky and smelly).

I'm probably going to drop the Tula ammo from the test cycle, because it's really nasty and has caused a lot of problems with extraction and fouling.  On the other hand, if a rifle or carbine can feed and function with it, it's a pretty good endorsement of that weapon!  I've found that top brands like Colt and Bravo Company can handle it OK.  Cheaper or no-name brands, on the other hand . . .  The range testing has also revealed problems with some older magazines.  They can be fragile critters, particularly military aluminum units.  Once the body is dinged or the feed lips are dented, they should be discarded.  Some of my disabled shooters are going to have to pony up for a few more mags, I'm afraid.  (Troy Industries had a Thanksgiving sale on their battlemags, and I snared several 3-packs for only $20 apiece - a really good deal.  The sale is still ongoing at the time of writing.  Click on the link and scroll down to the sale specials, if they're still listed.  At that price, it's cheaper to buy new magazines than to refurbish old ones!)

We're trying to bring each rifle to the point where it can fire 20 of each round (10 slow, 10 rapid) with no malfunctions or problems of any kind.  The first two have now passed that test, with the exception of a couple of bobbles with Tula ammo, and are on their way back to their owners.  The remaining four will take several weeks longer because we have to find more and better components for them, and in one case a whole new upper receiver.  (If anyone has a spare upper receiver with a 16" or 20" barrel, preferably with a mid- or full-length gas system [but beggars can't be choosers - carbine-length is OK], and feels generous enough to sell it at a 'friendly' price or even donate it to a good cause, please drop me a line - my e-mail's in my blog profile.  Also, if anyone is able to supply or sponsor a few lower-cost components and spares [e.g. mags, springs, etc.], both I and my disabled students would be very grateful.  E-mail me for more information.)

I continue to learn a lot.  This has been a very educational exercise for me.  I may not have known much about the AR-15 platform when I started, but I sure will by the time I finish!  It's frustrating at times, but also fun.



Inconsiderate Bastard said...

Welcome to the wonderful world of ARs, and the education that comes with them. Once they're set up right, they run well with minimal fuss and just basic cleanliness.

I've learned to not waste time on anything less than top tier parts and assemblies (Bravo Company, Daniel Defense, Spike's, Colt, etc. and Brownells also makes good parts) because trying to save a few dollars winds up being false economy.

A tip, if I may: keep a log on round count, parts replacement, parts (and ammo) pedigree, etc. It's sometimes handy to know that part X from company Y didn't work well with parts from company Z on gun alpha. I've found, looking at the logs, things like gun bravo being cleaned every 250 rounds to deal with a problem, indicating I should have resolved that problem with parts replacement (or maybe even caused it with a parts replacement...).

Sometimes the learning curve is steep; good activity records can make the climb easier.

John in Philly said...

And to paraphrase Neo, "AR tools, lots of AR tools."

Parts problems included, a brand new BCG that would fire the round, eject the round, but not move rearward enough to pick up the new round from the magazine. Brownells replaced the BCG and refunded the return postage. The new BCG worked great. And your statement about records keeping is correct, except that I think about records keeping to late to remember which rifle has what. And a buffer tube that hated one BCG and would not work reliably with that BCG.

And a few extra parts, (yeah Brownells) for when you are unscrewing the buffer tube and the detent and spring get away from you. Or during a lower assembly when you are sliding the forward takedown pin into place and the detent and spring take off. The snap you hear is when the detent breaks the sound barrier on the journey to places unknown.

I was installing a spring kit in a revolver, kitchen table, bright lights, magnifier headband, towel on table, (no not a good towel) the towel was tucked into my belt, (jewelers trick) and the coil mainspring took off. After a long search I gave up. My wife arrived home and said, "Did you look under the stove?" I opened my mouth to say something stupid and snarky and at the last second a bright ray of good sense broke through the haze and I said, "Actually I did not." She gets a flashlight and a few seconds later hands me the spring.

I am in the last stages of an AR pistol build, in the end the build will be quite the Frankenstein. (Maybe name it Franks?) Funding issues will preclude installing a belt feed option on the AR pistol.

Looking forward to more of your novels.

John in Philly

Peter said...

@John: A belt-fed AR pistol? I dare you!


MrGarabaldi said...

Hey Peter,

I m a long time fan of the AR platform and my rifle is made back in 1990. I have changed it 3 times to its "A4" configuration. A good place for AR parts is
Red Barn Armory. I have bought my AR parts from them and they are very reasonable and the customer service is excellent. On a different note, I am waiting for the net installment of your Maxwell series.

Anonymous said...

CDNN in Texas often has deals on
AR mags.
A current one is $89 for 12.

No connection but as a customer.

Inconsiderate Bastard said...

@John - Aquarium. About 12-15 gallons or so; lay it on its side, tape a towel over the opening, cut slits for your wrists (the advanced version secures the cloth with velcro). You can see what you're doing, and spring loaded parts are contained (I've seen similar "assembly boxes" done with plywood and plexiglass, which allows custom sizing). Field expedient is a 2.5 gallon ziplock bag and some duct tape (I keep a couple in my range bag). Not quite big enough for a lower with stock, but works for handguns and BCGs when at the range.

I've also used the shower more than once (mine has a glass wall and door one one side, but a tall curtain/tub configuration can help contain parts). Pro tip: tape over the drain.....

John in Philly said...

To: Inconsiderate Bastard
From: John in Philly

Yes those tricks would work, and if I still had my Harbor Freight Sandblaster Cabinet, (not much use as a sandblaster) it would have made the perfect containment zone!

I used the clear plastic bag trick to assist a buddy in changing his dust cover. The clip removal tool was a reworked paper clip. And if the clip had gone astray it would have been trapped in the bag.

Peter, maybe I can crowd source the belt feed?

John in Philly

Anonymous said...

Once froglube is used ONLY use froglube. It does NOT play well with other lubricants especially if they are petroleum based.

Also if you are applying froglube for the first time there is a froglube product to remove the old oil and residue so it does not mess with the froglube when you put it on. Otherwise it needs to be cleaned a specific way before hand.

I found that out when researching gun lube/solvents. That's the big reason why I chose something else.


Anonymous said...

What are you using for action lube?
The book says CLP, but the old Kleenbore brand product I have seems too thick, so I cut it w/ about 30% 3-in 1 oil. Seems to work just fine.

Maybe the Kleenbore CLP is not the same as Milspec CLP?