Annual AR function test

[stagpanther]

I have a rather large collection of ARs; as a result some of them may go years between use. It's a lot of work, but I've decided it's necessary to do an annual function check of all of them, even if they haven't been recently used or going to be used. Going through my AR 10's--my 358 win build, which heretofore had functioned flawlessly--failed to properly reset the trigger when doing the trigger hold-back test. This could have possibly resulted in a full-auto mag dump. Replaced trigger pins (both of which were slightly bent), passed function check and will test fire.

 

[jwamplerusa]

How did the pins get bent?

 

[stagpanther]

How did the pins get bent?

I'm not exactly sure; but it was an early model Jard adjustable which is fairly narrow and has a retainer plate on one side which--if it slips off the notch in the trigger pin--can cause the trigger and pin to move and the trigger getting a cant. I removed the trigger and replaced it with a conventional non-adjustable.

 

[stagpanther]

The AR in 358 win was one of my first AR 10 build attempts; so it's been through a lot of firings; and then just sat in my safe for most of the last few years. It's also pretty much the biggest thumper I have in an AR--even with a brake and gas system it's felt recoil is impressive--not unlike a 35 whelen which is sort of a "developmental sister cartridge." Here are some 225 gamekings ready to test the new trigger set-up.

 

[stagpanther]

Everything worked the way it was supposed to with a random charge of 39 grs of 2015 (155 yds). Even though I added a couple of lbs to the trigger pull I didn't notice.

 

[stagpanther]

I got to the last of my AR10 builds, this one is in 260 rem that I did a while ago using a Black Hole Weaponry barrel that they gave to me (long story) but it has sat in a safe for a couple of years as well. It too has an early Jard adjustable with the trigger pin retaining plate--but unlike the one in my 358 win it fits in the PSA lower without projecting up into the upper--so no trigger issues with it. It did have a problem with the bolt--actually I found this on two of my AR 10 bolts--it had a "frozen" ejector. Ther two rifles that I encountered this on fired fine last I used them (otherwise they would not have gone back into the safe). I haven't encountered these issues with my AR 15's--but I'm beginning to suspect the possible culprit is storing the rifles oiled vertically in the safe long term with the bolts still in them; I think I should remove them.

I also had a problem with the case sealing to the chamber wall; even with loads that were on the warmish side, every other case came out covered in soot from the mouth to the rim. This group was shot using nosler's RDF bullets at what QL tells me is a pretty warm load of 41.8 grs of AA 4350--appropriately enough at 260 yds. That seemed to reduce the soot to just the neck area and I saw no signs of pressure (though it still could be high). I shot a few groups of the rdf's--typically a few would land very close to each other and then a couple would land much further apart from the tight group.

 

[MarkCO]

If I think it will be a while before I shoot an AR, I will typically take the bolt carrier group apart and put it in the Ultrasonic cleaner that is filled with Lucas Oil Solvent/US cleaner. I take them out and lay them on a towel to drip dry and cool. Then I will reassemble the BCG without any added lube.

The Lucas Bore Cleaner leaves a little film which protects from corrosion/moisture. Great for shotgun chokes. Then a quick lube before use.

 

[stagpanther]

The Lucas Bore Cleaner

That's my standard go-to and my favorite--though I occasionally use other cleaners in cases of excessive copper fouling. I just wonder if over time gravity causes fluids to naturally flow down into the bolt and carrier when stored vertically long-term. When you say you take the carrier group apart and clean them--does that include tapping out the cross pins in the bolt to remove the extractor and ejector and their springs as well?

 

[jetinteriorguy]

I got to the last of my AR10 builds, this one is in 260 rem that I did a while ago using a Black Hole Weaponry barrel that they gave to me (long story) but it has sat in a safe for a couple of years as well. It too has an early Jard adjustable with the trigger pin retaining plate--but unlike the one in my 358 win it fits in the PSA lower without projecting up into the upper--so no trigger issues with it. It did have a problem with the bolt--actually I found this on two of my AR 10 bolts--it had a "frozen" ejector. Ther two rifles that I encountered this on fired fine last I used them (otherwise they would not have gone back into the safe). I haven't encountered these issues with my AR 15's--but I'm beginning to suspect the possible culprit is storing the rifles oiled vertically in the safe long term with the bolts still in them; I think I should remove them.

I also had a problem with the case sealing to the chamber wall; even with loads that were on the warmish side, every other case came out covered in soot from the mouth to the rim. This group was shot using nosler's RDF bullets at what QL tells me is a pretty warm load of 41.8 grs of AA 4350--appropriately enough at 260 yds. That seemed to reduce the soot to just the neck area and I saw no signs of pressure (though it still could be high). I shot a few groups of the rdf's--typically a few would land very close to each other and then a couple would land much further apart from the tight group.

I have a couple questions on the RDF’s. First, what weight bullets are you using and second, what OAL are they? I have some of the 140 gr that I’ve never been able to get any better than 1 MOA in my bolt Rifle that I’d like to use up in 6.5 MB (man bun) and am thinking perhaps I could burn them up in my AR10.

 

[MarkCO]

That's my standard go-to and my favorite--though I occasionally use other cleaners in cases of excessive copper fouling. I just wonder if over time gravity causes fluids to naturally flow down into the bolt and carrier when stored vertically long-term. When you say you take the carrier group apart and clean them--does that include tapping out the cross pins in the bolt to remove the extractor and ejector and their springs as well?

I actually don't use Lucas Bore Cleaner to clean bores. Yes, overtime, any oil will gravity move, if there is enough (too much) of it.

Yes, total strip of the bolt.

 

[stagpanther]

Thanks for that.

 

[armoredman]

Very nice work, sir. Beautiful rifles. I have never fired a thumper quite like that - must have some serious thump downrange on whatever you're shooting at!
I only have one AR, but even so it gets ignored a lot, too. I took it out a couple of weeks ago just to "make sure" like you did, and it did just fine. Just a Frankengun with a PSA lower, but it works well.

 

[stagpanther]

I have a couple questions on the RDF’s. First, what weight bullets are you using and second, what OAL are they? I have some of the 140 gr that I’ve never been able to get any better than 1 MOA in my bolt Rifle that I’d like to use up in 6.5 MB (man bun) and am thinking perhaps I could burn them up in my AR10.

Funny you should ask. As you probably already know in the 260 rem in an AR you are going to be constrained by the length of the bullet vs what you can get into the magazine max COL so seating the bullet deep means eating up case capacity. Even when I've seated the RDF as far out as I can, sometimes beyond 2.8" depending on the magazine, there's then the issue of the nose possibly jamming into the ramps/extension on the way into the chamber--when dry cycling a cartridge the nose of the RDF sometimes comes back out with a slight dent whenever I go as long as I can in COL. In the manbun (I assume you mean 6.5 creedmoor) you should be able to mitigate most of those limitations. The RDF is a frustrating "tease" bullet for me--I sometimes can get two or three in the same hole at ranges between 2 to 300 yds--but invariably I'll put a couple wide from the tight ones. Could be operator error as 44 would say. I use the 130 RDFs because that's what I scored 500 count boxes for cheap.

Very nice work, sir. Beautiful rifles. I have never fired a thumper quite like that - must have some serious thump downrange on whatever you're shooting at!
I only have one AR, but even so it gets ignored a lot, too. I took it out a couple of weeks ago just to "make sure" like you did, and it did just fine. Just a Frankengun with a PSA lower, but it works well.

Thanks--they are actually uglier up close when you see the gaps between the uppers and lowers--a notorious shortcoming of the AR 10 build world in that there is such a wide variability between manufacturers. I've even had a lower and upper made by the same manufacturer (whch will go nameless) not align well and was a major headache to get to work reliably. But I have a couple of AR 10 builds--one in 7mm-08 and the other in 338 fed--which when topped with Burris RT 3 are perfectly reasonable hunting rifles IMO and lightweight for the platform without using any exotic parts.

 

[jetinteriorguy]

Thanks SP. I had a feeling you were probably using the 130 gr bullets. It seems like most of the reading I’ve done on RDF’s that the 130’s tend to work better for people. I bought 500 of the 140’s and tried everything under the sun but never got them below 3/4” at 100yds. I still have 120 bullets left, I may give them a try in my Swedish Mauser just for S&G’s.

 

[stagpanther]

I could be imagining things--but the RDFs seem to have a bit less neck tension on them in brass than bullets like the ELDs and VLDs when I seat them.

 

[jetinteriorguy]

I could be imagining things--but the RDFs seem to have a bit less neck tension on them in brass than bullets like the ELDs and VLDs when I seat them.

That’s interesting, I could get an undersized mandrel for my Lee Collet Neck sizing like I got for my.223. Trouble is I no longer have anywhere to shoot beyond 50 yds so maybe for the future if I get access to a better place.

 

[stagpanther]

That’s interesting, I could get an undersized mandrel for my Lee Collet Neck sizing like I got for my.223. Trouble is I no longer have anywhere to shoot beyond 50 yds so maybe for the future if I get access to a better place.

Again, this is all pure conjecture on my part, but it seems like when the RDF engraves well and concentric to the bore it is extremely accurate--and then "all of a sudden" it flies a couple of shots wide. I can't conclusively preclude operator error though. I understand your limitations in range, over time I've learned I pretty much can't make any conclusions about a high BC bullet unless I shoot it to at least 200 yds.

The RDF seems to have an "ultra secant ogive" and "ultra pointy nose"--I sometimes wonder if those same features that increase flight efficiency also make it more vulnerable to upset when slightly out of whack.

 

[stagpanther]

If I think it will be a while before I shoot an AR, I will typically take the bolt carrier group apart and put it in the Ultrasonic cleaner that is filled with Lucas Oil Solvent/US cleaner. I take them out and lay them on a towel to drip dry and cool. Then I will reassemble the BCG without any added lube.

Having encountered function issues on two of my bolts--I have come to the conclusion that your suggestion of complete strip and clean of bolt/carrier prior to long-term storage is unequivocally the right way to go. Nothing like click and crickets chirping when bang is needed.

 

[jetinteriorguy]

Again, this is all pure conjecture on my part, but it seems like when the RDF engraves well and concentric to the bore it is extremely accurate--and then "all of a sudden" it flies a couple of shots wide. I can't conclusively preclude operator error though. I understand your limitations in range, over time I've learned I pretty much can't make any conclusions about a high BC bullet unless I shoot it to at least 200 yds.

The RDF seems to have an "ultra secant ogive" and "ultra pointy nose"--I sometimes wonder if those same features that increase flight efficiency also make it more vulnerable to upset when slightly out of whack.

I drove myself nuts trying to make the 140 gr RDF’s work. Then I bought some 140gr Hornady ELD Match bullets and the magic happened. It was so easy to dial these in it was almost boring.

 

[stagpanther]

I drove myself nuts trying to make the 140 gr RDF’s work. Then I bought some 140gr Hornady ELD Match bullets and the magic happened. It was so easy to dial these in it was almost boring.

I use lots of ELDs in many calibers. I don't know what kind of "magic sauce" Hornady uses in the design/manufacture of the ELDs--but I have found one of their most outstanding characteristics is that they seem to be highly tolerant of a wide range of "jump to lands" and still be very accurate/consistent. In my experience they usually shoot better even than their A-Tips which are their boutique match bullets that come packaged like exotic caviar--the A tips like the RDFs seem to put several shots at or near the same hole and then zip a ringer off to the side and like the RDF they seem to demand an arduous search for the holy grail of perfect load (at least for my modest reloading skills).