WoW, The AR Game Has Changed.. Is There Any Book That Covers Modern Day AR-15 Builds?

[26 Inf]

wow, great info all, learned a lot just on this post alone..

Basically it seems like the more things change, the more they stay the same..


so with that in mind here is where i'm at..

1. Going to buy this AR BUILD Book, because I want a hard copy just to always have something on hand, it has decent reviews, and one of the few that a look inside option and I like what I see.. DONE!

2. Whats with the fixation on FSB? I think I remember why from my past foray into the world of AR-15 but just in case, someone break it down for me..

Here is my thought process - most folks are using optics correctly, both eyes open, with a lower 1/3 co witness a fixed A2 FSB doesn't as intrude into the window as much as other options, PLUS, and this would be primary to my thought process - you don't have to fumble around to pop up a fixed FS under stress.

There are also concerns with flip up BUIS folding at in opportune times or breaking if dropped.

On the other hand, there are a lot of folks who are relying solely on optics for their rifles, due to increased reliability and battery life.

3. Back before I left there was some kind of chart floating around, I believe it was specific to this site, it basically had all the main rifles out at the time and which manufacturers was closest to MIL-SPEC and which one's weren't, I believe at the time the Colt 6920 was the only one that met that list 110%. Is that still the case? What ever happened to that list?

Here's a link to a thread about 'the chart' - https://www.m4carbine.net/showthread...jor-AR-Brands; the Tactical Yellow Visor site is no longer up, and a brief search finds nada, all the links I find to 'the chart' are no good.

As someone mentioned, even lower priced ar's are improved over what was offered a decade ago. More and more folks are putting rails/tubes on their rifles and those aren't part of the TDP, same thing with low-profile gas blocks, not part of TDP.

Additionally, most after market parts - think bolts, bolt carrier groups, barrels, list the materials they are made of and the testing. For instance a mil-spec bolt is C-158 steel, magnetic particle inspected, and high pressure proof inspected. That is more often than not listed in the specs. Today, most astute buyers know what the materials should be.

4. Is Mid Length v/s Carbine length even a thing anymore? WHO won? I think for 16 inch mid-length, but it isn't a closed book.

5. ^^ what other debates like that are out there, any I missed, or what are the new ones? A5 extension versus Carbine Extension might be one.

6. In 2018 is there any "common" staples that most agree on for an AR-15 build? ala FSB is the way to go? light and sling

** ^^ I know, I know, i just have to research all this myself to get back up to speed, but yall had some good posts on here in relation to my OP so figured I'd throw these immediate questions out there and see where all this went..

JMO YMMV

[Sean Price]

JMO YMMV

this is exactly what I'm lookin for, this is the feedback that points me in the right direction1!

Much appreciated, thank you!

oNe

[redpillregret]

If I were going to get an AR for home defense and didn’t plan to run it with lasers, I’d buy a 6920, a T2, fixed rear, a quality sling, and a Surefire Scout. I’d buy a ton of ammo and mags and shoot the piss out of it. Then I’d buy another one identical for training and one for defense. This may not be vogue, but it will not be inadequate for any task within those parameters.

For outdoors and medium range, I’d do a few things differently.

If I wanted/needed a gun with more reach, I’d get a railed upper, a Surefire Scout M600 with all the lumens, and a variable like the Vortex Razor. Perhaps upgrade the trigger. The optic may allow you to take advantage of an upgraded trigger and free-floating rail. I’d also consider irons or a second optic, and possibly a QD bipod.

I’m the idiot that likes to tinker and buy things. I have over a dozen ARs...these are the two configurations I’ve found most useful.

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[MorphCross]

JMO YMMV

Great overview, but there are some points of contention. One could reasonably be better off with a Bolt made from 9310 that has been shot peened, individually high pressure tested, individually Magnetic Particle inspected, and individually Industrial Radiograph inspected. Headspace that to a barrel that undergoes the same level of individual testing plus Air gauging, pre-chrome hand lapping, 11° Target crowning and muzzle threading in concentricity to the bore. That would probably fall under obsessed and overblown but that would be just my opinion.

[redpillregret]

We don’t know that air gauging isn’t happening. I’d say it is. But what good is air gauging without parameters?

And the 11 degree target crown, many, including some scientifically published articles, would suggest is bull.


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[JediGuy]

And the 11 degree target crown, many, including some scientifically published articles, would suggest is bull.

Not doubting, but would love to read that. Link?

[MorphCross]

We don’t know that air gauging isn’t happening. I’d say it is. But what good is air gauging without parameters?

And the 11 degree target crown, many, including some scientifically published articles, would suggest is bull.

Obviously you set a tight tolerance for straightness.

The crown having zero contact with the chosen muzzle device along with installing a properly timed device with shim or peel washers and Rocksett will guarantee that no additional stress is applied to the crown or the muzzle end of the barrel.

[26 Inf]

Great overview, but there are some points of contention. One could reasonably be better off with a Bolt made from 9310 that has been shot peened, individually high pressure tested, individually Magnetic Particle inspected, and individually Industrial Radiograph inspected.

There has been a lot of spirited debate about 9310 versus C-158. Here is a fairly succinct synopsis:

Bolts are becoming a pet subject!

It is always interesting to consider the bolt within the context of its application. To do so will draw not only on stress analysis, but also on fatigue theory and metalurgy. This will quickly move the solution beyond the simple question of which steel is best, for the best steel if applied out of context will not perform adequately.

So for simple illustration let us assume that the steels are applied well, before discussing the differences.

Carpenter 158 is without doubt an excellent material for the production of M16 bolts. The material is clean with negliable elements in the make up that are detrimental to the fatigue life. It can operate happily within the confines of the enviromental requirements imposed by the application and has a very low deformation of the parts as they run through heat treatment. The down side to the material is that it was designed to heat treat in large sections so the thin bolt material will respond somewhat voilently. Again not an immediate problem if the heat treatment is absolutely perfect but within the confines of a production enviroment it will throw problems.

By comparison AISI 9310 will on first inspection also make an adequate bolt material. It has several alloy elements that promote a better structure and in the correct heat treatment will provide a slightly higher toughness than Carpenter 158 which is benificial to the fatigue life. Corrosion resistance is slightly higher but as with C158 it should not be applied without some form of surface protection. Thin section response to quenching is somewaht less than C158 which makes it better suited to the manufacture of bolts. However by comparison to Carpenter 158, AISI 9310 has several elements present in its composition that are detrimental to fatigue while not being evident in the physical properties.

It has become evident from the industry that a number of manufacturers have jumped upon the AISI 9310 wagon in order to claim better performance. While in theory an AISI 9310 bolt may perform better I would not typically select this material specification. There are a wide number of superior alloys available without resorting to the nickel based maraging alloys which are expensive, difficult to machine and extremely temperamental in behaviour. The steel industry has advanced since the specification of Carpenter 158 but the basic premises for the selection remain even if the menu has now expanded.

https://www.m4carbine.net/showthread...highlight=9310 (page 4, post 34)

Regarding HPT and MPI - there are a number of folks who don't favor HP testing of the bolt as they believe the over-pressure events reduces bolt life.

[MorphCross]

Regarding HPT and MPI - there are a number of folks who don't favor HP testing of the bolt as they believe the over-pressure events reduces bolt life.

That would be why I qualify the Magnetic Particle Inspection alongside Industrial Radiograph after the High Pressure test. On the other points about 9310 you are correct.

[magister]

wow, great info all, learned a lot just on this post alone..

Basically it seems like the more things change, the more they stay the same..


so with that in mind here is where i'm at..

1. Going to buy this AR BUILD Book, because I want a hard copy just to always have something on hand, it has decent reviews, and one of the few that a look inside option and I like what I see.. DONE!

2. Whats with the fixation on FSB? I think I remember why from my past foray into the world of AR-15 but just in case, someone break it down for me.. FSB’s have been standard for over 50 years on US M16/M4 service rifles. I think many people are used to them, and value them being on duty rifles. However, I think there has been an acceptance by many people for rifles without an fsb, especially over the past few years.

3. Back before I left there was some kind of chart floating around, I believe it was specific to this site, it basically had all the main rifles out at the time and which manufacturers was closest to MIL-SPEC and which one's weren't, I believe at the time the Colt 6920 was the only one that met that list 110%. Is that still the case? What ever happened to that list?

4. Is Mid Length v/s Carbine length even a thing anymore? WHO won? Answers depend on barrel length, and who you ask. For a 16” barrel I’m fine with either as long as I’m getting my rifle from a reputable maker.

5. ^^ what other debates like that are out there, any I missed, or what are the new ones?

6. In 2018 is there any "common" staples that most agree on for an AR-15 build? ala FSB is the way to go? I see a lot of builds utilize free floated rails and lo pro gas blocks vs fsb builds. There’s no wrong answer, though. Whatever you do, buy quality components.

** ^^ I know, I know, i just have to research all this myself to get back up to speed, but yall had some good posts on here in relation to my OP so figured I'd throw these immediate questions out there and see where all this went..


FYI: From my previous hey-day, before I left the AR-15 world. All thats left is my 1st 2 original AR purchases.. a brand new SEALED in the box Colt 6920, and a Daniel Defense DDM4v3. Solid rifles. Keep them, buy extra mags, and use them. Maybe set one up as a training rifle and the other as your HD/duty rifle.

Current Hey-Day Plans: received my stamps for gang of suppressors and several SBR's last year so NEED to build those out.. plan is for a 5.56 SBR and a .300BLK out SBR, both running Omega's.

^^ I somehow have this nasty habit or shall I say "bad" luck of getting in on the tail end of things.. aka, bought those original AR's at Sunset of AWB, and then bought all the suppressors and SBR stamps a week before 41F.


However after each of those junctures LIFE took over, got a real career making real $$$, bought a house and AR's then dropped off of the world. 1 Month before 41F hit, I heard about it, and scrambled to put a trust together and bought 6 suppressors, and 5 SBR's, aka $10,000, but then LIFE took over, bought a house, did the wife and marriage thing, then 3 kiddo's later..

Anyways, I NOW once again have the time to get back into this AR hobby... UNFORTUNATELY It seems like I have to start from scratch..


NOT jus build a modern AR-15 but also have them be SBR's.

I think what I will do is build 1 "normal AR-15 to get a handle on things, and then from there build the 2 SBR's.


oNe


P.S. right after I purchased the 6920 there was some noise about certain models of them being worth more, something about COLT changing a proprietary bolt for a industry standard one thus potentially making the pre-change 6920's worth more? Does that ring a bell to anyone? I believe that may be why in addition to time constraints why i NEVER even opened up the box for my 6920. As maybe I was thinking its a potential heirloom I would be able to pass on to my family?

I defer Colt values to others more knowledgeable. However, most 6920’s, especially for the prices I’ve seen them recently, are what I’d consider users. Unless you have some really rare, valuable 6920, I’d put it to use. That’s just my opinion.