Looking to Build a Custom AR-15. Any Suggestions?

Raven41

New member
Rating - 0%
0   0   0
Location
Ontario
Currently looking at a custom build. One lower, two uppers. Something very tough and reliable to withstand battlefield like conditions. Currently looking at a BCM complete lower mod 0, one BCM 16” upper, another BCM 11.5” upper. Both with BCM bolt carrier groups and ambidextrous Raptor SD charging handles. A trijicon ACOG sight for the 16” and a EO Tech Holographic with a 3x magnification scope for the 11.5”. Then the typical grips and added accessories for QD slings, lights, etc. Was considering a V seven titanium bolt carrier group until I found out it doesn’t come with the high-speed bolt, titanium firing pin, and was told it wouldn’t be worth it by other folks I talked to and that getting the Cryogenically enchanced bolt V seven offers as an add on would be very difficult and take forever. Anything I missed or any suggestions on a better setup? I’d rather make this my last AR purchase.
 
Have you ever thought about buying used? You can have Colt Canada IUR 15.7" off EE for a pretty good price and get CC IUR 10.5 or MRR 11.5 uppers. With the money you save you can buy a Elcan DR 1/4X or/and a Geissele trigger.
 
I have considered used, but I figured this way I can have everything exactly the way I want it. Plus I’ve heard the MRR uses some specific parts that are only for MRR AR’s. I also considered the Elcan SpectreDR 1x-4x. Other than the variable lens, what makes it better than the two optics I suggested? As for the Geissele. How much better are those than the trigger tech triggers?
 
I have considered used, but I figured this way I can have everything exactly the way I want it. Plus I’ve heard the MRR uses some specific parts that are only for MRR AR’s. I also considered the Elcan SpectreDR 1x-4x. Other than the variable lens, what makes it better than the two optics I suggested? As for the Geissele. How much better are those than the trigger tech triggers?

The elcan DR 1/4 is awesome. The biggest issue I'd say is weight.
 
Building your first AR and hopefully thinking it woll be the only AR you will ever buy are the most common mistakes beginner could make. Start off with a used one, use it shoot at least a case of ammo thru it, see what you like, what you don't like, how you shoot and than start thinking customizing to suit your needs.
 
I’ve used AR platforms at work, I currently own one that I’ve changed up a bit, I’ve tried a few guys hardcore custom AR’s at the my range and at some spots in the US. I agree that I can never know everything and know far from enough to call myself a professional, but I am only a beginner at custom making an AR. I’m quite comfortable and familiar with the platform.
 
Elcans are overweight and over hyped and over priced. The acog is very proven. Eotech is junk. The bcm guns are excellent. Don't waste money on gamer bolt carriers. Stick with a milspec group. Geissele make the finest triggers money can buy. I'm not convinced you need one but that's up to you.
 
Instead of spending money on a load of tackiekewl gewgahs, set up a solid reliable carbine, and put the money into ammunition and range time.
 
Instead of spending money on a load of tackiekewl gewgahs, set up a solid reliable carbine, and put the money into ammunition and range time.

I already have an AR that was well priced I use for practice. The Troy Nothern Guard 14.5”. Now it’s time for the tacticool! The whole reason I’m going with this is for a better rifle and the two uppers for different applications. CQB and shooting at moderate distance.
 
Don't think that you are really going to see a huge performance difference from 11.5" - 16". If you really want the two upper combo build a SPR upper and a 10/11.5", plus with that 14.5" other than another ~200 FPS what difference are you hoping to see?
 
Don't think that you are really going to see a huge performance difference from 11.5" - 16". If you really want the two upper combo build a SPR upper and a 10/11.5", plus with that 14.5" other than another ~200 FPS what difference are you hoping to see?

From my understanding once you go below 16” the round no longer reaches its maximum velocity and loses both accuracy and distance. The 16” barrel is nice because unlike an 18” or longer it isn’t as long while maintaining most of the ability of longer barrels (minus a slight accuracy advantage with the longer barrels). The 11.5” is a good CQB rifle and is easy to manipulate in shorter distance engagements.
 
From my understanding once you go below 16” the round no longer reaches its maximum velocity and loses both accuracy and distance. The 16” barrel is nice because unlike an 18” or longer it isn’t as long while maintaining most of the ability of longer barrels (minus a slight accuracy advantage with the longer barrels). The 11.5” is a good CQB rifle and is easy to manipulate in shorter distance engagements.

The only thing you sacrifice with barrel length is velocity. Accuracy is related to projectile stability, barrel quality(manufacturing tolerances) and the quality of the ammo. Naturally the greater the distance the less velocity and the less stability the bullet has which has a negative effect on accuracy. Having multiple AR's in multiple lengths I can tell you that an 11.5" will ring steel at 500 with ease when the shooter does his part.

You are partially correct on the 16" barrel vs velocity angle. The 16" barrel length achieves around 94% of the velocity generated from a 20" barrel which saves you 4 inches in length and weight. However I can also tell you that with some ammo and a 12.5" barrel you can achieve 3000 fps. Ammo dependent is the wild card.
 
The only thing you sacrifice with barrel length is velocity. Accuracy is related to projectile stability, barrel quality(manufacturing tolerances) and the quality of the ammo. Naturally the greater the distance the less velocity and the less stability the bullet has which has a negative effect on accuracy. Having multiple AR's in multiple lengths I can tell you that an 11.5" will ring steel at 500 with ease when the shooter does his part.

You are partially correct on the 16" barrel vs velocity angle. The 16" barrel length achieves around 94% of the velocity generated from a 20" barrel which saves you 4 inches in length and weight. However I can also tell you that with some ammo and a 12.5" barrel you can achieve 3000 fps. Ammo dependent is the wild card.


Though you can use different types of ammo to achieve different results, I really only ever use 55gr FMJ. So I try and keep that in mind when I’m thinking about my build.
 
Though you can use different types of ammo to achieve different results, I really only ever use 55gr FMJ. So I try and keep that in mind when I’m thinking about my build.

Being the most common weight I agree. The velocities above were with 55gr ammo.
 
You can't go wrong with BCM. I've been exceptionally happy with mine (BCM lower with a 16" upper on top).
I've had no issues running it at close range and at a distance.

Eotechs are also great optics and anyone who says otherwise is just toying with BS online banter. The interweb operators all lost their #### when eotech admitted they have POA shift at extreme temperatures, yet the internet operators will never shoot in conditions in which the problem arises sooo..... I'm running a 10-15 year old Eotech Su-231 with zero issues whatso ever.

I'd honestly avoid the ACOG as others have mentioned. I initially had an ACOG on this 16" upper but it's amazing how quickly the fixed 4X loses its appeal when shooting up close. Granted you'll have a SBR upper for that, but believe me when I say the fixed power optic craze is dead. My 16" upper now sports a Nightforce NX8 (1-8 LPVO if you're not familiar) and I can't recommend something along those lines enough over a fixed power optic.
I also run a specter DR on a different rifle, and while it's still an incredible optic the LPVO's are pushing it aside. If you can find one for a good price they're worth it, but I wouldn't be paying retail.

While the technical differences between barrel lengths are worth noting, the biggest one I see people fail to discuss is manuverability.
Swinging a rifle with an 11.5" barrel you tend to notice a huge difference in maneuverability than you will with a 16".

I'd say your choice in rifle build specs is superb, both will cover a large spectrum of shooting and I doubt you'd see any issues.

Only two words of advice I'd note:
Fixed power ACOGS suck in comparison to LPVO's (IMO)
Gucci bolt carriers are a waste of money. I've still yet to see any viable, real word proof that titanium this or NiB that do anything advantageous aside from "they clean marginally easier".

Oh and best of luck with your "last AR purchase". Mine was 3 or 4 rifles ago. ;)
 
You can't go wrong with BCM. I've been exceptionally happy with mine (BCM lower with a 16" upper on top).
I've had no issues running it at close range and at a distance.

Eotechs are also great optics and anyone who says otherwise is just toying with BS online banter. The interweb operators all lost their #### when eotech admitted they have POA shift at extreme temperatures, yet the internet operators will never shoot in conditions in which the problem arises sooo..... I'm running a 10-15 year old Eotech Su-231 with zero issues whatso ever.

I'd honestly avoid the ACOG as others have mentioned. I initially had an ACOG on this 16" upper but it's amazing how quickly the fixed 4X loses its appeal when shooting up close. Granted you'll have a SBR upper for that, but believe me when I say the fixed power optic craze is dead. My 16" upper now sports a Nightforce NX8 (1-8 LPVO if you're not familiar) and I can't recommend something along those lines enough over a fixed power optic.
I also run a specter DR on a different rifle, and while it's still an incredible optic the LPVO's are pushing it aside. If you can find one for a good price they're worth it, but I wouldn't be paying retail.

While the technical differences between barrel lengths are worth noting, the biggest one I see people fail to discuss is manuverability.
Swinging a rifle with an 11.5" barrel you tend to notice a huge difference in maneuverability than you will with a 16".

I'd say your choice in rifle build specs is superb, both will cover a large spectrum of shooting and I doubt you'd see any issues.

Only two words of advice I'd note:
Fixed power ACOGS suck in comparison to LPVO's (IMO)
Gucci bolt carriers are a waste of money. I've still yet to see any viable, real word proof that titanium this or NiB that do anything advantageous aside from "they clean marginally easier".

Oh and best of luck with your "last AR purchase". Mine was 3 or 4 rifles ago. ;)
.

That is not true, there are a list of problems that Eotech sights suffer from and thermal drift is one. Sadly many seem to believe that thermal drift only occurs at extreme temps, this is not true. Thermal drift occurs at all temps, it simply has the most pronounced error at extreme temps. In fact Eotech no longer lists an operating temperature for their sights because the problem cannot be corrected.

Here are the other issues that Eotech suffers from.

"Cold weather distortion" or temperature influenced parallax. This issue causes POI shifts of up to 12 MOA at freezing(32'f or 0'c) and increases to a max of 20 MOA at minus 15'c or 5'f. Not exactly extreme temperatures.

Eotech also admits that their sights experience POA shift(thermal drift) at ALL temperatures and that due to this the sight may never return/hold zero even when the ambient(zeroing temp) is achieved. So zero today at 20'c and tomorrow at 5'c on a cloudy cool day and your zero may very well wander. Wait until next week for another 20'c day and your zero may well be off still.

Eotech sights also suffered from "moisture incursion" which means the sights are not waterproof. Moisture would enter the sights and cause "reticle fade" a condition where the reticle would become very dim or simply disappear randomly.

Eotech sights have admitted their click adjustment values are not consistent, but approximate.

Eotech sights have suffered a long history of battery contact failures resulting in the optics switching off due to recoil. This has been mostly rectified with the perpendicular battery position.

Eotech sights suffer from unknown parasitic battery drain, greatly shortening the already short battery life of the optic.

The worse part about their failings is that Eotech hid this information from the public and their military/LE customers for nearly ten years... That's some shallow sh*t right there..

Here's a quote right from Eotech's website.
https://www.eotechinc.com/hws-service-and-support/faq

Will the HWS hold zero as temperature changes?
EOTech’s sights experience a point of impact shift away from the point of aim when the sight is exposed to a temperature different from the temperature at which the sight was zeroed. After zeroing the sight at or near ambient temperature (73°F), the zero position will shift during operating temperature changes. For sights manufactured after October 2016, the typical shift will be between approximately 1.4 and 1.8 minutes of angle (“MOA”). Due to manufacturing variations, however, a particular sight has the potential to shift a maximum of approximately 3.5 MOA at -4°F and 122°F. Sights manufactured prior to October 2016 have the potential to shift approximately +/- 5 MOA at -40°F and 122°F.

Due to thermal drift, sights may not return to zero. The sights have the potential of approximately a +/- 2 MOA zero shift upon return to ambient (73°F) after being exposed to any temperature between -40°F and 122°F.

Shifts result from natural thermal expansion or contraction that is present in various materials as they are heated or cooled, and is greater the more extreme the temperature change. For example, when a sight is zeroed at 73˚ F then acclimated to 50˚ F, less shift occurs. On the other hand, if zeroed at 73˚ F, then acclimated to 0˚ F, more shift occurs. The shift may not be significant to shooters who use their sights at close-quarters ranges. For instance, 3.5 MOA is a shift of .875 inches at 25 yards, and is 3.5 inches at 100 yards. It also is worth noting that thermal effects are evidenced to varying degrees in common optics, as well as in rifle barrels and ammunition as the environmental conditions change. In all events, to achieve optimum accuracy, the sight zero should be verified whenever the sight is exposed to marked temperature changes, and the sight should be re-zeroed as necessary.

Does the HWS have parallax?
All optics experience varying degrees of parallax depending on use and operating conditions. Parallax is an apparent change in the point of aim resulting from a change in the position of the shooter. EOTech’s sights have little parallax when the reticle is in the center of the viewing window, which is the optimum sighting position and also is the correct place for zeroing the sight. On the other hand, if the user is looking through the sight at the outer edge of the sight window – an off-axis view – the parallax error might be up to 4±3 MOA (or a total of 14 MOA across the viewing window) at 71˚ F (for a sight properly zeroed). In other words, parallax can increase as the user’s view approaches the edge of the EOTech viewing window. To put this possible amount of off-axis error into perspective, 7 MOA equates to 1.75 inches at 25 yards or 7 inches at 100 yards. Viewing through the center of the window achieves the least parallax error. Parallax may increase as temperature changes from 71˚ F. At operating temperature extremes of -40˚ F or 122˚ F, there may be an additional 4 MOA of parallax.
 
Good call on the bcm gear. Their mcmr uppers are very nice. Skip the rando bcg with titanium crap in it. No one in the battlefield runs that stuff and you said you wanted battlefield reliability so... not worth your time. Get an alg trigger. Its not quite geissele level but its nowhere near geissele money.

Skip the eotech get an aimpoint or triji mro for the stubby forget about the magnifier, for the longer gun the acog is a great option.

Most importantly buy crates of decent ammo and blast away till you can make it sing.
 
[Insert factual but long winded post from above I'm not going to actually quote because no one needs to read that twice.]

This question is entirely rehtorical because I don't want to send this thread off course, and while yes these are all documented issues eotech optics "may" experience, have you yourself ever experienced any of these problems or is this just other interweb operators sharing the same internet experience? The internet tells us that eotechs are junk, unreliable yadda yadda yadda, yet they're still in large scale use all across the globe and I have yet to experience any of these issues, nor has anyone I've ever discussed this with first hand.

Food for thought.

Also, here's a little 16" BCM inspiration for the OP.

6ZICnOL.jpg
 
Back
Top Bottom