BCM - Aero franken rifle

[maximus83]

A new rifle I recently put together. Already have 2 reliable rifles setup for defensive use, one with an Aimpoint, the other with a Razor 1-6. With this one I wanted to do some different things and accomplish these goals:

- A lighter rifle (max 6.25 lbs unscoped/unloaded) than the others, that maintains quality and does not sacrifice reliability.
- Have fun, try some new-to-me parts. Don't get a chance to pick all the parts I want and put an AR together very often. So part of the goal was to experiment a little. Items new to me: Sionics 2-stage (Schmid) trigger, Fortis K1 LE castle nut/endplate, Aero Atlas S-One handguard, Primary Arms Cyclops 1x20 prism sight (ACSS reticle), Rainier Arms 'accurizing' installation of barrel.
- A 2-tone rifle with receivers and handguard in FDE, and black furniture. Yeah, usually I could care less about cosmetics, just got bored with the fact that all my 'black rifles' are black. :-)
- After testing and swapping out anything I'm not satisfied with to confirm reliability--with extra attention paid to the PA optic, the trigger, and the Fortis castle nut--the end goal is to be able to run this as defensive use rifle too.

Specs
-Weight: 6.0 lbs (unscoped/unloaded). A bit more when I get the BUIS mounted.
-Lower assembly: me
-Upper assembly: Rainier Arms. Decided to try something new, instead of doing my own had them do their 'accurizing' barrel install. Includes machining receiver face and bedding barrel into receiver.
- Receivers: Aero M4E1 FDE upper/lower
- LPK: Sionics ambi (includes non-reversible ambi selector levers)
- Trigger: Sionics 2-stage (Schmid). Interesting that they told me on the phone, they had direct input into the design specs of this trigger with Schmid, and this is 'their' version not exactly like the '1005' version being sold elsewhere. They were not able to share proprietary details, obviously, and I have none of the 1005 triggers to compare this to. What I can say is an extremely nice trigger for < $80. Crisp 2-stage, avg 4.75 lbs across 5 pulls, Lyman gauge. Hard-pressed to tell a large diff between this and my Geissele SSA-E's.
- Ambi mag catch: Troy
- CH: Radian LT ambi
- Handguard: Aero Atlas S-one FDE Mlok 15" (total weight w/ hardware: ~13oz)
- Barrel: BCM BFH 16" mid ELW and low-pro gas block.
- BCG: BCM
- FH: Forward Controls Design 6315 Stoner 63 LMG Style
- BUIS: Magpul Pro (just ordered, not mounted)
- Stock/grip: BCM Gunfighter
- RE: BCM A5, Vltor A5H2, Sprinco green rifle spring
- Castle/EP: Fortis K1 LE castle/nut end plate. This is a friction fit, non-staking solution of 7075 aluminum, costs about $10 more than a typical quality castle nut/endplate combo that I get. Easy to install or remove with a CAR-type wrench, just finger tight, then I tightened about an extra half turn to torque it down. Fortis says they've sold over 5K with zero instances of them coming loose, they tested on full-auto with thousands of rounds and also on heavy tumbler machines, again with zero failures. Curious to see if this holds up under my testing.
- Optic: Primary Arms Cyclops 1x20 prism sight ACSS reticle (adds 9oz to the rifle). These are interesting for a lot of reasons, they are super tough, obviously not as proven as an Aimpoint, but pretty impressive. Plan to test one and if I don't like, will use it on a 10/22 and switch back to the old Aimpoint T1.

https://hbqg1q.bn.files.1drv.com/y4mnbRAueb2ofGI3T97DxsZJpckW7cE6G2owDQmNdzF8PrLocJ6OKP8h5ne8w5vqFAS3vuaHO0fY8XjvnXNkTqPpfMFXWz5mI4ThnJCeYLac1HeN2zcTFKjabbqoCB4BhkJbLo8Z_ZaY3Esszhap8Llb8oZ4C8qdKI7gPbFx9WEtwT9PNU2B_DYixBpyVjiNc0L_0oRfEPjMXn02FzmFQ70Lw?width=1024&height=322&cropmode=none

https://hbqd1q.bn.files.1drv.com/y4mNekg7cNG_lJ6p5seSuAnbgNkUOOL6WuRXDhC2pewda0XnQaDS9bqL4jmJkdMMHaL49RzsWo-rwqRUHWA4qUlPNOzvemtmNzOcP0VKrEdSBBRERg80dyuEKK2yft94cGwFLQHqq-BSVgKlmyjcQs873mWPE_BxSyRpqwBg6mxNFaIB7YhdIFr8NmhOo2jOM3mbgkg2FGQeDApLNZ4W9AiTQ?width=660&height=522&cropmode=none

https://hbqc1q.bn.files.1drv.com/y4mT0L-XOL1aGuG8s6HFV0-_khhRSlWr8HdEFEzto6Y6P8IH5mTonmwyWRrFKzYcsPWSXnBkOnl5_Mj-sIdYqDwis2Tmt7VGAtQliUGDqkdkczIhIi-lQJltwMs88l3PGNcBJziz_b3_sXNQgNOtQlMPPpJdtCQDBpzLw9t5_jRAgQ2zpBg_-xCIRNp_Cka6aM4kotThbB85i0Une0BFvTjPw?width=660&height=555&cropmode=none

Also a tip if anyone installs the Fortis K1 castle nut/endplate: a CAR-type wrench like the bottom one, makes it a lot easier than a spanner like the one on top. Easier to torque it into final position without slipping.

https://hbqm1q.bn.files.1drv.com/y4m2C3WdHRMvzZ5RiVoSLAebuDqLJd1ePiLfPm_CIdoVtf_gx6yGuhA1nHy6BykjicP1PttN8d5tgMuWBedCKTERKFyERFr4nqem4BIAYgl9Y51_9dhdE2WUT4D2L5hrZ8kdVDkrTN64C-DY7EKRiLeKKd2yeGGDcrEJuoQPzJ-3D6d8eJEeEcLvbBgri8cv_v5FKh6-HFtwNngyrt8-jxsEg?width=660&height=299&cropmode=none

[gaijin]

I like it.
Interested to see how it shoots. First I’ve heard of Raniers “custom” work.
(I keep a spare Leupold 4-14x in a QD Mount for RD/LPV builds to test accuracy/precision.)

[maximus83]

Rainier is kind of a mixed bag, but local to me and do quality work, so I use them sometimes. Sometimes, they have a rep of doing kind of 'gucci builds' or whatever you'd call that--really heavy and IMHO kind of overpriced 'match' AR's and stuff like that which I'm not personally very interested in. But that doesn't mean they don't know their stuff--I've had them assemble I think 3 AR's over the last 10-12 years, all were outstanding quality. Plus great customer service and have given me good ideas for some previous 'builds' I did. This 'accurizing' thing is something new-ish, they add $50 to the standard charge of assembling an upper to do those 2 extra steps mentioned in the OP. It was something I wasn't set up to do here (machining face of receiver), and I didn't see it compromising reliability at all, so decided to try it on this rifle and see if it makes any noticeable difference in accuracy and precision.

About the optic, if I recall from other threads, you are a fellow PA owner, true? I have only recently become aware of PA's optics. Usually I get optics like the nicer Leupy's, Vortex, and just recently got my first Nightforce. Not really an optics snob, but I like upper-mid range optics usually. PA is kind of different--they build these super tough, well thought-out optics with some features that almost nobody else does--esp the reticle. The glass is not high end for sure, but it's not bad either, and good enough for combat rifles. What's your take on PA optics, would you use one on a defensive gun?

[gaijin]

I would if it wasn’t a hard use gun- read that if it was a bedside/house gun.
I’ve used PA optics on range and hunting guns without issue.

If on a gun I staked my life on, banging around in a vehicle/humping over rough terrain- I’d feel a lot more confident with a vetted “rough use” optic.
Just my opinion.

[VIP3R 237]

I’ve beat the crap out of a 2.5x and a 1x PA optics and I’ve never had an issue. They’re a lot of optic for the price.

[maximus83]

^Yeah, noticed that Kyle Defoor names PA optics as solid, though in context, he's referring to their LPVO's. One of many things I like about their 1x and 3x optics is, the glass etched reticle. It's so good that in daytime I can use it without illumination and it gives you a great backup option if batteries go out. I've seen a few guys running them without BUIS due to the etched reticle, I don't think personally I'd go that far on a defensive rifle, I'll still run BUIS as I'd want a physically redundant sighting system besides the scope, regardless if it has a fallback option for a dead battery.

https://www.arbuildjunkie.com/red-dot-vs-scope-ar-15-kyle-defoor/


As far as low powered variable optic manufacturers, essentially I would say you have your “big four”, which are Vortex, Schmidt & Bender, Nightforce and Leupold. And then you have your “other” three…Kahles, Steiner and Primary Arms. But all of those guys make LPVs that are good.

[tehpwnag3]

Ah, here it is. I remember the castle nut! ;)

Good build, have fun.

[JediGuy]

Nice stuff. But also, I’m commenting so every time I come to the forum, a poll that has the phrase “or nah” isn’t on my screen.