Critique my parts list!

[pontoon]

Looking for any suggestions. In particular the build is a little more expensive than I originally wanted. Also if possible I would like to find a good fit billet lower + milspec forged upper with no forward assist. Mega arms makes one except it's got forward assist. I'll keep looking. Also that adjustable gas block is super expensive! If there's a cheaper clamp style (I don't want the screw style as I read it not a good idea for accuracy) made of steel I'm all ears. Also if anyone knows a replacement trigger that's a decent price I'd be open to that. Under $150 for sure if it's possible.

Barrel: Liberty stainless 18" (includes bolt)
Bolt carrier: Rubber city low mass
Stock: A2 tube and plastic pad
Lower: Ranier Arms forged lower
Upper: Ranier Arms forged upper no FA
Handguard: AP Custom 9" carbon fiber
Grip: Magpul K Grip
Lower parts kit: DPMS lower parts kit (will probably swap out the trigger eventually. See grip above)
Charging handle: $10 mil spec
Gas tube: Del-Ton mid length
Gas block: Syrac Ordinance adjustable $$$
Buffer tube: AR Stoner
Muzzle brake: None--use thread protector
Magazine: E Lander 10 round
Trigger: Velocity

[1075 tech]

Trigger under $150. Velocity single stage drop in.
Gas block, adjustable, <Syrac, try JP Enterprises. They have a low profile and a railed adjustable both under $100
Charging handle. I like the BCM Gunfighter line up although I have no experience with anything else other than mil-spec. PF had a good price on these.

Good luck. I don't know enough about some of your other choices to provide an opinion.

[454bore]

Vltor.makes a good upper with no F/A.
I've seen them for $140.

[cory]

Looking for any suggestions. In particular the build is a little more expensive than I originally wanted. Also if possible I would like to find a good fit billet lower + milspec forged upper with no forward assist. Mega arms makes one except it's got forward assist. I'll keep looking. Also that adjustable gas block is super expensive! If there's a cheaper clamp style (I don't want the screw style as I read it not a good idea for accuracy) made of steel I'm all ears. Also if anyone knows a replacement trigger that's a decent price I'd be open to that. Under $150 for sure if it's possible.

Barrel: Liberty stainless 18" (includes bolt)
Bolt carrier: Rubber city low mass
Stock: ACE ultralight or similar (with self made cheek rest)
Lower: Ranier Arms forged lower
Upper: Ranier Arms forged upper no FA
Handguard: AP Custom 9" carbon fiber
Grip: Magpul K Grip
Lower parts kit: DPMS lower parts kit (will probably swap out the trigger eventually. See grip above)
Charging handle: DPMS
Gas tube: Del-Ton mid length
Gas block: Syrac Ordinance adjustable $$$
Buffer tube: AR Stoner
Muzzle brake: JP Enterprises
Magazine: E Lander 10 round

First I'd advice going billet upper + forged lower, as I think that's probably what you meant.

2nd spend your money on the barrel and trigger, everything else is comparatively arbitrary. I'd be sure to go with a SAAMI spec barrel. However, if you only intend to shoot factory ammo, then BHW is a great option. I'd spend a little more money on a Geissele Tricon or SSA.

BCG: for the price you can't beat the Precision Firearms Grendel BCG. It's as high quality as you'll get.
Stock: purely personal preference
Lower/Upper: I suspect that Rainier Arms set would serve you well. However, Precision Firearms sells high quality forged sets at a great price. I actually just ordered an upper receiver for another 5.56 build.
Handguard: Purely personal choice. I have completely fallen in love with the Spike's SAR3.
LPK: Go with a kit that has all stainless steel springs. I believe PF has switch to stainless steel springs. I know the WOA kit does.
CH: You can save some money here and go just milspec.
Gas Block/Tube: Depending on your barrel you can save some money here too, with standard parts. I've moved to clamp on; however, you'll be fine with a set screw if you don't over torque. You'd have to use a PENCIL thin barrel before that was a potential problem.

I would suggest a heavy buffer, if using a carbine.

[pontoon]

Can I use the adjustable gas block so that I don't have to worry so much about the buffer weight? I would rather use a lighter buffer tube and use the adjustable gas block to save weight if possible. I'm willing to pay $25 more for the Syrac gas block because it's an ounce lighter than the JP Enterprises one. I'll make some adjustments to this list. I'm getting a Grendel II style barrel. Not sure what SAAMI is.

[cory]

First the Satern (Grendel II) chamber is not the Grendel chamber and is not SAAMI spec. SAAMI is the governing body of rifle/pistol chamber and ammunition dimensional specifications. SAAMI chambers have to adhere to specific industry agreed upon standards, while the others do not. Stay away from the Grendel II and get a SAAMI spec barrel. You'll thank me later.

You can certainly use an adjustable gas block too. I only suggested not doing it because I thought you were trying to save money. I'd still go with the heavy buffer though.

[pontoon]

What exactly is stainless in a "stainless" LPK? I've seen some references to stainless trigger parts, but I decided I'm replacing the trigger anyway so that shouldn't matter. I'm just looking for a basic LPK no grip needed, no trigger guard needed, no trigger needed. Apparently the grip screw and washer will be needed unless the magpul grip comes with that (couldn't figure that out).

I'm going to stick with the Liberty/Grendel II barrel. Apparently it'll fire factory ammo and it looks like a great barrel at a good enough price. If I'm wrong about it firing factory ammo please correct me because I would hate to have a barrel that can't shoot my ammo.

I read that with a low mass carrier you want a low mass buffer. Basically turn the gas way down, then click it up till it cycles brass reliably. This should result in fast cycling and low recoil. That's what I read in a lightweight rifle build thread. I think the guy actually removed all weight from the buffer. Not sure if I'd do that. I'm going with a carbine buffer unless anyone says otherwise.

[A5BLASTER]

My grendel II barrel will shoot factory rounds.

[LRRPF52]

My recommendation is to not waste money on any 18" barrel with a MLGS that uses a .0935" gas port, unless you are prepared to dial it in with adjustable gas and a selection of heavy buffers to find the balancing point where it will extract and cycle slowly.

I've spent several range trips that could have been much more productive with a known performer, trying to tame a barrel like that, and it is frustrating because I've never had any cycling issues with correctly ported guns.

I tried to get one working with adjustable gas, and the guy I was doing it for had already waited months, so I sent it to him with the adjustable gas with the recommendation to use an A5 extension and heavier buffer, because I just don't have the time to keep hoping it will work with another tweak, when I can buy known performing barrels for less money, fluted, with the SAAMI chamber that will shoot out of the box, with recoil so pleasant, you barely know you're shooting anything bigger than a .223 Rem

With the gas slightly open on that problem upper, it felt like the buffer was trying to break out of the extension tube. I've never felt an AR15 recoil that hard that I can remember.

My recommendation right now is to go to AA and look at their $195 fluted barrels, and $680-$760 complete uppers. AA has the details of this system ironed out dating back for well over a decade, and the barrel and bolts are the real differences that count the most. Bill spent $10,000 on different reamers alone trying to get the chamber to shoot a wide range of bullets accurately, while running reliably in the AR15.

I talked with him at SHOT about some of the little tweaks that I do on other bolts, and he said he noticed that, and scratched his head wondering why I'm having to radius ejectors. He thought about it, and remembered that back when he first started trouble-shooting, he spec'd the ejector out so that you wouldn't have that problem of the case rim hitting the side of the ejector with a very simple approach that is easy to mass-produce, unlike radiusing ejector faces.

Now that AA is selling barrels again as individual components, I've been ordering them for people that want uppers. I went to de-edge and polish the extension, and saw that it was already done from the factory. Basically, most of the important mods I do from a hand-fitting perspective are done.

After years of not buying factory rifles, I'm looking at AA uppers as a comparable alternative to all the headache I've been going through assembling my own. I still like to Cerakote, but they have a laundry list of hydro-dip options for those who want a camo pattern or even carbon fiber pattern.

[COTNTOP]

I just purchased 2 of the 16in. barrels from AA and they are easy on brass. Both barrels shoot 123 amax sub moa but do not like the 123 scenar. I would buy complete uppers the next time.

[pontoon]

When you say "do not like" what do you mean? Bad accuracy, bad cycling, or something else?

My build list is almost done. I bought the lower today. The local shop didn't have anything I liked except a forged anderson lower. Luckily it's well reviewed and the matching upper will be cheap if I can ever find it in stock. Probably going with slick sided upper probably with dust cover (can get with no dust cover too).

Looking at smoke composites stock. Can't help myself it's so light weight and sexy. Figure 9.5" stock ok for a 5'8" person? Alternative length is 11"

Getting carbine buffer and spring and going to try that first, then I'll try it with more and more of the buffer weight replaced by wood dowels. I read competition shooters do it when using adjustable gas and a low mass carrier like I'm going with. I think they use rifle length stocks and rifle buffers and springs though (no weights or about 1 ounce total in the rifle buffers).

BTW the OAL for Grendel II can be longer right? If so that's better for reloading because you can make the OAL longer and put more powder in?

[cory]

...BTW the OAL for Grendel II can be longer right? If so that's better for reloading because you can make the OAL longer and put more powder in?

Sure, if you intend to single load by hand. You're constrained by the mag length and this negates any "advantage" the saturn chamber offers. Also to much jump to lands can be detrimental to accuracy.

[schrödinger's cat]

Joebobs has Anderson uppers in stock for $40

[LRRPF52]

That "II" chamber isn't even a good idea for micro action bolt guns because most of their magazine length restrictions don't allow that long of a COL.

Why anyone would think of it for use in the AR15 continues to baffle me, unless you're single loading.

I've shot multiple 5rd and 8rd groups with many different SAAMI chambers into the .3's through .6's. I've never seen the excessive freebore chambers come close to that.

[pontoon]

Joebobs has Anderson uppers in stock for $40

Thanks I saw that too. I'm looking for the one with no FA but does include an ejection port cover (or the option to install one).

[pontoon]

Sure, if you intend to single load by hand. You're constrained by the mag length and this negates any "advantage" the saturn chamber offers. Also to much jump to lands can be detrimental to accuracy.

I read up on it more. It looks like longer mag lengths are up to 2.3 and the COAL allowed by the Grendel I barrel is 2.23, so you gain up to .07 with a certain mag choice. The massive FPS gains I read about were someone who must have been hand loading into the chamber. I suppose the .07 real world advantage of the Grendel II would offer a minimal FPS gain and probably more importantly potentially better accuracy for a hand loader who has .07 more to play with. I'm not a hand loader (yet) so my knowledge is very limited.

[cory]

I read up on it more. It looks like longer mag lengths are up to 2.3 and the COAL allowed by the Grendel I barrel is 2.23, so you gain up to .07 with a certain mag choice. The massive FPS gains I read about were someone who must have been hand loading into the chamber. I suppose the .07 real world advantage of the Grendel II would offer a minimal FPS gain and probably more importantly potentially better accuracy for a hand loader who has .07 more to play with. I'm not a hand loader (yet) so my knowledge is very limited.

If your chamber only allows you to load to 2.23" COL, you've got a short chamber, or an older liberty barrel that lead to the Saturn Chamber cya exercise.

A (SAAMI) Grendel chamber should allow you to load to 2.26" at a minimum. Most will allow you to load to somewhere between 2.27" to 2.29".

These measurements are with the common 123gr bullets in mind.

[LRRPF52]

I read up on it more. It looks like longer mag lengths are up to 2.3 and the COAL allowed by the Grendel I barrel is 2.23, so you gain up to .07 with a certain mag choice. The massive FPS gains I read about were someone who must have been hand loading into the chamber. I suppose the .07 real world advantage of the Grendel II would offer a minimal FPS gain and probably more importantly potentially better accuracy for a hand loader who has .07 more to play with. I'm not a hand loader (yet) so my knowledge is very limited.

There are a lot of factory ammo 6.5 Grendel loads that are 2.245" to 2.260" COL. If someone is saying that the SAAMI chamber is limited to 2.230", they are misleading you or are not very knowledgeable about the actual dimensions of the Grendel chamber.

You don't get any real world gains by loading out longer. You get much better behaved pressures by sticking to the specified COL's and I have tested this myself with several different projectiles. If you run a projectile close to the lands, you will spike the peak pressure and produce more velocity, at the expense of departing from the working pressure of the cartridge.

There was a guy here on the forum a few years ago who was doing exactly that, just picking out loads without any basic reloading procedures (working up), then getting insane velocities with a short chambered barrel, claiming the 5R rifling was giving him an extra 400fps. He refused to listen to seasoned hand loaders, some of whom have been doing this since the 1970's, and claimed there was some type of campaign out to get the barrel maker.

The main issue is the AR15 magazine well length limitations. For a production gun, you have to work within realistic dimensions, accounting for variation in magazine lengths across tens of thousands of magazines, not single samples. To manufacture a magazine that tightens up those specs raises the magazine price 4-fold, with no performance gains.

What that means in the real world is that there are people with the existing SAAMI chamber and dimensions slaying every beast they point the Grendel at, as well as shooting small targets at 1518yds with mild hand loads that are 100-150fps slower than the equivalent factory load.

Then you will hear these guys who want to "make it better" start talking about moving the throat of the chamber forward a few thousandths, getting $42 mags, and "really pushing" the cartridge. I think some people just like to tweak, and that's fine, but if the established SAAMI chamber is doing what it does, and is able to shoot a wide variety of projectiles accurately, while extending the effective range of the AR15 beyond what anyone would believe unless they see it, why bother?