300BLK Upper build advice? please.

[Calculated]

Perfect. Thank you very much!

[MarkCO]

A couple additional questions for you gents. Does anyone use or recommend the JP silent capture spring and lo mass bcg? Is an adjustable gas block a good idea or unnecessary? I want it to be vewy vewy quiet...

Finally, for now, is the main benefit of a machined billet upper and lower strength?

JP SCS and lo mass BCG...not much benefit in a PDW. I run low mass systems in all of my .223 ARs, but in the heavier calibers, just not much, if any benefit. Low mass will open a bit sooner and technically, it might be a bit louder. I do not run adjustable gas in mine due to the fact that I do not want to chase the tune is it changes and want 100% reliability. THis is the BCG I use in .300BOs: http://www.usamade-ar15parts.com/product-p/bcgrnb.htm

I like a barrel with a slightly undersized gas port, get everything dialed in and the last thing I do is open the gas port incrementally until I get full function, then slightly ream that out. I good clamp style gas block that does not leak, preferably made of the same material as the barrel is what I prefer.

Billet receivers are bling only.

When you look at HGs, you want to consider the connection between the barrel and suppressor. Do you want that under the HG or not. I have one set up with a 10.5" barrel and a 10" HG and another with a 15" HG so the suppressor just barely peeks out. I do like the ability to have my support hand out a bit further on the 15" HG one, but I won't shoot that one without the suppressor.

[Calculated]

I know it has taken a lot of time, money and mistakes aka experience to have the knowledge base that you guys do and I genuinely appreciate you all taking the time to share it with me. I know how annoying it can be to have someone new come in and ask a ton of questions when you had to figure it all out yourself. In my defense, I have read through a lot of threads on various websites and the bulk of what I can find is a little too OAF to be taken seriously.

Mark, if I'm shooting w/o a suppressor will the blast damage the rail if the muzzle device is say an inch inside the end? Thanks for the meaty reply

[cstone]

I have an 8.5" barrel with a barking spider 2 under 10" handguards. This leaves about two inches of the brake outside the end of the handguard. I like the krink like linear comp as it seems to push the excess gas forward evenly and the sound is definitely easier for the shooter than anyone on either side.

I don't think I want anything hanging past the exit end of the barrel other than a comp/flash hider or suppressor. Short barrels tend to be little flame throwers, which can be fun in low or no light shooting.

[DangerLee_Industries]

You are still welcome to swing by and get all your questions answered in one shot!

[Calculated]

You are still welcome to swing by and get all your questions answered in one shot!

I'll definitely be by sometime next week when I'm off work. For now this is my only avenue to quench my thirst for controlled chaos. Also my wife will be with me so lets keep the numbers on the down low, I just want to hammer out some details on my flagship build.

Edit: The more questions answered the more I have...

[brutal]

While you're at Tim's, check out the Hiperfire Hipertouch triggers. I dropped an EDT2 in my 9" AAC bbl 300BLK and they're great for the price.

[MarkCO]

Mark, if I'm shooting w/o a suppressor will the blast damage the rail if the muzzle device is say an inch inside the end? Thanks for the meaty reply

It won't do any structural damage to the rail. But it might get some carbon and damage a finish. I am more concerned with a finger getting out front (if even to the side) of the muzzle. The cheap liner comps like cstone alluded to can add a few inches and be a solution.

[Calculated]

It won't do any structural damage to the rail. But it might get some carbon and damage a finish. I am more concerned with a finger getting out front (if even to the side) of the muzzle. The cheap liner comps like cstone alluded to can add a few inches and be a solution.

Yea I was kind of worried that I might forget where the end of the barrel is vs the end of the handguard. I've felt fireworks blow up in my hand, I imagine this would be a little worse. I actually thought it might do structural damage.

Brutal I'll def check it out, I saw it advertised on joebob's and was curious but it's all new to me. Thanks for the intel.

[MarkCO]

Just a little warning on the Hiperfires...I know of at least 4 match DQs from shooters whose guns fired upon dropping the bolt with Hiperfires and it was not a slamfire. It seems that almost all of the "unintentional doubles" I see at matches come from a JP trigger or a Hiperfire trigger. As such, two triggers I would not use in an AR15 that might be is use "off the range". At the range, it costs you a match fee...off the range, could be worse. Yes, the likelihood is low, but it is more than normal. Just something to be aware of.