Going to lighten up the entire gas system - Pllease advise

[bob4432]

Thank you for taking the time to read through this. This is my thought and questions:

My whole thought process has been to go with a 16" 'Monster" barrel, but I would like to still be safely supersonic @ 1000yds @ around ~1300-1500' Above Sea Level. I thought that going from 123gr [Insert Bullet Type Here] to ~108gr [Insert Bullet Type Here] would be enough to safely do just that, but after looking at some ballistic charts, the lighter bullet bleeds off speed at a pretty quick clip compared to 123gr bullets, so now I am considering going to a 18" 'Monster' barrel, just not sure if that extra 2" will add enough velocity to make it worth its length as the weight is negligible, and I know it is running a RLGS, but since I am going to lighten everything that interacts with the gas system, I feel an Adjustable Gas Block is still well worth the ability that I will be able to tune the gas system. I do not want to go a 20" barrel, and another person has suggest just doing a 16" 6.5Creedmoor, but the prices for moving up to the larger frame are quite a bit. If going to a 18" barrel still does not more than likely guarantee me being safely supersonic @ 1000yds, and I have read that supersonic @ 1500' ASL is 1097fps, so staying @ 1150fps should be safe unless there is something I am not aware of - if that is not the case, please advise, I guess I will move back to a 16" barrel and have a solid 600yd performer to bad SBR stamps are what they are as I could probably do a 12.5" or 11.5" 600yd nice little plinker, while I investigate the 6.5Creedmoor....

Carrier:
I know it is the whole BCG, but they offer the carrier for $65 when it comes in stock:
https://www.righttobear.com/RTB-Complete...n16-lw.htm

Or this one:
(Have to buy the whole BCG but another 5.56Bolt can't do me no harm ):
https://www.brownells.com/rifle-parts/bo...16267.aspx

Adjustable Gas Block:
Going with a Superlative AGB, Clamp on style:
https://suparms.com/collections/adjustab...ite-finish
dimensions:


Only issue w/ the SA one is how much clearance do I need between my rail and the Gas Block? Will be using a ALG Rail, so it is a bit tight and I do not want the Rail to come in contact w/ the Gas Block which would create and accuracy ghost, so while I want a clamp on, would the set screw be a better fit:
https://suparms.com/collections/adjustab...ite-finish
dimensions:


and here are the ALG Rail inner dimensions (Sh1t, here is to hoping all of the rails have the same internal dimensions):


I plan on using a standard adjustable stock but removing the tungsten weight in the buffer and replacing it with all aluminum, and running a SpringCo 'White' Standard Power Spring (I am actually planning on changing all springs out to SpringCo just so I will not have to worry about it for quite some time):
http://www.sprinco.com/tactical.html

Thank you all for all the education you have given, I appreciate it greatly.
Bob

[FRB6.5]

FWIW the ALG stuff is made to use a Geissele gas block which has the shorter height above and below the bore center line as pictured in your last drawing. From the drawing it looks like an EMR type that doesn't have a built in picatinny rail so that channel is very short compared to a typical rail. Oddly enough the G gas blocks are also thicker and have trouble fitting inside many narrow handguards.

EDIT:
Also FWIW I have a LaRue 6.5 Grendel with an 18" barrel, Hornady Black 123 gr ELD-M averages 2454 fps out of it. That is not quite fast enough to stay supersonic at 1000 at my elevation (also in AZ). A 20" barrel may get you where you need to be with that ammo, a 16" will put you 40-50 fps slower with that ammo. Even with hand-loading I don't think 2500 fps out of a 16" gas gun is safely doable with that weight bullet at our elevation.

[Swampfox]

What rail are you looking at run? I superlative arms is all I run.

[LRRPF52]

Just get the lowest profile gas block available and use a Bootleg Adjustable Bolt Carrier.

Use the 107gr SMK from an 18" at 2600fps and you'll be supersonic to 1000yds at 1300ft ASL.

I found a node at 2625fps with 8208 XBR in my 17.6" Lilja barrel well enough away from Hodgdon's max load.

[bob4432]

FWIW the ALG stuff is made to use a Geissele gas block which has the shorter height above and below the bore center line as pictured in your last drawing. From the drawing it looks like an EMR type that doesn't have a built in picatinny rail so that channel is very short compared to a typical rail. Oddly enough the G gas blocks are also thicker and have trouble fitting inside many narrow handguards.

EDIT:
Also FWIW I have a LaRue 6.5 Grendel with an 18" barrel, Hornady Black 123 gr ELD-M averages 2454 fps out of it. That is not quite fast enough to stay supersonic at 1000 at my elevation (also in AZ). A 20" barrel may get you where you need to be with that ammo, a 16" will put you 40-50 fps slower with that ammo. Even with hand-loading I don't think 2500 fps out of a 16" gas gun is safely doable with that weight bullet at our elevation.

Thanks for the info. I think until I get into reloading, 16” @ 5-600 yd will be where I stay. Plus I have to knock the rust off myself as I haven't shot in a few years due to numerous serious medical issues between myself and my wife, so between 6.5G & 223 that should get me back in the game upto ~600yd. Plus these 2 calibers will allow me to build quality firearms at decent prices, knowing their limitations and put my $$ towards an optic & mount. Currently have all parts to put together a 5.56 barreled 16”, just need to do it, waiting for the right time, which has been the main issue. The medical issues are why I just don't go to the 6.5Creedmoor and not drive myself crazy trying to get what I am trying to get out of 16" MLGS to possibly up to 18" RLGS setups.

[bob4432]

What rail are you looking at run? I superlative arms is all I run.

At the moment have 12" ALG ELM V2 M-LOK rails. They have seemed like a decent price for rail quality.

[bob4432]

Just get the lowest profile gas block available and use a Bootleg Adjustable Bolt Carrier.

Use the 107gr SMK from an 18" at 2600fps and you'll be supersonic to 1000yds at 1300ft ASL.

I found a node at 2625fps with 8208 XBR in my 17.6" Lilja barrel well enough away from Hodgdon's max load.

I need to read more about the Adj Carrier - any drawbacks compared to Adj Gas Block?

Also, any place in particular for good deals on Lilja barrels? Or any of the other higher end barrels? Not thinking Krieger as they seem to always be ~$1k, unless I am looking in the wrong places. Have a couple friend that are 07Manf, some with additional capabilities, but not sure using their info could help me out, or do I just have them order whatever parts for me?

Last, does the TMK make that much of a difference vs the SMK?

Appreciate the info everybody, I know I have asked a lot of questions and appreciate quality answers, not like many of the other forums.

[Swampfox]

At the moment have 12" ALG ELM V2 M-LOK rails. They have seemed like a decent price for rail quality.

The superlative arms gas block should work just fine, but to verify just to be 100% sure call ALG to verify.

[bob4432]

The superlative arms gas block should work just fine, but to verify just to be 100% sure call ALG to verify.

Sounds like a plan