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+--- Thread: Requesting Recommendations for a Hog Hunting Build (/showthread.php?tid=24336)
Requesting Recommendations for a Hog Hunting Build - michael1778 - 03-04-2022
Hello Everyone,
I have had many parts available for rebuilding an AR-15 or two but I wasn't sure what I wanted for the use case. I have decided. I want to build a 6.5 Grendel dedicated to hog hunting. I have not hunted before but I want to try it and build my proficiency.
Long term, I would like to have a suppressor and likely two different optic configurations, one for day and one for night.
Today, I have an 18" Satern barrel (mid-length gas) that was gifted to me. I have a S&W M&P15 receiver set from their original production run years back. MagPul ACS stock.
Given that I want to run suppressed in the near-ish future, I am keen to get your recommendations on the buffer, spring, bolt carrier, and gas block to use. Seems like piston systems are not in favor here? That's fine by me.
Thanks for your help,
Mike
Requesting Recommendations for a Hog Hunting Build - VASCAR2 - 03-05-2022
Youll definitely need an adjustable gas block with the Satern barrel. Is this a button rifled barrel or cut rifle barrel? The more recent Satern Liberty stainless steel barrels have a Grendel II chamber. Some cut rifled Satern barrels have a SAAMI spec 6.5 Grendel chamber. Satern usually use a very large gas port on their barrels and really need the adjustable gas block.
I suggest you try and measure the gas port size before assembly (you can try to get the size by using drill bits or pin gauge). If you use an adjustable gas block you should be able to tune the gas to accommodate most any AR-15 buffer and buffer spring. At most you might use an H-2 buffer with a suppressor.
Requesting Recommendations for a Hog Hunting Build - michael1778 - 03-05-2022
I appreciate your informative and thought provoking reply! This barrel was a strange blessing over 5 years ago. A guy on another forum pulled it off a buddy's rifle because he wanted to go another direction from 6.5 Grendel. Being a poorly paid school teacher at the time, he selected me as the gift recipient of a few that expressed interest on a forum post offering it up. It has about 150 rounds through it, so I have been told. I will need to carefully check the bolt face depth. I have no idea on cut vs button rifling but, I was wondering the same myself.
I am glad I am not the only one that thinks the gas port is large. Just looking at it I have always thought it looked huge. I like your suggestion to measure the port size will do that when I get a chance. I put it all over at a friend's place while I was in California for a few months. I am back in NC now so I can have nice things again! Time to return all my stuff home.
Requesting Recommendations for a Hog Hunting Build - LRRPF52 - 03-05-2022
Measure the gas port diameter and report back what it is.
If its .094, it isnt going to be a good place from which to start for a suppressed build, as it will need the gas choked off just to shoot unsuppressed reliably.
It would be good to have a modified gas block with a choke drilled and tapped into it.
For MLGS 18 barrel, the gas port should not be larger than .076 for 6.5 Grendel shooting unsuppressed.
I personally wont put a suppressor on an 18 MLGS barrel unless its a flow-through, low back pressure suppressor.
Intermediate or RLGS is much better for 18 suppressed, but that isnt an option with your existing barrel.
Requesting Recommendations for a Hog Hunting Build - michael1778 - 03-06-2022
LRRPF52 Wrote:Measure the gas port diameter and report back what it is.
If its .094, it isnt going to be a good place from which to start for a suppressed build, as it will need the gas choked off just to shoot unsuppressed reliably.
It would be good to have a modified gas block with a choke drilled and tapped into it.
For MLGS 18 barrel, the gas port should not be larger than .076 for 6.5 Grendel shooting unsuppressed.
I personally wont put a suppressor on an 18 MLGS barrel unless its a flow-through, low back pressure suppressor.
Intermediate or RLGS is much better for 18 suppressed, but that isnt an option with your existing barrel.
I will have the port measurement by Tuesday night.
Requesting Recommendations for a Hog Hunting Build - michael1778 - 03-09-2022
As promised, I have some measurements. I also have a correction. The barrel is a Shilen, not a Satern.
Gas port was measured two ways.
Method One: inserted a hex key into the port. The largest one that fits (and fits nicely, snug but I didn't have to force anything) is marked as 3/32 inch. That's 0.09375 inch, right?
Method Two: My friend got out his digital calipers and measured the inside of the gas port. He is using a small but flat pair of surfaces inside the circular gas port. He measured a few timers and got numbers from 0.074 to 0.078 inches.
My understanding of geometry tells me the inserted hex key (Allen wrench) is the better measurement method but am I missing something?
[Edited to add that I checked the headspace with my JP Rifles Enhanced Bolt using a round of factory Hornady 123 grain A-max (yes, I have some old ammo) and it fits well for that method]
Thanks for your help.
Requesting Recommendations for a Hog Hunting Build - VASCAR2 - 03-09-2022
Shilen make good barrels. I have a Shilen DCM Match (Service Rifle) profile barrel I got from Midway in about 2011. My barrel is 20 long with a bare muzzle (no threading) and 1:9 twist. It is a good shooter and unless your going to use a suppressor you probably wont need an adjustable gas block. I think Id trust the measurement from the calipers on the gas port.
Shilen website list an 18 1:9 twist 6.5 Grendel barrel, could be what you have or a gun smith couldve used a Shilen barrel blank.
http://www.shilen.com/ar15Barrels.html
Requesting Recommendations for a Hog Hunting Build - LRRPF52 - 03-09-2022
I concur with VASCAR on this. There is a lot of wisdom in there, especially on the port diameter.
Is it a MLGS 18 barrel with the gas block journal about 9 from the breech? If so, it should be in that .076 region. 3rd decimal is in the weeds, but the caliper reading was probably more accurate.
![[Image: ?u=https%3A%2F%2Fwww.pewpewtactical.com%...f=1&nofb=1]](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.pewpewtactical.com%2Fwp-content%2Fuploads%2F2017%2F05%2Far-15-gas-length-e1495753152529.jpg&f=1&nofb=1)
Requesting Recommendations for a Hog Hunting Build - michael1778 - 03-09-2022
Thank you.
The barrel had engraving on it that was the same font and style for all the wording. Shilen 6.5 Grendel. Seeing the table in that link you shared reminded me how I had looked it up a few years ago. 1 in 9 twist worries me for longer, heavier hunting bullets like the Nosler 129gr ABLR or the 130 Swift Scirocco.
Requesting Recommendations for a Hog Hunting Build - michael1778 - 03-09-2022
Yes it is definitely mid-length gas and 18 inches total length.
Requesting Recommendations for a Hog Hunting Build - grayfox - 03-09-2022
michael1778 Wrote:As promised, I have some measurements. I also have a correction. The barrel is a Shilen, not a Satern.
Gas port was measured two ways.
Method One: inserted a hex key into the port. The largest one that fits (and fits nicely, snug but I didn't have to force anything) is marked as 3/32 inch. That's 0.09375 inch, right?
Method Two: My friend got out his digital calipers and measured the inside of the gas port. He is using a small but flat pair of surfaces inside the circular gas port. He measured a few timers and got numbers from 0.074 to 0.078 inches.
[...]
Thanks for your help.
3/32, 0.9375 is flat to flat, your diameter is vertex to vertex, which will be slightly bigger than the 3/32 measured. I need to break out my geometry brain but it is calculatable.
edit to add: using cos 30* (corrected to 30) for the internal angle, and 1/2 of flat-flat as the adjacent side, the diameter is 2*0.0541, or 0.108" diameter.
Of course some 3/32 hex keys are not exactly 3/32, could be a tweak smaller, so I would say best est of the diameter is 0.100".
Requesting Recommendations for a Hog Hunting Build - michael1778 - 03-09-2022
OK. That tracks with what I measured myself on that Allen wrench with my own iGaging calipers. I measured vertex to vertex across the hexagon and got slightly more than 0.10". I'm wondering if I might be happier with a 20" rifle-length gas, 1-8 twist barrel. I appreciate all the help and comments so far. I have time to do this all "right"
I have a 12 inch barrel out of a forum group buy on this forum from 2 or more years back. That is set to become a pistol build like what LRRPF52 has done.
I have an old Loki Weapon Systems non-standard receiver set AR-15 that will get a new, long 6mm ARC barrel and become a long range practice and competition gun. If I enjoy doing that I could move up to a dedicated bolt gun. This was apparently one of the last rifles that guy shipped before he closed up shop suddenly and stiffed some customers.
Requesting Recommendations for a Hog Hunting Build - Morvandium - 03-13-2022
michael1778 Wrote:Thank you.
[...] 1 in 9 twist worries me for longer, heavier hunting bullets like the Nosler 129gr ABLR or the 130 Swift Scirocco.
While I'm sure someone else can offer some advice on the specific bullet weights you mentioned combined with 1:9 twist rate, the thing that made me go with 1:9 for my 24" barrel is because it's what Bill Alexander went with for Alexander Arms 20"-24" barrels. Alexander, I believe, acknowledged that his choice varied from standard wisdom on the topic, but it was based on his testing as he developed the cartridge.
From my limited understanding, the additional muzzle velocity from the longer barrel lengths translates increased RPMs over the same cartridge from the same twist but shorter barrel, and closer RPMs to the same cartridge from the shorter barrel with a faster twist rate. My understanding is admittedly cursory. Google will produce articles on the topic with the right keywords and some sifting through results. (Slightly off topic, any articles about Q's development of the 8.6 Blackout (8.6 Creedmoor) have a good chance to mention some progressive approaches to using twist rate to affect ballistics wound cavity size. Interesting stuff, if you nerd out on ballistics.)
Requesting Recommendations for a Hog Hunting Build - LRRPF52 - 03-15-2022
Bill A. went with 1/7.5 twist for the short barrels, 1/8.75 on some of the premium rifles with 20 and longer, and 1/9 on the Shilen 20-24 barrels.
My 16 AA was 1/7.5.
You can run 1/9 through a stability calculator and it will show that its marginally stable/not optimized BC at 2350fps. It loses about 7% of the BC but will still shoot.
Change it to 1/8 twist at the same speed and it is optimized for BC.