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Posted: 5/1/2020 2:50:39 PM EDT
The 6.5C is really starting to take off in the big block AR world it seems. The MRGG-S program seems to be working off a 17" barrel. DoD just announced 20" barrels for their MK13 replacements. Not sure what KAC M110K1 uppers to the .gov are going to be yet.
What is your ideal barrel length. For a rifle that would sport a 3-18x scope. Not a benchrest rifle, but something to hunt with, tote around the woods, and still have fun out to 600-800 yards. I'm leaning towards 20". Seems like most manufacturers are either 18" or 22" as standard offerings. |
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What is best in life? To crush your enemies, see them driven before you, and to hear the lamentation of their women!
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[Last Edit: cone256]
[#1]
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[#2]
20" wouldn't be bad. Mine is a 22". Both would do what you need. I was shooting the other day with my 20" .308 with the 1-10 Razor on it and dropping rounds at 550 easily. I am sure the Creedmoor would reach further without a problem with a 20".
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[#3]
20-22 is where I would go.
For hunting or dragging around the woods, 18-20. My AR-10s are 18s, but I also have cans on them. |
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[#4]
20-22 is where I would go.
For hunting or dragging around the woods, 18-20. My AR-10s are 18s, but I also have cans on them. |
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[#5]
Here's my own take - as just a guy.
The entire purpose of 6.5 CM is a distance engagement precision round. It's whole point is to be able to reach out to distance, and do it flat and accurate. That takes speed. But with that, the most common AR10 patterns are just massive pigs. People have developed smaller and lighter versions, but they are specialty, and tend to be less proven - and quite pricey. So most likely you're going to be running a common LaRue/PSA/DPMS/Knights/et-al sized AR10 frame. Putting a really long BBL on that, turns an already heavy pig into just a big old pig to lug around and use. In my opinion, 20" is about as long as you want to go for that, and is a standard length AR BBL for a long time. 18" can help with the weight and mass; but at the expense of losing some of that all-important Creedmoor speed. If you're willing to shed speed to save some weight, that's what 6.5 Grendel is for. Look up a 6.5 Grendel with a 20" BBL, that fits on a light standard AR-frame, and it's not bad; and still lighter than even a 16" Creedmoor. So in my own assessment, in an common AR10; 20" is the most generic general compromise BBL length for 6.5 CM to get it's potential without getting just a massively oversized gun. Combine that with a 6.5 Grendel in your armory, and you're really set. Just my own imperfect opinion. |
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[Last Edit: H4ppyB34r]
[#6]
I have a 22 inch and a pinned 14.5, both on built in Mega with Bartlein barrels, heavy for 24, and lightweight profile in 14.5.
I carry the shortie all the time, and have done a few run and gun shoots with it, great rifle, most likely my favorite. Since I got rid of 308, and went all 6.5creed, picking up another caliber like the Grendel didn't really appeal to me. I have connected on a 12inch plate reliably at 800 with Bushnell Elite on top. The 24 is wearing a TT, or sometimes another Bushnell Elite thats painted to match. I couldn't bring myself to cerakote the Tangent. |
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"If you think its expensive hiring a professional, try hiring an amateur first."
-A. Einstein |
[#7]
Originally Posted By H4ppyB34r: Since I got rid of 308, and went all 6.5creed, picking up another caliber like the Grendel didn't really appeal to me. . View Quote I absolutely get and respect that! Bringing in a new caliber means new inventory, new reloading dies, new brass systems - it's actually a whole new infrastructure train when I do it. So I totally get keeping it simply and not even bothering to do 6.5 Grendel, and instead going with a 14.5" CM as an option as well. In the end, that was likely a lot cheaper. I will say I do like the Grendel a lot, but yea, I also give the nod to those who don't want to bring in another caliber as well! |
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[#8]
20". I built mine as lightweight as I could for the specific purpose of hunting with a secondary purpose of target shooting. With a suppressor it kind of feels like a pole vault, but it's still easy to carry and maneuver. The furthest I've engaged a steel plate has been 1100 yards so far. 20" will do what you want.
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[#9]
Sounds like 20” is the way to go.
Wish Larue offered that length. |
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What is best in life? To crush your enemies, see them driven before you, and to hear the lamentation of their women!
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[#10]
Honestly,
As with everything it really depends on your how you plan on using the rifle. if you are in a wooded area with limited sight lines one could easily get away with some like a 14.5 to 16 inch barrel, KAC has been doing development of their 6.5 guns and have found that a 14.5 6.5CM is ballistically pretty close to the 20 inch 308 barrel and their M110's, so unless you are really shooting past 1K, a shorter barrel makes a lot of sense. Now if one was out west with longer sight lines and stronger winds, well, the longer 20 inch barrels really make a lot of sense, For example (very generic numbers) 16 inch barrel 140gr ELD-M@2500, Sub sonic at 1100ish, 1.58 wind drift(48 inches) at 800(10MPH) 20 inch barrel 140gr ELD-M@2650, Sub sonic at 1200ish, 1.38(43 inches) wind drift at 800(10MPH) 20 inch 308 barrel 178 ELD-M@2650, sub sonic at 1100ish, 1.98(58 inches) wind drift at 800(10mph) So if one is shooting in that 600 to 800 yard range, does it make sense to go with a longer barrel, especially if one may be thinking running a can on the rifle, one has start thinking about what they may gain from a shorter set up. I have a very nice shooting 20 inch, 6.5CM barrel for my MWS, and I am considering having it cut back and threaded for my Sandman K. |
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[#11]
Originally Posted By lazyengineer: Here's my own take - as just a guy. The entire purpose of 6.5 CM is a distance engagement precision round. It's whole point is to be able to reach out to distance, and do it flat and accurate. That takes speed. But with that, the most common AR10 patterns are just massive pigs. People have developed smaller and lighter versions, but they are specialty, and tend to be less proven - and quite pricey. So most likely you're going to be running a common LaRue/PSA/DPMS/Knights/et-al sized AR10 frame. Putting a really long BBL on that, turns an already heavy pig into just a big old pig to lug around and use. In my opinion, 20" is about as long as you want to go for that, and is a standard length AR BBL for a long time. 18" can help with the weight and mass; but at the expense of losing some of that all-important Creedmoor speed. If you're willing to shed speed to save some weight, that's what 6.5 Grendel is for. Look up a 6.5 Grendel with a 20" BBL, that fits on a light standard AR-frame, and it's not bad; and still lighter than even a 16" Creedmoor. So in my own assessment, in an common AR10; 20" is the most generic general compromise BBL length for 6.5 CM to get it's potential without getting just a massively oversized gun. Combine that with a 6.5 Grendel in your armory, and you're really set. Just my own imperfect opinion. View Quote 6.5 grendal is a cool little round, but for me, the odd ball mags and bolts kind of keep me from pursuing the caliber, I think part of the reason for the 6.5CM's success, and that just like the 300blk, its fairly plug and play, in regards to the its mags and bolts. |
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[#12]
Originally Posted By m4hk33: 6.5 grendal is a cool little round, but for me, the odd ball mags and bolts kind of keep me from pursuing the caliber, I think part of the reason for the 6.5CM's success, and that just like the 300blk, its fairly plug and play, in regards to the its mags and bolts. View Quote Yeah, I have a Grendel. And a 300 BLK. And a 6.8 SPC. Ready to mix it up and add a big block AR to the collection |
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What is best in life? To crush your enemies, see them driven before you, and to hear the lamentation of their women!
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[Last Edit: SuperJlarge]
[#13]
All of my 6.5creed gassers are 22”, and that works for me. The weight up front of the longer barrel helps for balance, recoil reduction and also velocity, but these are only built for range time and matches.
For hunting, 18” would probably be a better option, and still have enough velocity to make 800yds on targets without issue. |
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[#14]
I've never felt that I needed more barrel length than the 20" on mine. At the altitudes I typically shoot, the round (140 ELDM factory ammo) is staying supersonic out past 1300m or more.
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"What is socialism? The most difficult and tortuous way to progress from capitalism to capitalism." -Stated at an intel conference, East Berlin, Oct. 1988
"Every election is a sort of advance auction sale of stolen goods." -H.L. Mencken |
[#15]
Originally Posted By cone256: I just put together an 18" 6.5 Criterion barrel with Aero M5 receiver sets. Ordered a PST Gen II 3-15 for it and should be here Tuesday. Already spray painted it too. Mine is meant to serve the DMR role in my armory https://www.AR15.Com/media/mediaFiles/214520/20200410_185729-1361448.jpg https://www.AR15.Com/media/mediaFiles/214520/20200421_151103-1381684.jpg View Quote @cone256 Does that lower take m14 mags? |
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[#16]
Originally Posted By Ronin72: @cone256 Does that lower take m14 mags? View Quote View All Quotes View All Quotes Originally Posted By Ronin72: Originally Posted By cone256: I just put together an 18" 6.5 Criterion barrel with Aero M5 receiver sets. Ordered a PST Gen II 3-15 for it and should be here Tuesday. Already spray painted it too. Mine is meant to serve the DMR role in my armory https://www.AR15.Com/media/mediaFiles/214520/20200410_185729-1361448.jpg https://www.AR15.Com/media/mediaFiles/214520/20200421_151103-1381684.jpg @cone256 Does that lower take m14 mags? No, Aero lowers take DPMS/SR-25 type mags |
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[#17]
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[#18]
Originally Posted By Ronin72: Thanks! I am strongly considering duplicating the same build as yours. View Quote View All Quotes View All Quotes Originally Posted By Ronin72: Originally Posted By cone256: No, Aero lowers take DPMS/SR-25 type mags Thanks! I am strongly considering duplicating the same build as yours. To me, it seemed a really practical build considering it's intended role. |
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[Last Edit: DevL]
[#19]
22" is ideal without a silencer. 18" is ideal with a silencer if you dont hunt at 600 yards plus game animals and most shooting is 800 yards and in, 1000 max, and you might need to deploy from a hunting blind, etc. 20" is a compromise AR length great unsuppressed but a bit long suppressed. 24" is all the length for a gun that has no length restrictions suppressed and 26" is a competition only unsuppressed length. That is my opinion.
I am changing bolt gun barrels from 24" to 22" and doing a large frame AR in 18" with a Criterion, partially for weight, partially for length. If I did a carbon fiber barrel I would entertain a 20" so I could still shoot offhand. A 22-26" suppressed AR10 rifle is NOT an offhand capable rifle IMO. An 18" AR10 with a Leupold Mark5 3.6-18×44 is... but just barely. 20" can be shot offhand unsuppressed no problem but is a real beast with a silencer on the end. You might want a dedicated light can and the lightest barrel you can if you want offhand ability and 20" barrel. Then again that combo is still a pain inside a hunting blind due to length. BALLISTICLY you want 20" barrel but PRACTICALLY you want the 18" barrel the 18" barrel can shoot your 140s in the 2550-2600 fps range. Certain factory ammo will be down around 2500 fps. Handload or select 120-130 grain bullets. |
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Sarcasm is an art and I'm painting my master piece
WA, USA
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[#20]
Gas gun I would want 16.
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I've been blessed with many things in this life: an arm like a damn rocket, a cock like a burmese python, and the mind of a fucking scientist.
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[#21]
I have an LMT MWS with the 24” 6.5 Creedmoor barrel. It’s a long heavy pig but it’s accurate as hell! I’ve been shooting it in NRL/PRS matches the past couple years and I’m happy with how it performs. That being said I’m slowly collecting parts to build a 16” 6.5 Creedmoor upper as well. Yes there are speed losses but the better BC more than makes up for the loss in velocity.
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[Last Edit: alpha0815]
[#22]
Originally Posted By MPD142: I have an LMT MWS with the 24” 6.5 Creedmoor barrel. It’s a long heavy pig but it’s accurate as hell! I’ve been shooting it in NRL/PRS matches the past couple years and I’m happy with how it performs. That being said I’m slowly collecting parts to build a 16” 6.5 Creedmoor upper as well. Yes there are speed losses but the better BC more than makes up for the loss in velocity. View Quote Is the LMT with a stainless barrel? I know they are great rifles I just didn’t think they were known for their accuracy. I ended up going with an 18” Larue. Only had a chance to put 20 rounds through it but it’s a great shooter so far and is already under 1 MOA with factory Hornady 140 ELD-M. |
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What is best in life? To crush your enemies, see them driven before you, and to hear the lamentation of their women!
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[#23]
22". It's a slow round which most use for range so it needs as much velocity as is reasonably possible.
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[#24]
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[#26]
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[#27]
Originally Posted By beatsAstick: Where are your arms(and penis for that matter)? Did you try loading 6.5 Creedmoor to velocities befitting the AR10 platform?... View Quote View All Quotes View All Quotes Originally Posted By beatsAstick: Originally Posted By Rob01: Where are your arms(and penis for that matter)? Did you try loading 6.5 Creedmoor to velocities befitting the AR10 platform?... QFP, 'cuz I gotta see what orifice you pulled this from. |
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Originally Posted By SecretSquirell: I'll stick my dick in a WorkSharp before I let you try to sharpen anything of mine.
NRA Benefactor Member 2nd Amendment Foundation Life Member Madison Society Foundation Life Member VCDL mamber |
[Last Edit: bfoosh06]
[#28]
Originally Posted By alpha0815: Sounds like 20” is the way to go. Wish Larue offered that length. View Quote @alpha0815 This for me as well. And FWIW... here is a 6.5CM barrel cut down article. I have a 18", 2x20", and 22" 22" Criterion barreled, just to get the utmost velocity 20" , first PSA I bought, "HBAR" barrel profile. 18" , Criterion barreled... far more "nimble then the other 2.. with not a huge velocity loss. https://rifleshooter.com/2016/02/6-5-creedmoor-effect-of-barrel-length-on-velocity-cutting-up-a-creedmoor/ https://rifleshooter.com/2019/03/6-5-creedmoor-effects-of-barrel-length-on-velocity-2019/ |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. ________________________________ TOGC,IADC |
[#29]
Those rifle shooter tests are jokes. The first spread more bad info around the internet. Everyone saying the Creedmoor slows down after 24”. Lol a Joke!
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[#30]
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What is best in life? To crush your enemies, see them driven before you, and to hear the lamentation of their women!
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[#31]
Originally Posted By alpha0815: Where are you seeing that they claim FPS decrease with longer than 24” barrel length? View Quote Look at the first link and the 142 weight load. People have used that and the fact that factory rifles are more common in 24” to say the “ideal length“ is 24” for the Creedmoor. Anyone who has shot the Creedmoor knows better but an uphill fight with the internet. |
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[#32]
Originally Posted By Rob01: Look at the first link and the 142 weight load. People have used that and the fact that factory rifles are more common in 24” to say the “ideal length“ is 24” for the Creedmoor. Anyone who has shot the Creedmoor knows better but an uphill fight with the internet. View Quote What’s your preferred length? |
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[Last Edit: Rob01]
[#33]
Originally Posted By Lomshek: What’s your preferred length? View Quote I like a 28” barrel for a bolt gun. I get excellent velocities and it’s not hard to get around with at matches. The Creedmoor was developed around a 28” barrel so that’s what I started with in 2008 and it’s stuck. I do have one 27” and that was only because the blank was short. For a Semi I have a 22” as that was what they had at the time and it’s not meant for the same long range precision as my bolt gun. I would like it to be a 24-26” but maybe when it burns out. |
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[#34]
Originally Posted By Rob01: Those rifle shooter tests are jokes. The first spread more bad info around the internet. Everyone saying the Creedmoor slows down after 24”. Lol a Joke! View Quote While pretty unscientific... it is still more data than I have, concerning various velocities on a sample of one barrel cutdown... Lol And as always... YMMV. I consider the Rifle shooter tests interesting info, but not "Gospel". Rob01, no offense intended at all, nor debating your comments....but, I am curious are you firing reloaded ammo ? And what powders for your 28" / velocities ? My 22" is about as long a barrel as I prefer, so I am interested in your results. |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. ________________________________ TOGC,IADC |
Sarcasm is an art and I'm painting my master piece
WA, USA
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[#36]
Originally Posted By Rob01: My post was not done to offend you either but more from frustration about that "test" and having to educate since it came out. The problem is a lot of people do take that as gospel and preach it around the internet as truth. Even the person who did the test said he wasn't sure why and that it was probably due to the new barrel which makes sense and as they cut it was still speeding up as new barrels can do. As I mentioned in a semi auto 22" is fine and what mine is too. For what the OP needs it will work fine. I shoot factory and handloads in my Creedmoors. My team mates and I went with 28" barrels as I said due to the round being designed around it and when we spoke with one of the round developers, Dave Emary, that is what he recommended to us back in 2008 for our match rifles. I have always run H4350 and in my present 27" that mentioned I get 2850fps from the 140 ELDs and 2820fps from the 147 ELDs. I have had factory 140 ammo vary as they do from around 2750 for slower lots to 2930fps. Here is the back of a 2009 lot of 140 AMAX and as you see the listed barrel is 28" and 2820fps for velocity. https://www.AR15.Com/media/mediaFiles/19859/140a_PNG-1538016.png Here is a pic of a 2011 box of the same ammo after they switched to putting 24" data on the box as more factory rifles were in 24" configs due to it being more of a catch all for hunting and target. Velocity at 2710fps. https://www.AR15.Com/media/mediaFiles/19859/111-1538019.jpg View Quote Looks around nervously with his 17.5 barrel. |
I've been blessed with many things in this life: an arm like a damn rocket, a cock like a burmese python, and the mind of a fucking scientist.
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[#37]
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Sarcasm is an art and I'm painting my master piece
WA, USA
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[#38]
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I've been blessed with many things in this life: an arm like a damn rocket, a cock like a burmese python, and the mind of a fucking scientist.
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[Last Edit: smarcus]
[#39]
I have a 16 inch lightweight gas gun and 24 inch heavy as fuck bolt gun.
Attached File I had to block out the range I was at cause of rules. Attached File |
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[#40]
Originally Posted By smarcus: I have a 16 inch lightweight gas gun and 24 inch heavy as fuck bolt gun. https://www.AR15.Com/media/mediaFiles/167780/Cadex_Minox_1_jpg-1541733.JPG I had to block out the range I was at cause of rules. https://www.AR15.Com/media/mediaFiles/167780/Inked_6_5_cm_jpg-1541871.JPG View Quote Yeah, when I get invited to go shoot with the Delta Seals at their range, I have to do the same Nice stick. |
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What is best in life? To crush your enemies, see them driven before you, and to hear the lamentation of their women!
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[#41]
Originally Posted By smarcus: I have a 16 inch lightweight gas gun and 24 inch heavy as fuck bolt gun. https://www.AR15.Com/media/mediaFiles/167780/Cadex_Minox_1_jpg-1541733.JPG I had to block out the range I was at cause of rules. https://www.AR15.Com/media/mediaFiles/167780/Inked_6_5_cm_jpg-1541871.JPG View Quote What are your velocities for the same loads out of the 16" AR and 24" bolt gun? m4hk33 is showing about 150 fps difference between 16" & 20" barrels. I'm probably going to get a LaRue UU kit with either the 18" or 22" barrel and Tranquilo suppressor this fall. If the 22" barrel would let me get to 1400 or 1500 yards then it might be worth the extra length. The 18" might barely make 1200 yards before it goes subsonic. A suppressed 6.5 gas gun with a good reputation for about $2K seems like a pretty good deal and I like the LaRue handguard attachment method. |
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[Last Edit: bendigo78]
[#42]
I built a "light weight" deer rifle out of a PA-10 with a 18" criterion hybrid in 6.5 that I'm very happy with. The choice between 16" and 18" came down to getting a faxon or criterion barrel. I would of liked a 16" since it's suppressed but the criterion had more reviews displaying the accuracy I was looking for.
It wears a 3-18 FFP MIL/MIL Bushnell forge that is almost perfect for the application. It's lighter than the 34mm tube scopes, 3x work is ideal for close range, 18x is more than enough for longer shots, and the glass is impressively clear (I was counting the points on a small 7 point at 1000yards). I did realize that illumination is almost mandatory on a ffp hunting scope. At dusk/dawn when you turn down the magnification to get more light, the reticle almost disappears. ETA. I wouldn't go with a 20" just to get to 800. A 16" CM is probably very similar to a 20" 308 in ballistics if not a touch better. The "light weight" deer rifle is 12 pounds scoped with a bipod. My heavy target DPMS SASS wears a 20" heavy 6.5 BA is 15 pounds scoped with a bipod. My "long range" bolt gun has a 22" 6.5 CF Proof barrel riding in a chassis and is 12 pounds scoped with a bipod. |
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