This is where my AR collection is heading…
For close-in General purpose use, 14.5" Lightweight profile Cold-Hammer Forged barrels:
For longer-range General purpose use, 16" Midweight profile CHF:
For long-range Precision shooting, 18" Heavy/Mid profile Stainless Steel match-grade:
Next up: close-in Precision (Recce) 16" H/M SS
Concur?
You could consolidate the 1st two with a 14.5" middy. You are only talking about a 1.5" barrel difference between the two.
With how reliable guns like the 14.5" middy have turned out to be theres really no purpose in a 14.5" carbine anymore. With the same barrel length you can get a much smoother gun. SBR’s are where carbine gas lengths should be relegated to.
And just thought Id talk about this just because…but Im actually 2nd guessing the whole 556 precision gun thing. Ive been shooting a lot lately out to 500 and beyond that. Ive self discovered that the 556 sucks as a long range gun unless you are in calm conditions, and even then the round barely has any pop at that distance. Even with heavy 556 rounds I have trouble putting LaRue steel targets down. 308 puts them down with authority. Past 500 even light wind blows the rounds all over the place. I was out a week or two ago, and shooting at 750 with good ammo, and at that range the slightest breeze would blow the round 3-4 feet off target. Other guys with 30’s and up had no such problems. Not talking about doping for wind but when you have wind that goes from 5-15 between shots you simply can’t dope for that at 750 yards with such a light round. Other guys were shooting 300 magnums with 200 grain + bullets, and smacking the shit out of the gongs. Maybe just hold on the left or right side of the target if the wind picked up. That brings me to wondering what, exactly a 556 precision gun is good for. I can hit 500 yard gongs with relative ease with a reece setup so all the extra weight and glass is rather useless past a reece setup. Basically you can be just as effective with a good quality reece as you could with an SPR.
I hear you on the 14.5" middies; in fact I was planning another build using the same barrel as the one in the first pic, but with a DD RIS II and Aimpoint T1, to make the gun more capable (but I had to have a KISS too!). The barrel on the 14.5" CAR in the first pic is one of the new DD Lightweight CHF barrels; these barrels are sweet, something missing from the market for a long time. The 16" CHF is a Centurion heavy-duty barrel; it will be interesting to compare its accuracy potential to the Recce when it is completed. When I have them all and have done a lot of shooting with them, I may mor may not consolidate.
I was IMing with a guy on TOS who did two tours as a DM in Afghanistan, and he thinks heavy 5.56 out of a precision rifle is sufficient out to 700m (he himself has put then down at that range). However, I see he too now has a DM-type AR10…I will be doing one of those as well, as soon as my 5.56 arsenal is complete.
The reason the 30 calibers were performing better at long ranges is because the bullets being used have a better ballistic coefficient than the bullets used in your 5.56/223 ammunition. 55 gr pills in particular are notorious for having low BCs and being susceptible to being blown around by the wind.
Choose a bullet with the proper BC and it will make tagging those long range targets much easier. There is a reason why the AR in 5.56/223 has dethroned the 7.62x51/308 in High Power Rifle matches. They won’t hit with as much energy as the 300 magnums, but the punishment to your shoulder will be much less
77 gr. rounds can go out to 750, or 800m.
If I can see a guy put down more than 15 rounds out of a 30 round magazine, on target at 800m with 25-30mph wind. Then I am satisfied. I’ll just train.
(Watched a cell phone video of a guy I knew in high school do this with a LMT MRP 14.5’‘, and did 16 out of 30 with a KAC E3 16.1’’ gun.)
I would disagree with most of the above but to discuss the SPR/recce thought a bit more…
The NSWC who participated in the constructing and testing of both the Seal Recon Rifle a.k.a. recce rifle and the Special Purpose Receiver/Rifle program by in large felt the 16" recce was a waste of resources and time…thus canceling any future work on it and then adopting the SPR which ultimately grew into the mk12 so I think you kinda got the last part backwards in my estimation as the SPR is the keeper if one has to go between them.
End use…
I hunt with my AR’s and getting 100fps more with a 16" gun vs. a 14.5" gun more than makes up for the extra 1.5" barrel.
I’ll keep my 18" Noveske as well as my 17" Kreiger, seems to be a sweet spot right in there.
Yes, but the SEAL end users who started the process were dissatisfied with the SPR and built 16" Recces using unit funds.
Ive shot 77 GR SMK’s, TAP T2, and Hornady 75GR BTHP rounds out to 750, and noticed the wind deflection even with those.
Even with a good 556 bullet means they slow down quicker, and the same amount of wind has more effect on them. 30 cal both has more weight (less affected by wind), and retains energy better.
Thats fine. I just think a 30 cal SPR/DMR/whatever is a better choice for long range shooting than a 223. Just like the ELR guys are not even shooting 30 calibers but 375’s, 408’s and 416’s. The further out you go the more speed and bullet mass help you. Another example is the Army switching from 308 to 300 win mag because you can shoot heavier bullets at a faster FPS. Just upping bullet mass and speed raises the max effective range from 800M to 1200M.
Edit: Just doing some calcs on KAC BulletFlight a 300WM with a 220GR bullet has less than half (actually closer to a 3rd) the wind deflection at 750 yards than Mk262Mod1 out of a Mk12. The 300WM was a little over 3FT of deflection with a 15MPH wind from side to side whereas the Mk262 was over 104". With Mk262 at 5MPH its about the same as 300WM at 15MPH (35"). So gusty wind out to 750 with Mk262 ranges from between 3-9FT whereas 300WM is about 1-3FT. I think thats a pretty dramatic difference, and Id like to see someone make regular hits on a torso size target with gusty wind like that. Not saying it can’t be done but going up to a .30 makes a big difference at that range as I said in my 1st post in this thread.
I am not a current or former elite SEAL operator, nor am I a U.S. military small arms historian. But based on what I’ve read, I believe there may be truth to both of the quoted statements above. While researching my own SPR build, this is what I’ve gleened from the all-knowing oracle that is the Internet:
-The SPR concept - originally only a complete upper receiver before being provided as a complete rifle - was developed into several platforms that are currently in use with various branches of the U.S military.
-Some SEAL teams were unhappy with the Navy’s Mk 12 SPR, and have reverted back to accurized M4 ‘Recce’ rifle idea.
To return to wes’s question - yes, I concur. Recce next. Try it with an A1 stock. Or not.
wild_wild_wes, I think it boils down to what your definition of long-range vs. close-in is. In the end I think your new #4 rifle is going to end up being a lot like your #2 rifle except with a stainless barrel and the true usage for either (or both) of them simply determined by which optic you choose to put on it.
Could be wrong. Either way I think you’ll end up with 4 super sweet rifles.
On a side note: I really want to see Belmont31R and TRIDENT82 in a steel cage, barbed wire, ladder match at Ellismania 6 :lol: Just kidding guys.
Once I took a frog and placed it on a bench and said “Jump frog, jump!” The frog jump. I then cut off a leg and repeated the experiment. It jumped, though not as well. I did the same with two legs removed then three. Both times the frog at least tried to jump. Then I cut off the fourth leg. When the frog was given the order to jump it did not. My conclusion: Without legs, a frog cannot hear.
I use this story to illustrate the point the right observation doesn’t always lead to the right conclusions. Mass is not the only factor when calculating a bullet’s ability to buck the wind. The 200 grain 30 caliber bullet being used for long range shooting is a long skinny spitzer with a good BC. If you use 30 caliber 200 grain roundnose with a dramatically lower BC, not only will that bullet get pushed around by the wind more, but it will shed velocity faster.
The reason the 5.56 displaced the 308 as the preferred caliber for the 600 yard service rifle matches is because they found the longer 22 caliber bullets have a better BC than the 30 caliber bullets, shoot flatter, buck the wind better and do so with less recoil.
6.5mm bullets have always been long for the caliber and have good BCs. Though launched at slower speeds, their BCs allow them to retain velocity and buck the wind better than 30 caliber bullets launched at higher velocities, and the 6.5s will stay supersonic for a longer distance although they have less mass.
Time of flight plays a large role in resisting wind deflection. A bullet launched at a higher velocity is in the air less time, giving the wind less time to push it around. So if you launch two bullets of the same BC, the one with the higher velocity will have less wind deflection over the same distance.
While mass helps, it’s not the whole story, nor is it the most important part. A lighter bullet with a higher BC will fly flatter and buck the wind better than a bullet of greater mass and a lower BC.
It doesn’t mean the 30 caliber is a poor choice. It carries more energy. In the case of the 300 magnums launching 200 grain bullets, that energy will be felt at both ends as it will take it’s toll in the form of increased recoil
Aren’t those NM rounds firing 80 grain + bullets, and are basically single loaded?
I was just illustrating 2 common commercial rounds not specially loaded rounds that may or may not work from a magazine.
And 308 was what was common in NM before, right? My original comment was based more around the 300WM or other 30 cal magnums. I think my point still stands that at least for commerically loaded or otherwise common rounds the 30 magnums have a lot less wind drift. Also the 556 round I used is the Mk262 which is current mil issue. Outside of something like AMU are those 80+ grain bullets in use by the mil at all? I know sierra makes an SMK up to 90 grains but I don’t think its possible to load that to fit in to an AR mag. I also believe the NM guys shooting those heavy bullets are having to use non-standard chambers to get them to chamber correctly. Would a 90 grain SMK even seat in a 556 chamber? Ive seen some off the shelf type 80 grain ammo before, and all times it was warned not to use them in standard chambers.
The rounds I used in those calcs is the 77SMK (Mk262), and 220SMK. They can both be fired from standard chambers.
Wind bucking and drop are a function of two things only: BC and starting velocity. There are plenty of on-line calculators that you can plug data into and determine down range drop and drift values. Velocity will be a function of barrel length, so if you want to max out on V, get a long barrel, carbines need not apply.
You are correct, the 80 grain and longer bullets have been developed for competition and must be single loaded. Wylde chambers handle these fine. The 90 grain JLK may need a longer throated chamber, I’m not sure. I think those only come into play for competitors shooting F-class at 1,000. But standard service rifle competition, just about everyone tops out somewhere between 75 and 80 grains at the 600 yard line and uses a Wylde or NATO-variant chamber. Some even use a SAAMI chamber, but those rounds are loaded shorter and velocities are reduced slightly.
If you do serious research on wind deflection effects I think you will find wind deflection (and, to some extent drop) depend mostly on the “Delay factor”. The delay factor is the difference in flight time between two points in a vacuum vs in air. In other words, the faster the bullet slows down the more the wind affects it. This is the reason better BC bullets buck the wind better. There is no substitute for high BC at long range. At the same range a bullet that launches at 4000 fps with a terminal velocity of 2000 fps will drift more than a 2500 fps bullet that terminals at 2000fps, period. Check it out with any exterior ballistics program that does wind drift.
Hals1
Dat’s what I said 
Or tried to. Your explanation is clearer than my example.
I need to improve my verbiage when attempting technical posts. The other problem is I’m on the east coast and all my reloading data is out west. I need to fix that
Believe it or not for change I agree with you and the sentiment behind the horsepower of the .308 in say a m118lr over a 5.56 mk262 in any long range precision application however I had my views at least broadened from a thread on tos the other day. I was confused as to what Marcus Luttrell from the book Lone Survivor was packing to smoke the Taliban leader up in the Hindu Kush Mtns…I had just assumed after not reading the book in so long that Marcus being the actual shooter on that SDVT team aka the sniper, would take the mk 11 mod 0 as its a real deal sniper rifle in a very appropriate caliber vs. in reality what he did have which was a MK 12 and MK 262…turns out it was the right play as he had numerous volleys of fire with contact burning tons of ammo through the mk 12 over the course of that sad day and then next several days by himself…so just assume he has the much heavier mk 11 with ammo capacity limited to what he brought on his person as none of his teammates would have had any 7.62. So all four were able to interchange ammo and mags and while he gave up some in terms of range and lethality, it was not nearly what he would have given up if he had a mk 11 in the situation that actually transpired in real life.
eta…on the end user comment, I am pretty sure that the actual Seals do in fact dislike the recce as they have made a damn living whacking BG’s with Mk 12s for some considerable amounts of time now vs. a concept gun without a MK designation and thus no support behind it. Seals can carry what they what in terms of kit and they do…the MK 12s is one of their very best tools imho.
I own both type guns and although I would hate to do it, the recce would be shelved if I had to take only one.
eta 2:) This is clearly one of my favorite aspects to ARs…and the specific recce vs. spr is maybe my favorite thing to just ponder at a Dr’s office or day dream basically about. Its a wonderful topic for discussion and the debate in my eyes even though I have a formed opinion is still clearly open for discussion and I got a new chip in the game coming for my recce so I will have a new opinion I am sure soon on this topic.
I did the same thing WWW, I wanted to have a “set” of ARs for various roles/ranges. I think that an AR15’s capability is basically determined by its sights. So I set about getting 3, then 4, then 5 ARs, that had various barrel lengths and optics for their operating envelopes. I wasn’t as concerned with barrel profiles or cold hammer forging as barrel length for velocity and barrel quality for accuracy.
The close range carbines 10.5" 14.5" and 16" with Red Dot Sights have; NATO chambers, chrome lined barrels, and single stage triggers, whereas the 16" Recce and the 18" SPR have tweaked chambers, stainless match barrels, and 2 stage triggers.
Close range - LMT 10.5" MK18 Mod C with RDS
Mid Range - Daniel Defense 16" Recce with med scope 1.5-5
Long(er) Range - BCM MK12 SPR Mod 3 with long range scope 4.5-14 (the scope on it is from my .308 Bolt Action but will have a 3.5-10 with an off set RDS soon).
So really the only major differences are optic, barrel length, barrel quality, and trigger.
Rather than consolidating the 10.5" and 16" into a 14.5" I just got an extra 14.5" with a different optic. The latest edition a light(er) weight RDS equipped carbine for the pixies in the family.
BCM 14.5" mid length with RDS
Kinda rounds out a capable collection that has a commonality in feel and function, where real role differentiation is determined by the optic.
Cameron
Damn Cameron now I’m gonna have to say Hail Marys all night as I’m suffering from envy, hate, lust,… 
Well done!
and I’m not even Catholic:eek: