I have been playing around with factory ammo in both my 10 and my 10.3" SBR's. Pretty much everything in the 69-77 grain range chronos at around 2150-2250 and everything 50-60 grain chronos around 2300-2400. I was dis-appointed by these velocities and set out to work up something a little more affective. I typically use varget for almost everything I put through an AR, but I grabbed my jug of Reloader 7 in an attempt to take advantage of the short pressure curve I am working with. There is no published maximum for 5.56, but the published maximum with R7 for .223 was 22 gr behind 50 gr pill. Since I am using 5.56 chambers, I SLOWLY worked up to 22 gr behind a 60 gr Vmax in a LC case. This is just locking the bolt back on an empty mag and showing no dangerous pressure signs. Primer is just starting to flatten, but no extractor marks. I feel that it is safe for MY guns. Your mileage may very. I am getting consistent 1.2" groups out of a 10.3" BA LIGHT profile barrel with a 6x scope. I feel pretty good about this load for all light skinned critters I have to deal with.

What are your favorite hunting loads for your MK18's and what velocities are you seeing?

Well? How fast is it?

Whoops! Its running right at 2550-2560. How could I have forgotten that "detail"

Well, I don't reload and I'm not hunting with my 10.5 556 SBR but, for HD, I'm zeroed with Speer 64 JSP. With it's performance in LE applications and against barriers, I believe it to be a good load for my purposes.

No chorno so no idea on fps.

Yeah. I could load up a mag with any old HD load if I wanted to. I am particularly trying to find out what is most affective and what loads retain more velocity out of sub 11" barrels. I am sure you would hate to chrono the load you are depending on, and find out its only running 2100 fps....  On another note, I dug up some loads I had made a few months ago with 25.4 gr. Ramshot TAC behind a 60 gr vmax, and shot 2650 through my chrono. Unfortuneatly, I am out of TAC, but I think it may be the perfect powder for achieving max velocity out of an MK18 with mid range weight pills. Varget is too slow, R7 slightly too fast, but close... Hoping TAC is what I need. I would be thrilled if I could work up a safe load that would push 55-62 gr. pills out at around 2700 fps.

How is shooting it from a shorter barrel less effective against flesh?  Post pics of hogs that have survived being shot by a 10.5" barrel please because my experience says otherwise.

I think you are missing the point. All else being the same, if you could choose between 2100 fps and 2600 fps, which would you choose? So why not go through some basic footwork to get the most from your equipment? All bullets have minimum velocity barriers. Once they drop beneath that thresh hold, depending on the type of bullet, they will either not tumble, fragment, or expand. Not everyone shoots their intended target at point blank range. The more velocity you leave the muzzle with, the greater your potential range. Vmax for example is only reaches its full potential between 2000-4000 fps. If it leaves the muzzle @ 2100, I'm pretty much limited to sub 100yds, and even then, only at the very weakest end of its effective velocity range. Common sense says to get the most from your equipment as you can.

I wouldn't use Varget for anything shorter than 16".  Too slow for an MK18.  H335 is my go to for shorter barrel 223.

Yeah, I found this to be true the first time I shot a varget load through a chrono out of it. Hard to get more then 2300fps. I have never tried H335.. might have to give that a shot. Do you have a particular load you prefer?

25 grains of H335 under a 55 grain pill is pretty much the standard "Internet reloader" load.

Topic Moved

I got 2700-2735 from my 14 inch progressive rifled barrel in my Arms Tech Gas Trap.  I use 24.5 grains of Varget driving Nosler 77 grain bullets using Lapua brass.  No problem at all.

All of my rifles to include the MK18 are zeroed with Speer Gold Dot 64 gr.

I did a thread about different ammo loads through my 10.5 Noveske over the fall and winter and out of that I settled on BH 77gr TMK and 62gr MSR. This way I have both regular and barrier blind loads for a 10.5 out to 250-300yds. Full results here

Both of them would work fine for hunting loads as well

The TMK tested at 2410 and 2429fps averaged over 10 shots on different days

The MSR tested at 2516 and 2514fps, same 10 shot strings, different days.

Thank you for posting this test.  Since mine is a 14 inch barrel I'd bet we are right on for these cartridges.  The Arms Tech Gas Block's barrel is free floated and has a unique progressive rifling that has tested to give a few more fps than the test rifles we have used.

We'll soon know for sure. I just picked up a BCM 14.5 BFH Middy that I'll be testing when the temps warm up a little more, along with retesting the 10.5 and 12.5 on the same day. Hell I might even throw a 16" 1:9 Bushy I have in the safe if I'm feeling froggy. Won't be as many types of ammo because I don't feel like spending a bunch of money when I have a few loads that work well, but that could change if any of them don't like TMK and MSR.

OP,
   I mostly use TMK & TSX loads in 5.56MM (and 300BLK) for general purpose non-LEO SD/HD/hunting but am always looking at other options. Here are some factory load chrono readings from the 10.0" 1x7 Colt M4 I have used extensively. Just returned from a 30 day hunt/shoot over in MS and took 90 varmints/predators/bobcats/hogs plus a couple of long beards with a shotgun. The terminal performance of the 0.224" & 0.308" TMK bullets on flesh & bone targets continues to impress me. HTH

62GR. TSX loads fired from 10.0" 1x7 M4 with M4 can at approx. 80F/300FT. MSL/29.92":

Custom 5.56MM 62GR. TSX: 2681 FPS (MAX listed 5.56MM NATO pressure TAC handload)
BHA 5.56MM 62GR. TSX:-----2625 FPS
Barnes 5.56MM 62GR. TSX:- 2595 FPS
BHA .223 62GR. TSX:---------2595 FPS (Very fast .223 pressure load)

70GR. TSX loads fired from 10.0" 1x7 Colt M4 barrel with M4 can at approx. 85F/300FT. MSL/29.92":

2010 SSA 5.56MM 70GR. TSX:----------2575 FPS  
Custom 5.56MM 70GR. TSX:------------ 2543 FPS (MAX listed 5.56MM NATO pressure TAC handload)
5.56MM OPTIMIZED 70GR. brown tip: 2506 FPS
Barnes 5.56MM 70GR. TSX:------------- 2469 FPS
SWA 5.56MM 70GR. TSX:----------------2456 FPS (This load used Hodgdon Extreme stick rifle propellant so MV varied little from -10F to +135 F)
Ted Nugent .223 70GR. TSX:----------- 2376 FPS  (This is a .223 pressure loading)
2013 SSA 5.56MM 70GR. TSX:----------2205 FPS (The 2013 SSA load is 370 FPS slower than the 2010 load but both are listed as 5.56MM)

77GR. TMK loads fired from 10.0" 1x7 M4 with M4 can at approx. 80F/300FT. MSL/29.92":

BHA 5.56MM 77GR. TMK: 2379 FPS

While I wouldn't use this bullet for hunting, I get 2550fps from near max charges of W748 or BLC2 under a Hornady 55gr FMJBT in my 10.3" Colt 6945.

These same loads reach 2950fps in my 18" upper, for comparisons sake.

If I was hunting I would swap out a soft point or VMAX bullet and feel comfortable out to 200y on thin skinned game I was planning to eat.

Lots of great info there. Thanks brother. I see you mentioned TAC there. One of my fav. powders for sub 16" barrels. Whats charges were you loading those 62 gr tsx @ 2681fps? That is a VERY respectable velocity from a 10" barrel. Almost makes the MK18 vs standard M4 effectiveness discussion senseless.

OP,
    Barnes used to publish 5.56MM NATO pressure load data/ MV for just one barrel length. Just recently, they started publishing new data/MV for several barrel lengths including 10.5": http://www.barnesbullets.com/load-data/. MAX 5.56MM NATO pressure loads are extremely hard on brass so I limit it to (2) loads on new LC brass available thru Federal/ATK. Fired from a 10" class barrel, the 70GR. TSX will retain minimum expansion impact velocity out to almost 300yds. and the 62GR. will retain it to approx. 260yds. The 14.5"/16" M4 barrel extend this by another 100yds or so for each load.

I develop my loads using a chronograph and my 20" AR-15 match rifle. I'm looking for the most accurate load during load development with much less concern for velocity. Whatever my match rifle shoots the best is what the rest of the rifles use whether it's optimized for them or not. My match ammo always shoots very well from every rifle I've tried it in.

I doubt 100 to 150 fps one way or the other will have any effect on the outcome.