DD MK18- miserable accuracy

[m1ajunkie]

I love shooting my MK18, but I have an accuracy problem I cannot figure out. This problem has persisted for some time, at least a year I'd say.

Would you guys read through things and let me know what I can do to diagnose it? After today, I'm thinking the rifle just flat out hates 55gr ammo. At best I'd call this a 6moa rifle with multiple types of 55gr M193, however I fired 15 rds of IMI 77gr into 1.5 moa today so it appears the rifle, elcan and suppressor are capable. I'd be satisfied with 3moa....

Backstory: Rifle has probably 4000-6000 rds on it. Literally all of that suppressed with my Surefire 212 monster suppressor. This fall DD put a new barrel on it as they thought the gas port had eroded beyond spec, get the new barrel back and my troubles are still present.

Shooting position: Prone, Atlas bipod, rear bag, 100yds

Optic: Primarily, the rifle has worn my elcan SU-230. Today I thought the optic might be the problem so I slapped my Mk8 1-8 on, nothing changed so I went back to the Elcan.

Suppressor: Surefire 212 monster. Thought the suppressor might be the issue so I pulled it, accuracy is still terrible. I've occasionally run this suppressor on my Block II clone and never noticed any kind of accuracy trouble.

Ammo: I have shot tons of different kinds of 55gr M193, LC, MEN, CBC/ Magtech, Privi, Geco, but primarily IMI as I've been able to find it pretty cheap lately. Today I shot 15 rds of IMI 77gr into about 1.5 moa, this has me thinking maybe the rifle just hates light ammo? Would it be logical to try some M855 62gr ammo and see what happens?

What am I over looking here?

Should I be thinking something other than ammo?

My cousin also has a DD MK18, it shoots 55gr ammo at about 2moa. I've had him shoot my rifle, same terrible results. I shoot my other rifles just fine so I've pretty well narrowed things down to this particular set up having some kind of issue.

Pics for reference:

The rig

10 rds IMI 55gr M193, nevermind the 6 30 cal holes at the bottom. That black circle is roughly 3.5"....Suppressed with Elcan

First 5 rds IMI 77gr- top of paper. Suppressed with Elcan

 

[Pointman308]

Is the barrel free floated?

 

[schmi015]

read this: http://www.thefirearmblog.com/blog/...gr-razor-core-5-56x45mm-14-5-barrel-accuracy/

My thoughts are to go with a 62 grain or 77 grain ammo from black hills, federal gold medal match or hornady. If you have accuracy issues after this lets look at the other variables.

 

[J.Boyette]

Check it out.

​​​​​​Why do you even care, a SBR is for center of mass of a E-Type. Not bullseye targets. I think you need to use the tool for what it is designed to do.

Second, if you really want to tune it up, take the handguard off and torque the nut in 2lbs interments and shoot a group 10rnd group.

The best group wins the torque setting test.

Beyond that, shoot it and enjoy.

 

[hlee]

If you want match accuracy, start with matc( ammo. I’ve never been that impressed with M193. If it’s best quality is that it is cheap, your not shooting the right ammo.

 

[Nik H]

Any idea of the barrel's twist rate?

 

[scharfschutze762]

If Daniel Defence put the new barrel on then you should call them and tell them to fix it..6 MOA is not right.

 

[Keens]

Check it out.

​​​​​​Why do you even care, a SBR is for center of mass of a E-Type. Not bullseye targets. I think you need to use the tool for what it is designed to do.

Second, if you really want to tune it up, take the handguard off and torque the nut in 2lbs interments and shoot a group 10rnd group.

The best group wins the torque setting test.

Beyond that, shoot it and enjoy.

All due respect, have to disagree with the "an SBR is for" argument. Any platform is "for" what it is capable of achieving.

But, agree with the second part of the post- torque and shoot- find the sweet spot.

I would try match ammo.

I had weird issues with an 10.5 noveske a while back. After a new barrel, a few rebuilds, it was still shooting like yours. I switched BCGs.. and things tightened up. Not sure why, other than the possibility of early unlocking on the LMT enhanced carrier.. maybe try a new BCG?

edit: Of course, no disrespect on the "tool for the job" argument. I have personally taken 10.5-12.5 uppers out to 600 with great results with good, heavy ammo, and with certain projectiles expanding down to very low velocities these days, I don't think this can be fairly overlooked. I like versatility

 

[J.Boyette]

All due respect, have to disagree with the "an SBR is for" argument. Any platform is "for" what it is capable of achieving.

But, agree with the second part of the post- torque and shoot- find the sweet spot.

I would try match ammo.

I had weird issues with an 10.5 noveske a while back. After a new barrel, a few rebuilds, it was still shooting like yours. I switched BCGs.. and things tightened up. Not sure why, other than the possibility of early unlocking on the LMT enhanced carrier.. maybe try a new BCG?

edit: Of course, no disrespect on the "tool for the job" argument. I have personally taken 10.5-12.5 uppers out to 600 with great results with good, heavy ammo, and with certain projectiles expanding down to very low velocities these days, I don't think this can be fairly overlooked. I like versatility

I understand. I have a few 12.5" mid and carbine gas uppers myself that run at distance very well. But a MK18 is built to 3 MOA standards.

I would also look at clearance issues with the handguard, I bet you have that gas block touching when under load. I would look at issues with the break / flash hider.

 

[Pointman308]

I understand. I have a few 12.5" mid and carbine gas uppers myself that run at distance very well. But a MK18 is built to 3 MOA standards.

I would also look at clearance issues with the handguard, I bet you have that gas block touching when under load. I would look at issues with the break / flash hider.

^^^^^this what I was getting at.....

 

[TMR137]

I would look at a couple things and eliminate what you can. First off DD barrels are usually 1.5 moa barrels (with match ammo). Then take into account the ammo being used. IMI is probably 3 moa ammo at best. I know even my SPR has a hard time grouping M193 and that rifle shoots match ammo sub MOA. I was getting 3 moa with it the other day with M193. I would also take your can and break off. Shoot the rifle as it came from DD with match ammo. If it gets 1.5 moa (or your standard) I would say the barrel and rifle are good. Then I would re attach the break and shoot it with that. If same results add the can and shoot it.

I will also add that my department uses DD rifles and while zeroing over 50 brand new rifles, it was obvious that not all barrels are equal and not all barrels like the same ammo. We found that our issued duty ammo shot significantly better than the M193 we used for break in and initial zero. However we did have a few rifles shooting m193 at 1.5 moa.

Find what your rifle rifle likes and enjoy the rifle system. Your set up looks very nice!

 

[_Windrider_]

Check it out.

​​​​​​Why do you even care, a SBR is for center of mass of a E-Type. Not bullseye targets. I think you need to use the tool for what it is designed to do.

Second, if you really want to tune it up, take the handguard off and torque the nut in 2lbs interments and shoot a group 10rnd group.

The best group wins the torque setting test.

Beyond that, shoot it and enjoy.

This right here.

 

[Birddog6424]

I've have 2 DD rifles, the M4-V5 and -LV7. Both of them hate 55gr FMJs. They shoot 1 to 1.2 MOA with 75gr HPBT Match, but nothing under 62grs shoots worth a damn. Both are 1/7" twist.

My advice, shoot quality match ammo with 75 or 77gr pills if you want groups. Use the 55grs when it's good old fashioned mag dump or hammer time...

 

[Jefe's Dope]

Another vote for match ammo. I'm finding out, quickly, how drastic a difference ammo has in accuracy. I also recommend the Federal Match w/ Sierra Matchking in 77gr. But try the 65 as well. HUGE difference in accuracy and grouping.

 

[m1ajunkie]

Thanks for all the input guys! To answer some items in the thread:

1. The barrel is 1/7 twist.

2. I'm looking for sub 6 moa accuracy so I can plink and actually hit my steel. I've got various plates from 4", 6", 8", 10", 45" IPSC, 2/3 IPSC and shoot mainly between 100-300yds. Being able to only hit an 8" or larger plate at 100yds is frustrating and IMO not acceptable when trying to improve your marksmanship. Also, I really like shooting 2 gun matches... A couple of these had full size IPSC targets at 300-500 yds last year, that's a huge target and IMO opinion any "battle type rifle" should be able to hit that.

So today I went out with some american eagle M855 62 gr ammo. Below is a picture of the 15 rds I fired. In total, all 15 rds went into 4" at 100yds, with all but 1 going into a 3" group. I can totally live with that. Appears this rifle just flat out hates 55gr ammo which is fine as green tip is super cheap right now. Still not a tack driver at 3"-4" at MOA but good enough that I'm fine with it.

 

[TMR137]

I would be interested to see what some MK262 would do through it. I bet the “tac driver” would come out of the shadows.

 

[LSUbeatUby40]

Thanks for all the input guys! To answer some items in the thread:

1. The barrel is 1/7 twist.

2. I'm looking for sub 6 moa accuracy so I can plink and actually hit my steel. I've got various plates from 4", 6", 8", 10", 45" IPSC, 2/3 IPSC and shoot mainly between 100-300yds. Being able to only hit an 8" or larger plate at 100yds is frustrating and IMO not acceptable when trying to improve your marksmanship. Also, I really like shooting 2 gun matches... A couple of these had full size IPSC targets at 300-500 yds last year, that's a huge target and IMO opinion any "battle type rifle" should be able to hit that.

So today I went out with some american eagle M855 62 gr ammo. Below is a picture of the 15 rds I fired. In total, all 15 rds went into 4" at 100yds, with all but 1 going into a 3" group. I can totally live with that. Appears this rifle just flat out hates 55gr ammo which is fine as green tip is super cheap right now. Still not a tack driver at 3"-4" at MOA but good enough that I'm fine with it.

Not to be "that guy" or an asshole, but you keep feeding it garbage/lower quality ammo. Go get a few boxes of 77gr match ammo (i.e. Asym, FGMM, Hornday, Black Hills, Lapua) and see what it does. Federal American Eagle is not great ammo for shooting groups.

 

[J.Boyette]

The MK18 is spec'ed to 3 MOA accuracy. the ammo like XM193, M855 are both loaded to 3 MOA. so you will have on average a 6 MOA gun

3 MOA + 3 MOA = 6 MOA gun.

Keep in mind some MK18's shoot MOA, some shoot SUB-MOA, others shoot to spec.

For military use and the application of the MK18 6 MOA is good enough out to 300yds in the accuracy department.

Many do not know that the X in XM193 or XM855 means that single round failed Quality Control. Each round at Lake City sorting failed QC, not the whole lot. So the box of XM someone buys is from a wide assortment of lot numbers of low quality rounds that once LC bundled together gets its own lot number.

Anyhow, any non military ammunition will our perform XM--- in the precision department. I would go buy some match and non mil .233 and see what you get.

With all that typed, I shoot a lot of XM193 even at 3moa.

BTW, your ELCAN has point of impact shifts within 6 MOA between 4x and 1x

 

[scharfschutze762]

To the OP..
HERE...


All Daniel Defense products carry a 100% satisfaction guarantee against defects in original materials and workmanship. If your Daniel Defense product shows evidence of such defects, Daniel Defense will make every accommodation to fix, repair, or replace your product in the most expeditious manner possible. Daniel Defense does not warranty products or damage caused to our products by the correct or incorrect installation of other manufacturer’s products. Be sure to retain your sales slip as proof of purchase date when making a claim.
Should your firearm require adjustment or repair, make sure it is NOT LOADED and call Daniel Defense at 1-866-554-GUNS (4867) to obtain an RMA (Return Merchandise Authorization) or email: [email protected]


They're a good company and thats how easy it is.

 

[10ring1]

If you have a 1:7 twist, I would think it would prefer the heavier bullets. 70 gr and up. I primarily reload and am not too familiar with factory offerings that may be inexpensive. Do you reload? If not, that 77gr imi looked fairly promising

 

[oldfatguy]

Of the cheaper ammo, IMI M855 has been the least accurate in my rifles. Good for shooting through car doors, but pinpoint accuracy - not so much.

 

[MtnCreek]

I don't think M855 solves the problem if you're wanting to shoot steel.

 

[hlee]

I don't think I would pay DD prices to shoot 3 MOA, or to shoot M193 or M855 ammunition... But, do what makes you happy.

 

[_Windrider_]

Sharfshutz762 had the best advice. Send it back. Have DD evaluate it. It should shoot 55/62 gr just fine. At 800 bucks a case, mk262 isn’t even an option. Especially since it’s an SBR the velocity will be garbage to make that round effective.

I would also also try a new sight, iron sights even. Put it in the hands of a really good shooter and see what happens. Maybe it’s you. But at a minimum, it warrants a phone call to DD.

 

[schmi015]

put a different optic on it, nice high power scope that would look ridiculous but see what you can wring out of it shooting some different ammo

 

[padom]

I have a DD 10.3" 5.56 1:7 Govt Profile barrel on my 5.56 SBR and it hammers tiny little groups with 55vmax and H4895. Something is wrong.


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[J.Boyette]

I have a DD 10.3" 5.56 1:7 Govt Profile barrel on my 5.56 SBR and it hammers tiny little groups with 55vmax and H4895. Something is wrong.


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Handloads and XM193 are apples to oranges in comparison.

 

[padom]

Handloads and XM193 are apples to oranges in comparison.

as stated in the OP he has also shot 77 OTM match Razor Core so we aren't talking about just XM193....

 

[scharfschutze762]

Handloads and XM193 are apples to oranges in comparison.

I dont understand how you can be in this industry and without knowing the persons qualifications reccomend he work on a factory built firearm..I can tell you from first hand experience dealing with Daniel Defense and more recently PRI on seperate occasions with an accuracy issue, the first thing they want to know is if you worked on it. Both companies especially PRI did an outstanding job of rectifying the issue.
Also as someone intimately familiar with real Mk18s in both mod 0/1 those groups do not pass spec and would be rebarreled.

 

[J.Boyette]

I dont understand how you can be in this industry and without knowing the persons qualifications reccomend he work on a factory built firearm..I can tell you from first hand experience dealing with Daniel Defense and more recently PRI on seperate occasions with an accuracy issue, the first thing they want to know is if you worked on it. Both companies especially PRI did an outstanding job of rectifying the issue.
Also as someone intimately familiar with real Mk18s in both mod 0/1 those groups do not pass spec and would be rebarreled.

good point, the OP asked for options. I gave them to him.

 

[scharfschutze762]

good point, the OP asked for options. I gave them to him.

But I appreciate the tip on barrel nut torque sweet spot.

 

[fdkay]

Why would you complain about accuracy with M193? Why are you concerned with accuracy from M193?
M193 is good defensive ammo, but it is basic BALL AMMO it is not intended for accuracy.
55 grain bullets and fast twist barrels ie NOT a recipe for accuracy.
You need to be shooting 62+ grains and green tip is not the answer for accuracy either.
Midway has IMI 77 grain on sale. Try some of that.

Another decent load, though not really "match" is the prvi partizan 77 grain load. It is fairly accurate and offers good terminal ballistics.

 

[Forgetful Coyote]

I would look at a couple things and eliminate what you can. First off DD barrels are usually 1.5 moa barrels (with match ammo). Then take into account the ammo being used. IMI is probably 3 moa ammo at best. I know even my SPR has a hard time grouping M193 and that rifle shoots match ammo sub MOA. I was getting 3 moa with it the other day with M193. I would also take your can and break off. Shoot the rifle as it came from DD with match ammo. If it gets 1.5 moa (or your standard) I would say the barrel and rifle are good. Then I would re attach the break and shoot it with that. If same results add the can and shoot it.

I will also add that my department uses DD rifles and while zeroing over 50 brand new rifles, it was obvious that not all barrels are equal and not all barrels like the same ammo. We found that our issued duty ammo shot significantly better than the M193 we used for break in and initial zero. However we did have a few rifles shooting m193 at 1.5 moa.

Find what your rifle rifle likes and enjoy the rifle system. Your set up looks very nice!

This is kinda what I was thinking..?

 

[Forgetful Coyote]

Also, like others have said, maybe try some of the lower end cheaper "match" ammo, IE PP 77gr, ....IIRC Hornady has steel case "match"/pseudo-match, or heck try pulling/sorting M193 & handloading your own M193 with Hornady, Sierra, etc 55 FMJ..??

Are you happy with said 1.5" when using match grade ammo?

 

[m1ajunkie]

I appreciate the interest and the comments from each of you in this thread. For now I've found a solution I find acceptable.

For an SBR, I'm not looking for "match grade" accuracy, simply in the 3 moa ballpark so I can hit my steel with out questioning if a miss was me or some crazy flier. The 77gr IMI shot really nice, but for the kind of shooting I want to do is far to expensive, and handloading the amount of rounds I shoot out of this rifle is out of the question when I can find ball ammo for less than $0.30 per round delivered.

That said, it appears I'll just swap from 55gr M193 ammo over to 62gr M855 ammo. Went out yesterday with some new IMI M855 I got recently mid way and all the groups I shot of this ammo were in the 2.5-3" range. Exactly what I'm looking for, and when I moved to steel it didn't appear to do anymore damage from 100yds than M193.

Here is 10 rds in about 2.5":

 

[sinister]

2 MOA is pretty good for M193.

What trigger is in the rifle? Have you tried grouping the rifle using sandbags instead of that tilt and pan Atlas bipod?

Remove the variables you can control before sending it back to Daniel Defense. It may save you the embarrassment of them getting it back, shooting it, and finding it shoots sub-MOA.

 

[m1ajunkie]

2 MOA is pretty good for M193.

What trigger is in the rifle? Have you tried grouping the rifle using sandbags instead of that tilt and pan Atlas bipod?

Remove the variables you can control before sending it back to Daniel Defense. It may save you the embarrassment of them getting it back, shooting it, and finding it shoots sub-MOA.

Geisselle SSA 2 stage in the rifle. That last group was actually from M855. If the setup continues to shoot like that with M855 I'm not planning to send anything back, I'll just change up the ammo I plan to shoot out of this rifle.

Only downside to green tip is most matches won't let you shoot their steel with it....