Mk20 Questions

Strykervet

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I just picked one up, couldn't resist I guess. Along with 11 mags and an LRA ultralight bipod I'll be paying it off for a bit. I got the one in 7.62, wanted 6.5CM but for $3499 I couldn't pass I guess. I don't have any 6.5CM brass or dies but do have good 7.62 stuff already for the SR25. It'll be fun to compare these two I think.

So questions for the Mk20 owners and experts:

1. What suppressor was it designed to use? Does it come with a mount? I understand it's some kind of Surefire can but don't know which one. Or if there's a better one to go with.

I have a QDC for the SR25 that's the titties for what it does but I'm not sure I wanna share it with the Mk20. Then I have a TBAC 30CB9 but not sure I wanna use that can on that rifle. Then there are a pair of AAC SDN6's and, well, if you know suppressors then you know why those are out.

2. Can you convert it to 6.5CM? Uppers? Barrel swaps? I understand people were converting SCAR 17's to 6.5CM way back when, is that an option here? I read the barrels come out easy for cleaning and I wondered if that could be exploited.

Having one to do it all would be nice if the price is right, if not then 7.62 will just have to make do.

3. Optics. I hear these rifles are hell on optics, which I find troubling and interesting as I don't believe the DTA HTI in.50BMG carries any such restrictions. I'm guessing anything quality? Ones to particularly stay away from? What about a PVS30? Go or no-go?

4. 168 or 175 SMK's? Lapua brass? Those are the bullet selections I have available and I'm sure it probably favors one or the other in general. I have a bunch of FGMM brass (I know) if the Lapua is a problem --does the Mk20 beat up brass? Hard extractor marks? I don't wanna damage new Lapua brass.

I appreciate anyone who takes the time to answer these, thank you.
 

EIGTM1651

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The MK20 was designed to run the Surefire FA762SV can in conjunction with the FH762SV flash hider. I run all Surefire Socom RC2 cans on my 16, 17 and 20, and I use the SFMB on the 20s and 17s SBR.

received_713364796102878.jpeg
 
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Strykervet

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The MK20 was designed to run the Surefire FA762SV can in conjunction with the FH762SV flash hider. I run all Surefire Socom RC2 cans on my 16, 17 and 20, and I use the SFMB on the 20s and 17s SBR.

View attachment 7338646
Thanks, that was what I was gathering but I wasn't sure. Nice rifle BTW. I think MSRP on that "legacy" can was $1800, I can find something else, the KAC QDC isn't that much. The RC2's looked good... I'll look into those.

So that USO scope, you use that on there because it's a tank or some other reason? I have an LR17 on an SR25 and I was considering putting that on the Mk20 and getting something else for the SR25.
 

EIGTM1651

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You can find very good prices on the Socom762, either the RC2 or even the Mini2. RC2 is good, Mini2s on the scar (or any semi auto) are even better because of the reduced back pressure. Can be had for around $1000.

I had the LR-17 on an AR10 which I sold for the 20s, so I just carried it over. Optic holds up well on the SCAR. Any of the current offerings from quality manufacturers should do fine on the platform.

Regarding ammo, I only run factory loads. Gun shoots 168 and 175 both very well. I run the 168s because of the 1:12 twist and the slightly higher velocities over the 175.

Do you have a PVS30? I was looking at running that or a UNS-LR on this gun whenever I decide to go into more debt.
 

jeffl838

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I don’t know what can the mk20 was designed around but it got issued with a garbage FN can that weighed 3 pounds.

Any scar actually shoots alright with 175smk

I think fn makes 6.5 barrels now but worst case you could maybe take an old barrel to a smith and he could rat fuck that receiver extension onto a 6.5 blank? Like what some people were doing with lmt’s. not sure on this one

I never experienced optic issues but I only used t1’s and Elcans on the scar. I want to say the pvs30 is supposed to be ok on a 50bmg so I would be comfortable using it on the scar, but at the same time, the scar does have that optic eating reputation.
 

CrabsandFootball

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Should have waited for the 6.5CM, people are dumping the 7.6 blow now.

Based on scar 17 barrel prices you are probally looking at $12-1600 for the barrel when they finally release it. You could send it off to have an aftermarket barrel put on, but then it would be cheaper and factory warranted to wait for the 6.5CM to come out.

If it is like the 17, you will need a ring to support the suppressor mount. The shelf behind the threads is just too short, but it may be beefed up on the 20 with the heavier barrel. https://www.parkermountainmachine.com/store/p113/PMM_Surefire_SCAR_17/MK20___Shoulder_Ring..html

Stick with a QUALITY optic. The lightweight combined with the heavy bolt carrier was an optics killer for shitty quality optics and lasers. Everything in the SOPOD was hardened as a result back in the day. The MK20 should be much less harsh than the 17 due to its heavier weight and some design mitigations.

Stick with quality Optics (NF, Razor, S&B, Kahles, ect) and you should be fine. The AMG would be a great pairing with a good reticle.


Im about to sell my 17 to buy a 20.
 

Strykervet

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First big thanks for the replies, I appreciate it. FN issued a can, didn't know that, but military issued cans IME were always sorta like the junk nobody else would buy. From ten or more years ago.

Yeah, I think I'm probably gonna keep my LR17 and ER25 since I have a USO observation scope (their term for a spotter with a very narrow FOV) and they all have the milGAP reticle (still one of my favorites). I have a 1-8x USO with a small tree reticle I may let go but it's the only thing I have that can function like a dot and an 8x and all in between. Was thinking of maybe putting it on the Mk20 just for the meantime. I was thinking that eventually I'd like to use an S&B on it but it could be a while.


You can find very good prices on the Socom762, either the RC2 or even the Mini2. RC2 is good, Mini2s on the scar (or any semi auto) are even better because of the reduced back pressure. Can be had for around $1000.

--I like the small cans too but like the full size one in addition, if I'm only gonna have the one I'd rather it be the full size one. KAC's QDC compact model really is nothing more than a moderator (unlike the TBAC Ultra 5 which is actually JUST hearing safe).

I had the LR-17 on an AR10 which I sold for the 20s, so I just carried it over. Optic holds up well on the SCAR. Any of the current offerings from quality manufacturers should do fine on the platform.

--Yeah, I figure but I also wanted to see what others used/were using.

Regarding ammo, I only run factory loads. Gun shoots 168 and 175 both very well. I run the 168s because of the 1:12 twist and the slightly higher velocities over the 175.

--Wasn't sure about the twist, heard 10, heard 12. Pretty sure the SR25 is 10 so interesting.

Do you have a PVS30? I was looking at running that or a UNS-LR on this gun whenever I decide to go into more debt.

Yeah and it's a bad bitch too. That was my splurge last year, year before. They're rated for .50BMG and supposedly can be used on a DTA HTI but I gotta admit, I'm afraid to put it on there. Nobody talks about HTI's ruining optics, but goddamn, nothing else kicks like that thing either! But on an M2HB I'd feel a bit better, the thing is a tank in and of itself.

IMG_0881.JPG
Should have waited for the 6.5CM, people are dumping the 7.6 blow now.
Dumping 'em huh? A 17 vs. a 20 is one thing, the same rifle in a different chambering is another.

For $3500 I think I'll be okay with the 7.62. I wouldn't mind having the option of being able to swap uppers sorta like KAC did with the SR25 in the future, though I can live without it too. Not interested in forcing a square in a circle either. I'm setup good for 7.62, good components and dies, don't have jack shit for 6.5C. In fact, if 7.62 can't do it, I just pull out the BMG. I know it can. But another upper or option later on? Yeah, I'm interested in that.

I could have gotten the rifle from Proven Outfitters with the military/vet discount for $3900 for the 7.62 and $4000 for the 6.5 and those were the best prices I could find from any dealer so I figured the resale of a NIB 7.62 rifle to be the way to go.

I am a bit chaffed at the idea that the seller may have shilled his own sale when he realized I was about to win it for $3199 but I'm gonna let Gunbroker handle that, I can't prove his IP address or that the new guy that had never bid on anything before and just joined the day before and bid on a $3400 weapon as his very first bid is or isn't the seller himself. But based on some of his prior sales, I sort of get the feeling he's been getting away with it for a while. Lots of new, day old guys with no bid history seem to ambush bids last minute on a lot of his sales.
 

deersniper

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I don’t know what can the mk20 was designed around but it got issued with a garbage FN can that weighed 3 pounds.

Any scar actually shoots alright with 175smk

I think fn makes 6.5 barrels now but worst case you could maybe take an old barrel to a smith and he could rat fuck that receiver extension onto a 6.5 blank? Like what some people were doing with lmt’s. not sure on this one

I never experienced optic issues but I only used t1’s and Elcans on the scar. I want to say the pvs30 is supposed to be ok on a 50bmg so I would be comfortable using it on the scar, but at the same time, the scar does have that optic eating reputation.
50 rated /= scar rated
 
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MK20

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It uses a surefire can. I'm pretty sure it is this one.


You can convert it to 6.5 but it is expensive.

we used PVS 30s on ours. Just don’t run a cantilever mount for anything. Make sure you run good optics. You don’t have to get crazy.

Now for the ammo.

You can tell which brass comes from a scar as the scar leaves a small but noticable sharp ding in the case neck. It will kinda look like a crack at first. You need to anneal this to get it out, at least that is what i have found. You can reload without annealing, but the annealing helps soften the metal and let it smooth out.

This gun definitely prefers 175 bullets or hornady 178s which are cheaper. They carry better to distance.

Most scars are overgassed from the factory. Midwest industries is i think who sells new gas ports and it is worth experimenting with. Mine would beat the crap out of you even on the suppressed setting. Most of us who used the SCAR/MK20 ran them on the suppressed setting all the time with or without a suppressor.

Any questions, PM.
 

RyanScott

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Do not use a high backpressure can on an FN. the 16/17 were designed with AAC cans. Then in service they were porting the blast chamber to get them to run right and ended up buying FN made cans.
 

theLBC

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the 6.5CM versions are expected out by august , and barrel assys for 6.5CM conversions shortly after that.
some details offered here:

 

theLBC

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It uses a surefire can. I'm pretty sure it is this one.


You can convert it to 6.5 but it is expensive.

we used PVS 30s on ours. Just don’t run a cantilever mount for anything. Make sure you run good optics. You don’t have to get crazy.

Now for the ammo.

You can tell which brass comes from a scar as the scar leaves a small but noticable sharp ding in the case neck. It will kinda look like a crack at first. You need to anneal this to get it out, at least that is what i have found. You can reload without annealing, but the annealing helps soften the metal and let it smooth out.

This gun definitely prefers 175 bullets or hornady 178s which are cheaper. They carry better to distance.

Most scars are overgassed from the factory. Midwest industries is i think who sells new gas ports and it is worth experimenting with. Mine would beat the crap out of you even on the suppressed setting. Most of us who used the SCAR/MK20 ran them on the suppressed setting all the time with or without a suppressor.

Any questions, PM.
have you tried the optional recoil plates?
 

MK20

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I happen to have used the specific can i linked above in service.
I dont know if it is the best can, but it is what I used and is the "correct" can if you are into that thing.
 

Strykervet

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I happen to have used the specific can i linked above in service.
I dont know if it is the best can, but it is what I used and is the "correct" can if you are into that thing.
Thanks man. Well, I wanted to at least know which one was the recommended one, sometimes they do turn out to be the better one. I'm glad for instance I got the QDC for the SR25.

Do not use a high backpressure can on an FN. the 16/17 were designed with AAC cans. Then in service they were porting the blast chamber to get them to run right and ended up buying FN made cans.
THAT'S what kept nagging at the back of my brain! They used to come with like a four inch reflex mount coated in "Scarmor" didn't they? AAC discontinued it pretty damn fast IIRC. I have a couple of SDN6's but no way in hell that's going on this rifle, and like I said, I don't think the TBAC can is the best suit for this rifle and I don't really wanna use the QDC on it. So I have options I guess. If weight isn't an issue I may go with an Elite Iron can on it. They never let me down and also have good prices. I always hear mixed stuff about Surefire cans, usually that they're very well made but that they're also a little on the loud side.

It uses a surefire can. I'm pretty sure it is this one.


You can convert it to 6.5 but it is expensive.

we used PVS 30s on ours. Just don’t run a cantilever mount for anything. Make sure you run good optics. You don’t have to get crazy.

Now for the ammo.

You can tell which brass comes from a scar as the scar leaves a small but noticable sharp ding in the case neck. It will kinda look like a crack at first. You need to anneal this to get it out, at least that is what i have found. You can reload without annealing, but the annealing helps soften the metal and let it smooth out.

This gun definitely prefers 175 bullets or hornady 178s which are cheaper. They carry better to distance.

Most scars are overgassed from the factory. Midwest industries is i think who sells new gas ports and it is worth experimenting with. Mine would beat the crap out of you even on the suppressed setting. Most of us who used the SCAR/MK20 ran them on the suppressed setting all the time with or without a suppressor.

Any questions, PM.
Big thanks on the brass info. I'll be mindful with the Lapua brass, it's not your typical goto brass for a gas gun but I got a good deal on it. 175's... I'd have guessed it to be the 168's but whatever, good to know.

PVS30 is a tank but it's also a $4000 tank that turns into a $4000 paperweight the moment it goes black. I'm a bit bitchy about that device to be honest, I wanna keep it working. Just finding guys that have BTDT and had no problems with it helps take a big load off.

I guess most of the mounts I use are cantilever of some kind --Badger one piece mounts, super solid and they don't really cantilever much. I can't see how they'd be an issue and the rifle may have to wear a 1-8x USO temporarily and it's set in one. We'll see how it does I guess? Good to have a heads up on it, when I get an optic for it I'll try and stick with the rings if I can.
 

m1marty

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You're going to love it. Mk316 and GMM168s have both hammered in mine. The 20 doesn't seem to be plagued with optic "issues" like the 17 has.
20200517_191045.jpg
 
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Strykervet

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So it got here yesterday. I got to check it out while doing the paperwork but gotta wait two weeks to pick it up. First impression is it's a lot lighter than an SR25 and just extremely well thought out --all but the charging handle. WTF? I thought they had that fixed in the new SCAR17's? I know they had it unfucked seventy years ago with the FAL! So what gives? Is there an economical solution to this, a non-reciprocating handle? Maybe a conversion to the existing carrier? I guess I'll search around after this but figure I'll ask here anyway since you guys may have more to say on the issue.

I think them not using SR25 mags was a mistake, but whatever. $38 is still less than a SR25 mag and ten of 'em is still less than a lower made to accept 'em. The mags seem nice enough for the price though, not junk.

It comes with what I think is a very nice Surefire flash hider I'll probably sell on here once I have a suppressor solution. Surefire ain't inspiring confidence at the moment if you look at the suppressor forum.

Don’t neglect to check out those gas port screws if it feels over gassed. The are about an 8 dollar part.
Thanks, I'll keep that in mind. I reckon once I get the suppressor situation figured out (and the wait if I go with a new one) I'll probably be firing it suppressed 80% of the time.

You're going to love it. Mk316 and GMM168s have both hammered in mine. The 20 doesn't seem to be plagued with optic "issues" like the 17 has.
View attachment 7342311
Yeah, I think I already do. Primarily for the fact that it's not just "another" SR25. Or AR. I consider the SR25 actually as one of the best semi auto sniper rifles. But I think this one fits more in the DMR category (they call it a sniper SUPPORT rifle) and in that respect I think it may be the best DMR ever made? After all, it is an SCAR17 done up the way we'd do up most other DMR's --FF bbl., better trigger, optics, bipod, stock. That kinda shit. But still retaining the ability to put rounds downrange with the chrome lined CHF bbl.

I like what you did with the sling setup on there, I may do that. Gotta be better than HK or SAW clips that I have rattle around.

Really want an LRA Ultralight Scout bipod (picture below in thumbnail) but for the price I can take a Harris of another rifle and slap it on there and get a really good tripod I can use for all my rifles so I think I'm gonna go that route. That long rail underneath is screaming for an ARCA rail or some such ain't it?
 

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jeffl838

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I personally like the reciprocating charging handle, but it's kind of a bad spot. I think the only way to fix it is to get an ACR...
 

theLBC

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I personally like the reciprocating charging handle, but it's kind of a bad spot. I think the only way to fix it is to get an ACR...
nah, there is a device you can put on it if it bothers you.