MP5SD style upper for an AR15/M16

[ar15dave]

Well I am starting a new build. An HK MP5SD style upper for an AR15/M16. So far I have sorted out most of the parts except the barrel and a decent 7" handguard with an OD around 2".

The plan is to be able to swap the suppressor on my HK MP5SD I have now with this upper when I want to.

Parts So far:

HK MP5SD rubber handguard
stripped upper
BUIS
Dust cover

Wish me luck and appreciate any input you may have.

 

[jrumann59]

so a short barrlel AR15 upper that will accept your MP5SD suppressor. Handguard could be tricky 2" ID is big, I am doing a build and I went here for 1.8" ID

MAS DEFENSE 7'' SQUADRON LIGHTWEIGHT AR-15 QUAD RAIL

MAS DEFENSE 7' SQUADRON LIGHTWEIGHT AR-15 QUAD RAIL

www.masdefense.com

 

[ar15dave]

so a short barrlel AR15 upper that will accept your MP5SD suppressor. Handguard could be tricky 2" ID is big, I am doing a build and I went here for 1.8" ID

MAS DEFENSE 7'' SQUADRON LIGHTWEIGHT AR-15 QUAD RAIL

MAS DEFENSE 7' SQUADRON LIGHTWEIGHT AR-15 QUAD RAIL

www.masdefense.com

Maybe missread. I was stating the OD (Outside Diameter) would like to be around 2". The handguard cover from HK will be mounted to the 7" long handguard. The inside Diameter should be around 1.8" I think. I will measure my MP5SD OD

 

[smdub]

Interesting build idea re-using the SD suppressor. Getting a barrel threaded & drilled to fit it I guess? A CMMG RDB 9mm bolt would be the cats meow for not getting as much gas in the face.

 

[SCARCQB]

I took the easier route.
Spikes tactical brown recluse integrally suppressed AR9.

It has a ported barrel and an encapsulator to capture the vented gas into the can.

It’s quieter than a factory MP5 SD

 

[teratos]

I took the easier route.
Spikes tactical brown recluse integrally suppressed AR9.

It has a ported barrel and an encapsulator to capture the vented gas into the can.

It’s quieter than a factory MP5 SD

Is there some kind of delayed blowback on those, or is it straight blowback?

 

[SCARCQB]

It’s a straight blowback. But with a heavier bolt carrier and buffer spring.

Since I modified it to use the Troy tomahawk pdw stock . I used a heavier spring yo compensate for the lighter buffer.

Then upgraded to a hiperfire 9mm trigger.

 

[teratos]

It’s a straight blowback. But with a heavier bolt carrier and buffer spring.

Since I modified it to use the Troy tomahawk pdw stock . I used a heavier spring yo compensate for the lighter buffer.

Then upgraded to a hiperfire 9mm trigger.

Give the Scheel roller delayed system a try, if you are so inclined. It does a very nice job with a lighter bolt and spring. I put it on my Colt pattern SBR, and like it a lot.

Roller-Delayed Buffer System | Scheel Manufacturing

USPSA PCC 9mm ar15 roller- delayed buffer system. less recoil, faster split times. Roller-delayed

scheel-mfg.square.site

 

[SCARCQB]

Also, I’ve experimented with short barrels for an alternative to ported barrels.

I found out that a 3” ar9 barrel will keep the 124grain FMJ subsonic without the need for complex porting. Some anemic 9mm ( 115 grain ) will also be subsonic. The suppressor’s back pressure also helps with reliability on the short barrels.

 

[SCARCQB]

Brown recluse and 4” suppressed AR9 pistol.

 

[wbw2123]

Interesting build idea re-using the SD suppressor. Getting a barrel threaded & drilled to fit it I guess? A CMMG RDB 9mm bolt would be the cats meow for not getting as much gas in the face.

I sometimes find my mind wandering re SD supressor in other applications- sterling ala modern mk5 (actually planning to do this one), fbp, uzi, etc. I now this is added to that list.

 

[ar15dave]

Interesting build idea re-using the SD suppressor. Getting a barrel threaded & drilled to fit it I guess? A CMMG RDB 9mm bolt would be the cats meow for not getting as much gas in the face.

Will have to give that a look. I am using a standard 9mm ramped bolt for now but will change items out as I get new ideas.

The hardest part to get right now is the barrel. Cannot find anyone that has just the barrel. Ronin Arms makes a barrel/suppressor package but, won't sell the barrel separately.

Anyone know where I can get an AR15 9mm ported barrel 5.75" long?

 

[inkd]

I took the easier route.
Spikes tactical brown recluse integrally suppressed AR9.

It has a ported barrel and an encapsulator to capture the vented gas into the can.

It’s quieter than a factory MP5 SD

I've looked for one of those for a while and cannot find them anywhere. Are they still making them?

 

[ar15dave]

OK, so I have a few of the parts in. Will be posting pictures and descriptions shortly. I am thinking of going with a 3" or 4" barrel with a 3-lug end on it for now until I can get a ported barrel that would work with my MP5SD can. The handguard is 7".

Thoughts?

 

[outrider58]

OK, so I have a few of the parts in. Will be posting pictures and descriptions shortly. I am thinking of going with a 3" or 4" barrel with a 3-lug end on it for now until I can get a ported barrel that would work with my MP5SD can. The handguard is 7".

Thoughts?

Awaiting pics.

 

[ar15dave]

Sorry it has been a while. Life got in the way. I found a company that actually builds HK MP5 Uppers for the AR15.

I decided to hold off on the build for now to see if I wanted to opt for one of the uppers.

 

[Sgt6402]

Check this place out for an Mp5SD look.....

Homepage

 

[Gcs7th]

Check this place out for an Mp5SD look.....

Homepage

Cool look but 600 for a barrel handguard and upper receiver is a bit pricey.

 

[smdub]

Cool look but 600 for a barrel handguard and upper receiver is a bit pricey.

Don't look at real MP5SD parts then. A kit will run you several times that. I think B&T just converted about 100 HK SP5s to SD spec and they flew off the shelves at something like $5000. Dakota Tactical just came out w/ a MP5 cage that will fit both their MLOK handguard and the orig rubber one.

 

[Sgt6402]

Cool look but 600 for a barrel handguard and upper receiver is a bit pricey.

Specialty parts like those are not being made by many people and are gonna be pricey for a niche item, especially if they are quality parts. Don't like the price, don't buy it(not be smart, just saying). I like the AR15SD look and would pay their prices, much cheaper than HK prices. Suck's MD has the 29 inch rule for SBR's. I really like the one with the Q (Noveske'ish) collapsing stock in 9mm pictured.

Like what smdub said, don't go looking for an Mp5SD semi then if $600 is pricey. HK's start at $5,000.00 to $6,000.00 minimum with HK Parts. I imagine AR parts made to look like an Mp5SD are few and far between as far as manufactures go.