HK SP5 --> Dakota Tactical MP5SD

I converted my HK SP5 to an MP5SD.

Bottom Line Up Front – I couldn’t be any happier

Conversion was done by Dakota Tactical and I wanted to create a thread that has consolidated information on the process/results. While doing my research on the SD, it took a lot of searching. There are a lot of myths and contradictory information all over the internet.

Intent: to help those who are considering converting their SP5 (or clone) make an informed decision.

My background: USMIL with formal CQB and Sniper training. I provide this only as context to my perspective on accuracy/precision. There is a lot of information on accuracy (or lack thereof) with the SD platform. I put a premium on accuracy but have realistic expectations on what to expect from a PCC. In other words, when discussing MOA and accuracy standards, I know this is not a “sniper rifle”.

Reason for owning: This is a bucket list item. I have competed in the past (USPSA, IDPA, Steel Challenge) and will compete with it in the future. When I competed years ago, PCC was not a thing. I’m aware that there are platforms optimized for competition (JP9) but I believe that competing is an excellent/efficient way to build proficiency.

Taste/Preference: I’m not overly concerned with making it a pure German gun. More interested in function over form and optimizing it for the above.

Build Details (part/source):

“Host”: HK SP5 / Local FFL

Locking Piece: HK MP5SD 115 Degree / Blue Ridge Supplies

Barrel: B&T MP5SD Barrel / Dakota Tactical

Suppressor: B&T MP5SD APC9 SD Suppressor, Model Number: SD-988010-2-US / B&T

Cage: Gigliotti Rifle Works, “The One” cage / Dakota Tactical

Heat Shield: Broad River Tactical BRT CAR-15 SD/MP5SD Shroud / Broad River Tactical

Stock/adaptor: BT-20155 - B&T Foldable Stock Polymer w/ Adaptor For HK MP5, MP5SD / B&T

Optic Mount: MFI Ultra Low HK Scope Mount / MFI

Optic Riser: SCALARWORKS LEAP/04, Size: 1.57” / Amazon

Optic: Holosun 507 Comp / Amazon

As part of this thread, I intend to cover (among other things):

1. My decision to start with an HK vs a clone

2. My decision to go with Dakota Tactical

3. Accuracy before and after the conversion

4. Sound suppression & ability to be read by a shot timer

5. Accessories/cleaning gear & spare parts

6. Cleaning and tips to avoid carbon lock with the suppressor

7. Measurements (length extended & folded)

8. Different Stocks and Lengths

I hope this helps anyone considering undergoing the conversion and makes the decision easier.

In the meantime, I will add some photos:

As it arrived:

View of B&T barrel:

Fully assembled with 30rd magazine:

Folded with 15rd magazine:

In the case:

1. Why I chose an HK SP5 as the “host”:

Initial logic: since the gun was going to get “cut up” and re-welded, my thought was to buy a less expensive clone instead of paying for the more expensive HK to get “chopped up” and “gutted”.

I began my research and found that reviews/feedback on clone guns were inconsistent. Some people loved them, some people had problems with reliability, accuracy, craftsmanship, etc.

While doing my research, I came across James from Teufelshund Tactical and called him to get his opinion. Based on the name of his company, I knew we would have a lot in common. James was a tremendous resource, extremely generous with his time and answered all my questions.

Bottom line – James recommended starting with an HK. I’ll try to paraphrase his philosophy – “a house is only as strong as its foundation”. James and I share a similar communication style, and he was direct and clear with his recommendation.

Based on the James’ recommendation and the fact that gun would have to work as a system, I decided to go with the HK.

Note: Interestingly, while speaking with Joe from Dakota Tactical a few months after I bought the HK (but before I shipped it to him for conversion) he said the same thing.

2. My decision to go with Dakota Tactical:

Note - To reiterate, I have no affiliation with Dakota Tactical. This is not a paid advertisement. I received no compensation/special pricing and no promises were made by either party. This is my experience/perspective. Ultimately, I’m looking to “pay it forward” to anyone who is in the same position I was in a few months ago.

Bottom Line Up Front - I’m extremely happy with the choice I made and wholeheartedly recommend Dakota Tactical @Chopstix Kid for SD conversion. Joe and Amber were wonderful to deal with. They kept me informed throughout the entire process and were always available to answer my questions (no matter how neurotic). Fit/finish is excellent, the gun runs like a scalded ape and the accuracy is excellent (writeup to follow).

Research - I spoke with several vendors prior to undergoing the conversion.
Important personal criteria – I will not make large purchases with vendors that don’t provide telephone contact info or answer phone calls.

During my research I spoke with:

Wade at Black Ops Defense
Scott at Ronin Arms
Matt at HTA
John AKA “Grease Gunner” on HK Pro

ALL of the above folks were generous with their time. They answered all my questions and provided realistic answers on lead times. They were great resources and educated me on the conversion process. I’m thankful to each of them.

Decision:
In addition to the above, I called Dakota Tactical and spoke with Amber (Joe’s wife). She was extremely personable and answered all my questions. She also told me to reach out with any questions, whether I went with Dakota for the conversion or not.

I had several competition specific questions that Amber couldn’t answer. These answers would determine whether I converted it to an SD or not. Instead of guessing or saying, “I don’t know”, she put me in touch with Derek G from the HK shooting team. Derek was extremely generous with his time and answered all my questions in extreme detail. He spoke highly of Dakota Tactical and his opinion carried a lot of weight. Additionally, a fellow competitor in my local area shoots a Dakota Tactical D54N (MP5). His gun runs, has excellent fit/finish and is very accurate. I also knew that Dakota built James’ @Teufelshund Tactical SD. All of that, combined with a good gut feeling, led me to go with Dakota Tactical.

Process - It was simple. Amber walked me through the entire process step-by-step. I was able to source some parts on my own and drop ship directly to them. Joe also advised where I could source other parts that he didn’t need for conversion (i.e. heat shield).
Joe and Amber understood my vision for the build, knew how I wanted to use the gun and they executed my intent flawlessly.

Time for conversion - Total time for conversion was approximately five months. The “delay” was due to a shortage of B&T MP5SD barrels and my decision to stick with a B&T barrel . Joe called and gave me the option of using an RCM barrel to reduce conversion time. I chose to stick with the B&T barrel because I had sourced a B&T suppressor. I am big on “systems engineering”; a concept I learned the hard way while working on a ‘65 Mustang years ago.
Throughout the process, Joe and Amber gave me regular updates and advised me when decisions needed to be made (engraving, options for the “one cage”, sling loops, etc). Their customer service was second to none; by the time it was all over, they felt like family.

Conclusion - Once the B&T barrel was in, the conversion happened quickly - Joe and Amber committed to completing it before my birthday and they delivered as promised.
Since it arrived, I’ve put about 500 rounds through it and couldn’t be happier. I’ve zeroed it at an indoor range, conducted an “accuracy test”, shot paper/steel (competition practice) and even used it to hunt some hogs. It’s everything I wanted and more. Thank you Dakota Tactical!

3. Accuracy:

With respect to an MP5, my idea for accuracy is pretty simple – a shoulder fired weapon “bagged in” should be as accurate or more accurate than a pistol at the same distance. I’ve owned Wilson Combats and Les Baers and knew of their accuracy guarantees at 25/50 yards. I know the MP5 is not a hand built 1911, but I remembered that the MP5s I used in the military were accurate guns.

Bottom Line – I did NOT want to own (or convert) my gun into a PCC that held 4-6” groups at 25 yards.

Prior to conversion - When I purchased my SP5 I was extremely pleased by its accuracy and blown away by its consistency. I was shocked at how consistent the gun was during the zeroing process. I initially zeroed my gun/optic at a rec range aboard base using a very sturdy table and sand bags.

Ammo: Sellier & Bellot (S&B) 115 grain FMJ.

Target: NRA 25 Yard Standard American Pistol Target

“X” Dimensions: 1/2” x 1/2”

Zero Distance: 25 yards

The below photos shows target's "X" dimensions and the first 12 rounds out of the gun:

While doing my research for the conversion, I read the following thread:

https://www.hkpro.com/threads/mp5sd-b-t-barrel-accuracy.571462/

After reading this post, I was very concerned about the converting the gun to an SD. I spoke to several folks including “Grease Gunner” and Derek from the HK Shooting Team. They both told me that they had competed with SDs and hadn’t had accuracy issues. As stated earlier in this post, I chose to go with a “systems engineering” approach. I thought I could minimize problems by using a suppressor and barrel from the same manufacturer (B&T).

After Conversion: - I didn’t have access to the rec range when I zeroed my SD (hours are limited and work has been crazy) so I went to a local indoor pistol range to zero. I improvised the most stable platform possible and was able to get the gun (roughly) zeroed.

A couple of weeks later, I was able to get to the rec range and bag the gun to refine my optic zero, zero my irons and confirm them both.

Below are my results:

Note: I did not have to make ANY adjustments to the irons when zeroing. Hats off to Joe and Dakota Tactical! Considering all that goes into converting a gun to an SD, I was shocked that I didn’t have to touch my irons at all.

Barrel “Break-In”? - I have noticed that the more I shoot the gun, the more tightly it groups. Perhaps this is because the barrel is “seasoning” or breaking in? I know this is a thing with precision rifles and am wondering if it’s the same thing with an SD barrel. I use VFG pellets to clean my barrel. The first time I cleaned the gun; I noticed that there was a lot of cotton that had snagged in the vicinity of the barrel ports. Some ports were even clogged with cotton. I removed the cotton from the ports/barrel with no issues. In every subsequent cleaning, there has been less and less cotton snagged in the barrel. After my first competition, I cleaned the gun and noticed that there were no remnants of cotton in the barrel. Makes me wonder if there are small burrs where the ports are drilled into the barrel that get smoothed out over time…

Zero Distance: - Initially, I zeroed the gun at 25 yards (partially to test accuracy and partially based on what I’ve always done). Because I compete, use an optic/riser and a lot of the targets are relatively close, this created an issue where I had to think too much for holdovers when running a stage. A buddy of mine recommended zeroing the gun at 15 yards and it made holdovers less of an issue. Below is a photo of mechanical offset at various distances with the SD using a 15 yard Zero. My point of aim for all shots was the “-0”. All shots taken from the standing, unsupported position.

Ammo: Sellier & Bellot (S&B) 115 grain FMJ.

Target: Official IDPA Practice Target

Ammunition Tested - Again, in my research there was all kinds of contradictory information regarding SDs and ammo it likes or doesn’t like. The following is a list of rounds that I have fired through my SD with no failure to feed/failure to fire issues. Note: I have not accuracy tested all these rounds using a bench and bags.

- S&B 115 Grain FMJ

- S&B 124 Grain FMJ

- Federal HST 124 grain

- Hornady Critical Defense 115 Grain FTX

- Hornady Critical Duty 135 Grain FlexLock

- Monarch 115 Grain Brass (update)

I just tested Monarch 115gr brass. My local supplier was out of S&B 115 and I was looking for a similarly priced alternative. I was at Academy and I saw that 115gr Monarch was the same price as the S&B so I bought 100 rounds and took it to the rec range to see how it performed. I was looking for "good enough" on accuracy at 25yds.

Groups - I fired two groups of three rounds. On the first group, I forgot I had my dot set to 8MOA for competition (dot & horseshoe). I felt that first group was "good enough" as an alternate round but decided to fire three more rounds. As I sighted in, I realized my mistake of using 8MOA, changed the reticle to a 2MOA dot and fired three more rounds.

I was blown away! I only fired six rounds total but it seems like the Monarch is more consistent/precise than the S&B.

Photo below (zoom in to see 1st and 2nd three round groups):

Point of Impact was slightly high which is exactly what I expected with a 15yd zero.

I used the remaining rounds for competition practice. Zero failure to feed/fire malfunctions. Printed very consistently.

Left the range and swung by Academy. They had a sale for President's Day weekend and I picked up 750 rounds. Bonus...

Conclusion - I have had no issues with accuracy and am extremely pleased that the gun shoots just as good (in my hands) as it did before the conversion. Also, I am extremely pleased to see that, up to this point, the gun shoots anything I feed it. My perspective- converting the gun to an SD will not ruin accuracy and accuracy concerns shouldn't stop you from going with an SD.

4. Sound Suppression and Ability to Be Read by a Shot Timer:

I don’t have a decibel meter for quantitative analysis. The gun is extremely quiet and it’s difficult to describe how it sounds. Videos on YouTube don’t do it justice.

Several folks have remarked that it doesn’t sound like a firearm. Two of my buddies said the sound of the brass hitting the metal siding/overhead at our rec range is louder than the gun.

To me, the most distinct sounds are the action cycling and a “whoosh” of air. Sounds a bit like a low powered pneumatic nail gun or a slightly louder than a Daisy Red Ryder combined with dry cycling the action.

In my first competition, someone asked if I was shooting a suppressed .22. Without question, you can clearly hear bullets impact dirt and the impacts on steel are louder than the gun itself.

Can it be read by a shot timer? Absolutely. I’ve already competed with the gun and had no issues.

The inability to register on a timer was an absolute no-go for conversion. I was concerned because a prominent YouTube channel stated a shot timer would not read an SD. Luckily, I was able to speak to Derek G and Grease Gunner beforehand. They both compete and both said that shot timers will pick up the SD. They gave me tips/tricks to ensure the timer registers the shots (which I’ve implemented).

Considerations and tips/tricks:

- I use a CED 7000 Shot Timer

- Sensitivity setting is “4”

- Best results achieved by holding the timer close to the ejection port

- If competing, don’t set sensitivity too high or timer may pick up shots from an adjacent bay or may read impacts off steel, resulting in slower times

- If competing, make sure to tell the RO where your last shots will be. Most important shot to catch is the last one…

- VERY difficult to pick up accurate times at an indoor range. Timer tends to pick up echoes/impacts which provides false readings on shots taken, splits and total time.

5. Accessories/cleaning gear & spare parts

Case - I use the Savior Equipment Specialist Series Covert 34” bag. Sourced from Amazon. Minimalist, yet can carry everything I need for the range, ranch or a match. Purchased the accessory pouches through a variety of sources.

Sling - Still working on this one. Ordered an old school HK style sling and have had marginal results. I know there are countless threads on this topic but if anyone reading this has a good suggestion for a sling that won’t mar the gun, I’m all ears. I like the two point/three point capability of the original HK style sling.

Mag Coupler - I use the HK Parts 9mm Dual Magazine Clamp HKP MP5 & MP5K 9mm Dual Magazine Clamp. No issues with function/reliability. With repeated dry fire practice though, the inboard magazine tends to “walk up” a bit. No big deal, I just break out the allen tool and readjust. I love the idea of the HK tool-less version, but I just can’t justify the cost.

Spare Magazines – I only run HK magazines and don’t have any experience with aftermarket mags.

I was initially tempted to go with non-OEM based on price. Competing can be hard on magazines, and I didn’t want to destroy expensive magazines by dropping them on concrete, accidentally stepping on them, etc. Luckily, when I spoke to Derek G from the HK Shooting Team he recommended using HK mags. He stated that they were bomb proof and that he still competes with magazines he bought 10+ years ago. I took his advice and followed the philosophy of “buy once, cry once”.

Note: I was in a match recently and a fellow competitor had an SP5 that was consistently malfunctioning. I asked him what type of mags he was using and he told me he was using aftermarket mags (don’t remember what kind). I let him borrow my mags for the rest of the match and he had no issues. Coincidence? Not sure, but it fixed his issues that day…

15 round magazine – In my opinion, it’s a must for zeroing if bagged in. 30 round mags make the gun sit extremely high. Sourced from Blue Ridge Supplies https://hkpartspro.com/hk-mp5-mag-15rd

Q1: Why colored tape on mags?

Q2: Why yellow and red?

A1: After spending 20mins during a match looking for a mag that was hiding under a bush, I decided to make them easily visible. No fun losing an 80.00 mag, ever.

A2: Very visible, distinct and I’m kind of a dork…

Spare parts:

(2) extra extractor springs H&K MP5/SP5/MP5K/SP5K 9mm Extractor Spring

(1) extra HK O-Ring. Sourced it from Dakota Tactical. Joe recommended using the HK O-Ring with the B&T suppressor and not the “oversized” orange O-Ring.

O ring orientation – the round (non-beveled side) should be oriented towards the muzzle (I’ve seen a lot of stuff on the internet with contradictory information). As you can see from my this write up, no issues with accuracy, baffle strikes or reliability.

Cleaning Gear (MP5 Specific):

Chamber Face Brush -I sourced mine from Blue Ridge Supplies. https://hkpartspro.com/hk-mp5-chamber-face-brush Straightforward and easy to use. I was concerned with steel-on-steel contact with this tool (carryover from sniper training). No issues whatsoever.

Barrel Brush – Sourced from Dakota Tactical. In my opinion, an absolute must (see earlier in this thread). I opted for the handle as well. I was neurotic about steel bristles over the crown (see above). No issues with accuracy or crown damage.

Q: Why the blue tape?

A: Bottom Line Up Front – Let's me clean the barrel without having to remove the heat shield.

Not recommended to run the bristles over the barrel threads. The tape gives me a visual reference on how far to go down before the bristles contact the barrel threads. This is easy when the heat shield is off, but impossible when on without the tape.

6. Cleaning and tips to avoid carbon lock with the suppressor

Some context – I clean my guns every time I shoot them; this is how I was indoctrinated in the service. Under no circumstances do I want to risk carbon lock with this gun. I also recognize that I am a bit neurotic about cleaning guns; I’ve been brainwashed to always take care of my “life support equipment”.

Ask 10 guys how to/how often to clean a gun and you’ll get 10 different answers. Please take this into account when reading my thoughts on cleaning/maintaining the SD.

Q1: Is it true that the SD gets super dirty?

A1: Absolutely. Dirty is an understatement. It gets filthy, even with a relatively low round count (150-200 rounds).

Q2: Is it a PITA to clean?

A2: Depends on your perspective. It’s time consuming if you want to get a thorough clean. If you hate cleaning guns, I’d say this isn’t the gun for you. For me, the gun is such a joy to shoot that the cleaning is well worth it.

Q3: Can you just do a “hasty” (field) clean, where you remove the suppressor, scrub the barrel with a barrel brush, do a quick wipe down of the bolt and keep shooting?

A3: I don’t see why not, but I’ve never done it. I’ve been told by trusted sources that it works.

Q4: What’s the highest round count you've had before doing a detailed clean?

A4: Approx 500 rounds. On average, I shoot about 200 rounds per session.

Before cleaning my SD, I watched Tuefelshund Tactical’s “H&K Armorer Tips, Tools and Procedures For Cleaning a MP5” video - Tuefelshund MP5 Cleaning Video .

James’ video is an ideal resource for cleaning an SD. He has good tips on disassembly/assembly, getting out plaque (hardened carbon), removing/disassembling the trigger pack, etc. and I still frequently refer to it.

Perhaps the best tip in the video is to clean the gun using a dry rag first to get most of the carbon off before using oils and solvents. This prevents you from making unnecessary carbon sludge, which lengthens the cleaning process.

I shot the gun yesterday in a match (approx. 200 rounds) and took some before and after photos:

Before:

After hand wiping with a dry cloth:

After using solvents, picks, brushes and rags:

Chamber before (note the plaque; it has to be scraped out with a pick):

Chamber after:

Barrel before:

Barrel after:

Tools I use:

- Paint Brush – to remove dust and loose dirt

- 3/16 flathead screwdriver – to remove the heat shield (tape is to mitigate scratching)

- HK Parts barrel brush and handle – remove carbon plaque from barrel

- 12 Gauge Bronze Brush with brass rod – to clean chamber

- HK chamber face brush and brass rod

- (2) Dental Picks – scape carbon plaque from chamber, bolt, etc

- All-purpose (AP) brush

- Dewey coated pistol rod with 9mm bronze brush and VFG pellets and VFG pellet adapter (from Brownell’s)

Solvents I use:

- Hoppes # 9

- Ballistol Spray – for stubborn carbon and plaque (I let it soak for a bit)

- Slip 2000 EWL – Lubricant after I clean (less is more)

- SPRINCO Machine Gunner’s Lube – my preferred lubricant but he’s out of stock right now

- SchleTek suppressor cleaner

- Anti Seize Lubricant – for the suppressor threads

Magnifying Glasses (Visor) –

Amazon Magnifying Glasses (Visor)

I think this jeweler's visor is indispensable. It allows me to see carbon deposits and use my picks to remove plaque without digging in to the metal.

Silicone Plugs – to seal the suppressor when using SchleTek cleaning solvent.

Amazon Silicone Cleaning Plugs

Cleaning the suppressor - I decided to try the SchleTek suppressor cleaner recommended by B&T. I had my doubts but decided to give it a go.

It is not cheap. And the shipping was half the cost of the product.

Yesterday was my first time using it. I followed the directions and filled the suppressor (about half the bottle!) and let it sit for about 45 mins. Any doubts I had were addressed when I emptied the solution and rinsed it with water (see photos):

Removing all the moisture from the suppressor wasn’t fun however, using compressed air and a hairdryer with a funnel, I think I was able to do it.

Note - I had approximately 1,500 rounds through the gun before cleaning the suppressor. I don’t plan to clean the suppressor every time I shoot the gun. It’s way too expensive. Ultimately, I will probably do it every 2,000 rounds.

Tips for avoiding carbon lock:

As I already discussed, I spoke with Derek from the HK Shooting Team before the conversion and he gave me some advice to avoid carbon lock. I have implemented his techniques and so far, carbon lock hasn’t been an issue.

1. Use anti-seize on the suppressor threads

2. “Break” the suppressor from the threads when the gun cools down a bit. No need to remove the suppressor entirely, just break it loose and then tighten it right back down. In a match, I do this after I shoot each stage (between 25-40 rounds). If on the range or at the ranch, I do it after I get done shooting and the suppressor cools down a bit (could be up to 200 rounds).

Note: I neglected to do this in yesterday’s match, and by the time I got home, taking the suppressor off required some effort. It came off the threads easily, but it took some slight tugging to clear the barrel. Now that I’ve cleaned the carbon off the barrel, it comes off/goes on without effort.

3. At a minimum, take off the suppressor and use a barrel brush to remove the plaque from the barrel every time you get done shooting.

7. Measurements (length extended & folded)

Took some photos of various measurements to assist those in selecting storage solutions/case options. All measurements are approximate.

Note: I am not a professional photographer. Couldn't get the angle right on some photos and it created an optical illusion where it looks like the measuring tape isn't lined up. Where applicable, I added some zoomed in photos to show that the tape was lined up correctly.

a. Overall length - approx 32"

b. Overall length folded - approx 22.5"

c. Height with optic and 30 rd mag - approx 12"

d. Height with Optic to bottom of pistol grip - approx 10.5"

Note: 15 rd mag is much shorter than pistol grip.

e. Height from rear sight drum to bottom of 30rd mag - approx 10.5"

f. Height of rear sight drum to bottom of pistol grip - approx 9"

8. Different Stocks and Lengths

1. HK A2 - Recently purchased an A2 stock for the SD from Blue Ridge Supplies Blue Ridge Supplies A2 Stock To be honest, I only bought it for aesthetics however, after getting the stock I was very pleased with how solid it was.

Build Quality/Ergonomics: Simple design but both are excellent. Only issue, the drop causes me to be a little more head down when I shoot (relative to the A3F) but is similar to the B&T UMP folder.

Length of Pull is a little shorter than the B&T UMP folder.

Neither LOP nor drop had negative effects on my shooting.

Recently competed with it and did pretty well. Hard to catch guys shooting JP5s with 2.5lb single stage triggers, compensated 16" barrels and AR controls, but I'm nipping at their heels!

OAL with A2 stock is approximately 31"

2. HK A3F (3 Position) - purchased from Arms Unlimited Arms Unlimited A3F Stock I LOVE this stock. Was reluctant to purchase because of:
a. Potential for cheek weld on forks
b. Cost

Luckily I have a good buddy who sent me his stock so I could try it out. Always nice to "try before you buy" especially with such an expensive purchase. My buddy raved out how solid and well built the A3F was and he was right.

a. Cheek weld on forks - No issue. The extra plastic on the A3F ensures I get a solid cheek weld and keeps me from resting my cheek on the forks. Because the stock is more in line with the receiver I'm able to shoot more head up and take advantage of my optic riser.

Build quality - Superb, as improbable as it sounds, this stock is just as solid as the fixed stock. Absolutely no wobble/flex. Very solid mount to the gun and the forks are extremely sturdy.

Weight - It is noticeably heavier than the B&T and A2 stocks however, I think it rebalances the gun and makes it less "nose heavy".

Length of Pull - slightly shorter than the B&T UMP folder and about .75" longer than the A2.

I've only put a few rounds through the gun with the A3F but expect it to be my new "go-to" stock.

b. Cost - IMO well worth it. Great ergonomics, extremely sturdy, well built and deploys very quickly. If you're considering one, buy with confidence.