[dudeguybroman]

Hello everyone,

I just recently purchased an HK SP5K-PDW and I'm interested in making it a SBR. I've read through a couple of different threads on 922r compliance but I'm still a bit confused. I'm very new to HKs and the accompanying terminology so I'm looking for any and all help. I'd like to keep the internals and more complex parts stock if possible. The list below is my current list of proposed parts:

• Receiver
• Barrel
• Trunion
• Bolt
• Bolt Carrier
• Cocking Handle - HKParts Cocking Handle (USA) [link]
• Trigger Housing
• Trigger - HKParts Flat Trigger (USA) [link]
• Hammer - HKParts 90 Series Hammer (USA) [link]
• Sear
• Buttstock - Safety Harbor KES Telescoping Stock (USA) [link]
• Pistol Grip
• Forearm / Handguard - B&T Picatinny Guard (Swiss) [link]
• Magazine Housing
• Magazine Follower
• Magazine Floorplate - HKParts Magazine Floorplate (USA) [link]

I have a couple of questions regarding my list above and some general questions:

• What would be the simplest and best 6th part to replace (a link to the part would be greatly appreciated) other than the handguard?
• Are the trigger and hammer that I've linked compatible with the stock trigger pack and does anyone have any experience with or thoughts on the flat trigger?
• I've seen threads regarding people remarking their SP5K as MP5K, is this done just for aesthetics and collecting or is there another reason to do this?
• Where would be the best place to engrave the firearm after SBRing it? I saw someone suggest engraving it in the side channels where telescoping stocks collapse into, is this legal and a good idea? I ask because my proposed telescoping stock would cover it when collapsed (currently have the brace).

Any other advice or general recommendations would be greatly appreciated. Thank you all for your time!

 

[cactacular]

Engraving in channel where stock rides is what most will recommend. That's where I did mine. Looks good and very discreet.

 

[esh21167]

I'd consider the trigger housing and sear options for a US parts.

The US stock is ridiculously priced. I think the POF's were like $50, though I don't know their current availability.

Personally, I don't like the magazine part option. Every time you buy more mags, you 'have to' buy more mag parts.

BuildMP5VerifyCompliance < Gunwiki < TWiki

gunwiki.net

 

[Scott_157]

Before you go screwing that gun up with stupid US made parts, ask yourself something; have you ever been questioned about your parts count on anything or ever hear of anyone going to jail for JUST a 922r violation

 

[dwillHK]

I went US made charging knob, handguard, and Heckfire trigger pack (4 parts) on my SP5s, so I could use factory stocks and mags without modification.

 

[hawkin]

Before you go screwing that gun up with stupid US made parts, ask yourself something; have you ever been questioned about your parts count on anything or ever hear of anyone going to jail for JUST a 922r violation

This guy speaks the truth..

From what I’ve seen. I think engraving in front of the mag well or in the channel are a wash. I’d go either route.

 

[OCRifleman]

Why do you need to engrave an SBR? Last year I got the tax stamp to update my SP5K.

 

[dwillHK]

Why do you need to engrave an SBR? Last year I got the tax stamp to update my SP5K.

Because it’s required by the regulation. You have to engrave the name of the “maker” of the SBR, which is you (or your trust).

27 CFR § 479.102 - How must firearms be identified?

www.law.cornell.edu

(iv) In the case of a domestically made firearm, the city and State (or recognized abbreviation thereof) where you as the manufacturer maintain your place of business, or where you, as the maker, made the firearm;

You can’t just use HK that’s already engraved on the gun. They manufactured it as an existing gun, but you are the one making it into a SBR, which is technically a different gun.

 

[OCRifleman]

Ok, I just replaced barrel and added parts. I had asked ATF and was told it was not necessary. Interesting!

 

[OCRifleman]

I am now in search of an engraver

 

[JJS1313]

Does anybody know what rearmost point to measure from for OAL when using the SP5K folding stock? Link below for reference

SP5K Folding Stock | Handgun Accessories | Handgun Parts | Heckler & Koch

us.hkwebshop.com

 

[dwillHK]

Does anybody know what rearmost point to measure from for OAL when using the SP5K folding stock? Link below for reference

SP5K Folding Stock | Handgun Accessories | Handgun Parts | Heckler & Koch

us.hkwebshop.com

OAL is measured with the stock fully extended, so it would be the end of the buttpad.

 

[JJS1313]

OAL is measured with the stock fully extended, so it would be the end of the buttpad.

Got it, thank you! I’ve been told from the muzzle to the top-most part of the buttpad and from the muzzle to the bottom-most part of the buttpad but I suppose that wouldn’t be a huge difference

 

[dudeguybroman]

Before you go screwing that gun up with stupid US made parts, ask yourself something; have you ever been questioned about your parts count on anything or ever hear of anyone going to jail for JUST a 922r violation

I'm pretty new to NFA stuff in general so I don't really know if it's common or not. I'm guessing it isn't from your comment. My only concern is the chance that it may become more common with the current administration, especially if Chipman becomes the head of the AFT. I totally get what you're saying though, the idea of messing with perfection pains me.

 

[dudeguybroman]

I went US made charging knob, handguard, and Heckfire trigger pack (4 parts) on my SP5s, so I could use factory stocks and mags without modification.

How do you like the Heckfire trigger pack?

 

[dwillHK]

How do you like the Heckfire trigger pack?

It’s definitely an improvement over the stock trigger pack as far as being a good trigger goes.

 

[Uncle Billy]

I believe that the large majority of guys who SBR their pistols into rifle don't really bother to do the engraving.....you just don't hear from them because it'll just cause a s&it storms of post against them about how they're "breaking the law", "they're wrong" etc.....

now, when the ATF hires about 250 million ATF agent that their only job is to check SBRs engravings on every single range in the country, then that's when I would start to worry about if my SBR is engraved

 

[eodinert]

Everyone I know engraves their SBR info.

 

[straightgrain]

This horse is well beaten.