BRN-180 upper + SCR lower no go without modification

[RooftopKorean]

I got received my BRN-180 upper in the mail today. I was so excited to get this on my SCR so I could use a different style stock not being bound by the Remington style recoil system.

It seems as if part of the trigger system in the Fightlite SCR gets in the way of the bottom of the upper receiver (where my fingers are pointing).



The other problem is the protruding edge of the butt cap for the upper. The fitment issue is kind of like the AR-10 and DPMS-308 compatibility issues.



I fear that without some serious modding it definitely will not work.

I'd need to grind that edge off the butt cap, cut into the underside of the upper receiver to fit the SCR trigger group and who knows what other issues ill run into after. For all I know I may end up with trigger issues.

Any suggestions?

 

[garyv350]

Get the correct lower. Build it like it's meant to be.

 

[RooftopKorean]

Get the correct lower. Build it like it's meant to be.

Yup because that's a solution that will get me locked up toot sweet in NYC.

 

[dsdmmat]

Return it and get the right upper?

 

[RooftopKorean]

Return it and get the right upper?

I have an upper for it. The purpose of the BRN-180 was so I wasn't bound to the Remington recoil system that the Fightlite SCR utilizes since it uses an recoil buffer and guide rod / springs. That in turn would allow me to use a wider assortment of stocks rather than being limited to sporter or monte carlo styles.

 

[garyv350]

Did you say you needed a NYC legal option? Like @dsdmmat said. Buy a featureless upper instead of butchering that one.

 

[RooftopKorean]

Did you say you needed a NYC legal option? Like @dsdmmat said. Buy a featureless upper instead of butchering that one.

Good God, obviously you missed the point. But what else to expect from a person to responds to a thread with "Build it like its meant to be".

Not everyone lives upstate, some of the people on this board live downstate unfortunately.

 

[dsdmmat]

Good God, obviously you missed the point. But what else to expect from a person to responds to a thread with "Build it like its meant to be".

Not everyone lives upstate, some of the people on this board live downstate unfortunately.

and With that you are on your own, good luck.

 

[Jsmegs77]

I think I'd take it to a decent gunsmith or machinist. I was planning on doing this exact thing, BRN-180 upper to SCR lower. If there's enough meat to clearance for the trigger, I would move forward with it.

 

[RooftopKorean]

I'm already working on it. I'm grinding down a section on the underside of the upper to clear the trigger group. I've made some good progress so far.

I have to file down and shape the rear takedown pin notch to clear the backside of the trigger itself so it doesn't interfere with the operation of it.

I'll have to clean it up the divot in the upper once I have access to my friends drill press.

 

[Jsmegs77]

Please post pictures, if you can snap some. Loved what you did with the MAS, looking forward to seeing this.

 

[meketrefe]

you will be better with a contained para-ordenance upper if you can find one still in stock or preowned.

 

[Robin]

I'm already working on it. I'm grinding down a section on the underside of the upper to clear the trigger group. I've made some good progress so far.

I have to file down and shape the rear takedown pin notch to clear the backside of the trigger itself so it doesn't interfere with the operation of it.

I'll have to clean it up the divot in the upper once I have access to my friends drill press.

Sounds like you ade the commitment! Let us know how it works out.
Robin

 

[SuffolkArms]

It's been done before and posted by a Reddit user in this thread here. You may want to get in touch with them and see if they have more information on the machining required. Unfortunately they were not very descriptive in the comments, but it proves that it is possible.

 

[Jsmegs77]

That reddit one looks really nice. Reposting for the benefit of those who don't want to visit reddit. Really love the straight wristed stock.

 

[RooftopKorean]

I did got access to a drill press so I was able to clean up the work I did with my dremel yesterday.



I took roughly 3mm off the bottom of the takedown pin bracket and 2mm off each side since it seemed to be pressing on the trigger when the receivers were together.



I also went in 2mm in depth in that box to give clearance for the SCR trigger group.

Then I cut away 2mm on each side of the channel to make clearance for the SCR hammer.

I'm sure it would have come out much cleaner had I not done the preliminary work with a dremel.

Best thing is that it works on my friends AR lower no problems. It was well worth the hour drive into Long Island to use his drill press.

Now i just have to blue all the bare aluminum.

 

[Jsmegs77]

So it'll fit up to the SCR and also AR? Win win!

 

[technicalgadget]

 

[RooftopKorean]

It's been done before and posted by a Reddit user in this thread here. You may want to get in touch with them and see if they have more information on the machining required. Unfortunately they were not very descriptive in the comments, but it proves that it is possible.

I saw that but I don't know why he/she opted for the BRN because a Remington 1100 stock works with the SCRs recoil system. So it's not like they needed the BRN for its guide rod/spring system

When I first got my SCR I used a Remington 1100 competition stock for mine; before Boyd's started making their selection. It only required very little modification to work.

 

[GUNSICK]

Wow, is all that I can say.

 

[RooftopKorean]

Finished! Came out nice

 

[SuffolkArms]

Finished! Came out nice

View attachment 76455

Your build looks awesome. Props to you for going the extra mile and getting it done. How was removing the "buffer-tube-in-a-stock" assembly and adding the stock? Any special adapters or anything?

 

[RooftopKorean]

Your build looks awesome. Props to you for going the extra mile and getting it done. How was removing the "buffer-tube-in-a-stock" assembly and adding the stock? Any special adapters or anything?

Thanks. Im sure some troll will knock it because I modded my BRN upper.

Anyway...

Removing the factory stock / recoil spring and rod is easy. Found a guy who makes a Magpul SGA 870 stock adapter for the SCR.

Its basically a small piece of rod stock of the same diameter as the tube which houses the factory recoil rod/spring. It is threaded to the same pitch as the SCR lower "buffer tube" screw hole and its drilled/threaded in the middle to accommodate the SGA screw.



After you get this piece or fab it yourself, you just have to assemble which is easy-peasy.

Only terrible thing about the BRN-180 is the side chargers goose neck shape interferes with scope screws so i had to pop mine out and flip them to the other side. You can also use a cantilever; it's a minor inconvenience.

Edit: It definitely lost weight not using the factory stock and recoil system. I hope that other downstaters here can benefit to this build so they too can have ideas toward building something they like and is functional.

 

[Marine Cpl]

Good work. I’m glad you made it work despite the unhelpful comments you’ve received here.

 

[RooftopKorean]

Accessories mounted

 

[RooftopKorean]

Now i have to get a fake flash hider in the same style and have it pinned on. The pinning and welding I cannot do unfortunately, my welding beads are heinous.

 

[Robin]

Very nice set up RTK!!!! I wish I had known about this configuration before my last foray. My wife has defunded me.
Robin

 

[Marine Cpl]

Very nice set up RTK!!!! I wish I had known about this configuration before my last foray. My wife has defunded me.
Robin

Yeah. Seems very functional without looking stupid like many featureless AR’s here with the goofy stock, or ridiculous spur grips with that extension on the trigger guard . As a matter of fact, it actually looks quite modern and cool while still retaining 100 percent functionality. Something like this if sold in free states will still be desirable. Especially in long range calibers like Grendel or Valkyrie.

 

[RooftopKorean]

Yeah. Seems very functional without looking stupid like many featureless AR’s here with the goofy stock, or ridiculous spur grips with that extension on the trigger guard . As a matter of fact, it actually looks quite modern and cool while still retaining 100 percent functionality. Something like this if sold in free states will still be desirable. Especially in long range calibers like Grendel or Valkyrie.

Its funny that you say that. I was sitting here at work wishing it wasn't virtually impossible to get an FFL license in NYC. I'd open a shop and sell these for prisoners of anti-2A states such as NY, NJ and CA.

 

[dsdmmat]

I have an upper for it. The purpose of the BRN-180 was so I wasn't bound to the Remington recoil system that the Fightlite SCR utilizes since it uses an recoil buffer and guide rod / springs. That in turn would allow me to use a wider assortment of stocks rather than being limited to sporter or monte carlo styles.

that makes sense. At first it seemed like you just bought the wrong upper and were trying to modify it instead of sending it back to get the correct one.

I have ended up with a wrong part or two along the way. I end up building another gun instead of returning them.

nice work on your build.