BRP receiver

sscav · Post by **sscav** » Tue Dec 27, 2005 1:45 am

Well folks, Christmas arrived and I was finally able to open the box with the BRP receiver that my girlfriend gave me. It was killing me waiting but well worth it. This thing is almost ready to start building on. The barrel door was already attached (with a very small "an" stamped on the underside), as was the rear sight base and rear gripstick mount with tripod stud. Also installed was the trunion. Now, somewhere in the back of my mind, I recall hearing that BRP put on "dummy" trunions, but this one has serial numbered pieces, and AR in script stamped into the top. My sources say AR was Mauser Werke, Borsigwalde. I can't see BRP using original parts as "dummies", and they are closed this week so no info there.
The ejection port needs to be milled, and the plate that they weld into the rail holes needs to come out. Any ideas on how to do this without messing up the holes?
Also, the ratchet plate is attached already.

The gripstick slot is cut, but it seems to be cut for the original FA trigger group and from what I can see, there's no stud to block a FA bolt. I guess I really need to call BRP next week and find out if they need to be installed or is this receiver good to go as is.

I'm still trying to make heads or tails out of that picture posting sticky. If I can get it squared away, I'll post some pics.
She also got me one of BRP's recoil springs to go with this receiver and it's less than half as long as the one in my IO kit. Do you guys use the original spring cut down or am I OK with BRP's spring?

Sorry about the legnth and all the questions. ( I still have a ton more to ask!) This is all new to me.

Thanks,
Brian

Hoover 1 · Post by **Hoover 1** » Tue Dec 27, 2005 7:25 am

Congradulations!

Sounds like a really nice set up.

How was the barrel door attached to the receiver? Pop rivets or solid rivets?

Thanks,

Hoover

Post by **TOM R** » Tue Dec 27, 2005 8:16 am

sscav · Post by **sscav** » Tue Dec 27, 2005 8:21 am

The barrel door was attached with solid rivets with a small dimple top and bottom of each one.

Tom R, pics will be up as soon as I can figure out how to do it. Computers are not my friend, what can I say!

Karbinator · Post by **Karbinator** » Tue Dec 27, 2005 8:56 am

ss

Yes, the spring is cut down to make up for the bolt extension length, so you're good.
You have to try hard on the pics.... We want to see this thing.
Hey, do you know what the final total was she paid for it? Is this the $ 2k one?

Karb

Post by **villafuego** » Tue Dec 27, 2005 9:44 am

Here are some pics of the BRP "Dummy" that I bought myself for christmas........Total with Black oxide finish was 1063.00.............

Solid barrel door rivets

Solid trunion rivet.....it appears that the "guiding rails" (if that is the proper term) have been milled partially away to make it a "dummy" trunion. Is not welded to receiver......

Haven't installed the buffer catch/spring, or front sight (missing the plunger that holds the sight in position) yet........

Is this the same as you got Brian?????
The charging handle and buffer assy. were a little snug, but a little polishing took care of that. I am MOST pleased with it!!!!!!

Post by **88comm** » Tue Dec 27, 2005 7:14 pm

Suggestion for drilling out the welds that hold the blocking plate that is in the receiver.

For another application I purchased a "Ball end mill" that was the exact diameter of the finished hole that I wanted. Trying to center punch and then drill the weld wasn't working. The drill walked all over the place. I put the end mill in the drill press, located and clamped the work and slowly fed the mill cutter into the work. It worked perfectly. The mills are designed to take some side thrust, and it just ate the metal until it went straight through. For economy, I got what are called "double end mills" having a cutter on both ends. You also want mills that are "center cutting." I have also tried center drills, but I think the end mill worked even better.

Post by **88comm** » Tue Dec 27, 2005 7:26 pm

Another thought - If you want/need a flat surface after you have removed the weld from the blocking plate, something along the lines of a standard 3/8" end mill in the drill press will take off the rest of the weld that is in the pocket for the rivet. With a light touch, you can do an outstanding job. Actually I do what is called "pecking" its an up and down motion with the drill press, taking a little metal each time. It keeps the drill bit or mill cool, makes small chips and allows you to see what you are doing.

sscav · Post by **sscav** » Tue Dec 27, 2005 11:55 pm

Well, I've been able to take a few minuites to check out the BRP trunion and bump it against the one on the receiver. One of the roller guide ear's was milled/ ground off on the "U" shaped part of the trunion. Too bad they just dont leave it alone, unless it's one that's out of tolerance.

88comm, I don't have access to a machine shop or the tools to do the job the way you suggest, unless it could be done using a drill press. I am going to ask Brian at BRP Monday if it would be possible to exchange the receiver I have to one that never had the plate welded in. When this one was purchased, I did mention that I was going to build up a firing weapon, so maybe that's a possiblity.

Does anyone know where I could buy/ trade for a German top cover? The one in the IO kit is in excellent condition, but it has the Yugo crest on it. Just personal preference for the German one.

And lastly, tomorrow (hopefully) my girlfriend is going to set it up so I can post pics om this thread. Keep your fingers crossed.

Post by **TOM R** » Wed Dec 28, 2005 9:20 am

call dan @ angloa armory there is a link to him on the bottom of the main index page, he has the best prices on parts I think

Post by **LtShaffer** » Tue Jan 03, 2006 12:46 pm

Congrats on the Xmas present! Any luck on getting some pics to upload? I am very interested in buying one myself. Could you email me some pics if you can't get them to upload? Thanks.

big steve · Post by **big steve** » Tue Jan 03, 2006 7:17 pm

Congrats! How much does one of those set a guy back?

sscav · Post by **sscav** » Wed Jan 04, 2006 1:19 am

Big Steve, This receiver goes for $1050 dollars. The girlfriend must really, really like me.

An update, I center drilled the welds on the blocking plate and used a wooden hammer handle to knock it out. I'm thinking that I might have been able to knock it out with just the hammer handle and a good whack. I then used my dremel tool and a fiber cut off wheel to grind the welds flat. I went slow and it came out nice.

Next step was to cut off the rivet on the trunion to remove it from the receiver. BRP uses a dummy trunion and it must be replaced. I'm going to use a bolt to attach the one from my IO kit to make life easier should I need to replace it.

Using my receiver section with ejection port from the IO kit, I was able to transfer the measurements of the ejection port to the BRP receiver and used my drill press and dremel tool to cut it out. It's been cut on the small side by a few thousands so I can tweek it to work properly.

Right now I'm working on assembling the front sight and flash hider retainer on the receiver. There has to be an easy way to do this. After 1.5 hours, I still have nothing assembled. Am I just missing an easy way or is the assembly installation really difficult?

I called BRP to see if it would be possible to get a receiver without the blocking plate because I thought it was going to be hard getting that thing out, and Brian told me that all receivers must go out with it, otherwise it is considered an FFL item. Like I said, if you get one try to pop it out with a piece of wood and a good mallet before drilling anything out.

Still working on pics,
Brian

Post by **KATZBALGER** » Sat Jan 07, 2006 11:52 am

Very interesting...
I too noticed that the spot "welds" were not all that penetrating, although I wouldn't have ever thought you'd be able to knock it out with a hammer!
The second BRP example I saw had this thick block (they originally were much thinner), but was installed further back into the reciever as not to interfere with the camming piece. Although what this did, was in fact, prevent the install of the stock with the buffer attached.

One thing of interest to me would be your opinion of the weld under your "trunion".

I've seen a couple of different methods used to attach the front and rear receiver halves together. I think Brian stopped welding the camming pieces to the recievers early on (after bad reviews, no doubt) and started to rely on joining the two using welds on the receiver halves alone.
How would you rate the joining of your two?

I've heard a couple of stories (search the forum) about the reciever breaking in two. I also recall someone posting about a BRP that bent so bad, the shooter was unable to align his sights!
I believe in that case, the gun just stopped working, but I would personnally want to find out the hard way.

It all revolves around the fact the Brian (who is honestly a great guy) first advertised these things as being "made like the originals", but infact, they were welded up from several newly formed pieces.
I personnally, was upset to find that they were not one piece stampings, but considering the price and the fact that no one else was making them, I really couldn't complain.

Post by **KATZBALGER** » Sat Jan 07, 2006 12:24 pm

One more thing I forgot to mention.

Before you continue on you way (possibly to jail), please keep in mind that you may be getting yourself into trouble here.
It sounds as if your now in possesion of a receiver that will accept full auto parts.

Unless your properly licensed... my advise to you would be to now take the steps to ensure that the reciever can NOT accept the original bolt and trigger pack.

Just my .021 cents.
You never know who's watching.

PS. the front sight assembly is just a pain in the ass.
Try flipping the gun upside down on a table.
Having several different types of clamps helps alot here.
Use safety glasses please!

Man, I Do sound like a nervous nanny!

Post by **TOM R** » Sat Jan 07, 2006 12:27 pm

FRONT SITE, INSTALL BARREL THEN STICK A SCREWDRIVER IN FROM THE SITE TO HOLD THA BASE UP still a bitch but a little easier

Post by **xanadu_trader** » Sat Jan 07, 2006 4:26 pm

KATZBALGER,

I used a slave pin when installing my front sight assembly (one pin holding it in on each side). This held the sight in place when I pushed the main pin through.

Cliff T

Karbinator · Post by **Karbinator** » Sat Jan 07, 2006 10:27 pm

I thought the brp dummy/80% recvr is one solid stamp!?!
Is it not? Were you implying that these are two hlves brought together
at the trunion section?

Post by **KATZBALGER** » Sat Jan 07, 2006 11:09 pm

Every BRP receiver I've seen has been made up of THREE pieces!
The front half is actually two sections... top and bottom, laser welded together. (Nicely, I may add).
These two are then joined to the rear half UNDER the camming piece (what your calling the "trunnion").
BRP didn't actually do the stampings. Brian sub-contracted that to a firm in Chicago, I believe.
I think it was then Brian's employee who was tasked with assembling them into "guns".
The early examples had the camming pieces welded to both halves (I assume to help the marriage), but after learning that there was the need to make adjustments and or replacements to this part, I believe Mr. Polling stopped this practice. ( I could be wrong.)

I've also been told that the camming piece must have some degree of "freedom".
I'm not a big subscriber to that theory, since every "trunnion" I've seen has been well secured in place, but the individual who told me this KNOWS what he is talking about. He could be considered THE authority when it comes to the 42.
FWIW (clue).

The originals were truely sheet metal werking at it's finest. All one flat.

Post by **salt6** » Sat Jan 07, 2006 11:36 pm

Actually four the rear is two pieces.