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Posted: 10/30/2004 8:25:56 PM EST
[Last Edit: 10/30/2004 8:50:26 PM EST by SO-COM]
I was wondering if anyone out there could help me out with a few quick measurements. Let me first say what my problem is, maybe you can help there too. I have a PLO underfolder kit (russian marked) and when I assembeled it on an OOW reciever, the dust cover is too short. SoI thought etheir the reciever was left long, or this dust cover was ground short toaccomidate its original rifle. Etheir way, it doesnt engage with the tang on the front sight block. My reciever is exactly 10 & 1/4" long, and my dust cover is 9 & 5/16" (fixed) (from the bottom rear edge, to the top front edge that engages the front sight block).

Any ideas are welcome, this is my first build so I'm pretty sure I screwed this up somewhere for this to happen.
Link Posted: 10/30/2004 8:33:17 PM EST
Looks like the receiver on my Romy SAR-1 measures 10¼". But try as I may I can't seem to get more than 9 3/8" out of my top cover. And it's a perfect fit on my gun.
Link Posted: 10/30/2004 8:49:28 PM EST
[Last Edit: 10/30/2004 9:44:29 PM EST by SO-COM]
I mismeasured my cover in the first post, it is 9 & 5/16th's which would make up that 1/16" that I'm missing to catch the tang.
Link Posted: 10/30/2004 11:11:26 PM EST
That was one of the problems with OOW receivers, they need to be trimed down. My cover sits about half way engaged in the front trunnion but has never came off during firing. One thing I did to help it fit better was bend out the rear of the cover where it engages the rear trunnion, this pushed the cover forward giving me a bit more engagement up front.
Link Posted: 10/31/2004 1:27:39 AM EST
Did you have to notch the sides of it (relief cuts) to bend it out?
Link Posted: 10/31/2004 4:02:33 AM EST
Yup, your receiver is too long. If your dust cover does not fit, it is likely that your bolt carrier will also come off the rails in its rear most travel. In all actuality, you will need to unscrew or unrivet your rear trunion and move it forward. If this is the case, you more likely than not have to screw the trunion back down as your holes in the receiver will be too large for rivets. It is a common mistake. Ask me how I know.
Link Posted: 10/31/2004 4:44:20 AM EST
If your cover dosen't engage at all I don't think bending it will help. Hoploholic does bring up a very important point about the carrier becoming disengaged from the rails, I didn't think about that at first. You definately do not want to be taking the chance wearing your bolt carrier on your forehead!

Sounds like you may have to dissassemble the rear trunnion, weld up the holes, then position the rear trunnion in the receiver using the top cover to get the correct position.
Link Posted: 10/31/2004 5:14:28 AM EST
I have the same problem! All holes drilled and threaded and then I find a .080 gap between the rear of the dust cover and the trunion stop. Is this enough to worry about? Was thinking of sliding rear trunion forward and re-drilling with 1/4" bit to make up some of the difference. Also my cover does not want to come down over the rear of the receiver. Shoud I bend it out a little or file some relief on the receiver itself?hinking.gif
Link Posted: 10/31/2004 5:34:45 AM EST
[Last Edit: 10/31/2004 5:38:20 AM EST by Hoploholic]
Personally I say fix the real problem...that being that your trunion is placed to far to the rear. Your face is a horrible thing to waste.

I worked through all these problems myself. I placed my trunion too far to the rear so I formed 2 tits on the back of my dust cover and was happier than a pig in shit. The cover stayed put. I started racking some action proving rounds through and yanking the charging handle pretty good and my carrier rolled right off the back of my rails. It was then that I knew the depth of my folly. I bet there are tons of others who have done this. The OOW receiver do not come with instructions warning the initiate builder of the out of spec aspects of their product. It is a good enough product if you are forwarned of the pitfalls.
Link Posted: 10/31/2004 10:34:41 AM EST

Originally Posted By smokinyoda:
Also my cover does not want to come down over the rear of the receiver. Shoud I bend it out a little or file some relief on the receiver itself?




I had the same problem too. I bent out the sides of my cover and now it fits nice n' snug.
Link Posted: 10/31/2004 11:23:00 AM EST

Originally Posted By Hoploholic:
Yup, your receiver is too long. If your dust cover does not fit, it is likely that your bolt carrier will also come off the rails in its rear most travel. In all actuality, you will need to unscrew or unrivet your rear trunion and move it forward. If this is the case, you more likely than not have to screw the trunion back down as your holes in the receiver will be too large for rivets. It is a common mistake. Ask me how I know.



Well, I just tested it by using some small bolts (errector set ) to hold the trunnions in place. It did pop off at the end of its travel. There is around 1-2mm of extra space at the end of the rails more, then is needed for the carrier to come out for breakdown. Sounds like I have a combination here, the OOW is left long (why?) and my dust cover is a 16th of an inch shorter then the other posted measurement. Etheir way, a 1/16" can be made up on a new reciever, and that looks like what I'm going to do. Damn shame I'm going to chaulk a 100$ reciever upto learning.
Link Posted: 10/31/2004 12:06:17 PM EST
Why does OOW build a receiver that is too long?
Link Posted: 10/31/2004 12:17:56 PM EST
Link Posted: 10/31/2004 12:27:59 PM EST
Yeah, there are DEFINITELY some fitting issues with OOW receivers. I think I hit every possible one of them when I worked with one.

Although, throwing away a $100 receiver to me is unacceptable. And I can't weld up the holes, so I am left with the thought of somehow putting a metal shim (and I know this isn't the right term, but follow my drift) into that rear trunnion slot so there isn't so much play, and the dust cover is forced forward.

My gap is large enough for a small hex wrench to lay across the slot, and fill up the void. I was considering cutting one down to size, and welding it either into that slot, or somehow 'fattening up' the back of the dust cover that goes in that slot.

Since I only have a plumber's torch, that's the kind of weld i'd have to make. HMMMMM.



I'm still having trigger / disconnector problems with my build, so I am almost to the point of chucking the entire thing into a lake to resolve the issue.

Link Posted: 10/31/2004 12:47:16 PM EST
The blanks that I use come about a foot long. I trim both ends. Thats why you should measure everything from the front trunnion. Rear trunnion placement should be measured with the dust cover. Then the rear of the receiver can be trimmed to length.
Link Posted: 10/31/2004 1:14:41 PM EST

Originally Posted By gunny54:
The blanks that I use come about a foot long. I trim both ends. Thats why you should measure everything from the front trunnion. Rear trunnion placement should be measured with the dust cover. Then the rear of the receiver can be trimmed to length.



I took this for granted, and did it the other way around since the rear trunnion on the underfolder was harder, and I wanted to do it first.
Link Posted: 10/31/2004 1:17:26 PM EST
[Last Edit: 10/31/2004 1:17:55 PM EST by coffeeman]

Originally Posted By gunny54:
The blanks that I use come about a foot long. I trim both ends. Thats why you should measure everything from the front trunnion. Rear trunnion placement should be measured with the dust cover. Then the rear of the receiver can be trimmed to length.



Yeah exactly. OOW receivers are "too long" for a reason. Ever tried to lengthen a piece of sheet metal? You should consider yourself lucky that you only need to trim the back. I've heard of people having to do both.

Donno what others are talking about with the safety hole being in the wrong place though. The only adjustment I have to make on my OOW receiver is to trim a bit off the rear. Since this is a pistol build I don't even really "have" to do that.

To those who's dust covers are not fitting down over the sides of the receiver, it is more than likely that your rear trunion needs to be narrowed a bit. I had to do that to mine as it was pushing the sides out just a hair.

Link Posted: 10/31/2004 1:22:13 PM EST
Did you mock your rifle up before you started drilling holes? My OOW 5.45 receiver is slightly longer and by trimming approx. 1/16" from the front everything lines up and fits nicely.
Link Posted: 10/31/2004 2:09:03 PM EST
From what I gather, this is the order of operations when building a receiver.

1. Rivet mag catch/trigger guard
2. Use a magazine to test-fit the front trunion location. Once you have a good setup, drill and rivet/screw.
3. Once the front trunion in place, use your dust cover to align the rear trunion.
4. See what's left on the front and/or rear of the OOW receiver, then trim it.

Personally, I like this option much better. I was so bummed with the pre-drilled holes of the Vulcan/Tapco flats that I gave up on them. I'd fit the mag catch in the holes, then test a mag to fit, and the front tunion holes were off! Sucks...I'd rather trim/drill to fit.

take care,
Tec

Link Posted: 11/1/2004 8:00:23 AM EST
u can just try a diff cover i checked and none of my guns have same length they are all slightly diff
with the amd being the longest (wasnt expecting that ) its 3/16 longer then my rpk cover go figure
Link Posted: 11/1/2004 2:10:14 PM EST
[Last Edit: 11/1/2004 2:12:09 PM EST by SO-COM]

Originally Posted By Tec_Nine:
From what I gather, this is the order of operations when building a receiver.

1. Rivet mag catch/trigger guard
2. Use a magazine to test-fit the front trunion location. Once you have a good setup, drill and rivet/screw.
3. Once the front trunion in place, use your dust cover to align the rear trunion.
4. See what's left on the front and/or rear of the OOW receiver, then trim it.

Personally, I like this option much better. I was so bummed with the pre-drilled holes of the Vulcan/Tapco flats that I gave up on them. I'd fit the mag catch in the holes, then test a mag to fit, and the front tunion holes were off! Sucks...I'd rather trim/drill to fit.

take care,
Tec




I plan on doing a 74 kit after this, and I plan on doing it that way next time. My order was more like:
1) trigger gaurd (didnt rivet just used small bolts while mocking)
2) Inserted trunnion all the way, then inserted a magazine and let it slide back to give the mag a decently tight fit). Didn't drill of rivet
3) Mock up the rear, forgot to check dust cover length at this point. Assumed reciever was "spec"
4) Drilled rear, bolted it in place (temporary), function checked under folder. Everything good here.
5) Drilled front, and bolted it in place (temp).
6) Dropped bolt carrier assy and recoil spring in. Tried to install dust cover over the top. No go.

Awfully stupid of me to go the long route, and the way I did it. >.< Lesson learned. I will have a knowledgable person look it over before I scrap.
Link Posted: 11/1/2004 4:12:27 PM EST
dont scrap just adjust so its where it needs to b and weld it into place (give yourself a milled look)
not my first choice but actually works well
id trust a good welded gun befor i trusted 1 of those bolt together jobbies
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