View Full Version : Head spaceing a new DCI receiver

Dunk RD
February 24, 2009, 00:14
I just started building a new DCI receiver. timed the receiver and then started to head space. started off in the middle of my pins and went down from there to the smallest pin I have of 251. still not even close to closeing. I will end up in the 40's some where. Has anyone else found these receivers to head space this small.
Dunk RD

Also has anyone noticed the type of ejector block in these receivers

February 24, 2009, 12:14
Mine headspaced (two finger push) at .262 plus .001 for setback, .263 final.

February 24, 2009, 22:27
New from the last batch or the recent batch. I did three from the last batch that were from .258 to .262 all with Imbel bolts and bolt carriers. LS hole was .001 too large though. I could push a standard LS in and out with my fingers. Be sure and check that.

I also had a problem with the top of the bolt hitting the inside of the receiver which didn't allow it lock up with any LS until I used a Dremel to remove some material from the receiver. The bolt would not tilt down into lockup. It took me a long time to figure out what was going on!

Dunk RD
February 24, 2009, 23:30
cook Recent batch
Yep, same problem here. What was happening is the bolt wasn't going into battery. when I ended up with a 217 head space I knew the problem was some where else. Took the bolt out of the carrier and saw that it wasn't touching the go gage. if I lifted the rear of the bolt it would go into battery but then wouldn't go down on the rails. spent about two hours screwing with it honeing the bolt.
Tomarrow i'll get the dremel out. Doesn't make me real happy with DCI
receivers. And I have 2 more of these to build.
Dunk RD

February 25, 2009, 12:54
I didn't have the same problem, but I did have other problems. I used an inch bolt and carrier and did not experience the failure to lock up. However I couldn't get the barrel to hand tighten. It would only screw in about half way and seize up even after chasing the threads in both the receiver and on the barrel. I tightened the tap slightly and then the barrel screwed on with no problem except it over timed to 12:30. A shim .007 thick solved the problem and it hand tightened to 11:00. After headspacing I too found the LS holes to be .001 oversize. So I ordered a .2983 LS from Ed Vanden Berg and then found when I was installing it that there was something blocking the hole on the left side. A small ridge was present that appears to have been metal displaced when the ejector block was installed. About 30 minutes of careful filing and fitting removed the ridge and I was finally able to install the LS. Actually I am quite happy with the receiver. The problems I experienced were minor and the cost of the receiver more than made up for the minor inconvenience.

Dunk RD
February 25, 2009, 20:42
Spent a couple more hours today trying to get it to function. A big part of the problem is that the chamber is not in the center of the receiver. Moveing the bolt and carrier slowly as it contacts the gage or a blank it has to slide side ways and a little up for the bolt to slide over the gage. I'm talking about a 32nd
of an inch. I can see the carrier slide side ways with the bolt.
Honeing off a little of the top of the bolt I have it where it will function but I don't feel it is right.
Dunk RD

February 26, 2009, 13:37
Mine is perfectly centered. If I didn't know better I'd say you left the extractor in the bolt and it is rising and moving to the side in order to clear the rim on your blank or go-gauge.

February 26, 2009, 14:31
Mine may be off center as well. I machined my own headspace gauges to exact case dimensions and I encounter resistance (unrelated to the headspace) in the last 1/8" of bolt travel that I've never understood. This resistance does not exist with an unfired or resized case.

I just adjusted the headspace on my Izzy HB this week and ended up resizing cases of varying headspace lengths to use in lieu of the gauges to avoid this and get an accurate feel.

Dunk RD
February 26, 2009, 20:09
Well today I stoped on the Imbel.
The three receivers I have are two that are mine Nubers 203 & 204. I also have a customers rec. that is 206 to be built on a nice STG. Timed his barrel
on his receiver and found the same thing. Chamber off center. Bolt will not go into battery.
Thats two out of three. I have one more I am going to build tomarrow and will give a reveiw. If others are haveing these same problems chime in.
Johnny 308 yours may be from a different batch and you lucked out.
For $50.00 difference DSA is a better deal
Dunk RD

February 28, 2009, 09:08
You know Dunk, this really isn't the news I wanted to hear. I just got my shipping notice yesterday from Coonan. I am trading a PAC Imbel out for this, I hope I don't regret it.

February 28, 2009, 09:56
"Johnny 308 yours may be from a different batch and you lucked out.
For $50.00 difference DSA is a better deal"

Well, waiting for something that may not be available until after they are banned was not an option. While I had a couple of small problems they were only small bumps in the road, not stoppers. I got number 282 so I don't know if that is from a different batch or not, sounds pretty close to me. Waiting for your next review.

March 01, 2009, 00:01
Dunk, I have #305, so I am hoping my built wasn't in your batch. I mounted the IMBEL Barrel to the DCI receiver on Tuesday, and except for the normal troubles of not hand tightening to 11 o'clock, not troubles so far. Just lightly filed the receiver face and the barrel shoulder, and it hand tightend perfectly at 11 o'clock. The problem is that after reading this post, I am a little worried that the build won't headspace right when I install the LS, but that is next week. That means I will hold off Duracoating the upper until I install the LS next week.

March 01, 2009, 17:32
I have had the bolt top clearance problem with an old DCI. Lil Dremelry did it. Still headspaced 2fingers plus on a .254...

March 05, 2009, 21:15
I have #306 DCI ..The bolt seems to be centered and engage well. My problem is I can't get the receiver to snap together with the lower. Its like it has hinge bind or something. I don't know If I should take meat from the receiver or off of the lower sides behind the hinge pin. Hinge pin goes in fine. I'm new at this game , just trying to prefit my parts.
I have an Imbel Kit and a G1 kit and this problem is present with either lower. I just ordered another DCI receiver . Wonder if this problem will be a reoccuring one ?

March 06, 2009, 17:09
i have a dsa that took a .250. i barreled it 3 times, 3 differnt barrels & bolt & carriers

March 06, 2009, 21:00
I got # 460 today, it has a meeting with a 243 barrel tomorrow... time will tell.

March 08, 2009, 00:25
Figured out my problem today. Small interference burrs of material where the side plates meet the back stop in the lower. Timed my barrel this morning on my fathers lathe. All parts are currently fitting up nice. Anyone have headspace gauges in the cincinnati area ? I'd like some help. Maybe I could trade with some machine shop services or something .

March 08, 2009, 00:34
Originally posted by ducknhide
Timed my barrel this morning on my fathers lathe.

How much did you have to remove to get it hand tight to 10:30?

March 08, 2009, 22:23
I took out .006 - .007 off of the shoulder and stoned the end face on the end of the the threads . Mine was clocking in at about 10:00 . This got it closer to 11:00 and it torqued right in nice .

March 11, 2009, 19:24
#460 had issues with mounting to the lower. I had to reshape it a bit where it goes over the lower near the recoil plate as it wouldn't close. Other than that everything looks good.

Even after that issue is solved, the contour doesn't line up perfectly with that of the recoil plate. The receiver sits .030" or so higher than the corresponding contour on the recoil plate.

Fit is nice an tight on the lower, accuracy should be good.

Functionally it appears to be fine. No test firing yet as I can't find my 243 chamber reamer.

Dunk RD
March 11, 2009, 23:42
Third receiver with the lowest number went together fine. No missalienghment. 1 out of three works great . Retuned the otther two for replacement.
Dunk RD

March 12, 2009, 11:24
1 out of 3 not verry good

March 13, 2009, 21:48
are there anymore updates? i'm thinking of getting a dci but now i'm wandering if i need to shoot for an entreprise or dsa..cbr

March 14, 2009, 09:57
My 2nd Receiver in today . I will pick it up and post problems if any on my 2nd build.

March 14, 2009, 19:02
I got a chance to look over #477 today. The only obvious thing to me is that the ejector block is about a milimeter too low to install the axis pin. I can drill the block and ream the receiver, but it will be quite awhile before I can finish the gun so I emailed DCI for thier recommened solution for it.

Dunk RD
March 18, 2009, 20:26
Within a week both receivers replaced and replacements are a OK.
Went together without a hitch
Great people
Dunk RD

March 19, 2009, 22:36
Receiver # 478 looks good an is assembling quite well. Threads are quite smooth and the barrel timed perfectly. Hand timed to 10:45 and Torqued right in. ejector block looks good on mine .

March 20, 2009, 12:10
I finished #460 today, only the minor issue of not locking onto the lower. 2 minutes of file time fixed that.

It runs like a sewing machine.

March 30, 2009, 16:22
It was rather refreshing to leave the Ak scene and get back to building a FAL..

DCI latest batch, hand timed to 10:30 and everthing when together perfectly with my Imbel kit. Locking shoulder .263, very tight lockup.

I can't say enough about this receiver, very NICE piece! I actually have built on gear logal Imbel receivers with a heck of a lot more issues. On a scale of 1 to 10 (10 being best) I would put the new batch well into the 8+++ range.

thanks DCI


March 30, 2009, 17:02
Is your receiver higher than -485? I just bought 2 of the higher numbers to build a couple of older kits I found in my gun room. I'm trying to get the parts I may need in anticipation of supply problems.
These look OK with minimal burring. The upper seems to lock onto the lowers with no problem. Barrel screws in one easily and the other needs a little encouragement.
My last Imbel was an agrevating build. The barrel stopped on the inner face before the shoulder.

March 31, 2009, 19:29
Mine went together with only a minor problem with the locking shoulder hole,the diameter was different from one side of the receiver to the other. garyd1961

March 31, 2009, 19:45
just got done building on 2 dci's. 1 had no issues but the second had the bolt carrier binding and minor locking to the lower issue but all take care of and i hope to test fire them soon..the receiver overall is pretty good...might get 1 more...cbr :fal:

April 01, 2009, 08:52
Am I seeing a trend where the newer ones are better or is it just luck of the draw? I just ordered one and they shipped it today to my ffl dealer. I have a crappy Sarco kit,missing parts and no barrel yet.Ihave not decided what bbl. to use yet. This will be my third build, my first was slightly more than ten years ago. Looking back, I didn't know anything then but I got it to work. This forum is a huge help. Also the sarco parts kit has a 1 piece extractor,should I use it or get a 2 piece? thanks

April 01, 2009, 09:50
good luck on the sarco missing parts...i've been waiting for 3 months for mine, even sent them a e-mail w/no response. your gonna have to bite the bullet and buy the missing parts like i did, if your planning to build it this year :rofl: good luck and do post if you have questions or problems..cbr:fal:

April 01, 2009, 20:17
hey dunk, i see u from IN, what part of state are u in ?

June 15, 2009, 17:13
Just finishing up a friend's build on a DCI, #538. The only issue so far during the build was we cleaned the rcvr where the barrel screws in just a bit with the dremel. Got her timed up nice with a ratas barrel vise and a homemade rcvr wrench. Headspaced at .255". Just waiting for the locking shoulder to get here to finish it and see if she's ready to test fire.

Rcvr looks good and so far, has gone together nicely. I wish I had the money to get one myself!

BTW: is the DCI website down or is it just me??

Ron Walker
June 15, 2009, 20:07
I don't like giving ser#s but mine was early in the sale of this last batch and hand timed to 10:45 and took .262 to head space, and works perfectly. Ron

June 15, 2009, 23:21
My one and only DCI headspaces at .261-.262, but I can push the locking shoulder in with thumb pressure. Any suggestion as to what size shaft I need? (I tried a few lcs and they all pushed in with the same amount of pressure).

June 16, 2009, 08:06
Seaweed, you will need an oversized (shaft diameter) locking shoulder. Use the shaft end of drill bits and a caliper to find the size of the hole in the receiver and order order one a thousand larger,or in your case you could measure your old LS and order one a thousand larger.This seems to be a common problem with these receivers. I think gunpartsguy or gunthings has them. garyd1961

June 18, 2009, 11:25
Mine head spaced at .263 and took a .298 shaft size. I got a .263/.298 LS from Ed vanDenburg and he does beautiful work.

June 25, 2009, 11:07
LS hole .001 big - will order .298 oversize LS.
Canít figure out headspace, closed on Forster .261+1 setback=.262-2=260 pushed undersized .260 LS in bolt wont close. Not sure were the problem is also left extractor on when headspace would that make difference.
Help much appreciated first Fal

June 25, 2009, 11:09
Originally posted by sniperdude
LS hole .001 big - will order .298 oversize LS.
Canít figure out headspace, closed on Forster .261+1 setback=.262-2=260 pushed undersized .260 LS in bolt wont close. Not sure were the problem is also left extractor on when headspace would that make difference.
Help much appreciated first Fal

You have to remove extractor before headspacing it definitely will make a difference.

June 28, 2009, 23:01
No difference with extractor in place as long as you snap the gauge into the bolt before/as you chamber the gauge. Some folks (including military) grind a relief cut on the extractor rim so that it is easy to chamber the gauge without having to snap it into the bolt of remove extractor (pain in the ass with M-1's/m-14's/m1A's). Unless the extractor is contacting an out of spec receiver extractor cut, the results are the same in my experience.

June 29, 2009, 01:42
Removed extractor doesnít make any difference, but would say it closes more like .260 than .261 requires lots of pressure to close on pins.
LS hole diameter is different from one side of the receiver to the other, LS pushes in by hand until it meets other side and taps in with mallet.
You would think it would have closed on .260 LS if it closed on .261 pin gauge? Watching just bolt without carrier it almost locks in, I did get it to close with carrier after light rap with mallet. After examining operation I donít see interference with top of bolt too receiver. I did notice 2 ridges were top off bolt locks in carrier, should I hone a little?
Confused to witch oversized LS to buy I think .259 would work or would it be too tight for 7.62 ammo?
Looking for best accuracy DSA HB, trigger job, and Free float HG


July 13, 2009, 23:20
Most mil surp 7.62x51 is made to 1.628"/1.629" headspace. I'm running 1.631" headspace on new L1A1 build with no problems with Pak, SA, and FMN (didn't want to wait on a 0.001" smaller locking shoulder - had to lap bolt/locking shoulder to BARELY "hard" close on 1.630" go gauge before firing - got set back to 1.631" with DSA inch receiver).