Need advice on Fal headspacing issue

**Gunco** · 09-27-2009, 06:21 PM

I did some headspacing on my FAL's this weekend to get them ready to test fire.
I borrowed some shoulder locking gauges from Illya (thanks for the help my man!) I got 2 out of my 3 FAL headspaced. The third one I'm having an issue with.

With the shoulder locking guage of .253 in the receiver I put in my go guage and the bolt doesn't close.
Then put in my nogo gauge and the bolt doesn't close.

This is how it is with all the shoulder guages. Without the go or nogo guages in the bolt closes flush.

What am I missing? What are my options? I don't think locking shoulders go below .253 do they?

Here is the problem child.

**redchevyman** · 09-27-2009, 06:30 PM

If your go guage does not close than there is no way your no-go will close. Have you tried a live round yet (using safe handling). If a actual round will fit you should be good to go.

moleman · 09-27-2009, 06:35 PM

I did a FAL build years ago before it was easy to get all of the different locking shoulders. Mine was too tight also, so I cut a diamond hone down to the width of the locking shoulder/bolt contact area and used it to cut down the surface the 5-6 thousands I needed to get the bolt to completely close on the go. It was a pain in the ass as the locking shoulders are quite tough. I have read where others used a surface grinder to do the same thing.

**redchevyman** · 09-27-2009, 07:19 PM

Go guages are larger than an actual round so if the round fits I would leave it as is.

Blazerbender · 09-28-2009, 09:37 PM

Gun Parts Guy can custom grind locking shoulders, once you know the dimension. Guess how I know this.

Having a set of Fraction,Number and Letter drills helped, using the shanks to rough out the size estimate. Had to procure some undersize gauging pins,from Grizzly, to get in the ballpark.

gska3873 · 09-29-2009, 08:41 AM

redchevyman is correct about if it won't close on a go gauge then there is no way it will close on a no go gauge, however, I would not just go by it closing on a round.

Which brand of receiver on you using? The last few DSA's that I have built on needed smaller locking shoulders. One required a .253 and one was actually a .251. If you have any drill bits that the shank diameter is smaller than a .253 thry those with the gages and see what the results are.

I am assuming you do have the extractor removed from the bolt while you are doing the headspacing with the gages.

IRONMULE · 10-01-2009, 12:36 AM

Hello Gunco
Your chamber is too short. It sounds like you might be missing the barrel shim that goes between the threaded part of barrel to receiver end, or cutted the barrel to index the barrel for 12 oclock torqued. If you can get a barrel shim and get the barrel rotated out one complete turns out, creating a longer chamber, that will help the the too short of chamber. Keep in mind that most FALs don't use barrel shims but sometimes mismatching barrels or receivers and parts or brands to assemble a complete rifle, you just need shimming or trimming. Keep us posted the repair results. IRONMULE

**Gunco** · 10-01-2009, 12:15 PM

Quote:

Originally Posted by gska3873

redchevyman is correct about if it won't close on a go gauge then there is no way it will close on a no go gauge, however, I would not just go by it closing on a round.

Which brand of receiver on you using? The last few DSA's that I have built on needed smaller locking shoulders. One required a .253 and one was actually a .251. If you have any drill bits that the shank diameter is smaller than a .253 thry those with the gages and see what the results are.

I am assuming you do have the extractor removed from the bolt while you are doing the headspacing with the gages.

The receiver is a Dan Coonan. I'll try a live round this weekend and see how that goes. The drill bit idea is a good one I hadn't thought of that. I'll see how that does and post the results.

**Gunco** · 10-01-2009, 12:20 PM

Quote:

Originally Posted by IRONMULE

Hello Gunco
Your chamber is too short. It sounds like you might be missing the barrel shim that goes between the threaded part of barrel to receiver end, or cutted the barrel to index the barrel for 12 oclock torqued. If you can get a barrel shim and get the barrel rotated out one complete turns out, creating a longer chamber, that will help the the too short of chamber. Keep in mind that most FALs don't use barrel shims but sometimes mismatching barrels or receivers and parts or brands to assemble a complete rifle, you just need shimming or trimming. Keep us posted the repair results. IRONMULE

I was worried I would need to shim the barrel but when I built it the barrel was hand tight to the receiver at the 10-11 oclock then tighten to 12 oclock with a barrel wrench. So I assumed this barrel did not need any shimming.

One of my other fals needed shimming and it headspaced perfect at .266

I think I will try the live round trick first. then the small shoulder gauges using drill bits, then last resort would be barrel shim.

Thanks for the good advise!

White Devil · 10-01-2009, 12:25 PM

I was helping Gunco with this build and that barrel fit like it belonged to that receiver. All the other FALs we built that day all needed something done to make the barrels fit, but that one was the easyst to build.

When he called me and told me the issue I was like WTF. Guess that goes to show you the easyst build might be that hardest.