PDA

View Full Version : Barrel Timing Help


AEnemaBay
January 11, 2009, 03:00
Well I'm finally getting around to building my FAL carbine and I've ran into something I haven't faced yet... incorrect barrel timing. Below is a pic of my barrel hand tightened in a new production Century receiver:

http://i4.photobucket.com/albums/y143/AEnemaBay/DSC01731.jpg
http://i4.photobucket.com/albums/y143/AEnemaBay/DSC01729.jpg

Now the problem is I do not have access to a lathe in my shop, so how can I go about getting the barrel to time correctly (besides just buying a DSA receiver)?

Thanks for any input!

Survey Punk
January 11, 2009, 03:16
A sanding disk, at low RPMs and checking often, will give you the results you need. Also lightly filing the shoulder and checking often is another fix. Use majic marker as your layout fluid and go slow.
Did I mention check often? :biggrin:

JB







P.S. Don't forget the handguard ring!

AEnemaBay
January 11, 2009, 03:18
By the way, in case it matters, the barrel is a brand new DSA made and the receiver threads have already been chased.

AEnemaBay
January 11, 2009, 03:19
Originally posted by Survey Punk
A sanding disk, at low RPMs and checking often, will give you the results you need. Also lightly filing the shoulder and checking often is another fix. Use majic marker as your layout fluid and go slow.
Did I mention check often? :biggrin:

JB







P.S. Don't forget the handguard ring!

OK, cool. Would you happen to have an educated guess on how much material I might have to take off before I reach correct timing?

Oh and I didn't forget the handguard ring, lol.

Brush511
January 11, 2009, 04:00
Each full revolution of the barrel moves it .0625". So, looking at your picture and comparing it to a clock face. It looks like about 10:00 (barrel to receiver). I'd take .004 - .005" off. To move it 1 hr. on the clock (from 10:00 - 11:00) takes .0052". That's 1/12th of 1 revolution.

USMC 0341
January 11, 2009, 04:21
When I was back in the US last September I did two barrels that looked like yours.

I took some cardboard (not corrugated stuff) and some sand paper. Cut them in squares about 3" by 3". Make holes in each about the size of the hole in the front of the receiver.

Use a nice. sharp file and remove some material from the shoulder on the barrel (evenly, all the way around).

Then screw the barrel into the receiver with a piece of cardboard against the receiver and a piece of sandpaper against the barrel shoulder. Tighten until you can just move the sandpapper.

Rotate the sandpaper, removing material from the barrel shoulder and squaring it to the receiver.

Repeat as necessary. Check the barrel timing often until you see how much you are removing.

I started with 80 grit, then went to 150, then 220.

4x401
January 11, 2009, 13:11
I`ve had 6 Centurys time to the same spot. I used a reciever stub and cut sand paper to bear on the barrel shoulder. Tighten stub against paper and spin it. It`s taken about 15 min. on each to properly time the barrel.

AEnemaBay
January 11, 2009, 13:15
Originally posted by 4x401
I`ve had 6 Centurys time to the same spot. I used a reciever stub and cut sand paper to bear on the barrel shoulder. Tighten stub against paper and spin it. It`s taken about 15 min. on each to properly time the barrel.

This is what I plan on doing but I'm just going to have to use my receiver. I don't have any stubs unfortunately.

johnny.308
January 11, 2009, 13:20
By the way a new DSA receiver will not fix your problem, they all time to about 10:00 without work on the barrel. Warm up the elbow grease and use the sanding disk method. You might want to wear gloves as the skin on your fingers will go before the barrel times to 11:00-11:30.

ggiilliiee
January 11, 2009, 14:25
http://community-1.webtv.net/ggiilliiee/shaver/

ftierson
January 11, 2009, 14:34
Personally, I'd take the barrel into a shop and have the shoulder turned...

It's an extremely easy job, doesn't take much time and shouldn't cost much to have done...

Keep in mind, 5.7 degrees per 0.001" off the shoulder...

Don't take too much off, although breaching washers can fix over-timing problems...

Forrest

AEnemaBay
January 11, 2009, 15:36
Well guys, thanks for all your help, the sanding disk trick worked like a charm! Look all about 10 minutes to complete. I opened up the hole in the sanding disk only slightly and then threaded it onto the barrel. This made for a nice tight fit so it got the entire circumference of the barrel shoulder. Thanks again!.

http://i4.photobucket.com/albums/y143/AEnemaBay/DSC01737.jpg
http://i4.photobucket.com/albums/y143/AEnemaBay/DSC01739.jpg

ftierson
January 11, 2009, 15:46
Glad that it worked well for you...

Actually, the barrel would probably have turned on all right from where you started...

Personally, I shoot for about 20-25 degrees of crush on the shoulder...

I look forward to seeing pictures of the rifle when it's all together...

Forrest

AEnemaBay
January 11, 2009, 16:04
Originally posted by ftierson
Glad that it worked well for you...

Actually, the barrel would probably have turned on all right from where you started...

Personally, I shoot for about 20-25 degrees of crush on the shoulder...

I look forward to seeing pictures of the rifle when it's all together...

Forrest

You know I figured the same thing. It would have probably turned fine, but I figured I'd follow the advice of all the builders here who have turned out more FAL's than I'll ever see.

In retrospect, however, if I were to ever do this again I'd put some masking or electrical tape on the face of the receiver so as not to rub the park off of it. Oh well, lessons learned.

4895SHOOTER
January 12, 2009, 17:10
"A COAT OF PAINT CAN HIDE A WORLD OF SINS"

phillip
January 12, 2009, 20:43
Originally posted by 4895SHOOTER
"A COAT OF PAINT CAN HIDE A WORLD OF SINS"


So can 4 pounds of solder.

4895SHOOTER
January 15, 2009, 10:58
Or two tubes of JB Weld - but you'll still have to paint to match!

GunHo109
January 22, 2009, 16:40
Originally posted by ggiilliiee
http://community-1.webtv.net/ggiilliiee/shaver/

That site was very informative!

Thanks for the link!

Fixed most of my issues!

dAvE:cool: