View Full Version : Headspace on Kit Gun
I need some help on this headspacing.
Bolt and carrier WOULD close easily (smooth) on a 0.260 pin gauge with the GO gauge in place.
Would NOT close on 0.260 pin gauge with the NOGO gauge in place.
Would NOT close on 0.262 pin gauge with the GO gauge in place.
GP says to stay with in a 4ths on an inch but that was based on the fact that his bolt was barely closing on the pin gauge. Since mine is closing on the 0.260 (easily) with the GO gauge and will not close (even with thumb pressure) on the NOGO gauge I should use a locking should sized 0.260, CORRECT?
March 25, 2002, 13:12
i'm going to assume that the bolt would have closed with some pressure on a .261 pin. so .260 = 1.631 and allowing .001 for setback after firing gives you 1.632. .259 LS = HS of 1.633 .258 = HS of 1.634 if LS that came with kit is 1 of the sizes i mentioned i would use it to finish the rifle. and then go have some fun :D
I only have the even numberd pin gauges. do you think I need to order the odd numbered pin gauges. I am sure that the bolt would close on the .261 with pressure because it does close with just the push of my finger on the .260. The LS that came with the rifle is .261 inchs that I have at this time filed evenly down to .260 but have not hammered the LS in to check it yet.
thanks for the help HD99FXR3
Update: over the last 2 hours I put a .258 pin in and the bolt closed even easier on it with the GO and closed with a very hard Bi-thump press. I then took the LS and filed it down. After two tries I have the bolt closing smoothly on the GO with the LS in place. and it will close on the NOGO with very firm pressure using both, now sore, thumbs. the last time I measured the LS it was .257 left, middle, and right. Is this rifle head spaced correctly? if not please help. I have really tried to do this up right and want to be correct and safe.
[ March 25, 2002: Message edited by: Iso ]
March 26, 2002, 08:42
STOP!!!!! you have taken too much off of your LS at .257 your headspace is now 1.635 although that is in spec. for 7.62 nato you are out of spec. for .308 the choice is yours you can use existing LS but i would not advocate doing so in the intrests of safty. my recomendation is find a LS that is ether .258,.259,.260 you are looking for a HS of 1.632 min. to 1,634 max.
Okay I hammered in a LS .259 and the bolt closes easily on the Go but will not close with thumb press on the NOGO. I did peck on the bolt carrier with a brass hammer and it did move forward a bit but I did not con't to hammer to see if it would close all the way on the NOGO. Now am I okay you think?
thanks again for the help
March 26, 2002, 17:00
Why would you "hammer" on the bolt carrier to see if the bolt will close when there is a "precision made" no-go gauge in the chamber? Did you read that in the instructions?
A headspace gauge is a precision instrument, and setting it is almost like brain surgery. You are dealing with measurements of .001" or less.
By forcing the bolt forward it might be possible to swage the chamber larger or the gauge smaller. It is a precision instument. Use a very gentle touch.
Oh, by the way, it is a precision instrument.
By now you could probably use that .261 LS you already ruined.
I am sorry if I seem a little brash, but you have created more work for yourself.
Well capman I can honestly say that it was by chance that I even realized that the hammer would drive the carrier forward. Yes I understand that the gauges are precision made to 0.0000. The hammer landed on the carrier when it fell from the peg board mount and landed on the rat tale then hitting the carrier sliding the carrier forward. After I saw that I pulled the carrier back, forcefully, and tried to close the bolt with my thumbs, again. I could not so I just pecked again to see if the brass hammer would close it. It did move the carrier again. Here is where I stopped and rechecked the length and diameter of the gauge and thought, for some weird reason, that I would ask for some help and advice here.
But Ha' Thanks For All Your HELP and ADVICE! Let me know if you ever need any help with anything. :D
March 26, 2002, 19:22
Kinda scary. Of all the things we do assembling an FAL kit gun, headspacing is the most critical thing we have to do correctly, but is also one of the easiest to do. Those that are unsure of headspacing procedures, even after reading the numerous posts that thoroughly explain the process, should always just ask before leaping into something they may misunderstand. It ain't rocket science, but it must be right to be safe.
I've never filed a locking shoulder. I always had the impression that a properly heat treated locking shoulder had to be ground due to its hardness, but maybe not. Ending up with the right shoulder angle after removing a several thousandths with a file seems to be a difficult thing to do (for me anyway).
If you have a go gauge, use it to headspace. After you have installed your "properly selected" locking shoulder, then check your work with both the go and no go gauges. I think the no go gauge may confuse a few people when they are setting headspace when also using a go gauge (it is redundent).
March 26, 2002, 22:25
You are right, I did come down on you a little hard, I apologize.
Headspacing while not complicated to perform, is a very critical part of the build. I don't know how hard you hit your carrier or if you got it all the way closed on the no-go, but I suggest you try a different gauge or have someone else check your work, even if you have to pay for it.
March 26, 2002, 23:34
i don't know where to begin, will bolt close on your go gage, with the LS now installed?
shit happens some times, but if you ask advice we will try to give it, but try to remember if it ain't broke don't fix it. and don't undertake anything that wasn't in the insructions until you get a better feel for things, okay? ;)
March 27, 2002, 09:15
Hey Iso !
Don't be upset. Some times it's hard to give advise on these subjects, because of the feeling of liability. And these people care!
Sometimes Us [screw driver, pliers and hammer] People get carried away.
I think these people did a fine job trying to help.
Just remember in the future to Store the Hammer on the Lowest Peg for the Least Damage.
Thanks for the help guys. Not looking for anyone to blame if my rifle(s) go kaboom, just wanting to avoid a kaboom. The rack the bbl action was in is now mounted o nthe wall to the left of the peg board, where they can fall to the floor, and the hammer is mounted on the right side of the peg board, where it can fall and hit me in the head. :)
March 27, 2002, 13:04
NOW YOUR THINKING!
Keep in mind, if we all new everything! We wouldn't be here!
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