AK Sponsor
Posted: 10/13/2009 7:00:24 AM EDT
|
Just checked headspace on my 2nd build and got it closed fine on the "go" gauge. Unfortunately, it also closed on the "no-go" gauge.
I marked the closed position with a line on the bottom of the bolt and receiver. When I ran the no-go check, the bolt closed about 99.5% of the way. The lines didn't lineup completely, but pretty fargen close to where it would give me doubt. They were touching but not lining up all the way. The kit is Romanian, that was sold with a new, never fired barrel. Am I screwed? ETA: I tried using the bolt only. By judging the amount of rotation of the bolt by looking at the locking lugs, it looks like the bolt rotates fully with the Go Gauge. The No Go gauge doesn't go quite as far, but not by much. Using the entire bolt carrier and piston group, there is no way to tell the difference between the two. Thanks for entertaining the newb question. My last build was much more obvious headspace. |
|
Quoted:
You pulled the extractor?Yes. Leaving it in can cause a false reading. Gentle pressure to close?It's easy to force a bolt closed on a gauge? With the bolt installed in the carrier, both gauges close fully forward with no resistance. Checking with the bolt only, there isn't much visible difference, but the bolt will lock fully on the GO gauge, but will not lock fully on the NOGO gauge. BSW |
|
Quoted:
Quoted:
You pulled the extractor?Yes. Leaving it in can cause a false reading. Gentle pressure to close?It's easy to force a bolt closed on a gauge? With the bolt installed in the carrier, both gauges close fully forward with no resistance. Checking with the bolt only, there isn't much visible difference, but the bolt will lock fully on the GO gauge, but will not lock fully on the NOGO gauge. BSW I agree on the need to check with a field gauge. It's the one that really matters. Excess headspace can be fixed: You get a smith to press the barrel further back and he then redrill the cross pin hole for a larger cross pin. BSW |
|
Quoted:
Quoted:
Quoted:
You pulled the extractor?Yes. Leaving it in can cause a false reading. Gentle pressure to close?It's easy to force a bolt closed on a gauge? With the bolt installed in the carrier, both gauges close fully forward with no resistance. Checking with the bolt only, there isn't much visible difference, but the bolt will lock fully on the GO gauge, but will not lock fully on the NOGO gauge. BSW I agree on the need to check with a field gauge. It's the one that really matters. Excess headspace can be fixed: You get a smith to press the barrel further back and he then redrill the cross pin hole for a larger cross pin. BSW I suppose thats better news than what I was fearing.... So if it headspaces good with the field gauge, then I'm gtg, no worries about my beautiful face? 
Thanks for the input. |
|
Quoted:
Quoted:
Quoted:
Quoted:
You pulled the extractor?Yes. Leaving it in can cause a false reading. Gentle pressure to close?It's easy to force a bolt closed on a gauge? With the bolt installed in the carrier, both gauges close fully forward with no resistance. Checking with the bolt only, there isn't much visible difference, but the bolt will lock fully on the GO gauge, but will not lock fully on the NOGO gauge. BSW I agree on the need to check with a field gauge. It's the one that really matters. Excess headspace can be fixed: You get a smith to press the barrel further back and he then redrill the cross pin hole for a larger cross pin. BSW I suppose thats better news than what I was fearing.... So if it headspaces good with the field gauge, then I'm gtg, no worries about my beautiful face?
Thanks for the input. Yeppers. I don't even own a go or no-go since I don't build. I do check all the rifles yearly with the field gauge. I like being able to see. BSW |
|
Quoted:
Couple more questions with this... If I ended up having to push in the barrel and re-drill, where would I get an oversized barrel pin? <––-Found it. AK-Builder.com Would this cause problems with the gas tube fitting? Maybe. The later type gas tube has a spring and should be fine, the early type may need to be fitted. Remember, we're talking about a few thousandths of an inch here. BSW |
|
Alright... I decided I didn't want to settle for just passing a field gauge test, so I headed out to the garage to make this right. I removed the barrel pin, drove in the barrel a TINY bit farther and checked again. Passed with flying colors on both gauges! It looks like there would be enough room to pound the pin back in, but I'm going to play it on the safe side and take it to a smith to have him drill it out. I can't believe how such a small adjustment could have such a large effect on the no-go gauge!
Thanks to all that helped out!  
|
| Try here. Good Luck! I bought one 1/4" x 2" drill rod and it was enough for two pins when cut in half. |
|
Here are two options for fixing it;
1) (this information I got from another users so I can't take credit for it) Do not file or grind bolt lugs. Your loose barrel pin has to be taken care of. Remove barrel pin; push barrel for correct headspace (use headspace gauges, not cartridges); ream pin hole to larger diameter and install new correct size pin. You must figure out reamer and pin size. Use drill rod for pin. Pin should be .002 -.003" larger than reamer diameter for press fit. For example: If your barrel pin is 7 mm, decimal equiv .276" use oil hard drill rod 19/64 dia, decimal equiv .296875" you need decimal size chucking reamer, size .2940" .296875 - .2940 = .002875 slightly under .003, which will be OK for press fit. Any hole can be slightly increased in I.D. (inside diameter) by lapping to get the desired fit. Catalog, drills, reamers, drill rod, measuring instruments, and tools that you need to fix your Yugo, are available from: Production Tool Supply 800-270-5779 www.pts-tools.com **********************************************************************************************************************************8 2) Check with 32ndsigbn I think he sells the over size pins and also he can do the headspacing for you. Here is lad in the EE AD |
|
I've made pins out of old drill bits before.....
interesting thread...........I've built quite a few akm's and a bulgy ak-74, recievers and all work. but I always went with macthing kits,so I cannot offer any more than I have seen here,so far there are ways to improvise if you have the experience,tools and skills, but some may have a problem the suggestions....... |
|
so shes close enough where a larger pin will do the job?
I noticed in the past, that once you see the right spacing, you can take the bolt by itself out of the carrier, put a round in it, and slide it on the top rails, and rotate it into position........it has just the right feel at the end of the bolt, tight but with a tiny bit of wobble. when its excessive is when you are F-D |
|
Quoted:
so shes close enough where a larger pin will do the job? It looks like it. I'm waiting for my oversized pin to come in the mail and then I'm taking it to the machine shop. Hopefully it works out... Speaking of headspace, I'm just finishing up another build.... If the bolt closes with a bit of a push on a go-gauge, thats ok, right? I have to use my thumb to give it about 5-10lbs of force, but it closes fine. |
|
I dont know about that....... I would like to see ithe bolt roatate with no friction
what about live rounds, do they easily rotate into place. ie. no carrier, just a round on the bolt,while holding tail end of bolt and sliding/rotating into the chamber.when centered,it should turn into place without force, |
|
I would say that is perfect. just like BSW said it should wear in just right
I bet she shoots real nizzzze 
the ak platform is much more exciting and challenging to build compared to other platforms......especially when you start from a flat. nothing like the pride of knowing you made such an effective weapon all by yourself. |
AK Sponsor