headspace problem

edp3 · 04-13-2011, 09:38 AM

This is my first build and I am having some problems setting the head space. The rear trunnion is already riveted and I need to back the barrel out a little. I have a 12 shop press and ak builder tools. How can I back the barrel out?

allesennogwat · 04-13-2011, 09:50 AM

You may be able to fit some sort of crossbar or t-bar through the magwell and place some soft metal such as brass or coins against the barrel and press against the front of the trunnion. An air hammer with some brass in between it and the back of the barrel works too. Sometimes pressing the barrel makes it difficult to set headspace and some people tap the last bit of barrel in for headspace with a mallet on the end of the barrel.

edp3 · 04-13-2011, 10:07 AM

Thank you for the quick reply. I ended up doing something similar to what suggested.

After I got it headspaced I nocticed the pin channel is off just a little. Is this something that would correct itself when installing the pin or is there something else I should do?

allesennogwat · 04-13-2011, 11:05 AM

The pin won't fix it. Driving the pin won't move the barrel. It needs to be straight before pinning. How is it off? Front to back or rotated? If you want the headspace where you have it and the barrel doesn't need rotating then an drilling an using an oversized pin is best. A lot factory AK's will check as if they have too tight headspace. This is common and normal. If you push the barrel out, the top cover may end up loose. If the pin hole only requires pushing the barrel in a bit, that may be the thing to do. Are the trunnion, barrel and bolt matching?

edp3 · 04-14-2011, 05:34 PM

I bought an ak builder kit, I believe it already has an oversized pin. The barrel needs rotated in order for the channel to align. What is best way to do this?

allesennogwat · 04-14-2011, 05:42 PM

You have to remove the barrel to rotate it in the trunnion. The only other way is to hold an air hammer with a brass bit on the chamber end of the barrel and hammer the barrel with the air hammer while rotating the barrel. (blip it with the air hammer while rotating it) It won't turn in the trunnion by twisting it without damaging something.

04-13-2011, 09:38 AM	#1
edp3 New Member AKaholic #: 156804 Join Date: Apr 2011 Location: wv Posts: 5	headspace problem This is my first build and I am having some problems setting the head space. The rear trunnion is already riveted and I need to back the barrel out a little. I have a 12 shop press and ak builder tools. How can I back the barrel out?

04-13-2011, 09:50 AM	#2
allesennogwat Curio & Relic AKaholic #: 3738 Join Date: Apr 2005 Posts: 32,184	You may be able to fit some sort of crossbar or t-bar through the magwell and place some soft metal such as brass or coins against the barrel and press against the front of the trunnion. An air hammer with some brass in between it and the back of the barrel works too. Sometimes pressing the barrel makes it difficult to set headspace and some people tap the last bit of barrel in for headspace with a mallet on the end of the barrel. __________________ Daraclor: A brand of anti-malaria pills which we had to drink every week while on the border. Legend had it that these would make you turn yellow and that you wouldn't be able to tan.

04-13-2011, 11:05 AM	#4
allesennogwat Curio & Relic AKaholic #: 3738 Join Date: Apr 2005 Posts: 32,184	The pin won't fix it. Driving the pin won't move the barrel. It needs to be straight before pinning. How is it off? Front to back or rotated? If you want the headspace where you have it and the barrel doesn't need rotating then an drilling an using an oversized pin is best. A lot factory AK's will check as if they have too tight headspace. This is common and normal. If you push the barrel out, the top cover may end up loose. If the pin hole only requires pushing the barrel in a bit, that may be the thing to do. Are the trunnion, barrel and bolt matching? __________________ Daraclor: A brand of anti-malaria pills which we had to drink every week while on the border. Legend had it that these would make you turn yellow and that you wouldn't be able to tan. Last edited by allesennogwat; 04-13-2011 at 11:10 AM.

04-14-2011, 05:42 PM	#6
allesennogwat Curio & Relic AKaholic #: 3738 Join Date: Apr 2005 Posts: 32,184	You have to remove the barrel to rotate it in the trunnion. The only other way is to hold an air hammer with a brass bit on the chamber end of the barrel and hammer the barrel with the air hammer while rotating the barrel. (blip it with the air hammer while rotating it) It won't turn in the trunnion by twisting it without damaging something. __________________ Daraclor: A brand of anti-malaria pills which we had to drink every week while on the border. Legend had it that these would make you turn yellow and that you wouldn't be able to tan. Last edited by allesennogwat; 04-14-2011 at 05:52 PM.

04-13-2011, 10:07 AM	#3
edp3 New Member AKaholic #: 156804 Join Date: Apr 2011 Location: wv Posts: 5	Thank you for the quick reply. I ended up doing something similar to what suggested. After I got it headspaced I nocticed the pin channel is off just a little. Is this something that would correct itself when installing the pin or is there something else I should do?

04-14-2011, 05:34 PM	#5
edp3 New Member AKaholic #: 156804 Join Date: Apr 2011 Location: wv Posts: 5	I bought an ak builder kit, I believe it already has an oversized pin. The barrel needs rotated in order for the channel to align. What is best way to do this?

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