which trunion should I use?

amd65 · 03-25-2008, 09:57 PM

I have an all matching amd65 parts kit that I am plugging along on and I am at a problem area. I have the original matching front trunion with factory headspacing but two of the rivet holes out of the six were over expanded by whoever de-milled the kit because they used a drill. It is not very bad but is noticeable.

Now I also have a bulgarian trunion that is basically identical to the hungarian trunion and which also has good headspacing and no problems with the holes. This seems like an obvious question but which trunion should I use? Would the rivets expand enough on the original trunion with the expanded holes?

Koyotejager · 03-25-2008, 10:01 PM

Well, first off ,how big is big? You could check with a drill bit that just fits the hole and post the result here.

Koyotejager · 03-25-2008, 10:04 PM

How do you know the headspace is good on the Bulgy trunnion with the kit you are using?

kikilee · 03-25-2008, 10:05 PM

Unless the hole are over reamed a lot the rivets should fill and hold fine. If it were me I would try to use the original trunion if at all possible.

allesennogwat · 03-25-2008, 10:06 PM

It depends how big the holes are. Also if four of the six are good it likely won'y move in thereceiver. Also depending on their location. If using another trunnion measure the width of the rear sight block. Bulgarian AKM and AMD-65 should be the same but best to check. Also the height (depth) of the rear sight block may or may not be different. The AMD-65 has an 80 meter sight and the Bulgarian AKM has a 1000 meter sight. It may not a difference in the rear sight block to trunnion fit but best to check it. I would try to use the AMD-65 trunnion.

amd65 · 03-25-2008, 10:07 PM

I pressed the bulgy trunion on the barrel and checked the headspace. Thats how I know both trunions are suitable as far as headspacing goes.

Koyotejager · 03-25-2008, 10:13 PM

Quote:

Originally Posted by amd65

I pressed the bulgy trunion on the barrel and checked the headspace. Thats how I know both trunions are suitable as far as headspacing goes.

Ah, very good! What size are the holes drilled to on the original trunnion? You might still be able to use it if not too bad.

amd65 · 03-25-2008, 10:15 PM

The two holes are expanded about a millimeter on one side. Will the rivet expand enough to fill this?

Koyotejager · 03-25-2008, 10:17 PM

Yea, it should. I would use it.

chief4guns · 03-25-2008, 10:35 PM

I would use the original trunion and heat the rivet shank red hot with a torch. (a propane is good enough to heat rivets) Pop it in and press it. I guarantee it will expand and fill the whole hole if you press it hot!! Just make sure it's long enough. Thats the way they used to do Skyscraper beams, Oil tanks, Ships, ect. Sooo!! don't 15 of you well meaning metallurgists jump on me and start talking about rivets and changing the molecular structure. They are in an annealed (read soft state) to start with so you can crush them. Chief

amd65 · 03-25-2008, 10:38 PM

Ooooh, I think that is exactly what I will do. Any more good advice?

03-25-2008, 09:57 PM	#1
amd65 Member AKaholic #: 10323 Join Date: Dec 2007 Location: Florida Posts: 203	which trunion should I use? I have an all matching amd65 parts kit that I am plugging along on and I am at a problem area. I have the original matching front trunion with factory headspacing but two of the rivet holes out of the six were over expanded by whoever de-milled the kit because they used a drill. It is not very bad but is noticeable. Now I also have a bulgarian trunion that is basically identical to the hungarian trunion and which also has good headspacing and no problems with the holes. This seems like an obvious question but which trunion should I use? Would the rivets expand enough on the original trunion with the expanded holes?

03-25-2008, 10:01 PM	#2
Koyotejager Curio & Relic Contributor AKaholic #: 4230 Join Date: Aug 2005 Location: Lost Nation Posts: 2,180	Well, first off ,how big is big? You could check with a drill bit that just fits the hole and post the result here. __________________ FURTH FORTUNE AND FILL THE FETTERS MacMhuirich You may find my body in a ditch, but, I will be lying on a bed of brass "The 9mm may properly expand, but the .45 will never shrink." unknown" When the chips are down, having almost any gun availible can far surpass the value of throwing rocks.

03-25-2008, 10:04 PM	#3
Koyotejager Curio & Relic Contributor AKaholic #: 4230 Join Date: Aug 2005 Location: Lost Nation Posts: 2,180	How do you know the headspace is good on the Bulgy trunnion with the kit you are using? __________________ FURTH FORTUNE AND FILL THE FETTERS MacMhuirich You may find my body in a ditch, but, I will be lying on a bed of brass "The 9mm may properly expand, but the .45 will never shrink." unknown" When the chips are down, having almost any gun availible can far surpass the value of throwing rocks.

03-25-2008, 10:06 PM	#5
allesennogwat Curio & Relic AKaholic #: 3738 Join Date: Apr 2005 Posts: 32,200	It depends how big the holes are. Also if four of the six are good it likely won'y move in thereceiver. Also depending on their location. If using another trunnion measure the width of the rear sight block. Bulgarian AKM and AMD-65 should be the same but best to check. Also the height (depth) of the rear sight block may or may not be different. The AMD-65 has an 80 meter sight and the Bulgarian AKM has a 1000 meter sight. It may not a difference in the rear sight block to trunnion fit but best to check it. I would try to use the AMD-65 trunnion. __________________ 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.

03-25-2008, 10:17 PM	#9
Koyotejager Curio & Relic Contributor AKaholic #: 4230 Join Date: Aug 2005 Location: Lost Nation Posts: 2,180	Yea, it should. I would use it. __________________ FURTH FORTUNE AND FILL THE FETTERS MacMhuirich You may find my body in a ditch, but, I will be lying on a bed of brass "The 9mm may properly expand, but the .45 will never shrink." unknown" When the chips are down, having almost any gun availible can far surpass the value of throwing rocks.

03-25-2008, 10:05 PM	#4
kikilee Member AKaholic #: 7876 Join Date: Mar 2007 Posts: 102	Unless the hole are over reamed a lot the rivets should fill and hold fine. If it were me I would try to use the original trunion if at all possible.

03-25-2008, 10:07 PM	#6
amd65 Member AKaholic #: 10323 Join Date: Dec 2007 Location: Florida Posts: 203	I pressed the bulgy trunion on the barrel and checked the headspace. Thats how I know both trunions are suitable as far as headspacing goes.

03-25-2008, 10:15 PM	#8
amd65 Member AKaholic #: 10323 Join Date: Dec 2007 Location: Florida Posts: 203	The two holes are expanded about a millimeter on one side. Will the rivet expand enough to fill this?

03-25-2008, 10:35 PM	#10
chief4guns Member AKaholic #: 10570 Join Date: Jan 2008 Location: Temple Texas Posts: 256	Riveting I would use the original trunion and heat the rivet shank red hot with a torch. (a propane is good enough to heat rivets) Pop it in and press it. I guarantee it will expand and fill the whole hole if you press it hot!! Just make sure it's long enough. Thats the way they used to do Skyscraper beams, Oil tanks, Ships, ect. Sooo!! don't 15 of you well meaning metallurgists jump on me and start talking about rivets and changing the molecular structure. They are in an annealed (read soft state) to start with so you can crush them. Chief

03-25-2008, 10:38 PM	#11
amd65 Member AKaholic #: 10323 Join Date: Dec 2007 Location: Florida Posts: 203	Ooooh, I think that is exactly what I will do. Any more good advice?

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