Pressing Rear sight Blk

[ambis]

Hi,

What setup do you guys use when pressing a rear sight block onto a barrel that is already pressed into trunnions, and the trunnions are already riveted to the lower?

[SJgunguy24]

You need a pressing bar that's offset to press on the barrel directly. The only other way is to use the barrel press set up.(like when pressing the barrel into the receiver.) And use a pipe to press down on the sight block itself.
This is why you do the barrel work first before anything else.

[ar15barrels]

You need a pressing bar that's offset to press on the barrel directly. The only other way is to use the barrel press set up.(like when pressing the barrel into the receiver.) And use a pipe to press down on the sight block itself.
This is why you do the barrel work first before anything else.

Do you fully populate the barrel before pressing it into the trunion?
If so, are you only talking about new barrels, or also barrels that have been previously headspaced and all the pin holes drilled/reamed?

I have been doing a bunch of AK shorten/thread jobs lately where I completely strip the barrel down, shorten, thread and then re-assemble the gun.
Since the barrels are already headspaced and drilled, I just press the barrel back into the trunion (which is still riveted into the receiver), then press on the rear sight, gas block and front sight, using the receiver to align each of them as I press them back on...

Am I doing it wrong?

[SJgunguy24]

Do you fully populate the barrel before pressing it into the trunion?
If so, are you only talking about new barrels, or also barrels that have been previously headspaced and all the pin holes drilled/reamed?

I have been doing a bunch of AK shorten/thread jobs lately where I completely strip the barrel down, shorten, thread and then re-assemble the gun.
Since the barrels are already headspaced and drilled, I just press the barrel back into the trunion (which is still riveted into the receiver), then press on the rear sight, gas block and front sight, using the receiver to align each of them as I press them back on...

Am I doing it wrong?

No right or wrong way but normally I build up the barrel completly before installing into the receiver. I'll set headspace with the trunnion removed (if the new barrel) then pin and set all the parts from there.
If I remove the barrel to chop and thread, then I'll only pull the parts that I need to clear the chuck in the lathe. If they all need to come off, then reinstallation depends on how hard they were to remove.
I try to avoid messing with the receiver if I can but sometimes that can't be done. That's where the offset barrel bar comes in. It clears the back of the receiver and will go in far enough to get the barrel completly out.
You need that offset bar and a brass/copper/ or aluminum slug on the chamber end of the barrel to press the parts back on if the receiver is in the way. Or you use a long pipe to drive the parts back on from the muzzle end. Doing it that way you need to support the trunnion from the mag well.
I don't like doing that because you put undue pressure on the trunnion and barrel pin. You could get unlucky and crack one while doing that. Ask me how I know.

[kcstott]

Pull barrel, Populate, reinstall, Thats the way I "Like" to do it. As SJ said sometimes things don't work out that way.

Now I also like to measure all my parts and journals and make adjustment to get a .001" press at most. The extra time it takes to insure a good but not to tight of a press fit makes pressing a breeze and allows for relatively easy adjustment for alignment.

But either way I'm going to take the time to remove the barrel from the receiver or trunnion.


Oh and AK's Don't have lowers Just a minor point of irritation of mine.

[ar15barrels]

I try to avoid messing with the receiver if I can but sometimes that can't be done. That's where the offset barrel bar comes in. It clears the back of the receiver and will go in far enough to get the barrel completly out.

I'm not doing new builds so I always get in complete rifles to work on.

I have been making all my own press tooling that threads into my press ram including the offset pressing bars.
They thread on to the ram solidly so I can actually hang the whole barreled receiver there, then bring the pressing plates in around the barrel forward of the trunion and set everything up prior to pressing out the barrel.
I also have a few different length pipes, adapter sleeves eat to press any size of gas block or fsb on to or off of barrels.