Pressing on AK gas block and front sight. How?

[mutt]

I decided to start my foray into AK building by doing a front end conversion on my Saiga 7.62x39. I managed to press off the old gas block and front sight with my press. I tried using the Toth Tool barrel populating tool to press on the new gas block (Bulgarian AK74 type) and that's not going so well. I can only get the gas block going about a quarter of an inch before the threaded rods start bending. I am guessing the tolerances on the Saiga barrel are just too tight for the Toth so I need to use the press to put on the new parts as well.

My question is how do I support the barrel or receiver so I can press the parts on? I don't really see a good way. Is there some special jig I need to buy? And what should I use to press on the gas block? Some kind of steel pipe? I used a 15mm open end wrench as a support to press off the parts but that isn't going to work so well for installation.

Hoping those of you who have built AKs can give me some pointers.

[Joe_K]

I decided to start my foray into AK building by doing a front end conversion on my Saiga 7.62x39. I managed to press off the old gas block and front sight with my press. I tried using the Toth Tool barrel populating tool to press on the new gas block (Bulgarian AK74 type) and that's not going so well. I can only get the gas block going about a quarter of an inch before the threaded rods start bending. I am guessing the tolerances on the Saiga barrel are just too tight for the Toth so I need to use the press to put on the new parts as well.

My question is how do I support the barrel or receiver so I can press the parts on? I don't really see a good way. Is there some special jig I need to buy? And what should I use to press on the gas block? Some kind of steel pipe? I used a 15mm open end wrench as a support to press off the parts but that isn't going to work so well for installation.

Hoping those of you who have built AKs can give me some pointers.

Easy answer? Take a Rifle Dynamics AK builder class.


“Don’t go slow, be careful” Jedi

[Great-Kazoo]

Use a bearing splitter on the gas block, press bbl on to gas block checking alignment as you go. You need a decent hydraulic press to do it the right way, as well as easier.

SHAMELSS PLUG. I happen to have a 12 T blackhawk press for sale, cheap. ;)

[ray1970]

What's the interference between the barrel and gas block? I'm assuming you measured them both before trying to press them together?

You might try putting the barrel in the freezer overnight and heating the gas block in the oven to make it go together easier.

[Great-Kazoo]

What's the interference between the barrel and gas block? I'm assuming you measured them both before trying to press them together?

You might try putting the barrel in the freezer overnight and heating the gas block in the oven to make it go together easier.

There's so many different mfg of Ak parts, unless it was a matching number kit (even then) the gas block and front sight could be a tight tolerance, or one you can install with a soft mallet.

Best thing to do is watch lots of video's of AK builds, have the right tools, or find a COMPETENT smith to do the work.

[ray1970]

Best thing to do is watch lots of video's of AK builds, have the right tools

Like a certain twelve ton press that's for sale?
[Coffee]

[Great-Kazoo]

Like a certain twelve ton press that's for sale?
[Coffee]

Among other things, yes. A decent press makes the task easier, or so i've been told.

[68Charger]

All the points have been mentioned...

1) Measure the OD of the barrel where it is going to press on, and the ID of the gas block you took off and the one you're trying to fit. The OD-ID is the "interference" of the fit... if the ID of the new one is smaller than the original, it's going to be a problem... if it's too small you're just going to break things by forcing it, you'll have to ream it to the correct size. You'll need a dial or digital caliper for this...one that measures to thousanths...

2) As Kazoo mentioned, a hydraulic press with the correct fixture (to hold the action in place without distorting things) is the right way to do this... I've seen the other tools available, and they're cheesy on comparison.

3) if the interference isn't too much more than the original sight block, cooling the bbl and/or heating the sight block will help alot... if it's too much, it'll just add to the frustration.

4) Getting the sight block aligned (not canted) is another issue to avoid... if the pin holes line up with the previous sight are good, that would be a good way to line it up.

If you continue down this path, you be getting a lot more tools & tooling.

[def90]

Yep, you need to measure OD of barrel journal and ID of component being pressed on. If the component being pressed on is too small you need to either remove material from the barrel or the component, I would recommend removing from the component. Wrap some emery cloth around a dowel or drill bit and spin it around inside the barrel component until you get the correct interference fit which is about .001 (your component ID should be .001 less than the OD of the barrel journal) once you do this the component should press on without issues. If you try to press on a component that is too small you run the risk of bending the barrel or cracking the component.

[zteknik]

Late to the thread, you guys have it covered. Carry on..[Coffee]