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Discussion Starter · #1 ·
Got a couple of questions regarding possibly using a Izzy '88 parts kit for a '74 build. On most examples I have seen the front sight base, gas block, rear sight block, & gas piston are retained with the machine pressed dimples as opposed to steel pins. I read a thread in which later '74s once again have reverted to using steel pins. Possibly dimpled components might be susceptible to working loose over time with service use. My question is, how much more (or less) difficult is it for a builder to remove these components from the barrel stubs and reinstall them on a virgin (Bulgy) barrel? Seems it would be quite a task to put an adequate preset back onto the dimples; particularly while trying to line up the fsb, gb, & rsb...
 

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You read a lot of stuff on the internet. Not all of it's true, though.

There's no way dimpled parts are "working loose".
 

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Discussion Starter · #5 ·
So then, there are small nibs on the barrel which line-up with the dimples on the fsb, gb, & sb, so when the parts are pressed onto the barrel they more or less snap into place ? If so, then what would be the work-around if one used these parts on a replacement barrel without any nibs ? Would the builder line up everything & use something like a punch tapped thru the dimple holes on the components to make a mark on the barrel then remove & tack weld the nibs where indicated to now allow the components to be pressed onto the nibs maintaining alignment? I am trying to grasp the order of things, but it seems a bit of work...!
 

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Every builder has their own methods, I guess, but I know the main gunsmith I've dealt with over the years usually pins the parts on, then carefully welds (or solders over) and files flush the pin ends so they blend in perfectly and all you see are the original factory dimples on the sides, which are not really doing anything but looking pretty afterwards. You don't even really have to do any welding IMO.

I think that's likely the easiest of possibly several professional methods utilized, and will allow precise alignment and proper securing of used, previously dimpled parts. It's the only method I would try to do myself, I think. I've also known some guys that just weld them up on the barrel, then drill or mill out new dimples afterwards. This might be fine but that's not as good IMO. I don't like welding cast metal to forged barrels, heating up barrel temper, or burning off all the original paint and phosphate protective undercoating on the attachment parts.

It seems way better to save the old factory made dimple and covertly pin the parts on. It will not come off unless you want it to, and you can be sure to get everything aligned straight that way, or have a way to straighten it later, or even replace ti if you wish.

Trying to just align and mash a used dimpled part back into divots you've made into a new barrel seems superbly hit and miss, and very impractical. It will definitely not be secured like a factory barrel that has a solid, non-pre-dimpled virgin part hydraulically pressed into a perfectly aligned dimple hole.

I'm sure this is also the concern you have had, judging by your line of questioning you have carefully and logically thought out this process already. Some of your reservations have stemmed from the fact others have assumed the Russians have abandoned press-punched barrel assembly, but I think this is far from the truth. On military mass-produced standard quality rifles going to the domestic military forces, they have always used dimpled barrel assemblies, which increased production speed and cut down on man-hours. At least since 1985.

However, on limited run rifles like prototypes, or rifles being built for special purposes or clients, or custom orders going overseas, or to achieve what is often referred to as "export quality', or on most non-standard calibers, or on 7,62mm 103/104 rifles (where the barrel wall thickness is quite a bit thinner due to the larger bore), they have generally used the traditional pinned method.

The punch-pressed or dimpled assembly method is faster, but it's also more technically challenging and mechanically complex, i.e. it's more easily done in a very heavily automated manufacturing environment. The pinned method is something that is likely still very much a manual process to a certain extent. It's also considered more cosmetically pleasing and of a higher quality standard, simply because it's old school, done almost bu hand and takes more time. It can also facilitate replacement of parts (which might be a requirement to certain outside entities), while the punch-press method symbolizes more of a cheap, throwaway mentality. I'm sure customers entering into large contracts have the option to request certain levels of workmanship, and this could be part of a "premium level" package.

Or it could just be easier and preferable for them to do small runs using pinned parts. In almost all cases, all through the 90's and 2000's, lower volume rifle production models have been pinned. This seems to indicate the press-punch method is only relied upon when large numbers of rifles are being produced, while pinned on barrels are easier to do on a lower volume and preferred for special orders. It might be cheaper on lower volumes to do the pins rather than cranking up the powerful and complex horizontal jig presses that do the pressing. This is just conjecture on my part, but maybe they have more rejects due to canted parts using that method, so on limited runs it saves money by not having any discards?

In the last several years, Izhmash has not produced any substantial numbers of AK-74M for the domestic military, so in reality almost everything they have made for almost a decade could likely be considered "limited run" so to speak. Taking all this into consideration, and keeping in mind both the press-punched and pinned-on methods have both been used alternatively back and forth for the last 25+ years, I'm not sure how we can definitively assume at this point in time they have completely abandoned punch-press barrel assembly technology.

If they did, which is remote, it was certainly not a decision based on a result of them becoming loose. They would not have went to it in the first place if it was not deemed to be as effective as the conventional method. The Soviet's were historically very cautious to adopt new methods of manufacture that might in any way detract from the reliability of their small arms systems. A decision like that would have been related to a host of many other more logistical factors as I have touched upon here.

I believe this because, IMHO, press-punched assemblage is not as handsome but is far more secure for the long haul than pinned-on parts would be. Just try and take some off, hehe. They are meant to be permanent. Take a big pipe wrench to a pinned-on front sight base and you can eventually apply enough sideways pressure to bend the pins and the part will move, or even get loose. Do that with a press-punched part and you will break off the ears and/or destroy the part before it moves on the barrel.

In any case, i hope this helps you decide to build that '88 and get it looking correct without using any methods that you might feel uncomfortable with. Now you can get with your builder of choice and discuss it with some basic knowledge on hand. Find out how he wants to tackle it, and if it's not to your satisfaction then give him your suggestions, or change gears entirely. Many of the well known builders that often frequent this forum can do these types of builds with one eye closed these days. It's amazing the quality they put out. If you need any suggestions, then don't be afraid to ask.
 

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I just pressed the barrel stubs out of the dimpled parts (RSB, GB, FSB) as normal. They are stiff but I've managed to push them out with no problems yet. I pinned the parts on the new barrel as normally done. Note that the threaded shroud forward of the FSB is actually a separate piece on these 1988 kits. The shroud is actually pinned on the barrel.
 

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Discussion Starter · #8 ·
Thanks for the excellent information on this process, Tantal, and to everyone else whom helped to enlighten me. My dilemma is I want to add a Russian '74 dressed out in laminate. I had been thinking of getting a SGL21-62 and swapping out the furniture & gas piston. Coupled w/a US made (Arsenal) gas piston, magazine floorplate & follower, I can maintain 922r compliance. In this instance I wouldn't have to worry about lining up issues, and get a factory assembled rifle.

On the other hand, building from the kit provides another 922r component in the receiver, and is based on a military '74. My preference is not to go with a scope rail on this rifle, which I get with the SGL. I can have the "Y" pressing & full set of Cyrillic selector markings added as well, which I think given the two choices, provides a cleaner Mil-spec look & appeal. Cost might be a couple of hundred more for the build than a SGL21-62, but in some respects you are getting more for your buck. Had I gotten into the game ten or fifteen years ago, I would likely be a "purist" collector/shooter, but residing on the "left coast" pretty much precluded me from buying anything but bastardized AKs...
 

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Excellent write-up, Tantal. That's a great observation regarding the 'high volume' vs 'low volume' connection between the factory's choice to do a traditional pinned method vs the more automated punch press method. I never thought of it that way but I think you're right on.

I'm also in the process of building up a pair of '88 -74's and am coming to terms with the amount of work it's going to take to preserve those dimples. :) I know lots of folks have tackled this in a variety of ways (including just pressing out the stubs as mentioned earlier). I'm taking the path of milling out the stubs, pushing the dimples back out, and then trying to reform the dimples back into new pockets milled into the new barrel. I'm working out the new tooling necessary to do this, but the intent is to avoid pinning if at all possible. Pinning isn't a problem technically, and it's a good backup plan - but I'm really interested in knowing if re-formed-but-original dimples can be "re-used" in their intended capacity of reliably fixing the gb and fsb in place. I think they can be, given the proper tooling and technique.

BTW, I always try to build in pairs - that way I can learn from one, and end up applying the learnings to the other if I make some significant discovery. Then at least I have one really good one :D.

-Thirtycal
 

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So then, there are small nibs on the barrel which line-up with the dimples on the fsb, gb, & sb, so when the parts are pressed onto the barrel they more or less snap into place ? If so, then what would be the work-around if one used these parts on a replacement barrel without any nibs ? Would the builder line up everything & use something like a punch tapped thru the dimple holes on the components to make a mark on the barrel then remove & tack weld the nibs where indicated to now allow the components to be pressed onto the nibs maintaining alignment? I am trying to grasp the order of things, but it seems a bit of work...!
Yes "nibs" (dimples) in the barrel...Here are a few pic's or a Russian AK-74 barrel. It still has the RSB installed, however you can see the "dimples" milled out of the barrel where the gas block, and FSB would be...

I need to get one of the Izhmash 88 dated kits to build on this...








 
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