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How much pressure for barrel threading?


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Greetings. So I'm attempting my first barrel threading. I don't have a real vice and have instead rigged something up on a table,  so the rifle is laying horizontal instead of vertical. I start twisting and the die doesn't catch, so I apply more pressure. Still nothing. I do this for a little while until eventually I'm putting all my body weight into it while turning. Two things have now happened: I have what appears to be the beginning of a thread on my barrel.  2) It looks as though the first tooth on my die is gone on two of the sides. 

 

So I stop and verify that the TAT is still able to screw all the way in/ out of the die. All good there. 

 

So I guess my question is -- is it normal to need to apply this much pressure when starting the threading process? I've never done anything like this before so I don't know what to expect, and this is just really surprising.

 

Thanks!

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What is the O.D. at the muzzle? If it's too big, you'll NEVER get it started.

 

I'm not currently able to measure it. However, I'm curious as to why it might be bigger than normal (I'm assuming this wouldn't be typical)?

Edited by cfr
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I seem to remember hearing about two different sizes at the muzzle, I don't think there were any identifying traits other than that though, so you really just have to measure it, or find someone who can.

 

If you know any reloaders or machinists they should have calipers or micrometers to measure with.

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I seem to remember hearing about two different sizes at the muzzle, I don't think there were any identifying traits other than that though, so you really just have to measure it, or find someone who can.

 

If you know any reloaders or machinists they should have calipers or micrometers to measure with.

 

This brings up a good point, I don't have anything fancy to measure with, nor do I have any friends that do (recently moved, no friends local yet). Why in the world would these guns come with different barrel diameters? 

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I seem to remember hearing about two different sizes at the muzzle, I don't think there were any identifying traits other than that though, so you really just have to measure it, or find someone who can.

 

If you know any reloaders or machinists they should have calipers or micrometers to measure with.

This brings up a good point, I don't have anything fancy to measure with, nor do I have any friends that do (recently moved, no friends local yet). Why in the world would these guns come with different barrel diameters?

Vodka
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If you have end wrenches you can use them as go/no-go gauges. Slip them over the barrel to estimate the size. Is this a s-12 barrel. On the 12ga it takes about 30-50ft/lbs of torque. So like tightening a 1/2" bolt pretty tight. When you are cutting threads it's more about smoothness. If it stops or binds suddenly, don't force it. It does take several turns before it cuts enough and you start making threads. I'm not a fan of 1/4 back up 3/4 and repeat method. But I would recommend you do it differently as it take a really good feel. Once I start cutting threads I don't stop until the die "says to. Sometimes that's half a turn, sometimes it's 6. Decent die, very good lube(I love kroil)and even pressue. What I mean by even pressure is only twist the die, don't side load or pull harder on one handle than the other. It will cut at angle if you have unequal pressure. Make sure you have a gap between your tat and the end of the barrel at all times. Post pics of your started threads and the die.

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You need to make sure of what your barrel outside diameter is since you are having trouble getting the die to start. According to the info on the CSS site, their die will thread barrels with a diameter of .551 to .571.

 

After threading two of my Saigas recently I was attempting to help a friend thread his the diameter of his barrel was large enough that even in a vise it was difficult to start even after spreading the die. In the end we needed to to abandon the effort because the die was actually stripping the threads off the end of the barrel. If your barrel ends up being too large to start the die on, you may need to use an annular cutter to reduce the outer diameter of the barrel down enough to get the die started.

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Other option is to run the DIE loose on the 1st pass.. then tighten down abit after you get the threads started.. also make sure the TAT is not bottoming out on the muzzle face.. that will PULL the threads and ruin the last few threads..  (ask me how I know)..

 

The die tightener is completely loose. I think what you mean by "TAT not bottoming  out" is to make sure theres plenty of teeth to get plenty of threads, right? 

Edited by cfr
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Is this a s-12 barrel.

 

 

No its a 7.62.

I skim through stuff too quickly some times. It was clearly in the x39 section. Have you had any luck with threaded it?

Also what he means buy bottoming out is when the threads on the tat touch the muzzle your bound up and will stip your new threads of break the die. So make sure and you thread in, you back the tat out.

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Is this a s-12 barrel.

 

No its a 7.62.

I skim through stuff too quickly some times. It was clearly in the x39 section. Have you had any luck with threaded it?

Also what he means buy bottoming out is when the threads on the tat touch the muzzle your bound up and will stip your new threads of break the die. So make sure and you thread in, you back the tat out.

 

 

 

I don't think I bottomed it out as I intentionally gave it some extra "slack". No luck yet. I measured it with a regular tape measure and so far what's happened is I'm 1/16'' down the barrel with no threads. Not exactly hosed, not exactly desirable. However, I was just reading this thread and can't help but wonder if post 17 is me. The table I'm using for this is low, and while I'm putting all the weight I can into it in reality it' might not be very much as it's an awkward angle. 

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So I just got done taking another crack at this. 1/8 of an inch down, two baby threads. My only apprehension with continuing is that the threads aren't as deep as expected, and at no point does it catch the way I expect it to. Now keep in mind my expectations of it catching are solely based on videos I've seen.

 

Will the threads get deeper the further I go? Will it catch at some point? Am I over analyzing this?

 

Should I man up and press forward? Borrow a caliper from a family member over the weekend to make sure I don't have an abnormally large barrel?

 

Thanks!

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CFR,

Something is definitely not right there. Either your barrel diameter is too large, or your die is tool small. I would not proceed further until you confirm measurements on both. Measure the barrel and measure the TAT. (Assuming that the TAT is correctly threading into the die). I will get some measurements tonight on my TAT and threaded barrel and post the measurements for you for comparison.

 

Some barrels can be a PITA to get started, but in your pic, that it a lot of material removed from the muzzle end. I know you mentioned that you backed out the screw on the die to open up the die some for the first pass., I just want to clarify that you did this with the die itself, and not just the die holder.

 

I will post up the measurements and a couple of pics for you this evening.

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Yes I had the die itself loosened.

 

Thinking further I'd assumed it must be the barrel diameter, since the standard CNC TAT screws into the die with no issues (if the die was smaller than normal, the TAT shouldn't be able to screw in).

Edited by cfr
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Yes I had the die itself loosened.

 

Thinking further I'd assumed it must be the barrel diameter, since the standard CNC TAT screws into the die with no issues (if the die was smaller than normal, the TAT shouldn't be able to screw in).

Agreed, but you should still measure it just to make sure that you got the correct set. Another way to check would be to make sure the TAT you are using properly threads into a 14x1LH muzzle break or flash hider if you have one. That would confirm it is the correct set for the barrel.

 

If the wrong set was shipped, say a 1/2" x28 tpi, the TAT would still screw into the die, but would be incompatible with the 7.62 barrel.

 

Just trying to eliminate as many variables as possible.

Edited by Spacehog
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Just looked at pictures. It looks like your .050-.075 too big. By chance is this a saiga "m" that legion sells? It has a .308 sized barrel. My opinion is you either have to cut down the of of barrel, or jump up to a thread size that will work on your gun. Both the annual cutters to DIY, or having it machined will cost a fair amount to make what you have work. Going to a dif thread size means new die and muzzle brake. You will have to decide the best option. Any way you go, you have to start with an accurate measurement of the barrel O.D. in order to proceed.

Once you post the OD I'm sure everyone will have answers on both sides.

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