Up to 60% Off Daily Deal Products. Palmetto State Armory
The Ultimate Gun Belt, US Made, Lifetime Warranty, Free Shipping. Shop Now.
Gorilla Ammo Free Shipping when you order 10 Boxes or more.
Shop all the current Lone Wolf closeouts here

Go Back   The AK Files Forums > General Forums > Gunsmithing & Build It Yourself

Notices

Reply
 
Thread Tools
Old 08-06-2018, 03:34 PM   #71
robertmbowman
Member
Vendor
 
AKaholic #: 180147
Join Date: Apr 2015
Location: Hawthorne, Florida
Posts: 384
Default

It is IMPOSSIBLE to get an approved import permit for Russian or Chinese SVD.
Even the DOD is forbidden to purchase them, gov contract or not.

We used to sell the DOD most every Tigr that came up for sale on GB, because it is the closest rifle they could get for training.

We tried to import the [new made] semi-auto Serbian copy, an approved permit required that the rifle be sent to ATF for examination.
ATF said it was too easy to convert to full-auto, so they kept it, scope and all.
Why that semi-auto receiver was easy to convert, but AK imports are not, is still a mystery to me.
bob
robertmbowman is offline   Reply With Quote
Old 08-06-2018, 04:06 PM   #72
WolfmanReid
Member
 
AKaholic #: 154786
Join Date: Oct 2010
Location: NoVA
Posts: 340
Default

I had a metallurgical analysis done of of a scrapped SVD receiver a while back. They are made out of a structural steel that is only available in Russia and China (I forget the exact alphanumerical designator they use) but is fairly close to 5130 steel. Tested at 41 HRC.
WolfmanReid is online now   Reply With Quote
Old 08-06-2018, 05:54 PM   #73
Brick
Senior Member
 
AKaholic #: 1281
Join Date: Jan 2004
Location: MI
Posts: 642
Default

Thanks for the info. They will definitely have to be heat treated or they won't survive. The outer surface should be about the same as the bolt. This ensures one does not destroy the other. The next question is how deep the hardness should go. It probably should NOT be through hardened as this would make it brittle and prone to cracking. You want more of a case hardening so the crust is hard but interior is softer to take the abuse without cracking.

If I remember right the M-14 was case hardened to about .015-020" deep, but my memory is not what it used to be.


Brick
Brick is online now   Reply With Quote
Old 08-07-2018, 07:38 AM   #74
allesennogwat
Curio & Relic
 
allesennogwat's Avatar
 
AKaholic #: 3738
Join Date: Apr 2005
Posts: 46,749
Default

Quote:
Originally Posted by WolfmanReid View Post
I had a metallurgical analysis done of of a scrapped SVD receiver a while back. They are made out of a structural steel that is only available in Russia and China (I forget the exact alphanumerical designator they use) but is fairly close to 5130 steel. Tested at 41 HRC.
The original forged receivers are the Soviet equivalent of 5140 steel. (The Soviet steel has a bit more chromium, similar to 5135 steel.}

These are milled American receivers and are likely a form of 4140 steel.

As long they get heat treated above 40 HRC they should be alright.

Some."pre-hardened" 4140 has additional sulfur added which can change the heat treat results slightly.

The pre-hardened 4140 isn't hard enough to use as-is, but sometimes makes machining more consistent, and will still require heat treating to the correct hardness.

If these below 28 HRC, then they are likely not pre-hardened.
__________________
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.
allesennogwat is online now   Reply With Quote
Old 08-07-2018, 08:07 AM   #75
mace2364
Senior Member
 
AKaholic #: 10856
Join Date: Feb 2008
Posts: 949
Default

Quote:
Originally Posted by allesennogwat View Post
The original forged receivers are the Soviet equivalent of 5140 steel. (The Soviet steel has a bit more chromium, similar to 5135 steel.}

These are milled American receivers and are likely a form of 4140 steel.

As long they get heat treated above 40 HRC they should be alright.

Some."pre-hardened" 4140 has additional sulfur added which can change the heat treat results slightly.

The pre-hardened 4140 isn't hard enough to use as-is, but sometimes makes machining more consistent, and will still require heat treating to the correct hardness.

If these below 28 HRC, then they are likely not pre-hardened.

They are 4140. I checked mine yesterday with the "scanner" at work. I haven't had the chance to put them on a Rockwell tester yet, but hopefully soon.
mace2364 is offline   Reply With Quote
Old 08-07-2018, 11:40 AM   #76
Hilljack
Veteran Member
Contributor
 
AKaholic #: 29
Join Date: Nov 2003
Location: Albuquerque, NM
Posts: 1,550
Default

Thanks for the update. Great information.
__________________
http://dragunov.us/
Hilljack is online now   Reply With Quote
Old 09-07-2018, 09:10 AM   #77
mace2364
Senior Member
 
AKaholic #: 10856
Join Date: Feb 2008
Posts: 949
Default

OK, time for an update.

I finally got around to hardness testing the receiver. Mine is definitely NOT heat treated. I was getting something like 2 RC. I tested a PSL trunnion for comparison, and it was about 45 RC. So these will definitely need to be heat treated before they can be built.
mace2364 is offline   Reply With Quote
Old 09-07-2018, 09:34 AM   #78
AKBLUE
Curio & Relic
Bronze Contributor
 
AKBLUE's Avatar
 
AKaholic #: 5035
Join Date: Dec 2005
Location: Hilliard, Ohio
Posts: 28,569
Default

Really a #2 RC? I'm no metals guy ., but is that like soft as "buttah" ?
I thought common copper pipe was a #10 RC or something?
No big deal., just wondering over that number.
AKBLUE is online now   Reply With Quote
Old 09-07-2018, 09:37 AM   #79
mace2364
Senior Member
 
AKaholic #: 10856
Join Date: Feb 2008
Posts: 949
Default

Quote:
Originally Posted by AKBLUE View Post
Really a #2 RC? I'm no metals guy ., but is that like soft as "buttah" ?
I thought common copper pipe was a #10 RC or something?
No big deal., just wondering over that number.
Yeah, I did too. So I tested it 3 times, same thing every time. I tested some other stuff at the same time, some of which was basically a known hardness, and it was all where it was supposed to be. So I don't think it was me.
mace2364 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 07:08 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
©1998-2018 The AK FIles