Go Back   The AK Files Forums > Rifle Forums > SVDs and RomAK IIIs

Notices

Reply
 
Thread Tools
Old 07-29-2009, 03:38 AM   #1
Grantman
Member
 
AKaholic #: 12536
Join Date: May 2008
Location: New Zealand
Posts: 95
Default The Dragunov setup & handling heavier loads

I was wondering how the exact mechanics of my Dragunov recoil system worked. What exactly was the Dragunov design for stopping the bolt as it completes its travel rearward after a shot? What makes this question particularly relevant to me is that I shoot nothing but heavy ammunition through my Dragunov which some people advise to steer clear of.

Iíve put approximately 560 rounds of 203gr Barnaul SP, 40 rounds of 180gr Highland AX and 100 rounds of 183gr Hungarian heavy ball through my Tigr since I bought it new 14 months ago. So all up the round count rounds off to an even 700 rounds of powerful heavy ammo. Iíve found that no commercially available 7.62x54r under 180gr exists in NZ unless you reload cartridges yourself.

As to manufacturer information on shooting heavy ammunition, the age old sole Dragunov SVD and Dragunov Tigr manufacturer Izhmash specifically lists the 7.62x54r bullet weight for the Tigr as 13.2 grams (203.7 grain) which just so happens to be the only Russian hunting cartridge Iíve ever seen and profusely shot in NZ (203gr Barnaul SP). No real surprise since they market their Tigrs as "self-loading hunting rifles."
http://www.izhmash.ru/eng/product/tigr.shtml

Another interesting note is that the Dragunov Tigr (Tigr 9) is also chambered for the far more potent 9.3x64mm round which would indicate the Tigr receiver is easily strong enough to handle the comparatively insignificant 54r heavy ball.


So anyway while I was cleaning my Tigr after a shoot I decided Iíd see what exactly goes on.




If you own a Dragunov and wondered if these rivets in the receiver cover bear any weight as the bolt recoils you can be sure that if they did, they and their thin receiver cover pin holes would be rattling and probably a little mangled after a only few shots. Rest assured the Russians aren't into designing fragile small arms and the only strain those rivets endure is the light weight of the recoil spring assembly when you remove the receiver cover.





There are 3 parts of the rifle that take the weight of halting the bolt carrier. There is this goodly chunk of metal rotating in the receiver cover; I guess you would call it the bolt buffer. The buffer makes direct contact with the rear of the retreating bolt carrier.






Then there is the chunky takedown lever pin which sits in the back of the receiver and lastly the back of the receiver itself.




You will notice from earlier pictures that the buffer (if thatís the correct term) is wedge shaped. Also notice that the rear of the receiver is sloped forward to accommodate that wedge. As can be seen below, the scuffs on the rear buffer show a fairly good fit with the back of the receiver.





The back of the buffer slides down against the sloped receiver rear and is tightly crushed hard up against the back of the receiver when the takedown lever is rotated shut. From the earlier pics you can see that the buffer has a groove in its front to accommodate the takedown lever pin. A person could separate the recoil spring and buffer assembly from the dust cover (this would mean breaking the rivets of course so ya don't want to do it) and the Dragunov would operate just the same without it once the take down lever is clamped shut on the assembly.






Bolt fully retracted against the buffer. I had to remove the forward most recoil spring to make is easier to retract. As you can see the bolt handle comes up very precisely just short of the receiver cover. The recoil spring setup itself compresses to about 85% of its ability before the bolt is stopped by the buffer.






So all in all a rock solid setup. My riveted receiver cover pin has no play or slop (neither should it, there is no stress on it), and neither does my take down lever in approx 700 shots fired. Short of some pretty hefty metal deciding to give way this setup will be good to go indefinitely.

__________________
New Zealand Dragunov Tigr

Last edited by Grantman; 07-29-2009 at 03:48 AM.
Grantman is offline   Reply With Quote
Old 07-29-2009, 04:35 AM   #2
Tigr
Senior Member
 
AKaholic #: 22359
Join Date: Dec 2008
Location: United States, Hawaii
Posts: 548
Default

Great read and info. I'm hoping to pick up a Tigr soon myself when funds permit me so.

Also one thing to point out as well is your Tigr has the smoother, stronger receiver cover as pointed out by dragunov.net for being an improvement over the thinner, ribbed version.

Again, awesome looking rifle and your info has nudged me closer to buying one.
Tigr is offline   Reply With Quote
Old 07-29-2009, 06:04 PM   #3
Jaimenv
Veteran Member
 
Jaimenv's Avatar
 
AKaholic #: 9749
Join Date: Nov 2007
Location: San Antonio TX.
Posts: 1,270
Default

+ 1 thanks for the information.

My Tiger rifle came with a very hard polymer buffer installed on the cylindrical looking buffer that stops the bolt.

I figure it was installed by the prior owner.
__________________
Jaime
Jaimenv is offline   Reply With Quote
Old 07-29-2009, 10:34 PM   #4
Mr. O
New Member
 
AKaholic #: 51555
Join Date: Jul 2009
Location: USA
Posts: 2
Default

Interesting that Izhmash lists the 203 grain projectile, this would tend to debunk the heavy ball / light ball debates.

An observation regarding the Chinese design, it is a bit different.
The recoil spring piviots but the "buffer" stays put , as it is rivited in place
from the top.
Attached Images
File Type: jpg NDM_Cover 001.jpg (73.6 KB, 117 views)
File Type: jpg NDM_Cover 005.jpg (24.5 KB, 116 views)
File Type: jpg NDM_Cover 006.jpg (26.2 KB, 110 views)

Last edited by Mr. O; 07-29-2009 at 10:39 PM. Reason: spelling
Mr. O is offline   Reply With Quote
Old 07-29-2009, 11:31 PM   #5
Grantman
Member
 
AKaholic #: 12536
Join Date: May 2008
Location: New Zealand
Posts: 95
Default

Interesting, I'd never noticed that about the NDM before. The recoil spring in the Tigr also pivots downward to a degree independent of the buffer and locks back on the buffer when pushed rearward.
__________________
New Zealand Dragunov Tigr
Grantman is offline   Reply With Quote
Old 07-30-2009, 12:12 AM   #6
allesennogwat
Curio & Relic
 
allesennogwat's Avatar
 
AKaholic #: 3738
Join Date: Apr 2005
Posts: 44,098
Default

The heavy bullets aren't as hard on Dragunov's as they are on PSL's. The PSL with it's extended recoil length, recoiling parts and especially the longer recoil spring make it marginal in holding up to a lot of ammo. Brazil used a 30-06 version of the German 8mm G-43 after the war and the slight extra length required in the action tore the rifles apart. There are 308 Winchester AK's in standard length actions that produce a lot of gas without tearing apart.

Many military Dragunov's have an adjustable gas system while many Tigr's do not. The biggest problem in the Dragunov, which may not be a problem in the current Tigr, is the rifling twist in the older Dragunov's is slower and designed for the shorter non-armor piercing bullets. The newer Dragunov has faster rifling available to use the longer armor piercing and API bullets.
__________________
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 07-30-2009, 12:52 AM   #7
Grantman
Member
 
AKaholic #: 12536
Join Date: May 2008
Location: New Zealand
Posts: 95
Default

From what I recall the adjustable gas system on the SVD (and that has also been sold on select Tigrs here in NZ) has just 2 settings with the standard setting leaving the vent holes in the gas tube unobstructed and the second setting used for extreme fouling which rotates some sort of internal sleeve to block off a good portion of those vent holes. So basically the adjustable gas system is not designed to reduce gas pressure, just increase it in extreme cases. The default unobstructed gas tube holes are probably something similar in size to what Tigrs have.




I've measured my rifling twist to be 1:320mm or 1:12.6" which was said to be the original SVD twist before they tightened it to 1:240mm or 1:9.6" for the effective use of incendiary and likely armour piercing ammo and such. Still, the 1:320mm twist still seems to stabilise the heavy 203gr Barnual ammo Iíve used. Someday Iíll put some lighter ammo through to see how it performs.
__________________
New Zealand Dragunov Tigr
Grantman is offline   Reply With Quote
Old 07-30-2009, 10:19 AM   #8
Rick_A
Member
 
Rick_A's Avatar
 
AKaholic #: 32144
Join Date: Feb 2009
Location: Jacksonville, FL
Posts: 335
Default

Interesting stuff. I haven't looked at the innards of a Dragunov in 13 years.

I could see how the Tigr and Dragunov's have no problem with heavy ball (and don't recall hearing about that being a problem)...but PSL's have the rear of the receiver riveted to sheetmetal. That Tigr receiver is pretty beefy back there.

I too, used to long for those rifles...but while they still look a bunch better, are built better, and have a mystique associated with them...my PSL suits me just fine.
Rick_A is offline   Reply With Quote
Old 07-30-2009, 03:47 PM   #9
Berg
Member
 
Berg's Avatar
 
AKaholic #: 868
Join Date: Nov 2003
Location: The Golden State
Posts: 430
Default

Great photos and description. It's a good explanation of the strength of the rear action.

There really shouldn't be any debate about bullet weights as it pertains to a Dragunov (as in, real Dragunov design). As stated, the factory that makes these rifles states that they are designed for heavier bullets (over 200 grains).

The debate seems to stem from people's confusion over calling a Romanian PSL a Dragunov and then applying the light bullet rule too broadly.

My 1993 Tigr has the 1:12 twist and seems to shoot Wolf 154 gr and 7N1 very well. I have some Barnaul 185 gr ammo I will be testing soon and have made some handloads with the Lapua 200 grain match bullet I will also test.
Berg is offline   Reply With Quote
Old 07-30-2009, 05:16 PM   #10
Grantman
Member
 
AKaholic #: 12536
Join Date: May 2008
Location: New Zealand
Posts: 95
Default

Regarding the Barnaul 185gr, I'm guessing it is FMJ. I've tested about 20 rounds of it and found my Dragunov likes to sling it everywhere (not near as bad as the Hungarian heavy ball though). Granted it may have been while the glass in the eyepiece was working loose. I've still got a few rounds of it so someday I'll re-test. Those ammo tests will be very interesting.

__________________
New Zealand Dragunov Tigr
Grantman is offline   Reply With Quote
Old 08-02-2009, 09:16 PM   #11
Mr. O
New Member
 
AKaholic #: 51555
Join Date: Jul 2009
Location: USA
Posts: 2
Default

I had used some S&B 180 grain soft point through my NDM some years ago.
It was very accurate, but I was having pierced primer issues with it.
From that point on I have just used surplus through it.
But I am getting some handloads made up to try out, so I may be able to take
it out for this years deer season.
Mr. O is offline   Reply With Quote
Old 09-18-2009, 05:10 PM   #12
Grantman
Member
 
AKaholic #: 12536
Join Date: May 2008
Location: New Zealand
Posts: 95
Default

Well it is now doubly official.

1. As already mentioned, the Izhmash website officially details a 13.2gram (203gr) bullet weight for the Tigr http://www.izhmash.ru/eng/product/tigr.shtml

2. Confirmed in email below from B.B. Mikhalchuk, director on commerce "CONCERN "IZHMASH" OJSC



I had also heard the Dragunov SVD barrel differed not only in twist but manufacturing process vs the Tigr so enquired about that also.

Below is an email I sent to Izhmash on the 29th July, 2009.

Quote:
Dear Sir/Madam,

I am a 7.62x54r Dragunov Tigr owner (serial # -------) in New Zealand and would greatly appreciate if you could answer some questions regarding my rifle.

My Tigr has the 620mm barrel with 1:320 twist.

1. Is it fine to shoot heavy ammunition such as 203gr Barnaul SP from my Tigr without damage it? I notice on your Izhmash website that it lists bullet weight for the Tigr as 13.2grams which equals 203.7 grain. I thought I would email to make sure.

2. I was informed that the Dragunov SVD barrel is cryogenically strengthened and electromagnetically polished while the Tigr's is not? Is this true (I'm not worried about it, just wonder if it is correct)?

Thank you very much for your time.

Kind Regards,
Grant ------

and on the 18th of September 2009 I received this reply from Izhmash


Quote:
Dear Sir,



Thank you for your interest in our products.

In reply to your request please be informed


1. 7.62x54 cartridge with bullet mass 13.2 g can be applied for Tigr
hunting carbine shooting



2. The barrels of either SVD and Tigr are produced according to the same
technology and differs in thread pitch only. Cryogenically
strengthening and electromagnetic polishing are not applied in
tecnological process.



Sincerely yours,

B.B. Mikhalchuk
director on commerce
"CONCERN "IZHMASH" OJSC

Fax: 7-3412-78-36-35
Phone: 7-3412-495-491; 7-3412-495-073
www.izhmash.ru
mailto:arms-export@izhmash.ru
__________________
New Zealand Dragunov Tigr
Grantman 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 Off

Forum Jump


All times are GMT -4. The time now is 03:32 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
©1998-2017 The AK FIles