Yugopap4me 29 Posted February 26, 2014 Report Share Posted February 26, 2014 (edited) I've heard of some people turning their AKs into basically a straight pull " bolt action" rifle to increase accuracy for long distance shots. Don't yugos have this type of gas shut off feature for grenades? But does this actually increase accuracy? I thought the bullet leaves the barrel before any of mechanicals move. Making a straight pull AK a moot point Edited February 26, 2014 by Yugopap4me Quote Link to post Share on other sites
csspecs 1,987 Posted February 26, 2014 Report Share Posted February 26, 2014 My Yugo SKS is more accurate with the gas turned off. I'd imagine its the same. The group was about 3" instead of 4" with wolf soft point at 100 yards. Quote Link to post Share on other sites
Yugopap4me 29 Posted February 26, 2014 Author Report Share Posted February 26, 2014 That's unusual. I wonder if the hot gases in the gas tube have a part to play..instead of being shot out of the barrel. That's the only thing I can think of Quote Link to post Share on other sites
GregM1 241 Posted February 27, 2014 Report Share Posted February 27, 2014 there are vids on youtube of people in europe using straight pull (all their law allows) to shoot targets at 1000m. Quote Link to post Share on other sites
csspecs 1,987 Posted February 27, 2014 Report Share Posted February 27, 2014 A good part of the increased accuracy you may see by shutting the gas off, is that the action is not moving at all. Think of it this way, the moment the bullet passes the gas port things start to move in the action. Any movement is going to shift your point of aim a little. And in an AK due to the way the gas block is mounted the force of working the action is actually pushing down on the barrel, possibly bending it ever so slightly, which could also throw the shot a little. Several years ago, my brother had thought about plugging the barrel ports and using compressed air to operate the action, and timing it using a optical sensor to watch for the bullet to exit the barrel before cycling. That way you could have zero action movement until well after the round left the chamber... Never got far into that project, but it would be interesting to see. 2 Quote Link to post Share on other sites
Maxwelhse 1,285 Posted February 27, 2014 Report Share Posted February 27, 2014 Don't yugos have this type of gas shut off feature for grenades? I can't speak for the accuracy comment because I've never tried i... But.. .YEP! Yugo AKs sure do have a gas defeat feature! Here's my M-70 underfolder in normal and "grenade" modes. You can see that the change happens at pretty much the direct beginning of the gas tube. I could believe that it could put more some more guts to the round coming out of the barrel with the gas defeated. Of course, as you mentioned, that makes it a single round rifle. I've never tried it, but I suspect it's even worse than a bolt action because you'll be tossing every other round on the ground from all the feed jams. Quote Link to post Share on other sites
thebuns1 4,323 Posted February 27, 2014 Report Share Posted February 27, 2014 I don't know if you would get much gain. The receiver is still going to have flex and the carrier cycling wouldn't have that much effect on it. That's just my opinion on it. I may be wrong though. Quote Link to post Share on other sites
S12KS-K 40 Posted February 27, 2014 Report Share Posted February 27, 2014 I've heard of some people turning their AKs into basically a straight pull " bolt action" rifle to increase accuracy for long distance shots. Don't yugos have this type of gas shut off feature for grenades? But does this actually increase accuracy? I thought the bullet leaves the barrel before any of mechanicals move. Making a straight pull AK a moot point I've got a battery operated drill I want to turn into an air impact.... Quote Link to post Share on other sites
WardenWolf 6 Posted March 8, 2014 Report Share Posted March 8, 2014 (edited) To those who shoot their SKS that way, it's not good for the gun. Grenade mode was intended for use with blanks, NOT live ammo. It can lock the bolt up very solidly to the point where it can sometimes require a mallet to get the action open. Anything that causes that kind of lockup is going to be peening the metal parts and doing permanent damage. Now, the AK uses an entirely different system, with a rotating bolt and a much tighter lockup. It's functionally much more robust and there's no real difference in bolt stresses whether the gas system is active or not. Back in the days of the AWB, there was an interesting weapon. The Romanian PAR-1, and its .223 brother the PAR-3, PAR standing for Pump-Action Rifle. This was literally an AK with no gas ports, and a pump connected to the gas piston assembly. Reportedly, these were unusually accurate for an AK-type rifle. Judging by that, you likely could get some accuracy improvement. However, with a good AK able to pull around 2-2.25 MOA nowadays, is it even worth bothering with? Edited March 8, 2014 by WardenWolf Quote Link to post Share on other sites
DrThunder88 912 Posted March 8, 2014 Report Share Posted March 8, 2014 That doesn't make a great deal of sense to me. Since the camming surfaces and locking surfaces are separate, does it even matter that they aren't being worn or peened evenly? The locking surface of the bolt and its counterpart in the receiver take the full brunt of the pressure curve for as long as the bullet is in the barrel regardless of whether or not the gun cycles, so it seems like rapidly dropping pressure of the vented barrel would be almost irrelevant to it. Have there been any confirmed cases of this peening problem? I searched for it, but for all the SKS jams I found, none were attributed to peening caused by single-shot firing. Quote Link to post Share on other sites
Inebriated 31 Posted March 8, 2014 Report Share Posted March 8, 2014 I've yet to have an issue ringing torso-sized steel at 400 yards with any AK I've shot it with. Quote Link to post Share on other sites
WardenWolf 6 Posted March 10, 2014 Report Share Posted March 10, 2014 (edited) Have there been any confirmed cases of this peening problem? I searched for it, but for all the SKS jams I found, none were attributed to peening caused by single-shot firing. The problem is specific to SKS's due to their action design. They use a tilt-bolt with a totally different lockup mechanism than the AK. The jams aren't the result of peening, but rather the forces and movement that cause these jams will also cause peening. Generally, people learn fast after having to force their bolt open that this is a bad idea. It doesn't happen every time or with every SKS, due to differing tolerances and wear, but once it starts happening it will just get worse if you keep shooting it like that. In other words, don't use your gun in a way that it was not intended to be used by the manufacturer. Regarding pump AKs, while they would certainly be functionally sound, they would require a very long pump stroke (as illustrated in pictures of the PAR rifles). I would imagine it would be rather unpleasant in prolonged use. Edited March 10, 2014 by WardenWolf Quote Link to post Share on other sites
DrThunder88 912 Posted March 11, 2014 Report Share Posted March 11, 2014 What gets jammed? What gets peened? Why is it unique to SKSes? I know how the lockup on both the AK and the SKS work, what I don't understand is why the one would jam and the other wouldn't. Both rifles are designed to not open the chamber until the bullet has left the barrel, as is the case with just about every autoloader on the planet. The locking surfaces take the brunt from every shot, regardless of if the action cycles or not. I've been looking for confirmed cases of this happening but am coming up blank. The closest I've found has been this entry. Some guy at the range told the OP something similar to what some guy on the Internet just told me. Without any evidence to support it much less a coherent explanation of the theory, I'm inclined to believe it's an old wive's tale. It may be true for some guns, but that doesn't mean it applies generally or to an extent that is any more than negligible. For that matter, as problem-plagued as 59/66es are, I'd find it hard to believe any of the well-known and demonstrated problems might not actually be the real culprits. And I don't mean that "some guy on the Internet"-bit pejoratively. We're all some guy on the Internet. If I read that someone had experience X, I'm inclined to believe it's likely to be accurate. If someone says X is true, however (and especially when X is either not intuitive or counter-intuitive), I always wonder how it's known. Quote Link to post Share on other sites
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