A&K SVD FPS too low

[THE FNG]

UKARA sorted: A.E.G purchased. Very excited!

 

Back onto the SVD.Having a problem with consistency now.

I had a kind of double feeding problem initially. I would cock the gun and a bb would be released into the receiver as well as the chamber, required the dust cover to be removed in order to reach the bb. I changed the tightness of the rear screw in the hop unit and it I haven't had this problem since.

The other problem is more possible double feeding.

What happens is, I cock the gun and when I pull the trigger, it makes a muffled noise and nothing comes out of the end. If I take the magazine out, cock the gun, and fire, one will fire out of the chamber perfectly....despite there being no magazine. This was happening before I altered the screw for the first problem and still happens now. Does this require changing the screw position again or do I have another problem here??

 

One other question; what would be the best bucking to have? I have read in some places that altering the SVD bucking can create air problems.

 

Thanks in advance again!

[RR01]

Firstly, are you sure the inner barrel is sat fully into the hop unit? When it is sat correctly the rear of the hop rubber "should" stop any more than one BB being fed from the magazine at any one time and therefore only one round should end up in the hop itself once you let the cocking chamber move forward. However, I did have that happen a few times on my previous A&K SVD, although that had the OE hop unit in it. If you don't let the cocking chamber move forward smoothly, or stop part way and pull it back very slightly, then you can get a double feed, as the nozzle only has to move back about 6-8mm in the hop unit to allow the BB to rise from the mag. The rest of the pull is just to compress the spring. I haven't found that happening with my new unit, but I have only put about 50 rounds through it testing so far.

 

As regards hop rubbers, I've started using Falcon Double Point in all my rifles, both spring and AEG. I've got some great consistency and accuracy in my M16s using Falcons, so much so that with one of them I had the hop almost off, so that only about 1mm of each point was showing in the inner barrel and it was sending 0.25s out to 40+ yards in very tight groups with no trouble at all. I have one fitted at present in the SVD, but I'm not sure if it is a hard enough rubber. Falcons come in 55% and 90% hardness and I suspect I might need a 90% to cope with the 500fps power. Once I can get out to test it properly I'll see how it is doing with the softer rubber before buying a harder one.

 

If you want to try them they are available at Ehobbyasia for about $8 or $9 plus postage, so I usually buy 3 or 4 at a time to make it worthwhile on the postage. Just search under Falcon to see what they have.

[THE FNG]

I have found what may have been giving me some of my problems.

 

If you look at the pictures below, there is a dent in the piston head. I'm assuming that the piston head is meant to be completely rounded based off the pictures of the upgraded piston head available online. Looks like that's where my next purchase is!

[RR01]

Um, yes that would definitely be the cause.

 

Considering that a round tube should be quite strong, any idea what you did to dent it like that? I wouldn't have though hitting a plastic BB could do it. Is it possible you screwed the rear grub screw down too hard and then let the cocking handle fly back without the piston having caught on the sear, so that it moved back under mainspring pressure, not that of the weak spring that is there to return the cocked slide? That might be enough to dent the nozzle.

 

At least it shouldn't be too expensive to source a replacement, either from airsoftsniperparts.com or AirsoftPro.cz if they are out of stock in the UK.

[THE FNG]

I have honestly got no idea how it happened, nor when! I had no idea it was like this, I just noticed it when taking it apart to clean.

 

Something that I noticed; I put the piston head back in except upside down and for some reason, the gun cocks a lot easier (sometimes the bolt gets stuck halfway, requiring two hands) and the gun doesn't fire to the left as much.

 

I've bought the replacement along with the upgraded piston from airsoftpro.cz.

 

Do you have any idea how to install the steel piston head? I couldn't find a seam or screw of any kind that seperates the piston head from the rest of the unit. I've taken the bolt off of the piston as you can see in the picture, I just can't figure out how to take off the actual head. I'm such a noob aha!

[RR01]

I'm not sure either. I've just had a look at mine and I can't see how to remove it, unless it's an interference fit, in which case you would need to tap it out with a wood block and a hammer. Possibly an e-mail to AirsoftPro.cz, or airsoftsniperparts.com, might provide the answer, as presumably they should know how to remove the original bits in order to fit their replacement parts.

[THE FNG]

A quick email to them and they sent me this:

 

 

there's a bit in there that shows how you install; simply turn with pliers

[RR01]

Thanks, I thought that was how it must come apart, although mine seems to be missing that little grub screw on the side to lock it in. That said, if I was taking mine apart I would not hit the cylinder with a metal hammer if I wanted it to stay in good nick. A wooden block in between would save any damage either to the nozzle or the back of the cylinder, although you don't have that problem with your nozzle!!

[THE FNG]

I thought that when he was hitting it! Surely that wasn't doing it any good. I'm hoping they will arrive tomorrow so I can install: It's been one problem after another since I've had it and I'm yet to see it fire properly without problem. I also think that your theory of the slam fire hitting the grub screw to be true as that seems like the only logical explanation at the moment.

I have noticed that the bb bends at the moment depending on the position of the dent in the nozzle. If the nozzle is at the top, the bb bends to the left, if its at the bottom it bends to the right. I can't wait to see it fire straight and see how much the air seal is affected by a working nozzle.

[RR01]

It probably isn't going to make much difference if the new bits arrive soon, but as a short term measure, try fitting a small drill bit down the inside of the nozzle and then try pulling out the dented end by applying pressure on to the dent. That at least might give you an idea if it's just the dented end that is causing the problem, or if it's maybe the hop rubber and nub adding to it.

[THE FNG]

Having fitted the piston head and installed the upgraded piston.....wow! I cannot believe the difference it has made! It has made the bb fly really fast, really far and without any flaw so far. I've only ran about 20 rounds through so far and I still have to recalibrate my scope but it has made my day! It has even affected how smoothly the bolt can be pulled back as before it could get stuck halfway through.

Finally, I have a sniper that I can actually get kills with!!!!!!

Thank you so much for all of your support with my questions

 

I'm just waiting now on my aeg....it's being held by customs at the moment: It was 'Forwarded for UK processing' as of 6am today. Hopefully I can pay the tax/handling fee and get my hands on it tomorrow or monday! So excited!

[RR01]

I hope you asked the overseas retailer to put your UKARA number on the outside of the parcel, so the BA can check your eligibility / site membership.

 

As regards the SVD, if it's flying that much better you might want to get it chrono'd before you get to a site, as it could have gone over the site limits if there is that much improvement and you won't be able to use it, unless you take a lower FPS spring with you to change. At least it is a quick change spring system if you do, unlike most AEGs.

[THE FNG]

Yes, I asked the retailer to add my UKARA number to the box. I picked it up today and I am very happy with the items.

Regarding the SVD, I do still have the other spring, so I could add that to the gun. I reckon that the spring itself was okay, and that the airseal problem caused all of the problems. I will test this theory. Theoretically, it should be around 450-480 stock, and the m150 spring should take it up to 520 maximum. My local site is 500 fps max, but 450 would more than suffice.

I have exams now starting the 29th through till the 13th May so I can't go until after, but once they're out of the way, it's a long summer of airsoft for me!