Advice on Tightbore Barrel for A&K SVD

[ronin677]

Hi all,

I need advice. I want to put a tight bore barrel in my A&K SVD but not sure which to go for.

I have heard many good things about the Prometheus 6.03 barrel but not sure if this come in 650mm. In fact not even sure if I need the 650mm.

Any advice on what I need to buy????

cheers

 

[TacMaster]

Prommy do indeed make 650mm barrels, not sure if they come in AEG format as that's what the A&K SVD takes (I believe? Not sure)

 

[ronin677]

I'm not familiar with the difference between AEG format and other formats. What do I need to know?

 

[proffrink]

Prometheus/Laylax/First Factory and PDI make great barrels. ORGA for wider bores too, but PDI make a good 6.08.

Is a tight bore the best option for a sniper rifle though? Wide bore will give a slightly more consistent hop if you have the fps to play with.

 

[ronin677]

I have a R hop fitted and the upgraded hop up from Airsoft Pro. The problem I have is that it still isn't so accurate or consistent over 50m.

I thought a tight bore might help

 

[proffrink]

If you're using a stock barrel then as a rule most aftermarket barrels will help to come degree. Most stock barrels are a bit naff - especially A&K from my limited experience. A wide bore is definitely the way to go with an R-Hop patch though. The cushion of air you get with 6.08 is rather beneficial when it comes to lifting heavier BBs. Only go tight bore if you want that extra fps or a generic improvement over a stock barrel really.

Check the patch too. They may have bodged it.

 

[Mos]

Thinking of buying this gun. The things I am probably going to upgrade are, the barrel, the spring but I think the spring is quite powerful, if I upgrade, I'll upgrade the cylinder & head.. Just thought I'd let you know good luck with your gun

Edit: I don't actually think you'll need to upgrade the cylinder, as you won't be firing too quick, unless the cylinder is broken or worn down... Maybe the piston could be an upgrade, as I think you're using a powerful spring, as I'm pretty sure the gun comes with a powerful spring..

 

[proffrink]

Have you learnt absolutely nothing from that other thread?

 

[Mos]

Ugh fek... If your sniping, a wider bore is best, instead of a 6.01 diameter, change to a 6.05 if sniping, this is because, with a wider bore, the bb has more air around it, so the backspin on the bb is more consistent. This is all knowledge I have looked up and researched. Thanks.

 

[proffrink]

No, you have not - that's in this thread. In the majority of springers you cannot just upgrade a spring. Most (including A&K) are made to a spec. to allow up to a certain spring tension. Swap that out with something more powerful and you're going to blow seals or bust your sear. Usually the trigger mech and cylinder (and guide) are required upgrades for a higher-tension spring. Then the hop unit, barrel and spacers.

You cannot approach any springer upgrade with a handful of pocket change and expect good results. This was mentioned many, many times in that other thread.

 

[RR01]

I doubt an R Hop is a good idea in an A&K SVD, unless the hop is tuned exactly to the BB used without applying any additional pressure to the hop rubber. The method of adding hop in the A&K hop unit is by way of a very small hard nub sitting vertically over the hop rubber, which will impart a very small amount of contact to the BB, something that an R Hop is trying to avoid by adding much more contact area. You did not mention the weight of BB that you are using and which is causing the accuracy problems. Heavier is better, providing you are putting out between 450 & 500 FPS on 0.2 BBs. Try at least an 0.3 and upwards until you find what suits your rifle best.

As mentioned above, if you are upgrading to put out higher FPS then it is a good idea to invest in a steel sear and new piston, with steel band at the back, as the standard A&K sear is quite soft metal and wears very quickly. And a new sear can wear the back of the standard piston as well. For upgrades, AirSoftPro.cz is the place to go; http://airsoftpro.cz/eshop/index.php?cPath=93_204&osCsid=d6022784d5e8c212edbdecaac7a1c8ee . Even going for a full set of replacement parts isn't that expensive.

 

[ronin677]

So my range is ok, I'm getting approximately 80m +

My problem is the consistency of the shots. My fps is around 460. The R Hop has always caused me concern and I've often wondered about revert back to a traditional bucking. What would you guys recommend?

So the general consesus is a wider bore barrel yes? Approx 6.05? I've ugraded the sear on my rifle and so am happy running the M150 spring in it. The cylinder seems to be holding up well (almost 18 months now). When it goes I'll replace it.

Is what I've paraphrased about right? and will the modifications help with my accuracy?

 

[proffrink]

The R-Hop should be the most consistent way of doing things because there's no structural weak point like you have with traditional nubs. Maybe their handwork isn't so good, or maybe it's just that the barrel isn't all that decent. I'd say 6.08 is probably wide bore, and anything below 6.04 is tight bore. Stock barrels usually come somewhere in-between.

Accuracy-wise the only things that should have an affect are the hop and barrel. Unless you're getting fluctuating FPS from somewhere like a bad seal (though I'm assuming you've checked this). As RR01 has said, maybe an R-Hop patch isn't the best approach given the slightly novel A&K SVD hop, though I would say that one could effectively have a fixed hop by just replacing the R-Hop and sanding as normal until the required amount of material is sticking into the barrel when the hop is effectively off (relying on the old bucking to apply uniform pressure). Again, this means effectively a fixed hop, but if you're not switching ammo weights then this may be the way forward.

First though, make sure the FPS isn't all over the shop (honestly with a sniper rifle you want to be +/-5 or less shot-to-shot) then check your own patch to see it's not been unduly worn or poorly fitted and then get that new barrel. If you don't want to R-Hop it (though it is easy to redo if you use RTV) then obviously go the classic route, but I've still not seen anything out-perform the R-Hop patch yet. Flat hops come close, but they still don't have quite as much surface area as a patch.

 

[ronin677]

Nice on. I'm happy with my FPS as it ranges from between 455 and 465. I'll check the R hop though for wear. On hind sight I will probably keep the R hop as it compliments the upgraded hop up unit rather well.

I'll go for the wider bore barrel on the advice I've seen there and try a 6.08mm. I'll go steel.

I'll let you guys know the results once its all put back together.

thanks