Choosing a bucking for a stock Specna Arms SA-E12 hop-up unit

[Lightly_Salted]

I'm new here, and to the world of upgrades, pardon if I'm not following the proper format!

 

I'm planning to upgrade the barrel of my SA-E12, I'd like a longer one to make use of the 'extension' my suppressor (if you can call them that) provides, currently I can't use it because it seems the BBs get caught on the lip at the very end, I suspect it's a bit long for the current barrel length (it's roughly 170mm, and the barrel is 210mm if I'm not mistaken, not far off each other lol).

 

All well and good, barrels are fairly standardised, but thought whilst I have it all apart I might as well upgrade the bucking and nub as well. At the very least I'll have a spare in case I ruin the original one getting it out. In my readings, I see many people claim certain rubbers don't work well with the SA Edge hop-up units... and other say they work just fine... so here I am hoping for a definitive answer.

 

I'm running 0.28s currently, and would like to keep the stock hop-up unit for now. Can anyone recommend a good bucking and nub that will work with it?

 

I'm also all ears for any advice or recommendations! Gotta start somewhere, cheers lads.

[ak2m4]

Have you got your new inner barrel?  If so test it first, chrono and bb flight.  Just in case it affects the fps too much. 

[Lightly_Salted]

19 minutes ago, ak2m4 said:

Have you got your new inner barrel?  If so test it first, chrono and bb flight.  Just in case it affects the fps too much. 

 

Not yet, crawling along till payday tomorrow, but still need to get the exact 'new' barrel length measured out... rather not need to cut it down.

 

Anywho, I'm currently about 30 fps short of the limit for 0.28s from the last chrono I had done on-site. I do plan on buying a chrono at the same time, so I can test it all when it goes together. I'd still like to get a new bucking and such in case I damage the existing one, but if I need to consider getting a lower power spring I'll do that too. Stuffs not too expensive I guess!

Edited June 27 by Lightly_Salted

[Lozart]

32 minutes ago, Lightly_Salted said:

 

 but still need to get the exact 'new' barrel length measured out

 

It's 190mm. @ak2m4 might be able to help you out with everything you need!

[Lightly_Salted]

16 hours ago, Lozart said:

 

It's 190mm. @ak2m4 might be able to help you out with everything you need!

 

Oh it is? I kept seeing either 190 or 210 when I googled it (stupidly decided not to measure it when I had the bloody thing disassembled...), saw 210 'more often' and just assumed that was correct. But please, as I said @ak2m4 I'm all ears!

[Rogerborg]

Ahoy and welcome.  Barrel and bucking is a perfectly sensible place to start tinkering.  The issue with BBs clipping your suppressor may just be down to shooter's-droop, with the suppressor slightly misaligned. I've certainly had that on an MP5K where the front end isn't very secure.  Once you have a longer inner barrel in there, you can pack it out with rubber rings, tape, stiff foam, whatever you like, to help support the suppressor and keep everything aligned.

 

Huh, I'm seeing both 190mm and 210mm listed for the SA-12. Either way, it's the extra length of the suppressor, and how far down you want it to go, that really matters.  AK2M4 would get a hearty recommendation, but inner barrels are a bit thin on the ground at the moment: https://www.ak2m4.co.uk/internal-parts/inner-barrels The XT 6.02mm is decent enough. Going too tight can lead to issues, I'm getting a few wild fliers out of an XT 6.00mm barrel, even with the end opened up with a deburring tool.  Sight unseen, a 260mm or 285mm is probably what you want, pending measuring.

 

Bucking and nubs, my default is Maple Leaf and omega-style nubs.  Religious wars have been fought over the exact model and hardness, but you won't go far wrong with a 60 degree Macarona and an omega: https://www.ak2m4.co.uk/internal-parts/hop-up-buckings-nubs/maple-leaf-macaron-60-nub

 

Macarons works and feed fine with every M4 hop and nozzle that I've used them with, and specifically the Specna Arms blue rotary hop, which is a decent enough unit.

 

If you do come out a bit over power, the spring change on the Specnas is easy enough, and you can cut off a coil, or just heat and squish the end coil, to cool it down a little.

[Lightly_Salted]

9 hours ago, Rogerborg said:

Ahoy and welcome.  Barrel and bucking is a perfectly sensible place to start tinkering.  The issue with BBs clipping your suppressor may just be down to shooter's-droop, with the suppressor slightly misaligned. I've certainly had that on an MP5K where the front end isn't very secure.  Once you have a longer inner barrel in there, you can pack it out with rubber rings, tape, stiff foam, whatever you like, to help support the suppressor and keep everything aligned.

 

Huh, I'm seeing both 190mm and 210mm listed for the SA-12. Either way, it's the extra length of the suppressor, and how far down you want it to go, that really matters.  AK2M4 would get a hearty recommendation, but inner barrels are a bit thin on the ground at the moment: https://www.ak2m4.co.uk/internal-parts/inner-barrels The XT 6.02mm is decent enough. Going too tight can lead to issues, I'm getting a few wild fliers out of an XT 6.00mm barrel, even with the end opened up with a deburring tool.  Sight unseen, a 260mm or 285mm is probably what you want, pending measuring.

 

Bucking and nubs, my default is Maple Leaf and omega-style nubs.  Religious wars have been fought over the exact model and hardness, but you won't go far wrong with a 60 degree Macarona and an omega: https://www.ak2m4.co.uk/internal-parts/hop-up-buckings-nubs/maple-leaf-macaron-60-nub

 

Macarons works and feed fine with every M4 hop and nozzle that I've used them with, and specifically the Specna Arms blue rotary hop, which is a decent enough unit.

 

If you do come out a bit over power, the spring change on the Specnas is easy enough, and you can cut off a coil, or just heat and squish the end coil, to cool it down a little.

 

Appreciate the writeup! Unfortunately my suppressor is quite a hefty one, sitting at roughly 170mm (compensating for the short barrel, least it was the plan when I brought the gun!). I'd like to make as much use of it as possible, but it seems most barrels between 340mm-370mm are out of stock seemingly everywhere. Bit surprising, given they're just milled metal tubes, but I can't really comment!

 

I'll definitely look at the bucking + nub you linked though, I think that'll work best. I can't say what spring Patrolbase stuffed in the gun to get it to the required "350fps with 0.2s", so I plan to get one that I believe is slightly higher power, and one that is slightly lower. They're not terribly expensive, unlike some of the PDI barrels I've seen! How much?!

Edited June 28 by Lightly_Salted
Heretical spelling on suppressor

[Rogerborg]

The thing about airsoft barrels is that ~200mm is enough to comfortably reach typical 1.14-1.2J UK site limits (and you can get there with less). There's no real benefit to going longer for <1.2J, as the BB won't remember anything about its time inside the barrel once it's out. You might even find yourself losing power and consistency as you go longer, depending on your cylinder porting and air seal.

 

https://www.ak2m4.co.uk/internal-parts/inner-barrels/xt-inner-barrel-aeg-601mm in 300mm would give you enough extra to support the suppressor, with some baffling space left.  Airsoft is the art of the possible, there's no perfect configuration.

[Lightly_Salted]

31 minutes ago, Rogerborg said:

The thing about airsoft barrels is that ~200mm is enough to comfortably reach typical 1.14-1.2J UK site limits (and you can get there with less). There's no real benefit to going longer for <1.2J, as the BB won't remember anything about its time inside the barrel once it's out. You might even find yourself losing power and consistency as you go longer, depending on your cylinder porting and air seal.

 

https://www.ak2m4.co.uk/internal-parts/inner-barrels/xt-inner-barrel-aeg-601mm in 300mm would give you enough extra to support the suppressor, with some baffling space left.  Airsoft is the art of the possible, there's no perfect configuration.

 

Nope, I get that. Absolutely not meaning to sound like an "I'm going to nod and ignore your advice", but I've gone for a 380mm (mainly because I ordered before I saw your response). If it doesn't work, or causes problems, it's not too difficult to swap back and it'll be a lesson learned. If it does work, it gives me the peace of mind that I'm not going to be clipping any BBs on the suppressor and it's all going to be well supported. I did get that bucking/nub ordered though, so thank you for the recommendation!

 

That being said, 380mm may seem widely off, but I measured the inner barrel and lo and behold, it's 210mm! Dead on from where the barrel starts in the hop to the very end.

 

If it all falls apart when I get it together then I'll be absolutely sure to report the results, but I might as well try! Just got to wait for it all to appear on my doorstep...

[Rogerborg]

380mm is still in the sensible range, it'll be fine.

 

If it's not and you do end up wanting to shorten it a little, barrels are easy enough to cut with a cheap sub-£10 pipe cutter, and a pipe deburrer, or whatever else you have to hand.

 

[Lightly_Salted]

43 minutes ago, Rogerborg said:

380mm is still in the sensible range, it'll be fine.

 

If it's not and you do end up wanting to shorten it a little, barrels are easy enough to cut with a cheap sub-£10 pipe cutter, and a pipe deburrer, or whatever else you have to hand.

 

 

Good ol' pipe cutter lol

 

Thanks for your help mate, I'll report back on my success (or possible demise)!

[ak2m4]

23 hours ago, Lightly_Salted said:

just milled metal tubes

a little bit more complicated than that.  most made from a mold then need to be polished internally to get somewhere near the right advertised inner diameter.  in fact quite tricky for large production if looking for around £20'ish retail

@Rogerborg 100% correct, no real benefit from going past 300mm certainly within the UK.  I did try opening up the end of a XT 6.00mm to around 6.03mm, but found unless I could re-polish to a really high-level I found I just introduced more issues.  It's a shame, I wish I had access to a high-end polishing machine,