[Bushido]

My dear fellow airsnipers !

I would like your help choosing the inner barrel for my precious HK G28 DMR which will arrive in 1 day.

First of all : max speed for DMR in our country is 460 fps or 140 m/s, only semi auto firemode.
My intention is to get this weapon up to range and accuracy, that means a bigger spring, not greater than M130-M135, one inner barrel and here I would like your help choosing the right one, I will order also the Retroarms gearbox shell just to be on the safe side if the original breaks ( they have a history) and maybe a full cylinder.

My option of barrels are : Madbull stainless steel, Prometheus, Action Army, Deep fire.
Barrel lenghts is 455 mm, what bore sieze should I get ?
6.03 : Prometheus and Madbull stainless steel
6.02 : Deep Fire, didn`t found others ...
6.01: ?

I will use the original hopup chamber to check if its ok and the Maple Leaf 70 with the concave nub

Please give me an advice.

Peter.

 

[Asianwarchief]

I use a mad bull steel barrel and it works wonders especially if you lap it. I highly recommend it.

 

[Thenoobatsniping]

I prefer prom barrel.

 

[Asianwarchief]

Well if you have the extra money, then get the prom barrel but when the mad bull and prom are lapped, they perform the same.

 

[Sam]

Get Prometheus 6.03mm
Maple Leaf AEG Rubber Bucking 70° with Nub.
If your hopup unite plastic, i suggest you to replace it with metal chamber.
Hollow piston head O-ring for perfect air seal.
double o-ring air nozzle (metal).

 

[Bushido]

Thank you all for your replies.
I am using in my M4 and L96 the Maple Leap Aeg rubber with concave nub with great results, I am considering to use it also in the G28 build.

My problem is what inner barrel diameter tu get, tight bore or wide bore. There is alot of debate between the two, which is better for long range.

For example for my L96 which can shoot between 150 m/s and 212 m/s i could use a wide bore because I have the reserve to push the BB but with this G28 I am limited to version 2 parts and the electric gearbox nozzle movement, the tight window in which the nozzle seals on the hop bucking, hence the time air can blow the bb through the barrel before the nozzle retracts.

I am not looking for range records with this gun, I want consistent and accurate shots at 60 meters. In my opinion 60 meters range with good accuracy would be the sweet spot for this gun.
Knowing that I can go up to 460 fps and I want to use at least 0.36 bbs for a minimum of 430 mm inner barrel , i must choose between 6.01, 6.02, 6.03 and 6.20 diameters, i dont thing I can get the 6.13 prommy barrel.

 

[Sam]

Prometheus 6.03mm barrel will guarantee 65 meter to you, i have it on my SR25 v2.5 gearbox and accurately i can hit target range 75+ meter.

 

[Five_Seven(57)]

VFC inner barrels arent bad, if you feel the need then Prometheus 6.03 or PDI or Edgi

 

[Bushido]

@Sam
thanks, one thing to mention, SR25 have the longer cylinder so that`s a plus.

@Five_Seven(57)
I am also curious about that.
http://www.airsoftsniperforum.com/members/7361.html

 

[Swift]

If you are thinking about getting a prommy barrel just get an edgi barrel, they can be found on amped airsoft or other places
It will only be a bit more than a prommy but way way better

Providing you are in the us otherwise if you have to order directly from edgi it will be more like $130 not $75


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[Bushido]

Received today the weapon, it was a delay with the shipping, stock it shots at 125m/s
I will keep you guys posted as soon as I test it and change the inner barrel and spring.

 

[Bushido]

Only today i had time to test the weapon.

It shoots stock 410 fps and the accuracy at 15 meters is 10 cm (4 inches) spread. It can shoot more bbs in the same hole but then it spreads out randomly.
I must change the barrel, stabilize it and put a Maple Leaf bucking and nub. I`ll update as soon as the tests are done.

 

[Bushido]

I changed the inner barrel, Deep Fire 6.02 , Maple leaf 70 and concave nub. I only tested it at 18 and 30 meters. From 18 meters I can shoot a pen 8 from 10, from 30 meters I have a max 5 cm spread except the flyers which I got 2 from 10 bbs. I must increase it to 460 fps and put a full cylinder and test again.

 

[Bushido]

I received the bore up kit from ICS, cylinder, cylinder head and piston head.

The funny thing is that the piston head`s O-ring is tight on the piston, I can`t check the compresion as the O-ring doesn`t touch the cylinder wall.
I know that it should expand when the piston goes forward but it is to tight and it won`t move
I will replace that O-ring and check again after that.

I am still waiting for the RetroArms CNC gearbox and Hop up unit.

 

[pcherold13]

How is the G28? What was the diameter of the inner barrel to start off with?

 

[Bushido]

Update.

I received my Inferno Gen2 HPA kit, Valken 68Ci 4500 PSI bottle, tomorrow I get the Wolverine Storm High pressure regulator.

I am thinking to try a wide bore barrel:
PDI 6.05
PDI 6.08
Orga Lex 6.05

Should I buy a PDI 6.01 ? :yup:
All above are for an increased range.

I will test the gun in the next few days with the 6.02 barrel to see how much reserve I will have for a wider barrel.

What do you say guys ?

 

[whalesmash]

I'm not entirely sold on the orga wide bore. I had one in my own G28 but ultimately swapped it out for a rhopped 455mm PDI 6.05. Your barrel bore and length will not matter for range after a certain amount of length. Range will be solely dependent on your hop up, bb weight, and joule output.

 

[Bushido]

Final configuration is with a Edgi 6.01 barrel 500mm.
It was a pain in the ass to align the gearbox, Inferno Gen2 nozzle to be perfect. I had to put set screws on the RA shell, dremmel the body, dremmel the grip, modify the hopup holder to fit the RA hopup. After 3 weeks of terror and stress the gun shoots ok at 290feets. The field limit is 460FPS with 0.2gr bbs for DMR,and with 0.45gr bbs it shoots 405fps and 3.4joules. Max velocity f0r test purposes was 690fps with 0.2gr bbs and 470fps with 0.45gr bbs.
No matter what combination of cilinder, piston and whatever you put in it it will never shoot like a HPA sistem.

P.S. I am shooting with Nitrogen.

 

[Ryouske]

Hi Bushido, are you still considering the F2 to replace your inferno gen 2? Or are you pretty satisfied with your setup. Thanks was reading your post on FB but it seems like it got deleted.

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[BoesBoes]

You better make sure you know your minimum engagement distances(~120ft/35m) with those irresponsible 3.4 Joules.