Help needed G&G GR25 SPR

[Madmark]

Evening people. I have the g&g gr25 spr. Love using it as I like the idea of just using the single shot. 

I want to upgrade it for better range and accuracy but want to keep it shooting within the site 360 fps limit. 

Already have a tight bore barrel but I am wondering what else I should upgrade. ?

Any ideas would be much appreciated. 

Thanks

 

[Adolf Hamster]

or the tl:dr version, use heavier ammo (.3's or .4's), make sure all your seals etc are ship shape so you're not leaking air, and install an rhop

 

[Iceni]

Evening people. I have the g&g gr25 spr. Love using it as I like the idea of just using the single shot. 

I want to upgrade it for better range and accuracy but want to keep it shooting within the site 360 fps limit. 

Already have a tight bore barrel but I am wondering what else I should upgrade. ?

Any ideas would be much appreciated. 

Thanks

Misconceptions in airsoft:

Longer barrel is more accurate. Not true.
Tighter barrel is more accurate. Not true.
Upgrades make a gun more accurate. Not always true.

Longer barrel has more range. Not true.
Tighter barrel has more range. Not true.

The first thing to ask is what range are you actually getting? A well done AEG at 350fps would hit 65 meters -210ft- 70yards, A little more with a lob, a little less with a poor hop adjustment. Putting in a barrel isn't going to change that, nor is replacing gearbox parts unless there is a problem.

The very first thing you should do is get on a shooting range, or somewhere you can measure with google earth and get a solid number for the distance you are actually getting.

To use google earth pick a point at your local skirmish (provided its an outdoor site) and draw a line using the measure tool to a static object at the correct maximum range.

There is a hard limit on range of every gun. It's set by the energy output. If your gun is doing 350fps (1.14J) on the button then you have the correct amount of energy. This means the BB has the potential to travel up to it's maximum range.

So what affects range.

Air consistency.
Hop consistency.
Inner barrel finish.
Quality of the BB.

All of those factors can be dealt with but not individually.

Air consistency is a combination of a perfect airseal, The correct volume ratio between cylinder and inner barrel. These  can be worked out with an online volume calculator. When the consistency is great the deviation in FPS/energy between shots is very little. This means every BB has exactly the same starting energy and should have the same flight characteristics.

Hop consistency is how much spin the BB is been given, how straight the spin direction is, and how often the bucking fails to apply spin correctly. A decent bucking is vital for range, but it also has to be installed correctly, the hop unit needs to be build correctly, the arms need shimming, Dial type hops need replacing for rotary if possible. Any play on a hop arm is bad. To get the perfect hop unit done right takes time, an eye for detail and lots of practice. When it's done right a well built hop unit will send a BB to the target location minimising fliers and side pull. And once it's there provided the energy and air consistency are right it should be at about the same level as the last shot.

Inner barrel finish is far more important than the bore diameter. A polished barrel does a few things. It reduces friction for the BB travelling out of the barrel and reduces the chances of the BB becoming a flier. It provides the smoothest surface for the BB under the hop mound improving hop efficiency, It requires less cleaning and is less prone to BB debris build up. A well polished barrel doesn't have to be expensive, Stainless steel and brass are the only materials a barrel should be made from. Aluminium is not fit for the task, nor are PTFE coated barrels. Brass and stainless will both polish and hold a polish, Are easy to re polish, and are resistant to sand and debris scuffing the inside. Get a bit of sand in an Aluminium barrel and it's going to look like you were  shooting small rocks. Finished barrels are equally bad as there only as good as the finish and the finish life. Once it starts to wear you can't do anything with it.

The only way to get a perfect polished barrel is to do it yourself. The level of polish you can get is entirely dependant on  your wallet and the amount of time you can spend on it. Personally lapping liquids for straight razors are the go to product for me. This stuff on a swab ran in a barrel for an evening will make it look like a mirror.

https://www.theinvisibleedge.co.uk/pastes/171-invisible-edge-diamond-paste-025-micron.html

Quality of the BB is the final part. Crap BB's will fly like crap. Decent well polished and graded BB's will have a more consistent flight path.


Get all of the above right and you will be hitting targets out at 65M. Getting to that point can't be bought, no tech will spend the time needed to perfect a gun.

 

[Sneaky]

Time and patience are two more key factors.  It is worth doing but take your time and really understand the internals and what you need to do.

 

[Iceni]

To get back on barrel polishing, I've just picked up some new lapping pastes after having a little look on the internet.

The ones I have been using are oil based and require wiping out with a solvent between grits. One of the Chinese companies has released a water-based lapping paste that I didn't know about. So I've ordered a 7 tube set and once it arrives I'll be having a good look at how well they perform.

It should be a slower paste than the American stuff I normally use (lower diamond content) but that shouldn't be a problem at the price since you can just load a little more.

And if it washes out with just water then that makes the process a bit simpler.

I'll keep you posted once it appears and I get chance to have a good go with the product. I got mine on ebay £12 for the 7 tube set delivered.

https://www.thk.hk/online-cart-dtl.php?cid=38&sid=60&ssid=0&id=691

 

[Rogerborg]

[a polished barrel] reduces friction for the BB travelling out of the barrel

I'd be surprised if the BB was contacting the barrel at all once it's squeezed past the hop rubber.  This simulation suggests no contact, but simulations are not reality. I'd be interested find any actual experimental conclusions.

 

[Iceni]

I'd be surprised if the BB was contacting the barrel at all once it's squeezed past the hop rubber.

I assume that in a perfect simulation it doesn't touch the barrel. Trouble been that airsoft isn't perfect. You can see that it is touching the barrel when you clean the barrel and get those white marks off the inside. There was a thread on another forum (perhaps the UK sniper forum) where they were getting an fps increase for polishing the barrels. Having done fluid mechanics a little I can imagine that is possible. It might be worth having a little read of some fluid mechanics homework again.

I believe the reading that would apply is laminar boundary layer mechanics. Having a smoother surface provides a smaller boundary layer, Meaning a larger volume of free flow and less friction losses at the wall. I could be very wrong tho... It's been a long long time!

I'll do a test when the kit arrives. Chrono one gun, Then lap the barrel rebuild the hop as close to the same as possible and test the fps again. Might take me a few weeks to get round to running the tests but it should be interesting. The APS Aug a1 is the perfect candidate since it has a shortened (509 reduced to 340) stock brass 6.08 in it atm.

I also have a 364 ZCI that I was going to lap, It's already had a polish with some paste and crome oxide, but I didn't do a full grit rotation on it, So it's not going to be an example I can use since it was touched before I thought of testing. It's not mirror finished but it's not stock either.

 

[AshOnSnow]

Are you sure the site limits to 360?

Personally I don’t see the point of having that gun with those limits. The sites I play at limit SR25 semi auto guns at 500fps.

EDIT

Just checked Section 8 which you have listed as your only site, they allow 425fps DMR. So you may be able to throw in a 120 or 130 spring.