[iamh3ck]

I'm working on upgrading a G&P SR-25 that I just purchased used for a great price. However, some of the internal parts are completely worn out, which is good because it gives me a reason to do some upgrades. Anyways, the bad parts were a stripped piston, worn spring, and the fire selector was out of place. So far, I have fixed the selector switch problem, and ordered an SHS piston. My main problem is the spring. Because of the elongated gearbox I need a PSG-1 style spring, and the only place I can find one is at ehobbyasia, but it's around $35 just for a 200% spring. Is there any sort of spacer product I can buy so that I can use standard AEG springs? *Here the DMR limit is 450fps. Also, I plan on installing a Sorbo-pad if that changes anything. Thank you all in advance.

That was my old problem. So now that I have my gun in the shop, the only thing that I can do now is try to find some mags for this gun. I literally just spent the last half hour searching with every possible variation to the phrase G&P sr25 mag compatibility. I got very few results. I've already intensively researched for G&P brand mags but those are pretty much all out of stock in the US. And while looking at the Chinese stores they have the Magpul PTS 140LR mags(for those who dont know, basically PMAGS for an SR-25) for around $10 less. So my questions are these:
1)Is the Magpul mag compatible with the G&P SR-25
2)IF YES TO #1, which China-based store has the most reasonable shipping
3)What other brands of SR-25 mags are compatible with the G&P
4)According to my research, some Scar-H mags are compatible with SR-25. Is this true, and which brands?

And here is a very important detail: MIDCAPS ONLY -NO WINDING MAGS

 

[metallicafatcat]

You may be able to make a spacer for the gearbox to use regular style pistons and springs, but I'm not sure of the length. If this is your first AEG, take your time and make sure you clean everything and lightly re-grease it the parts. Then focus on shimming from the bevel gear.

 

[dhm078]

Well, you can just grab a standard AEG piston and essentially do an enormous AoE correction until it engages properly with the sector gear (you'll need a standard sector gear too though). At that point you can just use a standard AEG spring and get their usual power from them. You can use a spacer on the spring guide, but there is a limit to how big it can be, and I'm not sure how big that is. The easiest solution is just to get a more powerful standard AEG spring, but I'm not sure how much more powerful you'd need it to be. You'll probably have to do some testing.

 

[iamh3ck]

Could you please explain this in greater detail? ---> "Well, you can just grab a standard AEG piston and essentially do an enormous AoE correction until it engages properly with the sector gear (you'll need a standard sector gear too though). At that point you can just use a standard AEG spring and get their usual power from them."

 

[mateba]

You'll effectively short-stroking your SR-25. The sector teeth of a SR-25 and a standard gear are different. The amount of teeth correlate with the amount of teeth your piston should have. Technically you could also just file some of the teeth off your SR-25 sector too. You essentially loose 10FPS per tooth so you will need a strong SR-25 spring to maintain you velocity. I would buy the actual spacer though. A huge AOE correction like that could be messy unless you decide to cut 3/4" plastic rod once you have the right length. This is a retail product that does what we are talking about. You should still correct your AOE. To do so you just shim your piston and piston head out until the pickup tooth meets flush with the first tooth on the sector gear. http://www.airsoftworld.net/piston-spacer-for-army-armament-r85.html

 

[awagg]

You essentially loose 10FPS per tooth so you will need a strong SR-25 spring to maintain you velocity. I would buy the actual spacer though.

10 fps per tooth? I don't think you can generalize it like that... Maybe for the first tooth, you won't lose that much... but after cutting a few teeth off, you are going to loose more than 10 fps. Take the DSG for example. You go from 16 teeth to 9... and you loose much more than 70 fps. It also matters what spring you are using...

 

[mateba]

This is a rare circumstance. You rarely, if you short stroke at all, remove 7 teeth. Still, 16-9=7 and you said it, you loose 70FPS.

 

[awagg]

No... you don't loose 70 fps... Much more. Using a M170, you will get the same fps as an M110, which is a major difference. I'm not going to give exact numbers, because that's going to depend on the air seal, but you get it.

But yeah, SSing by 2 teeth will give you drops from 20-40fps.

 

[iamh3ck]

Ok just found a Problem, After ordering an elongated poston and spring, it looks like that the gearbox is regular , not elongated. Isn't G&P SR-25 gb elongated? I bought this used so no idea what original owner did, but i am soo confused... any help please?!

 

[dutton]

Ok just found a Problem, After ordering an elongated poston and spring, it looks like that the gearbox is regular , not elongated. Isn't G&P SR-25 gb elongated? I bought this used so no idea what original owner did, but i am soo confused... any help please?!

Yes, if it's a true 7.62 SR25 body, it'll have the elongated gearbox. G&G is the only company I know of that uses a standard sized V2 gearbox, with a super long air nozzle.

With that said, maybe the seller was mistaken and it was a G&G? Or, perhaps there's a way to mod a G&G SR25 gearbox into the G&P body.

 

[iamh3ck]

This is the rifle: http://www.airsoftpost.com/product_info.php?products_id=23916

So it is g&p. If I were to post a pic of the air nozzle would you be able to tell if it were elongated? I have the gb completely open atm.

 

[iamh3ck]

Wow google really does work here. After doing hellishly frantic research in under 10min, I found out that the GB must've been swapped for the elongated air nozzle sr25 GB, instead of the stock elongated piston/spring GB. I saw that the elongated air nozzle GB has a little spacer which goes over the nozzle to fit standard hopups. This now frusterates me b/c I just dropped around $35 to get now piston and psg1 spring. Oh well...

 

[dutton]

I would hang on to the parts you bought. I know, at least when they first came out, the G&G SR25 gearboxes tended to have problems. If that is still the case, it'll be better to swap back out to the original design.

 

[iamh3ck]

Just adding in a update, I feel bad to say this but I gave up on myself. After finding that the elongated GB was replaced by the original owner for the elongated air nozzle GB, I went for a shortcut, I dropped the gun off at my local shop and let them deal with all the shenanigans. Turns out I was seriously lacking compression in the air nozzle and cylinder head. Well, thats what the pro's are for. Actually i'm glad I got it into the shop because now I'm up at college, and it's illegal for me to have it up here in my dorm. So in conclusion, GB is in fact non-elongated, gun is in local shop, no major upgrades for me. If only I had this gun longer, just imagine. Toss in a nice AB mosfet, sorbo pads, spend some time to get near 100% compression, and follow the Holy Grail of building your DMR AEG letter by letter. Oh what I could've done with more time.