24 replies to this topic

[captainkirk05]

My new stock SR12 is shooting at 347 fps with .25g bb's. I am aiming for 400 fps with .25's, just for that extra bit of range. I have been looking at M130 springs to install in the gun. What brand should be chosen for consistency and putting me in the right ballpark for FPS? (I understand there's a break in period for the spring, so it's fine if fps is over if it settles under 400 in a reasonable amount of time). I noticed KWA has their own M130 as well...

ALSO!!! I've noticed the stock bucking in the gun takes about 10 - 15 shots of warming up before it actually kicks in and starts giving me straight flight paths. This isn't just when first shooting the gun for the day either, if I don't shoot for about 5 minutes, I have to waste more shots to warm it up again. Any reasons for this bucking behavior? (I've put the gun through about 1,000 rounds total)

[aaps59]

Heya welcome to the forums. The chrono reading you got is about correct for your gun. I see you want to raise it though. A KWA M130 should put you right where you want it to be once settled. I do recommend waiting until your 45 day warranty is up till you open up your gearbox to install any new parts. Your gun is still in the "break in" period, so I don't think there is any problem with your bucking right now. If you haven't done so already, I do recommend cleaning the inner barrel with gun patches and your cleaning rod. Also turning the hop up off and cleaning your hop up with Q-tips may help as well.

[superfrog]

Have you considered using .3s?  They will give you more effective and accurate range.  Your fps seems a bit low for a new 12, though. With .25s in a new gun you should be about 370ish because you should be shooting about 410. How are you getting your fps numbers?

[jpip]

Don't worry about your inconsistent hop up. As said, it's in it's break-in period and it will settle in soon. As superfrog said, try the .30's, especially the ksc/kwa's. I get incredible range with my stock sr12. body shots at 200 feet are not difficult, unless the wind is crazy.

Just remember to properly clean your bucking and barrel.

[niko_gpsy]

A Guarder SP120 or KWA M130 (may be a tad over 400FPS w/ 0.25) should get you to your mark.  The KWA 2G bucking doesn't need warm up shots unless you are in a cold environment.  I think you have excess gear grease on your bucking contacts that requires several rounds shot through it to clear the contact surface somewhat.  During your break in period I recommend cleaning the bucking and barrel very well because even a little bit of grease on the contacts will cause accuracy and range issues.

Look here................  http://kwausa.com/fo...?showtopic=8178

And here....................  http://kwausa.com/fo...?showtopic=4787

[superfrog]

Captain kirk, niko is dead on, but just know those figures are with a settled spring. Don't freak out when you first put it in and you are shooting 460 fps.  After a year of use 2 weekends a month my sp120 has finally come to 400 with .25s.  Just be aware that your gun will shoot hot for a while.

[captainkirk05]

I got my FPS figures with the chrono used to designate MED for guns at an event last weekend. I did notice it was on the low side, and the chrono was working because it correctly read my other guns at the same fps as previous chrono devices. Hop up was completely disengaged, and barrel cleaned.
My guess was a weakened spring or bad compression. Checking the seals may be in order when I change the spring. So the KWA M130 looks like one of the best picks at the moment, I'll order and install it closer to the end of the 45 day warranty.

As for the bucking, it is super accurate with long range, around 200ft. It just requires 10+ shots to get there after 5 min's. I'll clean it and see how it performs afterwards. Thanks for the link to the instructional video!

[superfrog]

May just need a danco #14 oring. What was the fps with .2s? If fps is low I'd send it back to kwa.

[captainkirk05]

I'm going to try to take it to the local indoor field tomorrow and chrono it with .20's. I'll post the results when I get them.  Does KWA's warranty cover having lower than advertised fps? Because most retailers won't even cover that with their own warranties.
And if it is just in need of a new O-ring, well $3 is much more attractive than $20 shipping.

[captainkirk05]

Yesterday I took my SR12 to get chronoed. Before going I finely cleaned the barrel and bucking as the videos posted above showed. With 0.20g, it very consistently shot 385 fps. So it's only 5 fps below advertised (of course now it's advertised as 400-410, so that's 15 fps now), of course it's 11 fps below what Airsoft GI reported on their chrono report sheet they give. I'm thinking they either gave a phony bologna number or forgot to decompress the spring after testing it (one week in transit of it in that state), or a thousand other things I really don't know enough about to put my finger on.  With this information, can anyone give their thoughts as to this minute drop below standard fps?

After cleaning the bucking and barrel, I'm sad to say I didn't really get a change in the warm up behavior of the bucking. I'll try it one more time, and give my self the benefit of a doubt that I may have contaminated it accidentally upon reassembly.

Oh and just wanted to throw this out there. Chrono'd a KJW M9 that I got for CQB... With 0.20g the thing shoots 360 fps and then slowly drops to around 340 fps, with green gas. Just my luck, I get the one lemon that's actually too hot to be CQB legal... Just some product awareness for everyone out there (might help KWA M9 sales).

Oh by the way, what's the best grease to use to lube up o-rings and other things inside the gearbox?

Edited by captainkirk05, 19 May 2012 - 01:31 PM.

[gcw360]

Sorry you are having issues.  First regarding grease, I (and many other here) use Super Lube for the gross (large) parts like the gears, piston, etc.  The o-rings and cylinder do very well with silicone oil like that found with KWA GBB pistols (25-30wt works well).

Regarding the bucking, have you tried turning up the hop-up all the way and swabbing with a clean dry Q-Tip?  I find this works extremely well.  If that doesn't work let us know and we can recommend some other options.

Hope this helps.

[jpip]

I had the same thing going on with my cqb wanting to shoot really short and then slowly starting to gain hop. The more I shoot it the better it gets. I probably have 1000-1200 through it so far. Now it only takes about 4-6 shots for it to be normal. This is the same regardless if I clean the bucking. It will go away in time.

[captainkirk05]

I did a quick wash and clean on the bucking once more. Then I rubbed it up with a Q-tip. Seems to have done the trick. I'm not having to waste 10 shots to warm up after every 5 minutes now.

Slowly going through the slightly annoying and cumbersome process of emailing the help desk's warranty section to try to resolve FPS issue.

[Ando]

In my quest for more range with my SR10 I ended up with a systema m130 spring and a modify sp130 spring. Everything else stock aside from a 509mm 6.03 and a new o-ring.  Both worked although the sp130 spring was consitently about 30-50 fps higher than the m130. 4 of my friends followed suit with sp130's and consequently all of us had to upgrade to Lipo batteries because the 9.6 NiMh batteries wouldn't pull the spring. I have since gone back to the systema m130 spring so I can still use my 9.6 as a back up if my Lipo poops out. I've had both springs installed respectively for about 8 months each and use bioval .30 bb's. I'll have to post the fps of both springs later since I don't have the numbers on hand.

Could the hop up issue be caused by the shifting of the bucking when re-installed?

[captainkirk05]

Ando, what FPS were you getting with the systema M130 and SP130, and what weight bb did you use to get the numbers?

I wouldn't think the bucking was really shifting. Because that would mean it was shifting in place, then out of place after each session, which would be plain weird. And since the latest cleaning job did the trick.

Turns out my SR12 is covered under warranty. I'm thinking about sending it in. Here goes another $20...

EDIT: I'm just going to hold on to it. $20 for a minimal 5 fps... not worth it. Just means it can eat a stronger spring.

Edited by captainkirk05, 21 May 2012 - 02:48 PM.

[niko_gpsy]

FPS readings can differ when using different brand chrono's, bb's, and etc.  You really shouldn't obsess too much about it when it's only +/-15FPS.  You are still in good range and I wouldn't waste the money to ship especially when you will end up changing springs down the road for what ever reason.  

[Ando]

Ditto!! but for kicks and giggles the info requested is as follows (caveat, i am in no means an expert and have certainly screwed stuff up in the process):
chrono: xcortech x3200

systema m130
bb: 0.25 kwa/ksc @ 445fps
bb: 0.30 kwa/ksc @ 424fps

Modify sp130
bb: 0.25 kwa/ksc @ 475fps
bb: 0.30 kwa/ksc @ 440fps
(shattered my friends scope from 40ft away with the last combination... fyi)
This is obviously by no means finite as niko stated above! Your milage will vary!

There is also other ways to increase range without changing the spring like modifying the hop up, which I seriously looking into! on a side note, the 2gx bucking has never let me down!

Edited by Ando, 21 May 2012 - 09:47 PM.

[captainkirk05]

Holding on to it is no longer an option. The stock magazine has become defective. It only pushes up about 2 to 10 bb's before it stops pushing, leading to jams and dry firing, much like when there are no longer bb's in the cavity to keep the pressure and wind going. No matter the number of winds or bb's in the mag it does this.

I'm sending it in to get the $30 magazine fixed, and figured I may as well get the low FPS fixed while they're at it...  Sadly shipping this item from the east coast is rediculously expensive. If some very nice people had been less generous, shipping would have cost about $76 with UPS (no way I would have sent it).

[superfrog]

That's why you don't use UPS, through the post office its 12.00

[captainkirk05]

It would have cost much less if a smaller package could be used. The smallest size UPS has that will fit a SR12 box is 12x12x48, which automatically bumps its dimensional weight to 50 lbs, and you have to use UPS boxing for an insurance claim to be respected. If they went by the real weight of 12.6 lbs, shipping wouldn't be a problem. I would imagine a similar situation would be encountered with the post office.