CA M15A4 Upgrade! Just need some advice.

[Mentana]

Well, I got a CAm15A4 a few days ago.. and skirmished it. I got it out of the box, and Chrono'd it right away with a charged 9.6 2000 mAh battery .. And was very unsatisfied!

300, 298, 296 fps. Isn't it supposed to be 310-330?

Well, anyway. After skirmishing it, I chrono'd it again.. This time 278, 282, and 283. Extreamly disappointing for 270 dollars.

Anyway, I'm not exactly sure what the stock M15A4s have in their mechbox, and I was wondering what I would need to replace if I were to put a M120 in it. Also, the rate of fire will concern me. It seems stable for a stock motor - but it's only stock.

Thanks everyone!

[Donster]

well its a CA, so change the piston head, or so im told, add in a Prometheus 110 spring, and a tight bore barrel, you can order one of those DB custom 6.01 mm ones; so long as you use good bbs like KSC perfects you will be fine as far as jams are concerned. if you want to play it safe, get a prometheus 6.03 barrel. and last but not least, just trade up the hop-up rubber cause ive heard some problems with that. again, this is all based on research, i have had no experience with CA guns other then seeing them have problems more often then TM guns.

[Mentana]

Right, but I'm on a budget .

Only have about.. 100 dollars to spend. So I need to play it safe.

I'd like a reliable shooter at the M120.. And I'm more so worried about the Gears than anything else. I've heard they strip - But CA is supposedly fine at an M120.

Also, have any clue what the ROF would be at an M120?

[Donster]

ROF is determined by the battery. if you are on that budget, change the piston head im told. that is first and foremost. the thing is a M120 will put your fps way up. if you later get a TB inner barrel, then you will be running really hot. thats why i said get the M110 spring. plus it will be easier on the gears if you are worried about that.

[Mentana]

The costs of what I'm seeing is..

M120 Spring : $16
Systema Aluminum Piston Head w/bearing : $25
Prometheus M4A1 407mm Barrel - 6.03mm tightbore : $60
( I have a 9.6 2000 mAh also )

That sound okay?

[Skruface]

Originally Posted by Mentana

The costs of what I'm seeing is..
Systema Aluminum Piston Head w/bearing : $25

That sound okay?

Nope. Stay away from Aluminum piston heads of V2 mechboxes and get a plastic/nylon/polycarbonate/POM one instead. Aluminum will kill your mechbox.

And don't waste your money on a bearing piston head - you already have a bearing spring guide, the bearing in the piston head just add more weight to the piston and slows your ROF.

[ThunderCactus]

Originally Posted by DONSTER 125

ROF is determined by the battery. if you are on that budget, change the piston head im told. that is first and foremost. the thing is a M120 will put your fps way up. if you later get a TB inner barrel, then you will be running really hot. thats why i said get the M110 spring. plus it will be easier on the gears if you are worried about that.

ROF is altered by FPS, and systema doesn't make an M110, I assume you meant M100?
Anyway the systema M100 spring is 365fps which is great for any gun, your going to want to buy a new piston, piston head, bearing spring guide, shims, hopup rubber and air nozzle. Around 70$ shipped I think, I'm not doing any math for you. Systema everything, but a guarder clear hopup rubber. Good upgrade for under 100$
Tightbore barrels will tighten your grouping, but the 5$ hopup rubber I find makes a bigger difference.

[Mentana]

But my sole question was, and is..

I'm going for an M120 - What do I need concretely?

[Mentana]

But my sole question was, and is..

I'm going for an M120 - What do I need concretely?

[Crunchmeister]

Generally, internals of newer CA M15s are quite good with the exception of the piston and piston head. They're known to be problematic. The hopup rubber is apparently quite poor too. Otherwise, the gears and motor are good and it already has metal bushings, so no need to upgrade those.

Based on the research I've done, I'd say if you're going to upgrade your spring, you should also upgrade the piston and piston head as well to prevent issues.

For my M15 rifle, I ordered a Systema polycarbonate piston, Systema silent piston & cylinder head sets. Shortly I'll be ordering a Prometheus MS110SP spring, airseal nozzle, and new hopup rubber. That should get me somewhere in the 380 FPS range and give me good range and accuracy. I may or may not get a tightbore barrel for it down the road.

That being said, my rifle has performed very well to date. I don't have access to a chronograph, but I know from the coke can test that the velocity you state is about right - 300 fps give or take 10. I can shoot into the coke can, but can't quite make it through the other side. Other than that, it's got a great ROF and it's really accurate at ranges even over 100 feet.