CA M15a4 rifle upgrades

Urban · 05-09-2010, 05:05 PM

I am currently using an Classic Army M15a4 rifle. With my birthday coming up I am wondering what kind of upgrades I can snag for Range and better accuracy/grouping.

I recently purchased a Promethus 6.03mm Tightbore as my first upgrade.

I'm sorry for sounding a bit newbish but I was reading a few posts through google and I believe that these two upgrades would be a good start. Would these 2 be wise choices?

Systema Bore up kit ( http://tinyurl.com/39ogox4 )
130m spring ( I'm not sure which brand works best with this setup. )

Any help / suggestions would be greatly appreciated!

**GeneralPoraboo** · 05-09-2010, 05:17 PM

An m130 spring will put you WELL over the 400fps limit so I do not suggest you get a bore up kit.

If it is accuracy you want to increase, then you need not even enter the gearbox, really all that affects accuracy is the barrel and hop up. (to a certain degree)

If you want better accuracy use a better hop up bucking, as you already have the tightbore. I like firefly bucking a lot but there are many other good brands too.

If you want a better range, you can always put in a higher tension spring, something around a PDI 120-150% should serve you well and keep your FPS under 400. (However with the PDI 150% you can potentially shoot at 410 FPS but I shoot around 360FPS with the 150%)

And remember, extra range is useless if you have bad accuracy, in my opinion the barrel and hop up are two of the most important things to upgrade.

**P7hk9** · 05-09-2010, 05:30 PM

I'd get rid of the CA hop chamber and get a Laylax strike chamber. It's worth the extra $$$ to have effective hop adjustment on the M4s

Stay away from the bore up kits. I've never seen any good come from them.

**GeneralPoraboo** · 05-09-2010, 05:31 PM

Quote:

Originally Posted by P7hk9

I'd get rid of the CA hop chamber and get a Laylax strike chamber. It's worth the extra $$$ to have effective hop adjustment on the M4s

Stay away from the bore up kits. I've never seen any good come from them.

What exactly do they do anyway? From my understanding aren't they just extra large cylinders with a wider piston/cylinder head?

Urban · 05-09-2010, 05:48 PM

Thank you for your input guys!

But I have another question.

I know what a Bucking is and I think I understand how it works.

However, what is a hop up spacer/nub for (not washer)? Or a Strike Chamber?

Can you please enlighten me? Or link me somewhere where I can read this? These are particularly hard to find via google. Thank you.

Tom

**GeneralPoraboo** · 05-09-2010, 06:07 PM

The nub is the little piece of rubber that pushes down on the bucking when you adjust your hop up. And I am pretty sure "laylax strike chamber" is just a brand named hop-up chamber/unit. It is what holds the bucking and nub together.

Urban · 05-09-2010, 06:47 PM

Thanks for the input!

What is the difference between say a m130 spring and a pdi 140% ?

**Palafoxx** · 05-09-2010, 06:54 PM

Click HERE

and

HERE

Quote:

Originally Posted by Urban

What is the difference between say a m130 spring and a pdi 140% ?

About 100 FPS.
The M130 is going to be well over 425 FPS, and the PDI 140% is going to be around 340-350 depending on other variables.

**Coeus** · 05-12-2010, 02:03 PM

There is a spring chart here on the forums that should give you a ballpark for the velocities.