Building a M4 with a cheap base rifle

[ThunderCactus]

My advice to you is to not use a cheap base rifle. It seems like a good idea at first, but it suffers from the same problem as buying a cheap rifle to use. Once your done, it's not worth anything!
Try to find a CA or G&P rifle to base it off of. Then your guaranteed everything is going to fit nice on that base, and when you replace parts, the stock parts have a monetary value!
Say you replace a G&P crane stock with a UBR stock, that crane stock is still worth 90$!!
Should you replace the receiver, you can turn around and sell that receiver for upwards of $300!!
Not to mention internals, stock G&P internals are sturdy, their mechboxes shells are tanks, and they're 100% compatible with all systema and prometheus parts!

Do your math to find out how much you'll get back from selling the stock parts from your base rifle. As I found out on many project guns, it doesn't cost much more to start with a good rifle

[Twin#1[Op-for]]

Originally Posted by Grattoj2

I'll put my vote in for Prometheus.

Don't forget a guarder clear hop up bucking and SCS spacer!

Gratto isn't refering to a clear hop-up, but the hop-up rubber and a SCS nub. It will help your accuracy and range a LOT.

[zollen]

Originally Posted by Twin#1[Op-for]

Gratto isn't refering to a clear hop-up, but the hop-up rubber and a SCS nub. It will help your accuracy and range a LOT.

I see there are two version of Hop-up rubbers

Guarder Hop Up Bucking for AEG (70° Hardness Rubber)
Guarder Improved Hop Up Bucking for AEG (50° Hardness)

70% hardness version is for SP130-150 Spring (stronger springs I assume). Is this one better than the clear version?

Would this bucking better?
MadBull Shark Hopup Bucking with Fishbone Spacer

I assume these hop-up buckings always come with spacers.

[CJay]

Originally Posted by HKGhost

Building a custom gun has a great feeling and a sense of pride. The bitch is mixing different brand of parts. Try and stick to a few brands so you have a better chance of compatibility. You better have a dremel with lots of bits of all shape and size. It will save you when the bitch comes out. Good luck.

P.S. If you're gonna build a custom gun, don't start with a clone.

hehe just nitpicking but if ur gonna build a custom gun - why start with a gun at all - just order the parts and assemble them :P

not getting at anyone so don't flame me just asking a legit question lol

[ThunderCactus]

It's actually cheaper to build a gun off another gun than it is to order all the parts

[yuhaoyang]

^ what he says is true; getting those little parts can be a bitch, and usually quite expensive...
Stuff like a decent cut-off lever, miscellaneous mechbox springs pack, and alike can cost around $7-10 each; much better to lift them from a previous gun.
Look around for a cheap FMU, and start your build from there.

[zollen]

Originally Posted by ThunderCactus

It's actually cheaper to build a gun off another gun than it is to order all the parts

I have been worrying about all of the little missing parts that I have not thought of. I hope I would simplified things by not disassemble the gearbox, but this gives me little comfort.

[TokyoSeven]

For me I dont see the point in buying a starting base gun. As you create the new M4 you will remove certain parts and replace them with the ones you want and before you know it you will have the original purchased AEG fully disassembled and ready to be reassembled into its original self once the project is done, perhaps minus a mechbox if you choose to keep the original mechbox.

Now perhaps if you wanted to make this a project gun that you want to work on over time and have as a functioning unit while you work then yes a starting base is a good idea.

In the end though I suppose you can resell the rebuilt original item to gain some of you money back.

I prefer the more direct approach. Buy my barrels inner/outer, front end, flash hider, sights, full receiver kit, mechbox, pistol grip, motor and stock and just put it all together. There maybe specific internals that I would want to swap out however depending on the brand of mechbox I may just leave it stock entirely.

[ThunderCactus]

Depending on the market, sometimes you can part out a G&P gun and make more money than you would selling the gun as a whole...

[TokyoSeven]

Agreed.

However the variable required is that the base gun is G&P to start. Which I do not believe it initially was. That decision can be changed though.

[zollen]

Are G&P M4 available for sale in Canada? Any compatible brand?

[TokyoSeven]

As far as I know there are no online retailers that have them in stock at this time. I do know that some existing retailers accept custom orders so you can attempt to source one that way. From time to time a full G&P unit will also show up in the classifieds.