M4 Upgrade Question for a novice

[airplaneman]

Hey!

So I'm new to the forums, and new to airsoft, but I have a gun and I want to get into it. The problem is, I don't like how my gun is configured, and I want to modify it so it suits my tastes better.

This is basically what I have, except the handle is fixed as opposed to being mounted on a 20mm rail.


This is what I'm after.


Basically what I want is to ditch the handle on the top for a 20mm rail, and to have a RIS on the front for a vertical grip, laser and flashlight. I have found the front RIS, but I can't mount batteries in it, and I have yet to find someone in Canada who sells the M4 battery stock. That isn't the big issue though, my main problem seems to be finding the "top" piece to replace the carrying handle. Do they make such a thing? Where can I buy it?

Thanks guys! If you need more info, let me know and I'll do my best to provide it.

[Mandalore]

You're probably better off just buying a whole new gun... Get AV'd and you'll have access to the classifieds and be able to pick up what you're looking for. Out of curiosity, what brand is the rifle that you have?

[airplaneman]

The gun I have is pretty nice (full-metal, upgraded internals, etc etc. Around 430-450 fps), or at least by my standards, so I'd like to avoid buying a whole new one if possible. If that is the only practical route, then I'll do it.

It's a Classic Army.

I'll look into getting AV'd, but its hard since I don't have access to a car, and the matches aren't exactly close to me. I'll read up on the FAQ .

[Curo]

the 'top' is called an upper reciever. Cant tell a non A.V.d member.

M4 battery stock? Easy to find try looking for a crane stock( which is what you have pictured.)

[L473ncy]

You're going to need a new upper receiver if the top carry handle is fixed onto the gun.

NB: Upper is non prohib but lower is prohib for importation. DO NOT ATTEMPT TO IMPORT A LOWER! You have been warned.

Hand guard is simple, just replace the current one with a rail system and you'll be fine. The holosight appears to be an EOTech XPS since it's super short, and the rear stock is a "clubfoot" stock. If the gun is rear wired you should be able to fit a cranestock battery into it.

[airplaneman]

Originally Posted by Cobalt Caliber

the 'top' is called an upper reciever. Cant tell a non A.V.d member.

M4 battery stock? Easy to find try looking for a crane stock( which is what you have pictured.)

What can't you tell me?

I hate this AV stuff, I'm 20, yet I have to go through a huge hassle to prove it. Ugh, getting into bars is easier than this :P.

Originally Posted by L473ncy

You're going to need a new upper receiver if the top carry handle is fixed onto the gun.

NB: Upper is non prohib but lower is prohib for importation. DO NOT ATTEMPT TO IMPORT A LOWER! You have been warned.

Hand guard is simple, just replace the current one with a rail system and you'll be fine. The holosight appears to be an EOTech XPS since it's super short, and the rear stock is a "clubfoot" stock. If the gun is rear wired you should be able to fit a cranestock battery into it.

I'll take a look for an upper, any places I should start looking?. And by lower, you mean the part the gearbox drops into right? I believe the sight is an EOTech 551, or at least that is what the website said that I got the description from. I'll search the Canadian retailers for a cranestock. The gun is front wired, or was, but the gearbox is fried so I'll have to buy a new one. I'm guessing I can just buy a rear-wired gearbox and it'll work fine?

Thanks for the reply guys!

[L473ncy]

That would make sense that it's a 551, usually they're longer (referring to the 552/553/556) and the XPS is the only one I know thats super short like that and can fit a single CR123.

Lower means lower receiver, basically the part under the upper receiver but above the pistol grip, here's a picture of what I'm talking about: http://soldiersystems.net/blog1/wp-c.../bhi_lower.jpg

Should be able to do that if you want to go rear wired but it really depends. The bonus of rear wire is that there's no PEQ battery box in the front so you get more "real estate" on your rail system for other things like vert grips, flashlights, etc. I personally have my gun wired to the front but that's because I have no place to put my battery in the rear seeing as how I have the standard simple M4 4-position rear stock.

[airplaneman]

Originally Posted by L473ncy

That would make sense that it's a 551, usually they're longer (referring to the 552/553/556) and the XPS is the only one I know thats super short like that and can fit a single CR123.

Lower means lower receiver, basically the part under the upper receiver but above the pistol grip, here's a picture of what I'm talking about: http://soldiersystems.net/blog1/wp-c.../bhi_lower.jpg

Should be able to do that if you want to go rear wired but it really depends. The bonus of rear wire is that there's no PEQ battery box in the front so you get more "real estate" on your rail system for other things like vert grips, flashlights, etc. I personally have my gun wired to the front but that's because I have no place to put my battery in the rear seeing as how I have the standard simple M4 4-position rear stock.

Yeah, I liked the 551 because it was so short. Do you have any idea what the differences are between the different versions? I couldn't seem to find much info online about them, or what I did find said they were all pretty much the same.

I want the rear-wiring because I want the option to use a vertical grip for CQB. It seems like I'm going to be spending around $300 for all these parts: $100 for the stock/battery and another $100 for the rail system and grip, then another $100 for the gearbox. I guess its still cheaper than buying a whole new gun...

[Maethori]

Originally Posted by airplaneman

Hey!

So I'm new to the forums, and new to airsoft, but I have a gun and I want to get into it. The problem is, I don't like how my gun is configured, and I want to modify it so it suits my tastes better.

This is basically what I have, except the handle is fixed as opposed to being mounted on a 20mm rail.

Basically what I want is to ditch the handle on the top for a 20mm rail, and to have a RIS on the front for a vertical grip, laser and flashlight. I have found the front RIS, but I can't mount batteries in it, and I have yet to find someone in Canada who sells the M4 battery stock. That isn't the big issue though, my main problem seems to be finding the "top" piece to replace the carrying handle. Do they make such a thing? Where can I buy it?

Thanks guys! If you need more info, let me know and I'll do my best to provide it.

Finding the crane stock shouldn't be very difficult, and installing it is super simple. Replacing the upper receiver to get the flat-top rail shouldn't be too difficult either, but will take a bit more searching.

If you want the battery in the back that will take a bit more work and since you're new to airsoft you will either want to a) not rear-wire it or b) pay someone else to do it. For the easiest solution I would just recommend getting rails to put onto the handguard. The one pictured can have rails on the top and bottom only, but there are several handguards, like Magpul ones, that can have rails on the sides as well.

EDIT: The differences between EOTech versions are very small. If the official website itself didn't tell you much the general idea is: some are built for different weapon configurations (ie size differences) some have buttons on the side for easier use with a magnifier, some have a quick dimming button for use with night vision. They also use different types of batteries. The larger ones like 512s are convenient since they just use AAs.

EDIT #2: If you were thinking you have to get a new gearbox to rearwire, you don't need to. All you need is someone who can open yours up and flip the wires around and shorten them.

[airplaneman]

Originally Posted by Maethori

Finding the crane stock shouldn't be very difficult, and installing it is super simple. Replacing the upper receiver to get the flat-top rail shouldn't be too difficult either, but will take a bit more searching.

Alright, cool, thanks!

If you want the battery in the back that will take a bit more work and since you're new to airsoft you will either want to a) not rear-wire it or b) pay someone else to do it. For the easiest solution I would just recommend getting rails to put onto the handguard. The one pictured can have rails on the top and bottom only, but there are several handguards, like Magpul ones, that can have rails on the sides as well.

The one I pictured has rails on the sides as well, but there are removable plates covering them up. I wasn't necessarily going to buy that one, I was just using it as an example. When I do buy one, it'll have rails on all four sides.

EDIT: The differences between EOTech versions are very small. If the official website itself didn't tell you much the general idea is: some are built for different weapon configurations (ie size differences) some have buttons on the side for easier use with a magnifier, some have a quick dimming button for use with night vision. They also use different types of batteries. The larger ones like 512s are convenient since they just use AAs.

Thanks for that! Maybe I'll just drop by the store I was going to buy them at and look at the different models in person to see which suits my needs best.

EDIT #2: If you were thinking you have to get a new gearbox to rearwire, you don't need to. All you need is someone who can open yours up and flip the wires around and shorten them.

I don't have a gearbox currently, so I figured if I buy one, I might as well just buy a rear-wired one. Is there any additional wiring work needed, or does the gearbox come with long enough wires? Any recommendations on a box? I was thinking of buying this one and swapping the spring out for something a little more powerful to get a few more FPS. Thoughts?

[DEATH2000]

Originally Posted by airplaneman

I don't have a gearbox currently, so I figured if I buy one, I might as well just buy a rear-wired one. Is there any additional wiring work needed, or does the gearbox come with long enough wires?

Wait, did your gun not come with a mechbox, or is it just not working? The only difference between a gun with the battery in the front is longer wires. As mentioned above you just re-run the wires to the back instead, and then cut them to length. If its your first time ever doing it we do recommend you get a gun doctor in your area to show you how to do it. Messing it up and making it worse would suck really bad. Their is a thread with all the gun doctor listings for different areas.

[airplaneman]

Originally Posted by DEATH2000

Wait, did your gun not come with a mechbox, or is it just not working? The only difference between a gun with the battery in the front is longer wires. As mentioned above you just re-run the wires to the back instead, and then cut them to length. If its your first time ever doing it we do recommend you get a gun doctor in your area to show you how to do it. Messing it up and making it worse would suck really bad. Their is a thread with all the gun doctor listings for different areas.

It came with one, but it's broken. It's pretty old too, so I figured I'd just replace it with something newer and more powerful.

I have experience doing wiring from custom-cabling in computers, and I took my old mechbox out just fine, so I think I'll be able to do it. Just a matter of figuring out where the wires go, really. I emailed a couple gun docs about other issues, and haven't gotten replies in over a week. Ah well.

[DEATH2000]

Was the mechbox broken when you bought it?

Check out www.mechbox.com. TONS of information regarding AEG mechboxes and diagrams to help you if you need it. As for the one you posted i dont know much about that brand, but i would personally recommend a G&P mechbox. I hear a lot of people love them and the quality is really good with the 8mm versions. But, do a quick search on here as well. Their is plently of information about the different mechboxes available if you are willing to do some reading.

[airplaneman]

It wasn't -- I bought the gun used from a friend, and he gave me a very, very good deal on it. The mechbox was pretty old and when I opened 'er up there were a few pieces that were pretty worn, and replacing them would have cost me around $60 (all the gears, the spring guide, piston head, etc, etc). so I figured I'd just buy a new one.

I'll do some reading, and take your recommendation of G&P into consideration. One quick question, does it matter if i use 7 or 8mm bearings? Usually the bigger they are, the stronger they are, so I'd like to go 8mm if it doesn't make a difference.

[m102404]

You're right in that, in general, the larger the bearings the "stronger" they are. However, quality counts. A large junk brand bearing is still garbage....

The axel size of the gears is the same...so the size of bearings that your mechbox can accomodate is dependant on your mechbox shell. You'll need to know the size before you purchase bearings.

IMO...it's absolutely pointless to put "good" parts into a sh*tty mechbox shell. The dimensions, cutouts, etc...are sloppy. Often you'll find that the bearing/bushings are just loose and rattling in their holes in the mechbox...kind of defeats the purpose.

So...start with a good base...build up from there.

Re. bearings...unless you're running 7mm+ don't bother, stick with bushings. A bushing can't break one way or another.