Well I got my sopmod....but now I want to tinker

[CK]

Re: Well I got my sopmod....but now I want to tinker

363mm for m4a1 carbines.

I think you made the right choice. The TM pro line's dont need upgrading out of the box. Use the stock gears until they break, mine lasted years.

[markeeeey]

Re: Well I got my sopmod....but now I want to tinker

I use a Prometheus tightbore 363mm. 6.03 in my.

[Boo-Sabum Ben]

A word of caution, be very careful with the hop unit. I broke mine, and I wasn't the only one. If its too stiff, use something like wd40 to free it up. Just be sure to give the barrel and hop chamber a super clean afterwards, and probably throw away the hop rubber.

It's worth it instead of snapping the hop unit in half like I did!

[Heinz]

Re: Well I got my sopmod....but now I want to tinker

WD40 in an Airsoft gun? Seriously, don't even go there.............it's awful stuff. It hates rubber, it hates plastic and it's not even a proper penetrating oil. The WD actually stands for "Water Dispersant".

[Boo-Sabum Ben]

Hmm I didn't mean to use it as a lubricant, but it's a very tricky balance between pulling the hop unit off the barrel, and pulling too hard and snapping it.

I'm not the only ones who's done it, and there are no working replacements available, the only one is the Lonex metal one, which doesn't feed properly

[Heinz]

Re: Well I got my sopmod....but now I want to tinker

Use a proper penetrating oil instead. WD40 really is bloody awful stuff lol

[Andrew March]

Re: Well I got my sopmod....but now I want to tinker

Never ever ever use WD40 on any part of your airsoft guns, it will eat through the rubber. Use silicon sprays to free or lubricate parts, your local airsoft retailer will sell it.

[B.E.N.]

Re: Well I got my sopmod....but now I want to tinker

Things I would do to a stock gun:

Firstly, I'd start with the SOCOM as opposed to the SOPMOD, and run it front wired. It's easy to do this with the SOCOM as it's already set up in that configuration. It's easiest to go with a PEQ-type battery box but if you know anyone with the right tools, nibbling off a sliver of the outer barrel to make space for a battery is an option depending on your choice of RIS/handguard.

You want to be using a 7.4v lipo with a discharge rate of around 30C. You can get away with less but you will have sloppy trigger response and you'll find yourself catching half cycles in semi quite a lot, which with the extra weight on the piston leads to stripped racks. A couple of guys I know have plumped for 9.9v LiFe batteries and are happy with them. These could be an option if you are tight of space or don't want a PEQ box. In short, the stock based battery system is a nightmare, is underpowered and doesn't cut it. If you are insistent on going with it, Puresilver's recommendations are sound.

The hop and barrel unit is pretty sound as it is and only if you have a wedge of cash burning a hole in your pocket do you really need to step up to a tighter bore barrel. It will gain you a bit of muzzle velocity at least. To reitterate what BooSabumBen said, be VERY careful with the hop unit. If you break it, a factory replacement is hell to find and the Lonex alternative requires some "jiggling" to get feeding right. Me and Ben have a shared experience of this nightmare!

If you are planning on upping the velocity of the gun, which I will talk more about in a moment, you need to open the gearbox to change the spring. The first time round, you will need to detach the spring from the piston which means digging a screw out of the piston head that is moulded in, alternatively buying a rather expensive Prometheus option to drop right in. I tend to go with the former and run stock TM pistons as they are a cheap, serviceable sacrificial part. Once you have the gearbox open, for the sake of the £25 SKS or Hornbill gears will cost you, you might as well throw them in at this point and not have to re-open the gun in the future. The stock gears DO run OK for a while and in some cases last longer than others, but I've known more than a few to give out fast under an upgraded spring. Once you have changed the spring the first time and it is separated from the piston, you have essentially a quick change system on tap. Just remove the buffer tube and the spring will come out without you having to ope up the gearbox.

A word of warning though. Go steady with the buffer tube/lower receiver threads, and DO NOT thread the buffer tube into the receiver until it touches the gear box. If you do, you'll break the lower receiver and they cost about £120 to replace. Not fun.

A word on FPS then if you will...

Whilst as Sean says, 40fps doesn't make a massive difference in CQB and will not afford you a great deal of range, one thing it will give you is a better "time to target". I ran a stock spring in my Recoil for a good while. I was happy rocking .25g BBs out of it and the range and accuracy was fine thanks to the apparently magical hop unit. The problem is though, when you start pushing out the range which bizarrely does happen at my local urban site, you start to notice that you time to target is much slower than that of somebody who's gun is closer to 345fps. When you are fighting around hard cover, the problem becomes worse because they are literally able to squeeze a couple of rounds off whilst your BB is in the air, before ducking behind their window frame again...

If you are playing at sites where the engagement distances are shorter, FPS isn't going to be so vital and I would generally go for the improved battery option and leave it at that. although if you are playing on more open terrain and pushing the range of your gun, FPS is going to play a part in it.

I've recently been experimenting with high torque motors in my recoil in order to get even snappier trigger response, but not too high a rate of fire, which will frankly be a death nell for your piston in a recoil gun.

[Mark D]

Re: Well I got my sopmod....but now I want to tinker

Thanks again for the replies. There's so much to consider!

I'm going to follow pure silvers advice and alter the stock first to take lipos and deans with gold connectors. Then I will add the tight bore and hopup. Does that sound like a reasonable plan?

I will have to get a tech to look at the gear box as I'm a complete novice

[ThePope]

Re: Well I got my sopmod....but now I want to tinker

Going to pipe in here on gears etc. My SOPMOD ran stock gears with upgraded spring and 9.6 battery for the best part of 2 and a half years for me and 1 and a half for previous owner. Don't bother touching them unless they break.

[B.E.N.]

Re: Well I got my sopmod....but now I want to tinker

All I'm saying is mine broke within 6 months, Ben, my colleague's broke twice in three games, John, a friends broke 3 times in summer in his AK before he upgraded to steel, Dan, another buddy ran through a couple of sets in a short while... As many people seem to break them as find they work for a while, it's a flip of a coin from the looks of things.

I've had no issues at all with the steel Hornbill ones I put in and nobody in the above list has either, so, for the sake of £25 it's worth getting them put in from the off, especially if you are paying for a technician's time to open the gearbox anyway.

[ThePope]

Re: Well I got my sopmod....but now I want to tinker

I get your point but why replace something if it isn't broken.

I always find it causes more problems than it solves, but I guess for the sake of £25 quid you are correct. Prommy gears cost a small fortune when I had mine...

[B.E.N.]

Re: Well I got my sopmod....but now I want to tinker

I'd only ever pick those up if I was building some kinda mega-spring monster...

From my point of view, I just figure that it's worth laying down the £25 just to save the hassle of potentially having to open the gun up again anytime soon. I upgraded my spring, had a shoot for a bit. stripped a gear, replaced that then stupidly stripped a piston twatting about with an 11.1v battery, so opened it up again, got it running then cracked the lower receiver... I had that gun in pieces more times than I cared to think about in the space of about three weeks! :D

This is coming from somebody that just stripped a set of Systema Helicals...

[CK]

Re: Well I got my sopmod....but now I want to tinker

At least a TM EBB m4 is easy to strip.

[ThePope]

Re: Well I got my sopmod....but now I want to tinker

I'd only ever pick those up if I was building some kinda mega-spring monster...

From my point of view, I just figure that it's worth laying down the £25 just to save the hassle of potentially having to open the gun up again anytime soon. I upgraded my spring, had a shoot for a bit. stripped a gear, replaced that then stupidly stripped a piston twatting about with an 11.1v battery, so opened it up again, got it running then cracked the lower receiver... I had that gun in pieces more times than I cared to think about in the space of about three weeks! :D

This is coming from somebody that just stripped a set of Systema Helicals...

(OT but meh!) Not as bad as my mate, ran a 11.1v on some SHS gears in a G&P and the teeth disintegrated, not a trace of them in the gear box at all not even dust. Figured they may have been drawn to the motor some how but there was no trace of them there either! (FYI CK it was Stiffy :P )