Upgrading for indoors

[diamond_SEA]

Im looking to slightly upgrade my SIG552, but i want it to stay CQB friendly.
So far i have tightbore and airsealed nozzle to tighten my groupings.

So if i want to upgrade the stock sig 280 fps with a stronger spring to a mild ~320 fps, should I need to change more internals for such a mild spring? Reshimming and perhaps new bearings might be on my list, but as for cylinder and the like, is it neccessary or can i keep them stock?

[ThunderCactus]

Nope, TM's are fine for indoors if you keep them stock, but 320fps isn't gonna kill it.
I suggest a Tanio Koba twist barrel instead of your tightbore. And everyone always benefits from bearing spring guides.

[The Saint]

Metal bushings and new shims should be definitely on your list. Anytime one goes through the trouble of opening a stock TM mechbox, one really should just take that little extra step of bushing replacement and reshimming.

I'd leave the stock nozzle in unless you know something's seriously wrong with it. Instead, consider adding a bearing spring guide.

So the shopping list looks like:
- Shim set
- Metal bushing set
- MS100-equivilant spring
- Bearing spring guide
- Tightbore

That'll keep it under $100 and get you around 320-330fps.

[CDN_Stalker]

Ya, bearing spring guide will add an extra 15fps or so, putting you right into your prefered area of velocity.

Last week I got my order of reinforced mechboxes in (among a bunch of other interals) and while I had a few other guns as priority to work on, a bud (Testtube) asked if he could borrow one of my MP5s to use at "The Mill" game (CQB game last weekend) in order to loan his SR-16 to a new local player, because the MP5-A I've used all year was my back up one (shooting 365fps), I decided to rebuild my MP5-SD (which has been in parts for months due to broken mechbox) first. The gun has a 330mm inner barrel, bearing spring guide, and used to shoot 385fps with the PDI 150% spring I had in it. New piston and head went into it (both Deepfire), some new wiring with Deans connectors, and stock spring. End result was 320fps using 0.20g BBs, and that was with the hop up set for 0.25g (no hop up with 0.20g I was getting between 335 and 340fps).

So just adding a bearing spring guide might get you into the area you hope for.

[Greylocks]

To me this makes no sense; if you are indoors, at close range, you dont need any upgrades at all. A completely 'stock' gun is just fine.

[Amos]

A team mate of mine has been using a stock gun for about 2 years... It's been just fine.

[seabass]

My Tm M16 has been on the go for 3, dont mess with a good thing

[Wilson]

Originally Posted by Greylocks

To me this makes no sense; if you are indoors, at close range, you dont need any upgrades at all. A completely 'stock' gun is just fine.

+1

Who wants tighter groupings at close range anyway? People are moving quickly... a wider spread will increase your chances of hitting something.

[ThunderCactus]

Actually I suggested the bearing spring guide because in a stock TM gun it'll increase the consistency of your FPS...
Anyway the two best 'don't have to open the mechbox' upgrades you can do would be the hopup rubber and TK twist barrel. Since your keeping it under 320fps theres no downside in getting a TK twist!

[The Saint]

It sounds to me like he wants to upgrade for outdoor use, not indoor. He just wants to keep the upgrade low enough so he can still use it in CQB.

[Skruface]

Originally Posted by diamond_SEA

Im looking to slightly upgrade my SIG552, but i want it to stay CQB friendly.
So far i have tightbore and airsealed nozzle to tighten my groupings.

So if i want to upgrade the stock sig 280 fps with a stronger spring to a mild ~320 fps, should I need to change more internals for such a mild spring? Reshimming and perhaps new bearings might be on my list, but as for cylinder and the like, is it neccessary or can i keep them stock?

King Arms M100 spring from XT gets me 328 fps in my M733. Forget bearing bushings, plain steel ones will do fine - don't forget to buy shims at the same time you get bushings. Add a bearing spring guide like TC said and you're done - it will run you about $70 for the parts above.

[diamond_SEA]

Originally Posted by The Saint

It sounds to me like he wants to upgrade for outdoor use, not indoor. He just wants to keep the upgrade low enough so he can still use it in CQB.

bingo. Tuition is expensive and i dont see myself affording another AEG for the springtime for outdoors. Im hoping i can keep it indoors legal but still get a bit more range and fps for outdoors.

Another part is im curious about the gearbox internals, I was planning on opening the mechbox up anyways to take a peak and see what makes it tick. Then again there are sayings for discouraging curious people.

So Im not looking for a crazy range or anything. As it is a SIG 552, its not exactly an ourdoors gun and im just looking to add a bit more kick to take it out of the CQB only range.

[Amos]

Nothing wrong with a 552 as an outdoor gun...

I know some one who more than successfully has used a MK5-K outdoors..

[Greylocks]

Most TM guns need only two things: A slightly stronger spring, and metal bushings. The rest is gravy or not really needed.

There are lots of recommendations for folks who want to 'peek' inside a mechbox, most of which say 'have someone show you'.

If you decide to go ahead; take the mechbox out of the gun and put it in a large enough clear plastic bag. Open it while inside that bag. If/when all the parts fly out, they will still be in the bag. Then you will have to follow the first bit of advice and bring the bag full of loose parts to a local expert.

If you play primarily indoors/cqb, and your gun is not broken, learn to adjust the hopup and you're set for years of gaming. If you play outdoors, a well adjusted gun will still serve you well for years.

It's your money.

[diamond_SEA]

Usually i agree with your advise, and i do agree with the two parts you have outlined.
but sometimes you just gotta learn things the hard way. There are only so many things you can learn by reading the FAQs, going to mechbox.com, reading countless threads and stickies, and then finally getting someone to show you all the inner workings and seeing it first hand. But you gotta do it yourself eventually, its the best way to learn.
Its also not my first experience working with small mechanics like a mechbox, and i am fully aware of the lost spring or small part danger.

If stock parts made everyone happy, there would be no aftermarket parts.