Assistance With Upgrading Gun

[Evan]

Hello

Ive just received my new S&T MATRIX KAC SR-25 Full Metal AEG which is great however, Id like to upgrade it but its not somthing that i am familiar with or really understand tbh.

 

Its shooting 390-420 fps but I need more power, my local airsoft site is HUGE so I need min 450-500 if possible. I've looked everywhere to see if anyone has upgraded this gun but I cant find anything. If anyone could point me in the right direction or give me some tips on what/how to upgrade it. If I can identify the parts then ill take it to a pro to install them.

Many thanks

[Adolf Hamster]

ok, first things first- do you have a reliable backup gun?

 

if you answered no to that question then, and i'm deadly serious about this, ignore the rest of this post because trust me on this the walk of shame gets old the tenth time you've done it.

 

however, i wouldn't have listened to me and teching once you've got some experience is a massive boon in this hobby.

 

 

so with that in mind:

 

is the 390-420 fps figure you're quoting the range you're getting on the chrono?

 

if so then the first area to address before even thinking about springs etc is the air seal.

 

i've a guide here should help familiarise yourself with what to look at:

 

 

given you're talking about a big site with lots of space i'm guessing your primary objective is range and accuracy.

 

in rough order of ascending difficulty you'll want to:

• use good quality heavy ammo, how heavy is up to you but for the dmr/sniper role i'd be looking at the proper heavies
• tweak the hop to lift heavy ammo, these days i primarily run a 50° maple leaf macaron with omega nub which can lift .48's at 1j, you should be able to run a higher degree given you're running more velocity.
• sort out the air seal as above
• once you've got a good air seal/fps consistency then if you're still a decent chunk under the site limit then look at a stronger spring

 

[BigStew]

just had a quick look at the spec it's says your gun fires full auto so would be need to be locked to semi auto before you have that sort of FPS. I would also check with your site that they will actually allow you to run a AEG DMR at that sort of FPS. As Adolf Hamster said FPS consistence a good hop rubber and heavy ammo will do more than upping the FPS.

[Adolf Hamster]

29 minutes ago, BigStew said:

just had a quick look at the spec it's says your gun fires full auto so would be need to be locked to semi auto before you have that sort of FPS. I would also check with your site that they will actually allow you to run a AEG DMR at that sort of FPS. As Adolf Hamster said FPS consistence a good hop rubber and heavy ammo will do more than upping the FPS.

 

that's a good point, i assumed it was semi only being an sr but for higher limits you're gonna need it semi locked.

[Skara]

A mechanical lock on a v2 (or 2.5) box is the easiest thing ever and doesn't even require opening the box. You just shave a tiny bit off the selector plate to prevent it from engaging the cutoff lever (which is the mechanical lever that disconnects the trigger contacts after one cycle). So that's sorted.

 

Then please read carefully Adolf's first post, read it again, and when you're done read it a third time just in case.

 

With such a large air volume, once the air seal is fixed, you may gain a lot of energy just from using heavy bbs (look up Joule Creep).

With that being said the current spring could be totally fine for your field limits. In any case I'd recommend to stay 0.1/0.15J below said limit to make sure you don't do the walk of shame because of a hot gun.

 

Please stop asking for upgrades right off the bat if you haven't skirmished your gun once.

It's dumb and leads to the TM recoil syndrome.

[Shaydee]

Is the "shooting 390-420 fps" actual chrono readings you have done yourself or something from a website ad? If it's the latter the first thing you should do is chrono it - and I wouldn't bother with any form of DMR upgrading/modification until you have yourself your own chrono. Like Adolf has mentioned, I'd advise not tinkering with the insides unless you have a backup at hand for game days, there is nothing worse than having to go back to the safe zone - or even home - as your gun has packed up. Thankfully I've mostly had a backup in one shape or form, bar the time I went to the mall and had by GHK bash it's hop to pieces and was forced to run a sidearm for the day 😄

 

You state 450 - 500 fps is what you're aiming for - are you UK based? Most sites have a hard 450fps limit on DMRs (some have it lower) and require them to be locked to semi. You'll also have to adhere to minimum engagement distances due to the higher energy you'll be slinging, so anybody that shows up within 20-30 metres you won't be able to take a pop at unless you've got a sidearm.

 

Also I'll echo Skara's point - play with the gun first! You'll soon pick up on what it doesn't do well and can look at that area first. That'll most probably end up being barrel/hop combo and decent heavyweight BBs.

[AlphaBear]

7 hours ago, Skara said:

It's dumb and leads to the TM recoil syndrome.

 

The what Syndrome?
I'v not heard of this one....

Does the WHO know about this?

Is this medically proven? 😂

Has someone told Trump?

[Skara]

21 minutes ago, AlphaBear said:

 

The what Syndrome?
I'v not heard of this one....

Does the WHO know about this?

Is this medically proven? 😂

Has someone told Trump?

Our Lord and Savior Luke has spoken about this terrible disease, not long ago.

[Killergirl_uk]

Hey Evan, my husband is a gun technician and would happily talk you through everything he also works at mpa airsoft so can get the parts you will need to upgrade. If your interested you can message him on facebook through MPA Defence industries or phone on Friday Saturday or Sunday on 01702 202318 between 9-5 :) 

[Rogerborg]

On 03/04/2019 at 18:59, Evan said:

My site limit is 450fps for single shot DMR's

 

On 07/07/2020 at 20:56, Evan said:

I need min 450-500 if possible.

 

Mmm hmmm.

 

Please be aware that if your gun is still capable of shooting full auto then what you currently have is a Section 5 prohibited firearm, not an airsoft gun, and if you bought that from a UK seller, they need their metaphorical balls booting

 

It'll probably never be an issue, but the first thing you should get it locked to semi, e.g. by removing material from the fire selector to that it can't raise the cut-off lever.

 

We all want more range, but chrono limits are there not just for safety, but so that everyone can have fun on a fairly even footing.  Even if you manage to sneak a 500fps DMR past the chrono, how do you think chaps with bolties are going to feel about being semi-auto spammed by something putting out the same power?

 

You're not far off of your site limit as it is, so I'd echo all of the above and say: air seal, air seal, air seal.  If you are going to change parts, I'd start with a barrel, likely a 6.02mm ZCI if you can get your hands on one.