20 FPS more on SRC RPK

di11on

Hi all,

Would be grateful for suggestions for the simplest way of getting another 20fps or so from my SRC RPK. She's currently firing around 300.

Don't really care about accuracy... just more FPS :-)

Puding

why do you only care about fps?

di11on

Because it's a support weapon...

I was happy with the dispersion when milling my snowman army out the back garden :-)

thermo

di11on wrote: »

Hi all,

Would be grateful for suggestions for the simplest way of getting another 20fps or so from my SRC RPK. She's currently firing around 300.

Don't really care about accuracy... just more FPS :-)

change the spring.

Leftyflip

Not a weapon *headdesk*
20fps extra is pointless in my experience, unless you'll be using heavier BB's and want it as close to the limit as possible...

di11on

Leftyflip wrote: »

Not a weapon *headdesk*

Tell my snowmen that! :-)

OK OK, what I meant was "6mm projectile firing device"

thermo

i agree with ger here a good gun with a decent hop-up and barel and shooting a bit low is better than a gun shooting on the limit with crap barrel and hop-up.

Puding

di11on wrote: »

Because it's a support weapon...

sorry that makes no sense to me really


fps does not make a support weapon, a change of hop up bucking will give you more range, stick with the stock barrel as spread is nice for support weapons, change motor for a G&P m120 for more rof

if you really want to get as close to 320 as you can then as has already been said you can change the spring althought some trial and error will be needed depending on how good the air seal is, what type of cylinder is used, all that kinda thing

its a long inner barrel so going to a tight bore could well put you over 328fps with .20 and over the one joule limit

Leftyflip

thermo wrote: »

change the spring.

Not necessarily, I'd work on improving airseals and compression first, a bit of teflon tape goes a long way. You should always check compression, I had an M4 on my desk recently firing at 250fps I think it was, bit of teflon tape and silicone oil had it up at 300fps. It had terrible compression, now it's great...

gerrowadat

It should be pointed out that not upgrading anything but your spring to go from 300-320 gets you about an extra 2 feet of range, which you can emulate by aiming a little higher.

thermo

Leftyflip wrote: »

Not necessarily, I'd work on improving airseals and compression first, a bit of teflon tape goes a long way. You should always check compression, I had an M4 on my desk recently firing at 250fps I think it was, bit of teflon tape and silicone oil had it up at 300fps. It had terrible compression, now it's great...

ger he said the simplest way lol easy to work on ak's it is!!!!
any way i use springs to do the big jumps and use the air seals for fine tuning!

@op if your unsure what to do, im sure there is a retailer or some one who could help you (for a small fee) close to you!

Leftyflip

It is a simple way, cheaper too. Take out the piston and pack out the O-ring add silicone oil and that's it.

Stercus Accidit

Leftyflip wrote: »

It is a simple way, cheaper too. Take out the piston and pack out the O-ring add silicone oil and that's it.

Don't do this on an rpk, the barrel length means you need the air seal vent to be able to open on the back stroke, or you get suck back on auto.

@OP you really don't need 20 fps(300 is perfect), get a better hop up rubber, like a madbull or guarder, you will gain a few fps but a lot of range with the better hop also.

Frank the Manc

As puding & others have said a few more fps is pointless really, a decent hop unit & rubber will make more of a difference.

All my guns are tuned to 300 or under & i guarantee you theyll outshoot any stock "350fps monster" in accuracy & range.
All these lads chasing the 328 is stupid.

If youre really after a few more fps & youre compression & airseal is ok, bang in a bearing spring guide, that should give you about 10-ish extra fps, a TB is sorta pointless in a SAW as better spread gives you a greater covering area.

When you go up a spring youll find that after its fully bedded in after a few thousand rounds, it will drop back down a bit.

Leftyflip

Stercus Accidit wrote: »

Don't do this on an rpk, the barrel length means you need the air seal vent to be able to open on the back stroke, or you get suck back on auto.

Silly Russian design... Thanks for that Sam!

Stercus Accidit

Leftyflip wrote: »

Silly Russian design... Thanks for that Sam!

Its purely barrel length dude, and cylinder volume, 650mm I think is a lot of barrel, an AK74 alone takes the same inner barrel as an m14 and g3, the rpk is very long.

Leftyflip

Stercus Accidit wrote: »

Its purely barrel length dude, and cylinder volume, 650mm I think is a lot of barrel, an AK74 alone takes the same inner barrel as an m14 and g3, the rpk is very long.

Oh yeah, I know that's what it's down to. It is a pretty long gun, can you say over compensating?

Stercus Accidit

Leftyflip wrote: »

Oh yeah, I know that's what it's down to. It is a pretty long gun, can you say over compensating?

Its a tube with wooden bits.

I'd call the rails and microwaves and eotechs and the kitchen sink attached to a gun is compensating

Leftyflip

Stercus Accidit wrote: »

I'd call the rails and microwaves and eotechs and the kitchen sink attached to a gun is compensating

Oooh...

Phractal

Well... If you are a FPS chaser (like a friend of mine who is now armed with a chrono)... Here is what he did. He removed the barrel. sprayed her insides with teflon spray (for lubing up motorbike parts) and then allowed to dry. He cleaned her and reinstalled. He then proceeded to test it and found it was shooting ~15 FPS faster, and that it shrunk his groups at 20 meters 'a fair bit'. However, he then installed a new hop, air nozzle, piston head and a few other gimmicks and they all cumulatively made her go a bit OVER the limit. So... He swapped out the spring for a lower FPS one and he was getting 320fps with hopup off using 0.2g G&G BB's - which is, IIRC, perfectly OK. BTW the barrel was a Prommy tightbore. Gun was an upgraded TM MP5 SD, which at stock got ~270fps with hop OFF.

Leftyflip

And the stock TM woulda been more reliable...

Puding

Phractal wrote: »

Well... If you are a FPS chaser (like a friend of mine who is now armed with a chrono)... Here is what he did. He removed the barrel. sprayed her insides with teflon spray (for lubing up motorbike parts) and then allowed to dry. He cleaned her and reinstalled. He then proceeded to test it and found it was shooting ~15 FPS faster, and that it shrunk his groups at 20 meters 'a fair bit'. However, he then installed a new hop, air nozzle, piston head and a few other gimmicks and they all cumulatively made her go a bit OVER the limit. So... He swapped out the spring for a lower FPS one and he was getting 320fps with hopup off using 0.2g G&G BB's - which is, IIRC, perfectly OK. BTW the barrel was a Prommy tightbore. Gun was an upgraded TM MP5 SD, which at stock got ~270fps with hop OFF.

sounds like he did a lot of unnecessary work and spent a lot of money for not much reason

Phractal

Lefty: 'Reliability' was not his main goal. He wanted to get better groups, and better FPS. Recently he gave it another overhaul, and its BEAUTIFUL. Shoots around 320 now, excellent groups, amazing ROF and it seems to be unbreakable - a 10,000 rounds 'torture test' was carried out - firing ten thousand rounds almost non stop, only breaks in firing to change mags, batteries, etc. I was the one refilling mags. It had NOT ONE stoppage in the test - the only reason we stopped was due to it costing us €40 in BB's and we had no money to buy more! HE then left it uncleaned or looked at, and fired a further 5,000 a week later. Reliability? I reckon that IS reliability (since the second 5,000 shot test he DID clean and mantain the device!). What do you define as reliability? I think the above sums it up.

Puding: He did it 'for fun'. He enjoys working on his AEG, as do I.

Leftyflip

I doubt it'll be reliable now...

Puding

and you could get all that with a lot less and have done in the past im dead against unnecessary upgrades, what you describe could easily be accomplished by a large number of stock aegs, i enjoy working on aegs as well that why im also trying to giving advice from experience to people

and why spray teflon in a barrel, you would never get an even coating and you would just be creating an artificially dirty barrel

Leftyflip

I don't mean to sound bad, but I do get the occasional feeling that Phractal talks sh*te sometimes, now if he doesn't I apologise and I apologise if he takes offence.

But all of those upgrades were highly unnecessary, a new spring and you would have been fine, but hell, its a TM, I'd have left it stock and I'm a c*nt for upgrading guns...

thermo

lefty and phractal boards answer to the couple that always fight in father ted!

but i do agree with ger here if its not broke dont fix it!

Phractal

Hahahaha I thought that was Masada and Firekitten :P

Lefty: I don't take any offense, you are entitled to your opinion, no matter how false or insulting. As if I give a damn what people think of me (talking ****e = spreading misinformation = BAD = being shot by someone like myself who despises posers) (I never understood why one would lie on the internets... Like, whats the point?)

Heh, I could say the same thing (being a ****e-talker) about many people. But I would possibly be wrong. So... I dont. The so-called anonymity of the internet is, in my opinion, no excuse for being blatantly rude, or downright unfriendly - not that I see any of that here on a regular basis anyway. It saddens me to see some people using the 'net as a place to take out their anger - save it for CSS lads!

Anyways, Back on topic. I myself 'dont see the point' in totally unnecessary upgrades (waste of money), but then again, this guy would replace a O ring if he figured it would give 1fps extra. He just is that way - goes a 'bit' too far IMO. And I love just taking my AEG apart into the smallest bits possible for the hell of it.

With the teflon spray a rather uniform coating can (apparently) be achieved by apraying it down, then pushing a barrel wipe through a few times, then repeating from the other end.

I used to always say 'if it aint broke, dont fix it' (being the son of an autoelectrician/ car mechanic, and at one stage working part time as one instilled a ethos of that in me), however, I figure that whatever makes one happy... Hell, I want to buy a second hand Galaxy MP5k just so I can replace almost all the internals with the best parts I can afford, pimp out the exterior, modify till I am satisfied... Just cos I can! I really regret selling mine now... I want it back just so I can enjoy myself upgrading it. It would cost a bomb, give bugger all performance increase, but I would ENJOY doing it.

Also, I reckon the upgraded one is actually more reliable than the stock TM one as the parts are better made (or at least they feel better made, prommy, systema, etc. High end bits.). Perhaps we shall see how long it lasts. He said after the tests the amount of ****e in the barrel was incredible - and an idea I just thought of - Teflon coating BB's? First wash em with detergent, then water, then put em in a tumbler with teflon spray stuff in it. Should result in uniform coating, and add to FPS - a bit like moly coating RS bullets.

Leftyflip

Firstly, spraying it down the barrel and wiping it out kind of negates the effect no?

And secondly

Teflon coating BB's? First wash em with detergent, then water, then put em in a tumbler with teflon spray stuff in it. Should result in uniform coating, and add to FPS - a bit like moly coating RS bullets.

:rolleyes:

Phractal

Well I personally dont bother teflon coating the barrel - my AEG is too close to the limit stock to even think of it.

However, my mate (who is yet to join Boards.ie) advocates it and he repeatedly tells me that 'some teflon is left behind in the bore, providing a thin lubricating layer'. Possible, but whatever.

Teflon coating the BB's (provided the solvent does not eat BB's) is merely a suggestion off the top of my head. I was merely throwing it out there for Ger to tear apart

Masada

Meh, this thread is fail., and to put a nail in the coffin of teflon coating the parts, Ive done it, tested it, and seen no change at all,.,

A good tip for accuracy though, get hold of some brasso, ya know that stuff yore nanny used to clean her knockers with (now now, behave...) and use it to polish the inside of the the barrel. its a very fine abrasive and it'll flatten the inside the the barrel to a nice even finish and leave it super smooth., that made a big difference.,:)

JonnyTwoCombs

My stock age is firing around the 260 mark using .25g’s. As I generally use this weight of BB I would like to get it firing around 300.

Would tweaking the air seals and compression do the trick?


I think I'll try out that basso tip, it sounds like it could work!:)

thermo

Ah Masada how can this be a fail thread?
After reading some of the posts here I'm inspired to go out and develop rocket assisted bb's that will be accurate to .5 of a mm @ 300m, I'm thinking of using my friends porta cabin as a lab to do my research in.

Masada

If only i could thank twice.,

thermo

JonnyTwoCombs wrote: »

My stock age is firing around the 260 mark using .25g’s. As I generally use this weight of BB I would like to get it firing around 300.

Would tweaking the air seals and compression do the trick?


I think I'll try out that basso tip, it sounds like it could work!:)

300 fps with .25g would be over the limit.

thermo

Masada wrote: »

If only i could thank twice.,

No bothers

JonnyTwoCombs

thermo wrote: »

300 fps with .25g would be over the limit.

:eek::eek:

Gatling

JonnyTwoCombs wrote: »

:eek::eek:

[IMG][/img]

di11on

Ok... looks like my RPK is firing at around 280fps... I really would like to get it up to at least 300. Sounds like a new tightbore would be the simplest way to get the fps... and upgraded hop rubber for extended range. However, I do like the spread of the current barrel.

I'd like to avoid a new spring to prevent stressing the internals.

Does this sound sensible?

Sod'o swords

Most of my guns do ~270 fps.

And they out range manys a gun i've seen.

Decent hop, clean your barrel, and don't use .12g bb's you get in Centra, and you'll be grand. I don't even have tightbores, which means i can use more bb's, where as i know people with tightbores and have host's of problems with bb's.

All the extra fps does is make it more likely that your gun could be over on a certain day, where as this way, you're graaaaaaaaaaaaaaaaand.

Leftyflip

Sod'o swords wrote: »

Most of my guns do ~270 fps.

haha newwwb!
We all know that 327.9999999fps is where its at.:P

Sod'o swords

Leftyflip wrote: »

haha newwwb!
We all know that 327.9999999fps is where its at.:P

Well i had all my guns at 133.7 for ages, but what i gained in leetness i lacked in range.

Phractal

Hahahaha this thread is gas! Another reason to spend more time here I suppose.

However... I would like to thank some people while I am here: (NO SARCASM IS IN THIS -> THIS IS STRAIGHT FROM THE 'HEART')

Firstly, Ger (Leftyflip) for always providing the arguments and fun that ensues - and for motivating me to double check the accuracy of anything I have to say. AND for being a total legend all round - very knowledgeable fella, have lots-o-respect for him.

Next, Thermo. Another knowledgeable, pleasant fellow, always posts something useful/interesting or just fecking hilarious. The 'rocket assisted BB' comment put a smile on my face after a bad day. Thank you.

Masada/Richie: Always coming up with something interesting (the Brasso thing... EXTREMELY interesting), and posts lovely photos of RIF's for me to stare at. And for writing good, informative articles. While we occasionally differ on opinion, I actually respect you.

Gatling: For posting such a valuable chart of data - it is an excellent resource which shall prove useful to many of us I am sure.

Again, thanks to all who made this thread so damn good.

thermo

@ op a spring change will not really strain your internals overly as the max your bringing it up will be 50 fps. And who knows it may have a 400 fps spring in it at the moment and have a drilled nozzle, did you strip it yet?

@ phractal glad you liked my post

JonnyTwoCombs

Masada wrote: »

Meh, this thread is fail., and to put a nail in the coffin of teflon coating the parts, Ive done it, tested it, and seen no change at all,.,


A good tip for accuracy though, get hold of some brasso, ya know that stuff yore nanny used to clean her knockers with (now now, behave...) and use it to polish the inside of the the barrel. its a very fine abrasive and it'll flatten the inside the the barrel to a nice even finish and leave it super smooth., that made a big difference.,:)

Ok, after polishing my barrel (insert own pun here) for a few hours, all I can say is…


MMMmmmmm shiny!

I will see on Sunday if there is any difference. :cool:

Masada

Yeah but did ya do the gun aswell?

JonnyTwoCombs

JonnyTwoCombs wrote: »

Ok, after polishing my barrel (insert own pun here) for a few hours, all I can say is…


MMMmmmmm shiny!

I will see on Sunday if there is any difference. :cool:

As I have said, I spend some time polishing my barrel and today was test day.

Two weeks ago my AEG was clocked at 267 fps and today using the same crono it was firing at 272fps :eek::eek: