Few things i would like to know .

[guard-sniper87]

Hey guys,

you all know im not new to the sport,

but i never had an m14 , until now, full length..

i have one from a memeber on here and its great, im after a few upgrades for it , the make of it is a CYMA , but it has a G+G dmr body installed.

ok question for the m14 bit, ----

- What hop rubber is the best for this for range and consistant grouping, ( i use madbull red in my l96 , and blue in my aegs, ) will one of theses work or would a different one be better ??????

- What length barrel is it , which make will be best for it again for accuracy, it has a element .04 installed but not happy with it as so many variations on results on my ammo from indoor testing . was thinking either madbull V2 .03 or pdi /edgi .04 ?????
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Another question , on different gun ,

Onto my masada,

right my masada piston decided to give up the ghost, and grind down
im running lipo and all the gearbox's are lipo ready , the piston was a metal toothed one from element,

im sending the gun off to a techy i know as after the first upgrade she had the gun shop broke the bolt cover/release mech anyway another story ,

Questions-

- What piston would be better , ive seen a ICS full metal 14tooth piston for £19, or a ultimate MODIFY piston for £20 ... was thinking of systema until found out they out of business ..

- What barrel length is the masada inner barrel , have a friend cnc milling me a stainless steel barrel, i just need the length in MM if anyone can help .
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Please feel free to elaborate on things ,

BUT I AM NOT HAVING ARGUMENTS ON CHEAP POLYMER PISTONS, ANY HINT I WILL ASK A MOD TO CLOSE THE THREAD OR REMOVE THE COMENTS .

REMEMBER IM RUNNING LIPO, HITTING OVER 28 RPS.....

[johnnyj]

Re: Few things i would like to know .

ok i would stay very clear of full metal pistons if they go wrong they can take the rest of the gearbox with it

the modify poly pistons look fine , i have used the acm copy's and there great for hi-speed set-ups the half rack is handy for losing teeth and having no holes to fill
just make sure the aoa is spot on and all should be fine

[guard-sniper87]

Re: Few things i would like to know .

yeah the AOA is perfect , thanks to the modify modular gear set pre-shimmed in the cage , just need a really strong piston or a full metal toothed or 7 toothed metal piston but unsure ...

[johnnyj]

Re: Few things i would like to know .

sorry to sound dumb how is the gears in the cage spot on for aoa ? never used these funky new gears yet haha , aoa should be a piston mod but if you have there gearset i would go with there piston aswell but i do recomend poly over metal , so many things can go wrong i would always be happy to see a mashed piston over the gears

[guard-sniper87]

Re: Few things i would like to know .

the modify series of gears mate , are pre shimmed and they slot right into the gear box without all the other parts moving around when trying to sort the gears sitting right ,

and the hard polymer piston inside just stripped after 3months so not bad

[TS_Welshy]

Re: Few things i would like to know .

Yep. Metal piston is a bad idea, especially in a high speed set up. If things go wrong, which is more likely at 28rps, you want a nice shredded £10 piece of plastic piston rather than X amount of shredded everything.

I personally don't recommend cheapsoft, but from experience with guns I've had upgraded, Classic Army and G&P pistons are good. Tm and Prometheus are better. Try them, and remember - NOT METAL!

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As for the M14... well for a start what fps are you running at? (Sorry if you posted it after typing all the above I kinda forgot!).

Obviously if you're going 425 and semi auto, then I possibly a harder bucking would do, i don't have any personal experience here so perhaps someone else can clarify.

If you're going for 300-350, then the first thing I would say is USE HEAVIER BBS :D. Make the switch to 0.25. If you're running 350 on a 0.2, then you will get around 300 on a 0.25 and IT WILL go further and IT WILL be more accurate. It's been proven. I also run 0.25s in all my AEGs and have seen the performance increase everytime.

So try that before you spend money on a barrel. But if you do, then element 6.04 probably isn't the best option. Madbull 6.03 Black Pythons are awesome, or try a Prometheus 6.03 if you can afford it. Sorry, I don't know the barrel length.

Also, at 350, if it fits, get a TM M14 hop unit with TM M14 hop rubber etc. I'm pretty sure the CYMA is a TM clone so it should fit? TM M14 is basically the best hop unit evarrr... and even if you don't change the unit, bang in a Tm hop rubber. Prometheus and Madbull and Guarder clears are also supposed to be excellent, but I generally use Tm hop rubbers in my guns and they really are awesome.

[guard-sniper87]

Re: Few things i would like to know .

with the masada piston mate , been on the phone with my techy and he said to get the ultimate modify piston and short stroke it again just the rear tooth,
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the m14 is running at 320fps, i never stated it , and on a .2g bb i was getting a very nice range , i ran out of spare hop rubbers so trying to gauge whish to go for , but now you've said tm im thinking- see if can find one laying around , but i've had mixed results with the guarder and systema , so had madbull and stuck to them and they are sweet, but with a tm i think...

also im using .2s on the m14 , as the only bb's i have are AEG .2s , piston .3's , sniper rifles .36's and .43s ..... never really tried the .25s as my site and store dont stock them .

[TS_Welshy]

Re: Few things i would like to know .

yeah short stroking is probably a good idea.

and if you can't find 0.25s, try the shop that supports with fire, they sell loads of different brands.

[guard-sniper87]

Re: Few things i would like to know .

Ah ha , cheers mate ,
and short stroking the piston and gear is great , aslong as do it on the correct side of the gear :p

[HuntR]

Re: Few things i would like to know .

Right. The reason the hard piston you had broke is because a hard piston is crap in a high speed setup. You want something softer. The Modify ultimate piston is great for high speed setups as is the marui piston. The barrel in the masada is about 40 cm long.

[North West Outpost]

Re: Few things i would like to know .

Metal on metal always wears. I use Element orange reinforced pistons never had a problem and they are a lot cheaper than other named pistons.

I also agree that having everything metal in a gear box shouts of terminal breakage when it does occour.....BUT if you do some research on the Philipino Airsoft sites, they use Alluminium pistons in set ups with up to 40 bb's a sec. So I'm going to do some reading. I'd love to build a gear box with a ROF over 40 a sec. Soz that was slightly off topic.

There comes a point with a barrel of 400mm where the piston is creating negative pressure, caused by not being able to return to rest with a bb still trying to exit the barrel. Couldn't tell you tha exact ROF as I usually use short barreled guns for my projects.

[ThatblokewiththeScar.]

Re: Few things i would like to know .

Hi Guard.

Ok first off the TM M14 Barrel length is 510mm so I will assume that the Cyma is the same. Personally I would try and find a stock original TM barrel and pop that in. My first M14 had a systema TB my second had the stock barrel no other mods. The range on the stock barrel was the same as the systema within a few feet. However with the stock barrel the BB's stayed flatter in the air longer than the systema. By this I mean that at the end of their flight path the systema would drop gradually with a low arc but the stock would stay up and then fall more dramatically with a high arc. This meant they stayed in your sight picture longer. Close up the systema pulled better groupings but at distance there was no determinable difference in spread pattern. Oddly the stock barrel always looked like it had less range as the BB's would just disappear from sight instead of being able to follow them to the ground. These two guns were tested side by side before one of them had the balls tuned out of it.

If you do go TB then I seem to be the only person who likes the Vanaras Barrels. I have a few of them and so far (touch wood) I have not had a bad one. About £30 will get you a stainless bore 6.03 of a suitable length. I even had one in my AW338 and it was glorious.

I'm with Waltz on the TM hop rubber thing. Unless you are going to run higher power levels then TM is Bestest. Always worth trying one of the H-Nubs sometimes they make things worse sometimes the improvement is amazing. I also tried some Madbull Match BB's at the weekend. They are my new best friends!

I am also building a modify gearbox with the hi-speed gearset and I cant decide what piston to go for. I suspect I will use the modify piston, At least until i strip it! Again I am unlucky with high end parts I have had 2 systemas let go on me and an ICS aluminum piston lasted 500 rounds or less and I wont go into my VFC. My favorite piston by far is the stock TM very hard to fault and its cheap. Next on the list for special guns is the white G&P piston this is a great piston and I believe that if you ask a Warrior for it they have a pre-short stroked version! But as I was discussing with hunter the other day most of My own guns that needed a rebuild over ones I have done for other people the first piston I go for is the Element Duracon. And if i am going a short stroke this is always my fist choice.

In a standard gearbox running upto 9.6v I also use the clear poly piston from Element they are about £6 or so and if they do go it aint the end of the world. Pus being poly they tend not to break up as much as shred which is much less damaging to your gears.

[No1_sonuk]

Re: Few things i would like to know .

There comes a point with a barrel of 400mm where the piston is creating negative pressure, caused by not being able to return to rest with a bb still trying to exit the barrel. Couldn't tell you tha exact ROF as I usually use short barreled guns for my projects.

I've got an Excel sheet for some of this

400mm barrel length @ 350 FPS gives a flight time of 0.00375 seconds.

Assuming the piston doesn't start to withdraw during that 0.00375 second period, no negative pressure would result. Even if it did, there's usually some excess pressure that blasts out of the muzzle behind the BB.

If you assume no need to draw a piston back, a THEORETICAL maximum ROF is 266 rounds per second (about 16000 RPM!). i.e 266 BBs could go through that barrel in 1 second with no other BB already in there.
However, you'd need to factor in the motor driving back the piston. I think it's this, rather than barrel length, that would have the most effect on maximum ROF.

[North West Outpost]

Re: Few things i would like to know .

I've got an Excel sheet for some of this

400mm barrel length @ 350 FPS gives a flight time of 0.00375 seconds.

Assuming the piston doesn't start to withdraw during that 0.00375 second period, no negative pressure would result. Even if it did, there's usually some excess pressure that blasts out of the muzzle behind the BB.

If you assume no need to draw a piston back, a THEORETICAL maximum ROF is 266 rounds per second (about 16000 RPM!). i.e 266 BBs could go through that barrel in 1 second with no other BB already in there.
However, you'd need to factor in the motor driving back the piston. I think it's this, rather than barrel length, that would have the most effect on maximum ROF.

Great maths but unfortunatly you have missed the point. Not sure how you would get negative pressure with out drawing the piston back....Never mind thanks for that.

[guard-sniper87]

Re: Few things i would like to know .

Cheers for the input about the Masada guys
I'm going for the modify piston as had a chat with the stockists
and well I'm impressed by it

Now for the m14 bits and bobs