What does this mean in terms of FPS?

[Crunchmeister]

OK. I got a brand new, totally stock JG MP5-J a couple of weeks ago, and I'm really liking this gun. It's got some pretty incredible range and accuracy. It was easily outranging my Real Sword Type 56 and easily as accurate or better. I was totally impressed by this gun. But what's puzzling me is how powerful this thing is.

Now, I don't have access to a chrony, so I don't have firm numbers. I posted some results I got with my other guns using the pop can test as outlined on Redwolf, and had a lot of people discounted the results. Obviously, cans in one country aren't made the same as in another, so there's only so much one can tell from that unless you compare can & chrony results side by side. So I can't use those numbers as a guide. However, I'm sure the pop can test can still be used to determine rough fps.

In my basement, I usually shoot at one of those Crosman gel covered targets. Works fine for my pistols, and even my other stock AEGs which fired in the 280 to 320 fps range. When I upgraded my C8 with a Prometheus MS110SP spring, I could no longer use it with the target, as BBs tended to break the plastic backing and eventually go through the target and hit the wall. Theoretically, that spring (with other stock components) should have put that gun in the 360 fps range, give or take a few fps. I tried the pop can test with the C8 and I could easily plough thru both sides of a pop can, but couldn't quite make it through the centre of the bottom of. It merely made a dent trying to shoot the edge of the bottom.

So, now we move on the the MP5. I can't shoot it in my basement at all. I have to use a long upstairs hallway and use one of the mesh-backed BB traps to shoot it. At 15 feet in my basement, BBs will go right through my Crosman target and damage my wall. The first shot on a brand new, unused target went right through. The target merely slowed the BB down a bit. So I figured I would try the pop can test.

As you can see from the attached picture, the .20 Metal Tech BB went straight through the centre of the bottom of the can without stopping. The BB fired at the edge made a pretty significant dent and actually punctured the can, but didn't make it through.

So, based on that, how fast is this thing shooting? Redwolf's guide states the bottom centre is 420-450. I can't believe this gun is shooting at that velocity. It's already had about 1000 rounds put through it, mostly in full auto and outdoors in -5 degree weather. I have a REAL hard time believing that this stock gun could shoot that hard, that long, without essentially blowing itself apart internally, or at the very least cracking the mechbox if it was really shooting that hot. I know JGs shoot a lot hotter than what the box advertises. It states 330, but I was expecting something in the 360-380 range, as are most of their regular MP5s. I know the metal RIS ones are known to do 400-410 consistently.

So, can anyone shed some light on this for me and what these results mean?

[The Saint]

You can talk theories and popcans all day, but it's not really reliable. What you really should just do is hunt down someone local to you with a chrony. Most PB fields and shops have one, if you can convince them to let you use it.

[Donster]

results dont lie. i think your mechbox is held together with prayers. if you are really concerned, i think you should either reinforce the mechbox, or downgrade the spring.

[Crunchmeister]

Yeah, if it survives another month, I'll bring it with me to my first game and run it through a chrony there. I'm not overly concerned about internal damage, as I wanted to eventually upgrade it with a reinforced mechbox, stronger gears, and better piston / head / guide. I bought this gun strictly as an upgrade platform. If I blow the mechbox apart, it's not really a big deal.

But if it truly is under 400 fps, I'd love to try keeping it stock and using it as long as possible just to see now long a totally stock, overpowered JG can last. It would be a great durability test. It's already had 1000 rounds or so through it. I'd like to see how much more abuse it could take.

[jesster202]

stock jgs are good i havent had a problem with them only had one come form the factory messed that was propbaly shipping. thats not the point my firs m4a1 jg i put at least close to 3 bb bastard bags threw it and not problems. cant say it held up because i snapped the wireing agian user error but stock i swear they are now real comption with tm only problem is no trades. can be easly fixed with a metal body. but to awanser your woes dont worry about it it breaks it can be replaced whole thing max 50 shipped to your door or u can open it and if it but i havent had a problem with their shells. so dont worry thats all but yeah 400 to 430 sounds right stock i was just shooting cans form 10 ffet away lineed them up blowing threw 4 cans befour it left a huge dent in the fifth so yeah it pretty nuts. oh yeah btw jg 416 the new mechbox love it just reshim it no problems will happen if u do that

[Crunchmeister]

I'm really curious as to how hard it shoots. I'm not one of the "gotta be as close to 400 fps" people. I want it to shoot hard for good range, but I prefer consistency (which it seems to have) and reliability (which I can't really vouch for yet) over power. My end goal is to eventually have an all-metal MP5 with a good quality reinforced internals shooting around 340-350. I figure that with this JG as a starting point, I can eventually get that for not a whole lot more than a stock TM would cost me. And with the failiures I've had with my stock TM guns, I can't see myself ever buying one of those new again.

[Styrak]

Breaking through a can bottom happens about 370-380 in my experience. I built a custom M4 that had a Systema M100 in it that shot 350 and severely dented the bottom of a can but didn't go through (basically the hole was cracked ).

My AUG has a Systema M120 and it shoots 400, and it goes through the bottom of cans.

Just to give you some perspective.

So it could be anywhere from 370+.

[jesster202]

to be hoest some china clone companys are moving up on par with tm. dont gte my wrong im no expret but i hear that a lot of new tms are breaking down and i never had problems until i fucked with it so it was user problem. also if u wantted an all metal mp5 why didnt u go with the jg mp5 navy i belve form shootsoft.ca its 350 comes under 400 with shipping and is allredy all metal.

[tunabreath]

Just a DIY chrono idea if you're so inclined:

Tape two pieces of light but loud paper taught to frames (or chairs ) spaced one meter apart. Shoot through both pieces into a silent trap (towels/etc) from a little over a meter away, recording with a computer. Just using any old free sound editing software, figure out the time difference between the 2nd and 3rd peaks (first is the gun's firing noises, second and third are the paper).

That gives you the time it takes for the BB to go 1 meter. Invert it and you have m/s, which you should be able to easily convert into fps.

[BBS]

maybe you should try doing a stress test to see how long your gun will last in stock form before requiring attention. btw whats the point of have a CQB designated weapon to shoot over CQB limits?

[Cheesevillage]

Originally Posted by BBS

maybe you should try doing a stress test to see how long your gun will last in stock form before requiring attention. btw whats the point of have a CQB designated weapon to shoot over CQB limits?

What's the point in having a cumbersome weapon perform the same as a smaller one?

Airsoft isn't like real life in many respects - ex: sniper rifles.

In other words, who says he's going to use the MP5 indoors?




-Cheese

[BBS]

Originally Posted by Cheesevillage

What's the point in having a cumbersome weapon perform the same as a smaller one?

Airsoft isn't like real life in many respects - ex: sniper rifles.

In other words, who says he's going to use the MP5 indoors?




-Cheese

only Crunchmeister can answer that question.

what you mentioned is very true...to an extent. the shorter MP5 barrel means it wont be as accurate as an AK or M4. the battery will also drain faster. Other than that, it has its advantages by being very easy to manuver. what i stated might make little to no difference in the heat of battle because it mostly depends on the skill of the shooter.

On the other hand, all i know is it definately wont be easy to use an M16 in CQB.

[Omi-san]

Considering how many AEGs and GBB you bought, you can easily afford a Chronograph. It will save you a lot of time and you'll be guaranteed to be under 400 or 350 for indoor. It will also show you right away the positive or negative effect of any change you make.

[m102404]

Originally Posted by Omi-san

Considering how many AEGs and GBB you bought, you can easily afford a Chronograph. It will save you a lot of time and you'll be guaranteed to be under 400 or 350 for indoor. It will also show you right away the positive or negative effect of any change you make.

Crunchmeister,

Couldn't agree more with the above. For what you've spent on rifles/pistols etc...and for how much it seems like you've upgraded/fiddled with stuff already (and it doesn't seem like there's an end in sight... ), drop the $100-120 for a chronograph.

You'll be able to test out your stuff right after upgrading instead of messing around with pop cans and paper/mics.

Airsoftparts.ca has a couple in stock and can have it to you probably within two days, maybe the next day since you're just outside of Toronto.

[Ibby]

Originally Posted by Omi-san

Considering how many AEGs and GBB you bought, you can easily afford a Chronograph.

+1

Pop cans are retarded to use as a guide. So is paper. Get a chrony. I bought mine second hand for $100, which is WELL worth it when you consider how much time you save in making sure your gun meets field limits when you get to a game. I've seen plenty of players show up to games with guns they've spent all night working on, only to have them banned from the field for being hot. A chrony is your friend.