Son's G36 Chrono'd At 370fps At Weekend Event - Why?

Mark#1

Hi Guys.

His G36 chrono'd fine at between 290-312 or so for the whole week during Fingal Airsoft's camp in August, but chrono'd at 370fps yesterday (Saturday 7th) at the Elite Force event at Fingal Airsoft.

Everything was the same - same batteries, BBs from the same bottle that he used during the camp, no mods to the G36, similar air temperatures...

Any ideas what might cause this increased fps?


Thanks,

Mark

Southern Dandy

Mark#1 wrote: »

Hi Guys.

His G36 chrono'd fine at between 290-312 or so for the whole week during Fingal Airsoft's camp in August, but chrono'd at 370fps yesterday (Saturday 7th) at the Elite Force event at Fingal Airsoft.

Everything was the same - same batteries, BBs from the same bottle that he used during the camp, no mods to the G36, similar air temperatures...

Any ideas what might cause this increased fps?


Thanks,

Mark

There could be a number of reasons.

The chrono used, chronos vary in readings from brand to brand and can be affected by things like low battery power and poor lighting. For instance my chrono (xcortech 3200) gives a reading of 315-320 for my M4, at a site I go to it fired at 280fps, the chrono was a madbull which are known for dodgey readings from time to time.

The AEG could have compression issues, reading low sometimes then give a high reading, out of interest where was this aeg purchased?.

What brand and weight bb's do use?, I doubt this is the problem though.

Was the hop-up fully off when it was chrono'd at fingal and elite ops?.

Mark#1

Thanks for your reply Southern Dandy.

I'll hold off on naming the dealer for now - it'd be unfair to associate them with an issue when they might not be responsible, and haven't had a chance yet to check it out.

Not sure about the hop-up adjustment. I do know that hop-up adjustment was a subject they touched on in the camp back in August, so I'd presume the hop-up was adjusted correctly after that "lesson", and I'm pretty certain he wouldn't have touched it again after that. I'll be speaking with him this evening and I'll confirm that then.

BBs were ASG Devil .20g.

Not sure what brand chrono was used.

Have to say, I find the notion that there are variations in performance/readings between chrono's out there a bit suspect - surely by definition they all have to comply with specific standards?

How much integrity is there in an enforcement system when the tools used to enforce that system vary in performance?


Thanks again.

jayod30

I would say most likely the chrono used. I had same issue at a site, two of my guns chronoing from between 350/370fps. Knowing that the readings were in no way true and my guns were fine I asked they use another chrono (thankfully there was two chronos on site) and low and behold, both guns were fine.

Note, my issue at the time didn't happen at Fingal. But they usually have 2 chronos on site so if he's unsure about the reading, ask them to chrono it on another. They should be happy to do this

TheDoc

Mark#1 wrote: »

How much integrity is there in an enforcement system when the tools used to enforce that system vary in performance?

It's an unfortunate situation that arises from site to site. I get a different reading every site I go to, because every site has a different environment to chronograph. In an ideal world it should be streamlined and done in the correct environments, but that's not always possible or feasible and there is always an excuse as to why not to do it.

It was pretty much outlined ALONG time ago the environment by which a chronograph should be operated in. Things like sunlight, wind, air tempeture, angle of fire through the chrono among a host of other things all effect it.

I think the reason it continues to be done the way it is , is because in fairness, it's unusual that you get a mental difference in reading. Like when I say mine chrono different every site, by maybe a variance of a few FPS.

I know all my guns are between 280-300 FPS. If I had a chrono that showed over that, I'd immediately be suspect of the chronograph. If it happened on a site, I'd be looking for a second chronograph. I wouldn't be having a hissy if there wasn't a spare, it would possibly just bring about assumptions of the site. And when you consider there was a numtpy site owner who used to have a disclaimer that he would "call the guards" when an AEG fired over the limit, and refuse to hand the gun back, you could see why it is normally in the best interest of the site owner to make sure their chronographing is as accurate as possible.

Mark#1

Got the gun back from the dealer today - tested between 290-328.

I suspect it was a combination of:

• My son not adjusting the hop before testing.
  
• A poorly- or not-calibrated chrono.

If an experienced player's gun had chrono'd at 370fps, I imagine they'd have immediately questioned the chrono on the spot, and ensured their hop was adjusted properly. I think my son, being a relative new-comer, never thought to question it - he just accepted what he was told. I'm curious whether any other guns tested on the same chrono were so far over 328, if at all.

I gather climatic/environmental factors can affect fps, but IMO 370 was clearly worth investigation - as I understand things, that's technically an illegal firearm, that could warrant police involvement...

To be fair to Fingal Airsoft, they did give my son a rental gun, free-of-charge, for the whole day. It seemed to be a very busy day, and I guess the guys there figured it less hassle to loan the gun than to call the kid's dad to come and collect him or organise paying for the rental.

So after all's said & done, while my son was disappointed not to be able to use his beloved G36 (with his Eotech 552 fitted) on the day, and that such a high chrono reading wasn't investigated further on-site, by loaning him a rental M4, Fingal Airsoft did ensure he still got to play. He also learned a few things:

• He doesn't like M4s as much as his G36.
  
• His gun's energy/fps is fine - it was confirmed by the dealer to be performing as it should.
  
• He has to adjust his hop-up appropriately before chrono-ing on-site.
  
• He shouldn't be shy about questioning a chrono reading that says his gun is hot (he knows now from the dealer that it's not).

Thanks to Bren at Fingal Airsoft for loaning the M4 for the day to allow my son to play, and to Alan at Strikearms for checking the gun and offering to do whatever it took to rectify the gun's problem FOC, if any problem had been found.

I'm curious now as to how valid chrono equipment is at all airsoft sites (if it can happen at one, presumably it can happen anywhere?) - how regularly/often are they calibrated? How reliable are they? How reliable is the calibration process/equipment? Are there back-up machines to verify suspect readings? What's the point in doing the test if the equipment or system is prone to or capable of discrepancies of some 13% over the highest reading the gun gave the dealer's chrono?


Thanks all,

Mark

tyrone03

As far as I know, the hop has to be fully off when you chrono your gun to get a proper reading, because with the hop on, its touching the BB and reducing the FPS. Most sites iv been too down "there" you must turn the hop off.