Something...strange happened.

PonchoTron

I rolled up to my local site today fully prepared to play with my not quite stock G&G M4 to find something unusual had happened.

Every weekend for the past 4-6 months without fail my rifle has fired at 302fps on the dot, time and time again with .20g BBs.

Today it fired between 350-380fps. What could have happened? Nothing in the slightest has changed. Same gun, same bag of BBs and the same chronograph. I couldn't be more confused.

What is the problem people?

DeBurca

Are you sure that you were using 0.2g BB and not 0.12 BB
The reason I ask is because 300fps with 0.2g BB = 0.83Joule and 380fps with 0.12g bb = 0.80
Was the test done with your mag and BBs or with there BBs

PonchoTron

My mag, my bbs, and the very same bag of bbs as the previous week. I assumed .12's were mixed in somehow as well, but it doesn't seem to be the problem.

Inari

What brand chrono was it?

Erratic readings have many causes - some brands of chrono read hot, some read low. Some get very titchy when on low-battery, and some are more susceptible to dodgy readings in sunlight. In all probability, it'll be the chrono at fault - we see it all of the time in work; gun comes in having chrono'd in at >1joule, only to find that it is 0.93J etc.

Now there is a possibility that it was your gun - if the rifle was drilled to bring it in-line with Irish requirements, then if the hole gets blocked up your rifle's power will jump. It can happen if the cylinder turns, or if grease gums up the hole etc.

Also, you say "not stock G&G" - could you please give a parts list, and modifications done?

Just a Plinker

PonchoTron wrote: »

I rolled up to my local site today fully prepared to play with my not quite stock G&G M4 to find something unusual had happened.

Every weekend for the past 4-6 months without fail my rifle has fired at 302fps on the dot, time and time again with .20g BBs.

Today it fired between 350-380fps. What could have happened? Nothing in the slightest has changed. Same gun, same bag of BBs and the same chronograph. I couldn't be more confused.

What is the problem people?

Not a skirmmisher myself, But Check your spring mate I have seen some guns were the spring was cut instead of replaced And it had lodged on top of a Ballbearing spring guide or was bent in the middle, Not sure if that would result in such a massive fps issue mate, But as I said just worth a look


rgds

cfuserkildare

Hey mate,

If the M4 is a blowback version, then it is possible that the blowback piston has jammed.
That could explain the sudden jump in fps.

Other opinions please.