Tm G17 wont fire

[daishi]

So I just finished putting together a glock and everything works fine...except for one thing.

If I put a mag into the gun without it first being cocked and the hammer sear being retracted out of the mag well, it wont seat properly and no matter how many time I cock the gun with the mag in it will not fire.

The only way to get my gun to fire is to have the gun cocked with the magazine out and with the hammer sear retracted out of the mag well, before putting in the mag. If I don't do that the hammer sear sits ontop of the valve and fails to engage it.

Is this typical, or do I have to do something here?

As well I only get about 18 shots out of the glock using propane, is this normal as well?

FYI, this is using it at room tempurature.

[apilar]

I have noticed that when installing new 'firing pins'/valve knockers on my 1911's that they are often over sized OR have a squared end to them.

Due to their oversize and square end/face they get caught on the magazine release valve not allowing them to retract fully when the magazine is in. This is why it works when you rack the slide with the mag out.

I usually round the bottom edge of the firing pin so it can more easily slip down and over the mag valve.

I suspect a similar problem arises with the glocks when installing after market trigger groups

[jamuke]

What did you build
I have a glock with GM zero hammer and SD valve knocker
same issue, will think about the rounding.

I can get about 2 mags a fill so your 18 sounds like a problem.
Make sure your piston cup..or ring is firm, maybe a crack in your loading nozzle

whats your FPS like

[daishi]

I have no idea what my fps is.

Im using the gunsmodify lightweight bbu housing, with their weird red piston head and the stock O-ring head thing. Just took it apart and did some testing.

With the stock TM bbu housing with their built in piston and O ring I can get about 35 ish shots or more out of the mag.

Going back to the gunsmodify with their red piston that has no rubber on it coupled with the stock TM o-ring head...maybe get about 25-27 shots. I tightened down on the screw and added some silicone and got better gas efficiency....but its still a pretty bad drop from the stock.

Im waiting for an Airsoft surgeon nozzle and piston O ring....maybe that might help. Unfortunately GM's actual piston seems lacking compared to the stock TM one.

[HKGhost]

Remove the slide, insert mag into lower, determined how much is getting caught when the mag is in, and file just that much. I had to do this to a few guns with upgraded valve knocker.

[apilar]

I have the gunsmodify light weight unit also. I found their piston head to be crap.. also broke my stock nozzle so was forced to replace it.. I used the airsoft surgeon one and found that the piston head that comes with that nozzle is much better! 30 shots easy shooting rapidly

[daishi]

How exactly would I file steel tho? I dont know if the material in the shooters design is stainless or hardened steel or what. Then i need to find a file that's a harder material then that...

[daishi]

Update.

Went to home depot today and got a Nicholson Generic purpose mill file. A single cut bastard, no need for the double cut. Pulled the trigger on my glock, stuck the file through the mag well to rest on the sear and pushed up about 5-6 times slowly, and cut down the straight edge nicely. Gun works and functions perfectly now.

[Styrak]

What's in your build? A stock TM G17 should be able to go through probably 2 mags of BB's on one gas charge.

[daishi]

I just installed the airsoft surgeon nozzle/piston. Can get about 40 shots before I need to gas up again now.