FX Fx m4 .177 to .30, hammerweight?

[IndiAirgun]

I have a 600mm .177 M4 that I changed to a 500mm .30 cal. After turning reg up to 125 it seemed like it takes alot of micro wheel to get fps up (macro at 16). It seemed like I could not get to the knee as fps just went up until I was maxed on micro. Also took like 4+ just to get into the 800’s.

My question is do I need a different hammer weight than what came stock on .177 M4? Or maybe something else?…

Thanks

 

[Chukar60]

put a heavier hammer weight in it. When I changed my 22 cal M3 600mm to a 30 cal 600mm I already had a hammer weight from a slug power kit in the gun and it works perfectly

 

[IndiAirgun]

Thanks, just ordered that 8-10 gram adjustable brass one on ebay.

 

[Trucker3573]

I think fx puts all the same weight hammers in the impact with the exception of .35 right ? Weird as they put a heavier one in the Maverick for 30. However I don’t find that I need the heavy hammer for pellets, at least 44.75 and 50’s.

 

[IndiAirgun]

I see on exploded parts diagram it looks like your correct. Thats what I thought too but Im puzzled as to why its takes so much hammer spring tension to get in range.

At 120 on the reg Im getting 900fps with the hammer spring tension maxed. Im using the tuning method where you start with low hammer tension and find the knee where fps dips instead of increasing. But the problem is Im not seeing it since I don’t have enough hammer tension even at max. I don’t have this issue with a m3 I have. That one was bought as a .30 cal so no wonder

Im wondering if I received a sub 12 model with low power springs or maybe since the M4 has a larger plenum than my M3 I need a lower reg setting like 110ish. I really just want to 880fps nothing special

Thanks

 

[IndiAirgun]

After further reading, looks like my situation is completely normal for M4. They max out hammer tension at 125-135. Stock hammer is 6g. The 8-10g hammer on ebay is one solution. Another is just to use tuning method that starts with max hammer tension and turn reg up till I get to my target (920fps then tuned down to 880).