Air Arms Owners Club

What makes the mpr only 6 ftlb is the hammer spring softer or shorter? Or hammer weight lighter? obviously the ventrui will play apart im guessing.

Not sure with the MPR, but , with the S200 there are two different hammer springs for 6ftlb and 12ftlb so I would think that would be the same for the MPR

John814ce wrote: ↑

Mon Jan 14, 2019 9:41 pm

What makes the mpr only 6 ftlb is the hammer spring softer or shorter? Or hammer weight lighter? obviously the ventrui will play apart im guessing.

MPR Sporter and Precision have Lighter spring, lighter hammer, different firing pot design, different cylinder.
Same firing valve and same venturi design though.

Would i be able to fit a mpr hammer straight on my s510 and fully open the ventrui screw? Any idea what fps id achieve just within the sweet spot if it fits? Or any one tried this. The point being the gun could never ever creep over 12 ftlbs and it would need a strip down to do so.

Probably, if the hammer rail is the same size, as I said before, not really up on 6ftlb stuff, or you could reduce the weight of your standard hammer, at least you would know it fitted, and then maybe use the MPR hammer spring, but it does seem a lot of messing about to keep it under 12ftlb, just my opinion

No i dont want to go down to 6 ftlbs, if the mpr hammer is lighter then i keep/will use my hammer spring but have the ventrui fully open, this way even if the law were to ever confiscated my gun for testing, then they can wind the ventrui out and it will never increase the power. this all based on sweet spot pressure 160-120 Bar of course, i never fill to 190bar. I just wondering if anyone has tested this?

Why not just increase the spring pressure on the firing valve?

Hope it's ok with the mods Airgunforum in technical- Light v Heavy hammer, this might be of help to you

If you faff around mixing low and high power parts and leave venturi open you may not have a sweet spot.

Ye see what your saying, just thought id ask if anyone has tested this. I think im going to buy a mpr hammer and test for my self anyways, be interesting to see what the results are for the sake of a few quid for the hammer.