I don't have a chrony

[Locker50]

My first and only air gun is a .22 Benjamin Maximus. 

Had it a few months and love it! She shoots the JSB 15.89 & 18.13 the best, not sure yet which one is THE pellet. Anyway, does anyone out there with a Maximus know the fps the Maximus fires these pellets on average? Also the fpe for each?

 

[JimNM]

FPE is easy to figure out....



FPS*FPS*grains/420450

750*750*18.3/420450= 24.48 FPE

 

[Saltlake58]

The Maximus will supposedly shoot around 850 fps with the Crosman 14.3. Since you aren't the 14.3, you'll need a chrony at to determine FPS. The 18.13's could be as slow as 750, or maybe as fast as 800. Just all depends. 15.89 will be closer to the 800 to 850 mark, but the guns all have their own personalities and are all adjusted a bit differently from the factory, your mileage may vary.

 

[Locker50]

Saltlake58

The Maximus will supposedly shoot around 850 fps with the Crosman 14.3. Since you aren't the 14.3, you'll need a chrony at to determine FPS. The 18.13's could be as slow as 750, or maybe as fast as 800. Just all depends. 15.89 will be closer to the 800 to 850 mark, but the guns all have their own personalities and are all adjusted a bit differently from the factory, your mileage may vary.

Thanks Saltlake. I was figuring about that. Just thought maybe someone had a maximus and chronographed those 2 pellets.

 

[Saltlake58]

Wish I could help there. Since the only difference in the shots is the weight, I wonder if you could back into it with the math. (Excel can do great brute force calculations!)

If 750*750*18.3/420450= 24.48 FPE

then

850*850*14.3/420450= 24.457 FPE

Also

805*805*15.89/420450= 24.49 FPE

So, assuming ( and that's a big assumption) that the gun shoots the specified 850 fps with Crosman 14.3 domed pellets, then it should be shooting close to 750 with the 18.3 and 805 with the 15.89's. I'm sure there are other factors that influence, and the numbers are at best approximate, but if the math holds, it should be close. Maybe I'll have to try it with my Marauder and see if the math holds up.

Update - Just ran the numbers and if memory serves me correctly, the math is pretty close. So, you can back into FPS if you have beginning values and know the FPE. Reciprocity Rules!

 

[JimNM]

Thanks for confirming that math...now can you help me find where we actually use the quadratic formula in real life?



(A^2 + 3A) + (b^2 + 6b)= WHY???

 

[Saltlake58]

No, I can't tell you why Quadratics exist. Never had a real world need for one.

Never was that good with the algebraic stuff. Wife was a math teacher though, she could always figure it out, but then I got VisiCalc (shows how old I am, any one remember VisiCalc?) VisiCalc could always figure it out if I could figure out how to punch it in.