Pellet Testing with a Pumper

[cea1960]

 I've had a 397 since last summer and have only shot it handful of times. I have no real knowledge of these types of guns, and the last time I shot a multi-pump was a Crosman 760 in the mid 70s.

I'm going to start testing pellets to find what this gun likes. Here is my question. If the gun gives the best groups with pellet "A" at 8 pumps, will pellet "A"' still give the best groups at 5 pumps? 3 pumps?

Will I need to test all the pellets with each level of pumps?

 

[hawkeye69]

The short answer is yes. Pellets will act differently depending on the speed. 

 

[cea1960]

That's what I was afraid of. I could burn through a lot of pellets, targets, and time. It would be a heck of a work out though!

 

[Mike_Lenardon]

I would start with JSB or H&N. Something around 7.5 to 8.5g. Buy one or the other to start and I feel you will be happy with the results. Just dont buy chicken poop pellets and expect chicken soup. 

 

[Guest]

I've had a 397 since last summer and have only shot it handful of times. I have no real knowledge of these types of guns, and the last time I shot a multi-pump was a Crosman 760 in the mid 70s.

I'm going to start testing pellets to find what this gun likes. Here is my question. If the gun gives the best groups with pellet "A" at 8 pumps, will pellet "A"' still give the best groups at 5 pumps? 3 pumps?

Will I need to test all the pellets with each level of pumps?

As muzzle velocity changes (more or less pumps) rotational velocity will also change (rate of spin). You will probably find that you rifle will shoot one or more pellets well and that the number of pumps one pellet prefers is not exactly the same as the number another pellet prefers. For plinking and short range target work you will likely settle on a pellet and number of pumps based upon accuracy alone. For hunting you will likely settle on a number of pumps and then seek a pellet that shoots well.