help me make sense of this?

[Army-medic]

Aha!

were you shooting for group at the same time as shooting for velocity?

Yes. Do you think the chrono affected harmonics ? It’s only just occurred to me.

[bullbarrel]

Yes. Do you think the chrono affected harmonics ? It’s only just occurred to me.

If its attached to the barrel then will have some. But if it was that bad I'm sure there would be warnings about it.

[loiner1965]

If its attached to the barrel then will have some. But if it was that bad I'm sure there would be warnings about it.

it will have an effect but only shooting with it on / off will determine how much

[Randy Bohannon]

Yes. Do you think the chrono affected harmonics ? It’s only just occurred to me.

Anything hanging off the barrel will affect the harmonics, for better or worse.

several companies make barrel tuners which screw in and out to “tune” group sizes.

i tried a magnetospeed and found it made groups open up on two of my rifles.

given that introducing unquantifiable variables is an anathema to good reloading practice, I err on the side of caution and use a conventional chrono.

did you shoot the factory ammo with the magnetospeed on the harrel?

[Army-medic]

Anything hanging off the barrel will affect the harmonics, for better or worse.

several companies make barrel tuners which screw in and out to “tune” group sizes.

i tried a magnetospeed and found it made groups open up on two of my rifles.

given that introducing unquantifiable variables is an anathema to good reloading practice, I err on the side of caution and use a conventional chrono.

did you shoot the factory ammo with the magnetospeed on the harrel?

Factory ammo was pre-magnetospeed.

What I have concluded is that what I thought was an optimum load, probably isnt. I chronographed to see why some of the groups were poor after sticking to what I believed was a good load. I assumed it would be related to inconsistent velocities etc. It does not seem that way.

I’m going to look at the load again and once decided upon a reliable OCW I will stick with it and just use the chrono to fine tune the load without making too much of a fuss about exact group size. Once I have chosen the load with a good velocity, low SD and ES I will check the final result without anything else added to the barrel.

I think I may have made a bad call at the first stage and have struggled since. A morning at Bisley should resolve this once and for all!

[Randy Bohannon]

FWIW I’m not a fan of the OCW method

Maybe it shot at 300 yards plus on an utterly still day but as per the example I gave above the ifferwnces you are looking for just don’t show up at 100 yards.

try shooting ten round groups and don’t be hasty to call fliers.

For proper stats tats you need to shoot thirty, as you probably know.

i would find the highest charge that doesn’t give pressure signs and then fiddle
with seating depth to bring the groups in.

When devloping my tatget load load for my wall varmint 308 I found that 10 round groups showed the truly consistent from the lucky.