338 Norma Flyers

[Drop Port]

This is my second 338 Norma, Broughton Barrel, Pierce XL action. It is a proven combination that shoots sub 1/2 MOA with 300 grain SMK's, 215M primers and five different powders. Just for a little background so it is not the rifle.

RSM is the only powder that has flyers and it is the only ball powder out of the powders I've used. It is one of the most accurate powders in this rifle but not consistent. At 600 yards it is common to put 4 shots sub 1/2 MOA then have a flyer at 3:00 that brings it to MOA.

H-1000 and R-22 are more consistent with larger groups. Any ideas on what can cause flyers? I was thinking maybe primers but have not tried it.

 

[BigDMT]

Inconsistent pressures as barrel heats up to a certain temperature.
Have you chronographed the load to check the spped of the fier against the rest of the shots?

The other possibility is that you pull the last shot in excitement that the othber 4 shots are under 1/2 MOA at 600 yards

 

[Drop Port]

Inconsistent pressures as barrel heats up to a certain temperature.
Have you chronographed the load to check the spped of the fier against the rest of the shots?

The other possibility is that you pull the last shot in excitement that the othber 4 shots are under 1/2 MOA at 600 yards

I have chronographed the load at 100 yards beyond 5 shots and didn't see anything that should cause it. I will set it up at 600 again and log each shot.

I didn't pull it, too many good groups with 1000 and 22 and a pattern forming with RSM. I have checked it a few times, always wait for a calm morning with no wind.

 

[338 Mollett]

I found that scenars flew the best for me. N 165 also shot well in the three different 338 cartridges I've shot.There is some voodoo in getting a 338 to shoot over longer strings of fire. Got 5 years fooling with them, any way I can help !