Explained flyers but how do I fix

[ofdscooby]

I took out two completely different rigs today and had the same problem they were putting up great groups but I would get random flyers and on my Magneto chonograph that flyer would be about 50-75 off in FPS. What could cause this. I have my ideas but I wanted to see what people with more experience than myself think.

 

[lazylabs]

You cut a inch off the barrels? Didn't measure powder? Different bullets? Cornmeal duplex load? Sorry.....

With no information on the guns or ammo it's kind of hard to tell.

 

[ofdscooby]

Ok I'm sure there are some explanations without every detail but here you go
7mag stiller,bartline ,McMillan load is 168 Bergers 69.5 Retumbo in new Norma brass win primers 30 thou. off

30-06 trued 700 action laminate stock pillar bedded factory barrel with vias brake
165 GMX new win. cases 56 gr. H4350 CCI br2 primers 30 thou off single digit ES until the flyers

 

[LoneTraveler]

Was the powder accurately weighed in both loads???????
Was the same lot or box of primers was used in both loads ??????
These would be the first 2 things to check. I have seen some lots of primers that would not be uniform, affect group size and chronograph showed in one lot near 200 fps variance.

 

[Greyfox]

It is possible that the problem is not your load but the set-up. I got random flyers when first using the Magnetospeed. I also have found that if the unit shifts from recoil, even slightly upon firing, that the flyers were worse and I got variations in my velocities. I would not use the MS when accuracy testing. The unit can effect barrel harmonics. See if you eliminate your flyers when the unit is not attached. I would then test for velocity making absolutely sure that the MS is tightly mounted to the barrel and does not move using witness marks. See if your velocities are more consistent. I'm not sure that this is your problem, but it would be the first thing I would check upon reading your post.IMHO.

 

[Laelkhunter]

deleted by laelkhunter

 

[ofdscooby]

Was the powder accurately weighed in both loads???????
Was the same lot or box of primers was used in both loads ??????
These would be the first 2 things to check. I have seen some lots of primers that would not be uniform, affect group size and chronograph showed in one lot near 200 fps variance.

Same primer lots on both primers used.

Powder was weighed using a Pact Digital Scale and dispenser. I was thinking this is where the problem is coming from. I bought it not because it was cheaper but because it was made in America. I'm gonna weigh some charges today and verify them on another scale. I do remember when I was starting out reloading I would use a scoop and a trickler over an old RCBS distal scale and my ES's were more consistent.

 

[stonehands1]

I started weighing every cartridge after they were all loaded up and ready to shoot. I then separated loaded cartridges by weight into 5 shot groups. This accounts for any variations in brass weight or miscalculated powder charge. I found that my groups were better. I then began to eliminate variations while reloading trying to make all loaded cartridges the same. It's worth a try.

 

[Wedgy]

Also look at consistent neck tension....do you measure and turn your necks ?
Keep us posted.

 

[Canadian Bushman]

It is possible that the problem is not your load but the set-up. I got random flyers when first using the Magnetospeed. I also have found that if the unit shifts from recoil, even slightly upon firing, that the flyers were worse and I got variations in my velocities. I would not use the MS when accuracy testing. The unit can effect barrel harmonics. See if you eliminate your flyers when the unit is not attached. I would then test for velocity making absolutely sure that the MS is tightly mounted to the barrel and does not move using witness marks. See if your velocities are more consistent. I'm not sure that this is your problem, but it would be the first thing I would check upon reading your post.IMHO.

+1.

 

[ofdscooby]

Well I started looking to the Pact dispencer for answers. I should have done this test before I recalibrated it but I screwed up. So yesterday I recalibrated it and reread the manual. I had the powder baffle pointed in wrong direction but I dont see how this could affect the scale weight. So with a fresh calibration I dispensed 10 charges of 69.5 of Retumbo and reweighed them on another scale (RCBS) and 6 charges came back 69.6 and 4 charges came back 69.7. Then I turned off the dispenser for 20 min and ran the test again with pretty much the same results. I'm not sure if some people would consider this acceptable or not. My next will be to load with scoop and trickle and see if my groups are better. If they are I think the Pact is history or at least it's back to the factory for a recalibration.

 

[stonehands1]

.2 grains shouldn't make 50 to 75 fps. Make sure to sort your brass by weight as well but do it after they are all prepped and resized. Trim brass to exactly the same length. Bevel necks after trimming as consistently as possible. Weigh each bullet and sort.

 

[stonehands1]

I just re read your 7mm setup with new Norma brass. Are you resizing all the new brass before loading?

 

[ofdscooby]

Yes the Norma brass is brand new and sized. The smith that built my rifle is shooting next to me with the exact same setup and doesn't have the problems I do so the search goes on. I've dodged the question a couple times but I do not turn necks nor have weight sorted. I was hoping that going with a higher end brass I would not have to deal with neck issues as much.