Definitely don’t want to zero with a magnetospeed!

[Joefrazell]

Just removing my brake makes mine change poi

 

[Korhil78]

I used to use a magneto speed and then when I found the velocity, ES and SD I wanted, I would load those loads and shoot them without the magneto speed attached. Now I have a labradar and I don't have to load the extra rounds to test without the magneto speed. Especially cost effective if you are shooting hammer bullets in all your rifles.

 

[Joefrazell]

I used to use a magneto speed and then when I found the velocity, ES and SD I wanted, I would load those loads and shoot them without the magneto speed attached. Now I have a labradar and I don't have to load the extra rounds to test without the magneto speed. Especially cost effective if you are shooting hammer bullets in all your rifles.

This is the way to go. I've had my magneto speed change poi and group size. Only in one particular rifle/load

 

[WildRose]

That surprises me also. A #5 barrel is fairly stiff and as long as it isn't over 26" long.it would be close but as said, It is always best to prove something as you did.

J E CUSTOM

Barrels are a lot like people in my experience, even "identical twins" cut with the same reamers and rifling tools from the same lot of barrels are rarely identical twins. They all seem to have their eccentricities.

 

[J E Custom]

Barrels are a lot like people in my experience, even "identical twins" cut with the same reamers and rifling tools from the same lot of barrels are rarely identical twins. They all seem to have their eccentricities.

Ain't That the truth !!!

J E CUSTOM

 

[snox801]

I get an impact shift with the can on of about 1" right one inch low. Then put the magneto back on and goes .5" high .5" left. So it brings it back closer to zero on my 6.5 creed.

 

[th82457]

I have seen POI shift & group size grow with magneto speed. So I just ise it after finding a load that shoots well to verify velocity & E.S. No longer try to shoot groups or zero with magneto speed on barrel.

 

[blackbrush1]

It's a geometry thing fellas. You ever see the pressure wave coming off the tip of a bullet in high speed photography? What do you suppose happens if the bayonet is close enough to the bullet's path to reflect that wave back into the bullet? Try this....put the bayonet on top of the barrel and tell me where your bullet goes. Longer, slower bullets catch that reflection more readily of course. Geometry.

 

[Jeffrey Van Zandt]

Went out and load tested today at 300yards. Decided on the last group of 4 to test the speed. Threw on the magnetospeed for the first shot. Took it off for the next 3. Here is the target:

View attachment 165809

Guess which shot had the chrono attached?

well ya anything that attachs to your barrel will shift your zero when I do loads and vel I use the stock attachment set up so my magnetospeed is not hook to my barrel

 

[Gwine]

My light barreled 7-08 shoots to poa with the ms attached using my 162grain load. Same setup shooting my 150grain load hits 5" high.

 

[Runandgun]

I'll be doing load development tomorrow with the MS to verify velocities since I'm switching primers. Won't be too concerned with POI or even group size at that point.

Then the suppressor will go back on and I'll verify where the groups are relative to my original point of aim. Bottom line, MS or suppressor might affect POI, so best to have your final rifle configuration established before final sight in.

 

[oldpilot]

When a projectile exits a barrel it is going PDF and makes a noise that is the bow wave shifting from the tip of the projectile...to the supersonic position. Anything beyond the end of the barrel will affect the travel path until the flight path stabilizes which occurs within a few hundreds of a second, anything beyond the barrel will affect the longitudinal direction!

 

[jrg]

I have never understood why you would shoot groups with a Magneto Speed attached in the first place. We use it to get the numbers then remove it for shooting groups
We have one that we use on our Bartlein MTU contour which is a heavy barrel & it doesn't affect the POI much at all.

 

[Gone Ballistic]

I have found it to cause a shift similar to what you did. Now, I only use it to average the speed of 5 rounds.
Interestingly years ago when I purchased my first muzzle brake I noticed a similar problem when I would remove it and replace it with the thread cap my smith made. I assumed it was dynamics that were created by the muzzle brake.
I was getting my gear ready to go on a hunting trip and was replacing the brake with the cap so it would fit into it's hard case and by chance happened to have a scale sitting in front of me. I weighed the cap and the brake to find a huge difference in weight. After having a new cap made within a few grains of the weight of the brake I started shooting much closer. It amazed me that the weight of a small amount can change point of impact so significantly.