Magneetospeed questions

[gixxerjunky]

I use a Magneetospeed for precision rifle and for my handgun loading.

 

Right now I am losing for about 132 PF with 147 9mm and N320.

 

My question is how much velocity difference you all think I would see if I go to a match and get chronoed at 10-15 feet or so?

 

I am checking my velocity at the muzzle with the MS and with traditional chrono they are usually down range.

 

I am seeing a lot of people running hotter loads then I am with my N320. I'm usually around 3.1-3.2 in my CZ's.

 

 

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[Youngeyes]

3.1 seems very light for that PF. What OAL? 

[Steve RA]

What velocity do you show for your load ??

[gixxerjunky]

I'm loading at 1.100 and running about 890-880 FPS with the MS out of a CZ Shadow.

Should be noted that accuracy was terrible so far but works for paper and steel for USPSA. It won't win any bullseye loads.

3.2 was extremely accurate with extreme plated 147's but I have switched to Hi-Tek coated lead and still messing around with it.


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[PaladinPrecision]

I did a rough calc, from absolute muzzle (0) to 10 feet with a 147 gr bullet. Assuming 897 initial velocity. @ 10 ft you would lose about 12 ft/s. With minor loads you really want to have a good idea of how much velocity you will lose when compared to photo cell type at 10-15 ft. 

The table of values I used. I took the Ballistic coefficient from a hornady 147gr jhp. Should be close enough to get an idea of how much initial velocity loss.

My Table of values