Fire Forming Success

[Markhor]

Thanks to all especially Boyd & Outdoorsman, I am happy to report great success in my first fire forming venture. I got some great groups to boot as posted below. The 5 shot group was shot using prepped brass that came with the rifle, it was .245". The fire forming 3 shot group was .063".
I hope the new fire formed brass shoots as well.

Thanks,
Ed

 

[BoydAllen]

Congratulations on your fine effort. Now just remember how well you shot fire forming, when you start thinking that the highest velocities are needed for accuracy. The next time that you fire form, it would be interesting to set up a chronograph, to see what the velocities are running. If you do, let us know.
Boyd

 

[artbosco]

Thanks to all especially Boyd & Outdoorsman, I am happy to report great success in my first fire forming venture. I got some great groups to boot as posted below. The 5 shot group was shot using prepped brass that came with the rifle, it was .245". The fire forming 3 shot group was .063". I hope the new fire formed brass shoots as well. Thanks, Ed

Not to burst your bubble, but none of my zero groups have ever looked like a cloverleaf. Zeros will look like one hole, albeit one that's been expanded, ever so slightly outward, but will retain the one hole look. You might want to remeasure that group. Press on, you're doing great.

 

[Markhor]

Outdoorsman, no problem with bursting bubbles, I am here to learn. I will remeasure. I am sure I made a mistake. I am using the Tony Boyer method as mentioned in the book. I must have read the caliper wrong.

Thanks,
Ed

 

[Ackman]

Your measuring isn't quite right. The .063" group is more like in the .2"s, the .245" group is closer to about twice that.

 

[artbosco]

A quick method for measuring groups, as a substitute for using one of the official measuring devices, is to use a Digital Caliper.

Open the caliper to the caliber you're shooting, in this case, for the 6PPC, .243".

Zero out the dial.

Continue to open it further, until the inside of the arms or blades, touch the extreme outer edge of the farthest two bullet holes.

The result is your quick and dirty group size.

Good target paper, a good backer, and a good tune, will help produce sharp bullet holes.

 

[hedditch]

Outdoorsman,
I learn something everyday! Here I have been measuring outside to outside then substracting bullet diameter. You way is so much smarter and easier. Thank you!
Dave

 

[BoydAllen]

There is one more modification that you should incorporate. Bullet holes (measured to the outsides of their black rings) vary in size, for various reasons, including the type of paper. They are always smaller than bullet diameter. I suggest that you measure a single bullet hole, made on the same target, and subtract that, instead of bullet diameter. Using bullet diameter will result in smaller numbers that are not as accurate.

 

[SS427]

I print my targets on 65lb paper and .224 holes always measure about .215 and the 6mm holes measure about .235. When using dial calipers those are the numbers I subtract for the outside to outside measurement. If I use the digital calipers I adjust it to match .215 or .235 and then zero it there. Both methods work good, and when I scan them into OnTarget software I'm only off a hundredth or so.

 

[hedditch]

Damn, all my groups are now bogus. I never thought about hole size being smaller. I measured from black to black if I could see it or by the edge of the hole outside to outside. After 52 years of shooting, I am still learning.

 

[Ackman]

Group size is center to center of the two furthest holes. It's not difficult to put a caliper tip in about the exact center of a hole. With those group sizes it's easy to see where that is.

 

[artbosco]

There is one more modification that you should incorporate. Bullet holes (measured to the outsides of their black rings) vary in size, for various reasons, including the type of paper. They are always smaller than bullet diameter. I suggest that you measure a single bullet hole, made on the same target, and subtract that, instead of bullet diameter. Using bullet diameter will result in smaller numbers that are not as accurate.

Boyd is correct, and that's why I included the caveat, Quick and Dirty. Here's what our friend jackie had to say once a upon a time:

Measuring a group

If you take a typical bullet hole in a piece of quality target paper and closely measure the diameter, you will notice that it appears to be about .010" to .015" smaller than the actual bullet that passed through.

If you do not want to cheat yourself, take this into consideration when measuring your groups. That means, when you carefully measure the spread of the two fartherest bullet holes, (ie .243/6mm), subtract about .230 from the measurement, rather than the full .243. You'll come up with a more honest measurement using this method. ... jackie schmidt

 

[artbosco]

If interested,

Here's a measuring aid from Sinclair International: http://www.sinclairintl.com/.aspx/pid=38778/Product/Sinclair-Group-Measuring-Caliper-Attachment

And one from Neil Jones: http://www.neiljones.com/html/target_measuring.html