First reloads for G20

rvrrat14 · 07-15-2012, 14:26

South central Texas
82 degrees in AM and rising
Clear
Wind S 5-10

Starline brass
WLP
165 gr GDHP
AA 9

Tested 14.8, 15.0, 15.2, 15.4. 10 shots each.

No signs of pressure or smileys on any.

Chrony results.

14.8 AVG - 1297.0
15.0 AVG - 1281.6
15.2 AVG - 1271.5
15.4 AVG - 1302.0

Can't explain why 14.8 was higher. It also grouped better. All powder was dispensed with RCBS Chargemaster Combo.

Will retry 14.8 and 15.4 for accuracy. Today was about velocity and pressure signs. More focused on not hitting the chrony than hitting the target! Both these loads showed groupings of 1/2" to 1 1/2" at 15 yds. Worthy of retesting.

Taterhead · 07-15-2012, 21:09

Interesting chrony readings. Higher, lower, lower, then highest.

They were generally in the ballpark with what I have seen, if not a wee bit slower. I wonder how close you were to the chrony? There might be a bit of chrony "noise" in the numbers if you were too close. I would suggest backing up a bit.

I have shot my diffuser rods on my chronograph. The best thing I have found is to put a target behind it. "Aim small, miss small". Ha! It has been quite a while since I hit my chrony.

robert91922 · 07-15-2012, 21:57

It happens to me occasionally that a bit lower charge batch goes some faster in average. It's probably inconsistent powder drop or/and inconsistent neck tension on brass issue.
Hand weighing each charge and weighing brass cases would help to solve that problem, but that's what reloaders have to do for long range shooting reloading. I won't bother with that for pistol shooting.

rvrrat14 · 07-16-2012, 08:10

Chrony was 5 feet. Many years ago Pact tech advised 4-8 ft.
Did have some anomalies with brightness when I started. Set up umbrella over screens and all was good.
Have never had this issue in 28 years of reloading. Challenging. Just means more shooting.
I will cross check powder charges with manual scale. COAL is 1.255 and all loads taper crimped same.

firefighter4215 · 07-16-2012, 08:18

Quote:

Originally Posted by Taterhead

I have shot my diffuser rods on my chronograph. The best thing I have found is to put a target behind it. "Aim small, miss small". Ha! It has been quite a while since I hit my chrony.

I've never shot the chronograph, but I too managed to shoot a diffuser rod once. I quickly replaced those metal rods with wooden dowels. I haven't shot any of those yet, but I figure they'll break instead of just bending, which should keep the chrono from flying off the box I set it on. I usually put it out at fiftwen feet, too. I thought I'd read somewhere that muzzle flash could mess with the readings if it was any closer than that.

rvrrat14 · 07-24-2012, 17:48

Quote:

Originally Posted by rvrrat14

Chrony was 5 feet. Many years ago Pact tech advised 4-8 ft.
Did have some anomalies with brightness when I started. Set up umbrella over screens and all was good.
Have never had this issue in 28 years of reloading. Challenging. Just means more shooting.
I will cross check powder charges with manual scale. COAL is 1.255 and all loads taper crimped same.

Rechecked chargemaster pro with manual scale. Right on the money. However......noticed when u calibrate scale and zero tare weight for pan, you'll get different readings if you leave cover open or closed around the pan. Possibly reason for anomaly on prior test loads. Will start over with same strings: 14.8, 15.0, 15.2, 15.4.

_The_Shadow · 07-24-2012, 22:04

Try this for your CHRONY...Re-purpose Ironing Board Chrony Stand
Here is some things I did with a "FREEBIE from the curb Ironing Board", CHRONY mounted with wing nut, Flip-Up Target Stand, mounted on backend, and the sacrificable diffusers are made from water/milk jugs. Take a gallon water jug or milk jug, cut an 2 1/2" strip around the circumference of the lower flat square section.
Then cut 90 degrees accross the middle of one of the wide flat sections, then fold in half and cut at 90 degrees again yielding two pieces of equal length about 11" long each. Now use an "ice pick" (or simular) to push a hole in the middle of each end about 1/4" in from the edge for the bamboo skewers to slide into the holes. There you have it very simple and a freebie!

This piece of plate helps with CHRONY protection

rvrrat14 · 07-25-2012, 06:59

Cool ideas. Thanks Shadow.

rvrrat14 · 08-25-2012, 16:51

Finally revisited the 10mm loads. Chrony was placed 12 ft away. Here ya go....

165 gr. GDHP
AA 9 - 14.8 ,15.0, 15.2, 15.4

14.8 - 1226.6 fps
15.0 - 1242.0 fps
15.2 - 1256.4 fps. MOST ACCURATE LOAD
15.4 - 1270.4 fps. 2nd accurate load

Stock Gen 3 Glock 20.