Finally got a Chrono and clocked my 10MM loads

[Lennyjoe]

It finally happened. I stopped by Sportsmans Warehouse in Goodyear AZ Saturday. As I was loading up the basket with reloading stuff I came upon the Chronographs. They had an F-1 Chronograph for $69 so I snatched it up. After tax and my military discount it came out to $72.

So I took it Sunday to the Buckeye shoot and ran my 10MM reloads thru it. The weather was 50's and sunny.

Heres what I got.

180gr Hornady XTP over 11.5 grains of Blue Dot in a Starline brass and Winchester primer. The lowest FPS was 1285 and high end was 1325. Ammo spent the night in the truck and it got cold enough to frost the windows.

200gr Speer TMJ over 13.5 grains of AA#9 in Starline brass and Winchester primers. (didnt have any CCI magnum primers) Low end was 1080 and high was 1120.

Platform was S&W 1006 with a 5" barrel. No signs of overpressure in any cases.

Fun stuff.

 

[Black Snowman]

I've never had ignition issues with AA #9 or Blue Dot so I'd give the magnum primers a miss. They're more likely to cause early pressure spikes and actually hurt your accuracy and velocity not to mention add stress to the brass and maybe the gun.

Chronos are really nice to have, before I got mine I had some pretty strange ideas about how fast my ammo was going. Fortuantely I erred on the side of caution so my ammo was all slower than I had hoped rather than faster than was safe

 

[P95Carry]

Glad you now have one Lenny - it's really a very inexpensive way to keep tabs on what loads are doing. Look out for a printer to go with that - I got mine from a guy here and have found it a very useful adjunct.

 

[Lennyjoe]

Yea, a printer is a must. Sucks having to write down the data after every shot.

I also need to get a program for my computer. I tried downloading pointblank and it wouldnt install. Said a program file was missing.
(edit, the pointblank program works fine now)

I still have to learn the math on Standard deviations and all. One step at a time.

 

[P95Carry]

I still have to learn the math on Standard deviations and all.

if you can find a printer Lenny - it does that for you. I am a lazy sob and can never be bothered with the number crunching to get SD.

The printer spits out pretty much all you need ... Hi, Lo, Average, SD etc ...

 

[Werewolf]

I am a lazy sob and can never be bothered with the number crunching to get SD.

Ooooooohhhhh [cold shivers from the memories]

You really, really don't wanna calculate Standard Deviation by hand. It's very tedious and easy to make a mistake. Most $10 calculators you can buy these days will do it for you if you absolutely need SD.

IMO unless you're a target/benchrest guy all that's really needed is to do at least 5, 5 shot samples for the load you're testing and look at the average and min/max.

If you wanna see it graphically (useful) on graph paper (easier in excel) draw a straight horizontal line for the max and min of all the groups. Number your samples. Then plot the average for each numbered group using the group number for the X position - i.e. x=sample number and y=average FPS for the group. You've just created what in SPC is called an Xbar/R chart. You'll easily see how consistent your load is. (if you've got MS Excel or another spreadsheet program it's very easy to create this type of chart).

 

[stans]

I just go by the extreme spread to determine consistancy. I know it might not be the most scientific method, but it is darned quick and so easy to figure out.