A Real Question on my Reloads

[frankwright]

I started reloading in 1976 on my apartment kitchen table with a Lee Hand Loader so I have been doing this a while.
About a year ago I won 5lbs of Shooters World Clean Shot pistol powder. I have been using it and some more I acquired ever since with no problems.
I shoot some sanctioned IDPA pistol matches that require your ammo to make a Power Factor. Power Factor for 9mm is 125 fps. PF is velocity times bullet weight. In 9mm with 125 gr bullets it has to be a little over 1000 fps.
I loaded some rounds with 3.9 grns and a 125 JHP. I got PF of 117 with my F1 Chrony. I upped it to 4.2 and got PF of 123. Just to be safe I upped it to 4.5 which is one grain over max but I have learned the Shooter's World Data book is off in what they say weight and velocities are.
I did not chrono the 4.5 load but expected about 132 PF. (My Mistake)
I used once fired cases and a Federal Mag primer I got during the great primer famine. I checked my loading on a digital scale and verified on a RCBS 505 Balance Beam.
I chronoed everything with a Sig 320 Compact with a 3.6" barrel. I shot the match with a 2011 with a 4.5" barrel.
I know barrel length and twist can make a difference.
At the match they used the new Garmin Xero Pro Chrono and the best they could get was 123.5 PF, thus I was disqualified. They let me finish the match but no scores counted.
I am baffled by this. Any comments are welcome. I know I made mistakes but I was not worried about not making PF at all.

 

[jglenn]

The obvious miatake was not checking velocity with the 1911..I'd also get your Chrony checked against another unit..it may well be off. By all account the new Garmins are very accurate

i have to ask.... why in the world would you load 1 full grain over the suggested max.

 

[bullgator]

I never load handgun ammo to maximum, much less over. I just don’t need to for my casual shooting. That said, most data is purposefully kept on the conservative and safe side. Find a reloading manual from the 50s or 60s and see what they showed back before the lawyers became so prevalent in how society conducts business.

 

[Jester896]

I have most bullet company manuals back to the first edition if someone needs me to check something. It wouldn't do any good for Shooters World tho
sounds to me the chrono might be off...wish I was closer and we would compare it to the radar.

 

[jglenn]

What you're missing when comparing old data to new is the measurement method has changed from cup to psi, which is much more accurate.

Yeah never trash old manuals, far too many old powders are only detailed in them.. ken waters Pet Loads is a great collection of older loads but use them with caution!

 

[tcward]

I started reloading in 1976 on my apartment kitchen table with a Lee Hand Loader so I have been doing this a while.
About a year ago I won 5lbs of Shooters World Clean Shot pistol powder. I have been using it and some more I acquired ever since with no problems.
I shoot some sanctioned IDPA pistol matches that require your ammo to make a Power Factor. Power Factor for 9mm is 125 fps. PF is velocity times bullet weight. In 9mm with 125 gr bullets it has to be a little over 1000 fps.
I loaded some rounds with 3.9 grns and a 125 JHP. I got PF of 117 with my F1 Chrony. I upped it to 4.2 and got PF of 123. Just to be safe I upped it to 4.5 which is one grain over max but I have learned the Shooter's World Data book is off in what they say weight and velocities are.
I did not chrono the 4.5 load but expected about 132 PF. (My Mistake)
I used once fired cases and a Federal Mag primer I got during the great primer famine. I checked my loading on a digital scale and verified on a RCBS 505 Balance Beam.
I chronoed everything with a Sig 320 Compact with a 3.6" barrel. I shot the match with a 2011 with a 4.5" barrel.
I know barrel length and twist can make a difference.
At the match they used the new Garmin Xero Pro Chrono and the best they could get was 123.5 PF, thus I was disqualified. They let me finish the match but no scores counted.
I am baffled by this. Any comments are welcome. I know I made mistakes but I was not worried about not making PF at all.

I know weather (temp) can change velocities and pressure. Could there have been a temp difference when you tested vs the test at the match? Looks like you weren’t off much.

 

[frankwright]

The obvious miatake was not checking velocity with the 1911..I'd also get your Chrony checked against another unit..it may well be off. By all account the new Garmins are very accurate

i have to ask.... why in the world would you load 1 full grain over the suggested max.

Because I have been using this powder for over a year and I have discovered by using my chrono and also a friend's labradar that the velocities listed in the Shooters World book are totally unrealistic so I felt completely safe going one grain over.
Don't go to Glocktalk and look at the 10MM reloading page, you will pass out!

 

[jglenn]

I'm glad you felt safe...BTW some barrels are just slower than others even from the same maker

 

[rosewood]

If you are having to go max just to make the PF, maybe swap to a different powder so you don't have to go max?? Use that powder for practice instead maybe?

Load manuals many time lie, and so do ammo manufacturers.

Rosewood

 

[Jester896]

and many times they report the results they got in their tests. We all know every barrel isn't the same speed.

 

[trial&error]

They use longer barrels. 20 " barrels will give different velocities, based on some of the claims I wonder if it's a smooth bore too to reduce drag. I have never gotten the advertised speeds in a pistol.

 

[rosewood]

They use longer barrels. 20 " barrels will give different velocities, based on some of the claims I wonder if it's a smooth bore too to reduce drag. I have never gotten the advertised speeds in a pistol.

Many manuals say "universal receiver", which may very well be a smooth bore. Who knows.