OzFclass

Thanks Frank.
This does help with H4350 / ADI2209 ... This data backs up what im also experiencing with pressure.

You’re welcome Jezl!

From the data I got out of the test barrel and if your reamer spec is like mine etc…

I’d say about 52.5 possibly 53.0 is a max load without going over the 65k psi limit. Which would put you upper 28xx’s to right at 2900fps.

At 53.5 with the 183smk that gave an average psi of 67333. 52.0 gave 64018 with the 180 Berger.

Again your barrels actual dimensions, lot of powder, primer bullet lot etc… all variables.

I don’t know if this applies to all powder makers but I’ve told that even with the same lot of a production of powder there is a +/- 3% variance on the burn rate.

Later, Frank

So I got the test data for the 190 ATIP's and the H4831sc load with 57.5gr.

Avg. velocity was 2900fps, SD = 8, ES = 25

Average pressure was 69,284! Most ran upper 69k and one round came in at 70,690!

See the updated sheet....

What I marked in blue where the most accurate loads. Keep in mind and don't go saying this or that bullet is better than the other. The difference in accuracy was at times only .050"! A change in a powder charge of say .2gr or changing the seating depth on the bullet can make all the difference. No load tuning was being done.

Notice how a 1gr powder charge increase with the H4831sc and the 190ATIPs bumped the pressure 5k psi.

Later, Frank

[font=Georgia]Frank now has his test results up on the Accurate Shooter website.[/font]

So all powders/loads have been tested.... here is the updated sheet.

As a side note on the N568 powder...

too bad you can’t get more powder in the case with the N568. Seating the bullet was already compressing the powder. Maybe you could stuff 58.0gr and get 2700fps or so. 3rd smallest group fired if I recall correctly taking a quick peek back at the data.

Thanks Frank!

This has been a great thread to read as I’m undecided on the 7mm cartridge to build my next gun around I have been tossing between 7saum and 7prc maybe 7-6.5prc is the answer

Benji wrote:This has been a great thread to read as I’m undecided on the 7mm cartridge to build my next gun around I have been tossing between 7saum and 7prc maybe 7-6.5prc is the answer

If your using it as a F Class gun.... I'd say the 7PRC is too much case. It's more case capacity then what you need and will just burn the barrel faster.

Later, Frank

Frank Green wrote:

Benji wrote:This has been a great thread to read as I’m undecided on the 7mm cartridge to build my next gun around I have been tossing between 7saum and 7prc maybe 7-6.5prc is the answer

If your using it as a F Class gun.... I'd say the 7PRC is too much case. It's more case capacity then what you need and will just burn the barrel faster.

Later, Frank

Hey Frank,
Shouldn't you be encouraging barrel burners

Tim L wrote:

Frank Green wrote:

Benji wrote:This has been a great thread to read as I’m undecided on the 7mm cartridge to build my next gun around I have been tossing between 7saum and 7prc maybe 7-6.5prc is the answer

If your using it as a F Class gun.... I'd say the 7PRC is too much case. It's more case capacity then what you need and will just burn the barrel faster.

Later, Frank

Hey Frank,
Shouldn't you be encouraging barrel burners

Nah I don't like doing that. It brings other issues that I don't want to deal with. Just like the guy who not to long ago here burned up a 300RUM barrel. He was already loading 95gr of powder and bought the BB material in hoping it would last longer... but then he went and did the stupid +P chamber reamer stuff on his barrel. He lengthened the throat .375" and opened up the freebore diameter / cut half the land height away... think he took it to .302" if I remember correctly. All so he could load 100 grains of powder. Then complained the barrel only lasted 480 rounds.