OzFclass

A heads up!
The following info might relate to John Weigel's post about throat erosion >> viewtopic.php?p=118689#p118689
and 2209 powder temperature/pressure/throat erosion. 2209 has certainly changed a lot in the last couple of years.
I have had to reduce my .284W loads by 1.5 grain to get in the velocity window I want.

I loaded up some cases for fire forming. It was a lightish load of 49.5gn 2209 in a 6.5PRC case to enlarge to 7FCP. I have used this load over 200 times with no issues, same primer, projectile, seating depth and case.
I was using older (2+ years old) 2209 blended form the tail ends of various 4kg jugs.
Unfortunately I mixed it up and used a newer lot MEM7290. the results can be seen in the image. I'll be backing this load off by a couple of grains.
The lower left primer has been pierced, fortunately without damage, one is severely flattened and one appears normal. GM210 primers.

I have now moved onto another batch of 2209 and it is at least 1/2 grain faster again in my 284. WTF.

It seems that 2209 is just a labelling exercise that doesn't tell us anything about the contents.
Pete

I found much the same with my last bottle change of 2208. Mid last year. The new bottle pushed velocities up well over 50fps (that was from load testing with the old powder on one day to running the same loads with the new powder the next day)

30 fps between lots of 2208 hasn't been uncommon for me.

What was your old "slow" batch number Peter?

I have a batch purchased about 2yrs ago that is about 1gr faster than previous lots. If it's the same batch and this one is faster again it's pretty concerning.

Here are some three shot speed comparisons of 2209 batches I have at hand, as tested a couple of days ago w SAUM Have been using relatively slow batch MEM 7563 for some time now, so did this test so as to have an educated guess of comparative speed differences between batches I am holding. I randomised the test to negate creeping speeds due to barrel temp or fouling by sequentially shooting one cartridge per test batch at a time, cycling through until either all three cartridges per batch were shot, or speed was scary high. All with 55.3 gr.

MEM 7563 2922, 2921, 2925

MEM 7256 2944, 2945, 2938

MEM 7571 2974, 2978, stopped test

MEM 7705 2960, 2950, stopped test

BATattack wrote: Sun Jan 05, 2025 1:18 pm What was your old "slow" batch number Peter?

I have a batch purchased about 2yrs ago that is about 1gr faster than previous lots. If it's the same batch and this one is faster again it's pretty concerning.

Numbers below are average fps in a 284W with 180 Bergers hyb.

Old lot is MEM 7230 - 51.5 gn = 2770fps
A next lot was MEM 7290 - 50.5gn = 2770 fps. With the old load of 51.5gn with this batch, velocity was around 2850fps
The current lot is MEM 7397 - 50.0 gn = 2780 fps

John has a few batch numbers there and none of them match any of mine, so I don't know what I can learn out of this.
Pete

Not surprised, 2208 got slower between 2000 and 2004 to the extent that my new load weight in 2206h was the same weight load as my original load in 2208 with the same batch of primers.
I don't worry about it anymore; each time I buy a new batch of powder or primers I ladder test.

MEM 7397 is definitely on the warmer side 7 Saum load test this morning on a newish barrel 110 rds.
Purchased 8/22

SAUM 2209 WRE 180HYB 2.300 BTO ADI 2209 MEM 7397 24 DEGREES CELSIUS
# Speed (FPS) Δ AVG (FPS) Time Clean Bore Cold Bore Shot Notes
1 2904.6 -22.4 52.9g
2 2913.6 -13.4 52.9g
3 2919.2 -7.7 52.9g
4 2927.7 0.8 53.2g
5 2902.1 -24.8 53.2g
6 2926.2 -0.7 53.2g
7 2933.6 6.7 53.5g
8 2935.4 8.5 53.5g
9 2945.8 18.9 53.5g
10 2961.0 34.1 FIRM BOLT LIFT 53.8g STOPPED

AVERAGE SPEED 2926.9
STD DEV 17.3
SPREAD 58.9
SESSION NOTE 0.0
DATE 8 March 2025 at 7:31 am