Thread: Reloading 25-06 - Opinion on Primer

Originally Posted by Oldbloke

Hi,
Sooo, I found it a tad difficult to follow the above post GPM. I’m assuming there are no typo’s in the post, pretty easy to do. So I thought I would lay it all out in a spread sheet to help me better understand. See attached. I hope I got all the info & No’s right.

The way I see it there have been three changes since the original loads back in 1991.


New powder batch.
Bullet change from 129gr to 120gr
Rifle change from M38 to T3


The original loads were:

M38
1993
1991
46
129 SST
2781

The fastest with the new batch of powder is:

T3
2019
New
46
120
2870

In this instance the rifle and bullet have changed.

A difference of 89 fps.

Given the changes and the 89 fps increase I don’t honestly believe you can blame the powder. Just the change from M38 to a T3 could easily account for that.

P.S. You don’t mention barrel lengths or primers??

My 2c
OB

Greetings @Oldbloke,
There are two sets of data. The first was loaded in new Lapua cases with Federal 210 primers and 129 grain SST projectiles. The powders were 2,019 and 2,000 lots of AR2209. These were loaded on the same day with the same gear set up and fired in the same session. The rifle was my Tikka T3 with a 570mm barrel.

45.5 grains of 2,000 AR2209 chronographed 2,720 fps.
45.5 grains of 2,019 AR2209 chronographed 2,805 fps.

For the second trial some old unfired handloads containing a 1,991 lot AR2209 were broken down and a series of test loads assembled loaded in twice fired Norma cases with Winchester W120 primers and Sierra 120 grain projectiles. The rifle was the same T3 with the rounds loaded on the same day and fired in the same session.

46 grains of 1,991 AR2209 chronographed 2,806 fps.
46 grains of 2,000 AR2209 chronographed 2,798 fps.
46 grains of 2,019 AR2209 chronographed 2,870 fps.

Digging through my old notes from 1,993 I found my chronograph results for the 6.5x55. these were shot with my M38 with a 600mm barrel. 120 grain Sierra projectiles and Norma cases with W120 primers.

46 grains of 1,991 AR2209 chronographed 2,781 fps.

The chronograph is an Oehler 35P using a 4 foot screen spacing. A minimum of 2 shots of each load were fired with low velocity variation between shots.

The Hodgdon data appears to be for the old H4350/ AR2209 and the Nosler data lines up with the later and faster version but quits earlier due to some of their harder projectiles. I did find a reference to the change in powder speed on some of the US websites which dated it to around 2,002.
Regards GPM.