You need to advise the board of which MAXAM powder you have. The two most available has been CSB-1 and CSB-5. You don't want to use one data with the other powder, bad juju. CSB-1 is more for the heaver 9/8 loads, not so good on the lighter loads IIRC, but mebee 1 oz might work OK. CSB-5 is a much better light load powder. If you can not find anything else, the VECTAN powders are becoming more available than our domestics, and is top flight powder from what I hear.
Mokeman should be able to give you all the data you need
dirt stirrer has it all mostly correct, - thanks for making those points.
Bogey, - which of the CSB powder do you have access to? I'm guessing that you've either heard about, and/or have access to the CSB-1, or CSB-1M powder (being sold out of Hi-Tech ammo)?
CSB-1, and CSB-1M (identical ballistics) are excellent 1-1/8th oz powders in 12-gauge, and there is pressure data for them in American taper hulls (Winchester and Remington) that was generated by a well-known pressure testing facility . I've posted that data before, but can point you to it again.
MAXAM's CSB-1 is a very user-friendly powder, and there are not a lot of guys using it in 1-ounce with pretty good results, even though it's not the most ideal and efficient 1-ounce powder.
CSB-5? whew, where ya getting THAT ? As far as *I* know, that stuff's LONG gone (well, other than what I have left). It's an excellent 7/8th's oz, and 1-ounce powder in both, American taper hulls as well as the Euro straight-wall hulls. There is one 1-1/8th oz that I had tested in a Winchester AA HS hulls (with Maxam's CSB-5) that seemed to do alright that clocked in around 1,200 fps at just around 10,000 PSI.
If you can get MAXAM CSB-1 locally for around ~$18/Lb, and if most of your loading will be (12-gauge) 1-1/8th oz, with "some" 1-ounce", then yes, buy all means, look into it, - you won't hate yourself one iota.
But like dirt stirrer has stated, the VECTAN powders are the new kid on the block, and the performance so far is outstanding to say the least.
If you haven't bought powder yet, I'd encourage you to look into the Noble Sport Vectan powders being sold out of Graf and Sons (cheapest place), as well as BPI.
So let us know which Maxam powder you are inquiring about, and we can take if from there.
Well there ya go. Thanks Pete for posting that data, - you got to it before I did...
Whew, 23 grains @ 1235 is "very light recoil"? You guys are hard-core (or I'm just a wimp).
Don't forget, - you guys can use this in 1-ounce too, and it (CSB-1) does reasonably well (in Remington/Winchester hulls). Just use the data above, and change your charge bar and drop 1-ounce of shot instead of 1-1/8th ounce.
Also, CSB-1 is great in Straight wall hulls too (what it was originally designed for).
In the 2015 Maxam Components Catalog, they list the max charge weight as 25 grains.
CSB-1M is ballistically identical to CSB-1, just a smaller flake (for pistol cartridges). I had a little bit of the CSB-1M left that was donated to me (for some 20-gauge pressure testing) by a member at the club, so I decided to make up some test loads and check that published velocity with the full 25 grains in a Rio hull with a Rio primer the other morning. My 6-shot chrono test was within 7 fps of what they have published.
With what little powder I had left after that, I also decided to test the low end as well. Even at 21 grains, the CSB-1 powders offer pretty good stability with a medium-strength primer (W209 in this case) :
The crimps for the actual loads tested above looked like this:
The actual charge weight that you decide on will depend on the velocity that you are trying to achieve with your payload. 23 grains of CSB-1/CSB-1M with a medium-strength primer in the Fiocchi hulls with a Claybuster CB2118-12 is going to yield you about 1,200 fps, with 24 grains yielding about 1240 fps. More with a G-600.
With what little 1-1/8th oz that I do shoot (in straight-wall hulls), I was surprised just how well those slower velocity loads in Test String #2 above performed at the Trap range. It's a great way to manage the extra recoil associated with 1-1/8th oz loads. The loads in Test String #1 however, while clay smokers on a Sporting Clays range, and extraordinarily clean burning, they will wear you out with recoil fatigue in a hurry with a hinge gun.