I have heard that clays may be a bit fast for .40 s&w. If that is the only powder that you have I will just say stay away from max loads with that one. On the other hand Universal Clays will prove safe for your .40 also you might want to try tightgroup, I use it quite a bit and have found it to be very plesant to shoot. I think alot of the competition shooters use titegroup with good results.
I do not shoot competitivly (spelling?) so maybe some others will chime in with more help. One other thing if you really want to make that bullet move out give Longshot a try, it seems to be very powerfull with low advertised pressures.
If you are willing to assemble the load long then you might be okay. By long, I'm talking 1.200" overall length. I think I tried Clays when I was deciding on a load for my Limited gun. I saw a definite increase in primer flattening with Clays. I ended up using Vihta Vorhi N-320 behind a 180 gr Mont. Gold bullet.
If you have a chrono and are willing to load long, give it a try. Start out on the low side and increase carefully.
Maybe get a good reloading manuel that deals with clays and check it out. It might even be on Hogdons web site. Meanwhile, check out the photo I just took of a major reloading manuel. It says you can use Clays in 40SW
However I am with the rest of the bunch----be very very careful of fast powders like Clays in a small case like the 40----Clays pressure spikes very hard.... The slower buring powders are my choice.
If you are going to load CLAYS powder for 165-175 PF loads you have to use a) fully ramped bbl for case support b) small rifle primers c) the round is loaded long (ie. 1.200 oal).
Having said that there are better powders to use for the .40 for IPSC that are slower. I do personally use CLAYS for practice loads, and load VV320 for big matches. This is not a new to reloading proposition though.
The reason you load the bullet long is so it feeds better in the 1911 pattern guns used and so the pressure spike is reduced in the more space allowed in the case. Fast powders and heavy bullets can be a Kaboom waiting to happen. Be careful working up a load and use a chronograph and look at fired cases for pressure signs.
It came from the new Sierra Bullet Ballistics and loading manuel on CD. It is called Infinity Suite 5. It is a super program and has tons of load data. Plus you can do all the Ballistics stuff with the program-----very handy for long range rifle and long range pistol shooting.....
I paid around $50 for it from an online vendor. Check it out at Sierra bullets web page.