sub sonic bullets backwards
 

More info please. Are the 200 and 220 flatbase or boattailed to shoot them backwards? I have not loaded any 300 yet but will be when my gun comes in from JD. I will be shooting my loads out of an AR-15 is this a problem? Do they build pressure less quicky in the chamber when loaded backwards? If not I guess the reloading data would remain the same? Thanks!

If I was you, I'd stick with published loading data to start with. One of the main reasons I was shooting the boat tail bullets backwards was because I wanted to try them out on game and see if I was able to get the subsonic rounds to give me any more killing power (heavy subsonic match bullets don't expand on game).

There are several websites that I have read that talk about the teardrop shape of a bullet being most efficient at subsonic speeds. This is a loaded discussion since there are so many different factors that come into play with subsonic bullets. I think the jury is still out until someone reports on extreme range shooting results with them. I personally have no interest in shooting subsonic bullets beyond about 150 to 200 or so yards. But with the right rig, I have heard that the 300 Whisper with subsonic loads is very impressive at very long range if one has a scope that will allow for yardage adjustments and you know your exact target distances.

If I had a new AR in 300 wisper and was only going to plink with it, I would just shoot 'normal' loads through it. My interest is in single shot subsonic suppressed rifles and the feeding etc is totally different.

Mark White of SoundTech has had good luck with putting bullets backward. I have better luck with the HJ bullets made for subsonic expansion, they look like an ashtray. The only problem is that the guy who owns HJ is a crook, so buy with caution.
I have had very good luck with 170g FB bullets that are used in the 30/30 rounds with 8.1g of H110 and a very heavy crimp.