Does BH209 burn faster or slower than T7?
Good question.
Can anybody shed some light on this?
I have information from a VERY reliable source that the pressure curves of BH209 & 777 are almost identical under the same load. With the very light projectiles <200 gr, the 777 can be give better velocities with some loads. With projectiles >200 gr, BH209 wins every time, and continues to outrun 777 even more as bullets get heavier. So with that information, MY thinking is that BH209 would be slightly slower as 777 is spanking the bullets out just slightly faster on the light projectiles, but as weight increases BH209 spanks 777 due to bullet dwell time and more efficient burn.
I have a 24" Huntsman that just loves BH209, just load and shoot until the cows come home. Then get up the next morning and do it all over again. BH209 with the MU breech plug gives me, no crud ring, no swabbing, no blowback (except for a hint of soot on the standing breech where smoke is leaking through the primers themselves), no stopping to drill carbon out of flame channels (99.9% of it goes right into the charge where it should), never a stuck breech plug. I have also tested several primers (10 now), and never had the slightest hang-fire with the MU breech plug and BH209, and that includes the 209-4 (410 primers), Rem Kleanbore ML, 777 ML primers. Now using the factory plug is a whole different story, you MIGHT get good ignition IF you use a brand new primer carrier each shot AND the hottest Fed 209A or CCI Mag primers, but hang-fires on 90%+ were normal in my testing.
Back to your question, very little difference in velocities of comparable loads between the two powders. If you are shooting <200 gr bullets a slight advantage may go to 777, but if you are shooting >200 gr bullets the advantage goes to BH209. After getting past that, you need to weigh out all the other factors mentioned above. My SWAG would be that the BH209 is slightly slower, but more efficient with a wider variety of hunting bullets.
