Powder

[Midas]

What is the purpose of using a fast burning powder compared to a slow burning powder.

So in other words when would one use a slow burning powder .

When would one use a fast burning powder.

I want to find out what type of powder to use for 147 gr 9mm.

Mostly IDPA and IPSC.

Thanks

[Merlin Orr]

Try starting here.

[Brazos Custom]

The short answer is slow powders for comps and ported guns and fast powders for un-comped guns. Within that range you have to find a load that feels and shoots best for you. Use the clock to see what works best not necessarily the feel. Soft feel usually means slow.

[Carlos]

Use a fast powder/147 for lower recoil & better time/HF.

Some old timers who do not compete may offer you advice that you should use a slow powder which is really bulky so that you will more easily see a double charge.

My take on that is: if your reloading practices routinely create the possibility of a double charge, you should not try to correct that possibility by using the wrong powder. Slow powders belong in open gun loads and magnum handgun calibers for hunting.

The beginner using 147s should look at Hodgdon Tightgroup.

[lneel]

Rainier 147gr along with 3.3gr of TG at 1.140 works great in my G34.

[Wap wap]

Because a slow burning powder usually has a higher charge weight it has a higher ejecta mass, couple this with a longer burn time and less contribution per volume of mass by the added nitroglycerin, a lot of shooters believe that they help their compensators "work better". The difference would be say in a 9mm 4.5 grs of WST for a 115 gr. or total mass of 119.5 grs vs. say 10 grs of WW 571 or now 125 grs. of mass. or 3.7 percent vs. 8 % or a gain by using the slower powder in a comp of about 5%. Highest velocities are usually attained using slower powders because the pressure curve act longer to increase the velocity of the bullet. It a gun could be made strong enough, the same wt. of fast burning powder would cause a higher velocity but at a much higher pressure. Why- beacause the faster burning powder has more chemical energy per unit volume than the slower powder. A better work around is a med. Universal, 700 or WSF. Slow powders cause extreme muzzle blast. I have a 9mm/25 using cut down 45 Win. Mag cases that uses 20 grs. 296 for 147 gr bullets at 1600 out of a 5" BarSto that gives headaches, also a Casull with 33 grs. of 296 with 300 gr bullets that is good for about 25 rounds in this shooter. One big advantage of the low pressure 45's is this point.

[Midas]

Wap,

Thanks for that reply. A little physics and a little Chemistry. WOW.