Newbie Question - powder weight results

[HeinyO]

I am new to reloading. And enjoying, but I have a question concerning powder weight. I am reloading 9mm luger with Sierra FMJ-RN. I started with Accurate #7 at 6.8 grains. Oal at 1.10. I am shooting consistently 2" high. Increased my powder to 7.0 grains. My grouping improved slightly, but still about 2" high. My question is: Generally speaking, Will increase or decrease in powder weight effect how high or low my target results? My initial thought was that increase in powder would raise my target result. Any rules of thumb from the experts.

 

[Mauser69]

IN GENERAL, the rule of thumb is that faster and/or lighter bullets tend to shoot lower. This is because the bullets spend less time in the barrel and exit it before the recoil has had time to push the muzzle as high as it will for the slower/heavier bullets.

 

[Rotting]

All else the same (same gun, no change in sighting, same projectile, seating depth, etc.), the higher the powder charge, the higher the muzzle velocity. The higher the muzzle velocity, the less time the bullet spends "trapped" by the barrel. The less time trapped in the barrel, the less time the bullet "rides" up with the barrel during the recoil/muzzle flip that occurs with the shooting of a gun.

So, the higher powder charge, the less upward mechanical deflection of the bullet due to muzzle flip, the lower on paper the shot placement is.

This is all generally speaking, of course. Other factors can and do come into play, but I hope this answers your question.

 

[Rotting]

Haha, Mauser. 30 seconds quicker on the draw!

 

[HeinyO]

Excellent, Thanks

Makes sense to me, and is a good thing because I still have about .6 grains that I can gradually increase my powder to get to max. I think that the testing, for me, seems to be one of the most fun parts of reloading. Then moving on to a faster burning powder I can start again, taking notes on the different recipes, different bullets(when comfortable, going to EDC bullets.) Thanks for the replies. I don't want to ask dumb questions, but I have to start somewhere and I consider myself quite dumb at this point. I will certainly appreciate your patience.

 

[Steve C]

Going from the start load to the max load with most 9mm bullets will not increase velocity enough to notice any significant change in point of impact as the difference in velocity isn't that great. Going from a heavier to a lighter weight bullet will have a much greater difference in velocity and the point of impact difference on target will be more noticeable.

You don't say at what range you are shooting at but if you are using the typical 25 yd target, the range most handguns are sighted for with fixed sights, 2" high from point of aim is pretty insignificant. Closer range like 10 yds and the bullet will typically be over line of sight as it will be climbing in the initial travel of it arc to the target so short range targets really don't tell you much.

 

[SARuger]

Sierra makes a 115g FMJ and a 125g FMJ in 9mm. Which one are you using?

 

[ArchAngelCD]

Welcome to the forum.

You don't adjust the POI with powder charges. (I know you weren't, just saying)
If you are shooting 2" high and you don't have adjustable sights aim 2" lower. No mystery.

Why did you choose the OAL you did?

 

[murf]

if the powder weight affects your muzzle velocity, then poi will be affected as well.

murf

 

[HeinyO]

"ArchAngelCD" - If you are shooting 2" high and you don't have adjustable sights aim 2" lower. No mystery.

Thanks for the insight. But I am new to reloading, not new to shooting. The question was in regards to the effects of powder loads. And I am using Sierra 115gr FMJ-RN. The 1.1 OAL came from my load data, both on my Lee die info and the Accurate (online) load data.

 

[ArchAngelCD]

"ArchAngelCD" - If you are shooting 2" high and you don't have adjustable sights aim 2" lower. No mystery.

Thanks for the insight. But I am new to reloading, not new to shooting. The question was in regards to the effects of powder loads. And I am using Sierra 115gr FMJ-RN. The 1.1 OAL came from my load data, both on my Lee die info and the Accurate (online) load data.

I'm just trying to help, that's all...