9MM Ammo Question.

[jim57]

I have a CCW am going to start carrying my S&W 6909 9MM, and found the sights were regulated to 147 gr slugs. It prints the 115 JHP's about 2.5" low at 15 yds, and I can compensate for that if needed. I'm concerned about over penetration if I use the heavier slug. Any advice?

jim

[slamdunc]

I found the sights were regulated to 147 gr slugs. It prints the 115 JHP's about 2.5" low at 15 yds, and I can compensate for that if needed. I'm concerned about over penetration if I use the heavier slug. Any advice?

First of all, always practice with the same weight bullet you will be carrying. Second of all, sights are not "regulated" to any particular bullet weight.

Heavier slugs, such as the 147 grain will not over-penetrate; the 115 grain is faster, and will have more penetration. The 147 grain will have more muzzle-energy, and less velocity. This translates to knock-down, versus ripping a hole in something (or someone).

[jim57]

Thanks for the info, I appreciate it. I tried the 147 gr Winchester loads and they printed level with the standard sight picture at 25 yds, so I assumed that this is what the pistol was indended for. It's a nice pistol and so far has gobbled down everything I shot in it.

I was shooting some Winchester 115 FMJ's yesterday, and I must have gotten a light load, because the slide failed to lock back on the last shot even though the mag was properly seated. No further problems for the rest of the session.

Thanks again
jim

[slamdunc]

It's a nice pistol and so far has gobbled down everything I shot in it.

Actually, they are great weapons, rarely ammo sensitive. Just keep it clean and it should be very dependable.

I was shooting some Winchester 115 FMJ's yesterday, and I must have gotten a light load, because the slide failed to lock back on the last shot even though the mag was properly seated.

This could also be a lubrication or 'limp-wristing' issue.

[Sleuth]

1. The 6906 was the issue pistol for U.S. Customs Investigations. As the Firearms Instructor at the academy, I found them to be reliable, accurate, and a good choice. Our issue ammo was the 147g JHP.
2. Slamdunc is a bit confused, heavier bullets tend to penetrate deeper, lighter ones penetrate less. Neither is a problem, with a national LE hit percentage in the 20% range.
3. One failure does not make a trend.
4. 90% of police shooting take place at 7 yards or less, 50% at 5 FEET or less. Tactics and gunhandling are more important than accuracy.
5. Find a USPSA (www.uspsa.org) or IDPA club, and start shooting and learning with them.

[CruiserClass]

The sites are set figuring a certain distance and bullet weight. For example, the ones that came on my first 1911 were set figuring a 25 yd shot with 230 grain bullets. The rationale was if it was dead perfect at 25 yards, it was within an inch and a half at 0 yards and 50 yards. Close enough for handgunning.

Fixed sites are a compromise between "good enough" and resisting being knocked off line like adjustable sites can be.

As far as worrying about over penetration with a handgun round: Don't. Worry about under penetration.

[Nightshift va]

Absolutely your gun will shoot better with some ammo versus others. Thats not just true with the model but with the paticular firearm. As for the heavier grain bullets, typically "yes" heavier slower moving round have deeper penetration. But it's not just about the speed it's about the make up of the actual bullet. With 9mm i do not reccomend 147grains. The high quality "bonded" bullet in that grain just might exist but too many test ive seen and conducted even the best round in 147grain sucked. I'd rather have a 115grain or 124grain round in anything vs 147grain. Also do not worry about "Over" penetration. The fact is one of the biggest problems ive seen is not enough penetration both on bad guys and other factors such as wood,glass,etc.. If you are truely concerend with penetration still and you want excellent trauma use glaser safety slugs or magsafe ammo.

[jim57]

Gents

Thanks for the help. My main concern was shooting through someone and hitting an innocient bystander. I don't know if that is really a concern, but I thought it best to be responsible and not cause unintended injuries or problems for myself.


I appreciate the advice, and will go with a 115-124 gr JHP.

Thanks!
jim