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9mm 115 grain vs. 124 grain Login/Join 
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It depends what's available or what I've got on hand. I just did several thousand rounds of 124 grain coated lead (Bayou and SNS). I got a good deal at Midway for some 115 gn Berry's round nose, and have some of that sitting around...they just had a special so I ordered a couple thousand more.

At the moment, I'm finishing off some Winchester WST, and 4.8 grains worked well for the coated lead in 124 grain, and for the 115 grain plated. I've got a bunch of Hi-Skor 700X, Power Pistol, and Titegroup next.

The farther the bullet sets forward, the greater the accuracy potential to a point, taking into account maximum overall length and feeding reliability. This is sometimes realized with a heavier bullet with a greater sectional density.

I prefer 124 grain for carry, or 147 grain. I'm quite happy with 115, as well. The bullet weight isn't particularly important, given the critical issue is shot placement.
 
Posts: 611 | Registered: September 13, 2006Reply With QuoteReport This Post
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Thanks. I have used 115 Berry HB, which are longer than the usual 115, using close to 5 grains of WSF. I also have used HAP 115 with same amount of WSF.
Suggestion about overall length is useful too. I have been using 1.10 measured when using HAP 115. Should try setting bullet out farther.

Your observation that bullet weight in 9mm is not very important might be the answer to the question. However, I would like to learn from a solid scientific study of internal ballistics more about the interplay of twist, bullet length, weight, seating, and powder. Such a study must exist in published form somewhere.
Mac


Mac in Michigan
 
Posts: 175 | Location: Below the Bridge in Michigan | Registered: July 04, 2015Reply With QuoteReport This Post
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quote:
Originally posted by P320Mac:
However, I would like to learn from a solid scientific study of internal ballistics more about the interplay of twist, bullet length, weight, seating, and powder. Such a study must exist in published form somewhere.
Mac


It's not nearly so simple, nor formulaic.

While ample loading data exists for most cartridge/bullet/powder/primer combinations, they consist of minimum and maximum loading values, and field opinions by individuals based on their own observations and preferences. All good and well, but only part of the picture.

Each firearm requires customization of a load to enjoy the full potential. That is, you may have six of the same make and model firearm, same twist, same chambering, and fine that the particular load which yields the best round for a given purpose will vary with each one. You'll also find that with some powders, the ballistics will vary by the day, and certainly by the temperature.

The WST I mentioned above is an inverse powder and it's performance and pressure (and cartridge velocity) changes with the temperature of the cartridge and the day. Leave it in the sun or leave it in the snow and you'll see very different results, and in a handgun, may have inadequate capability to cycle the slide, or an excessive pressure spike.

To really see the benefits of loading for accuracy, one needs a rifle. Handguns in general are all pathetic performers compared to a rifle, and the benefits to be gained won't be nearly as apparent as the results a hundred or several hundred yards down range would be with a rifle.

If you're handloading for the range, a round which feeds reliably and cycles reliably ought to be the goal. Once that's achieved, experimenting with velocity and accuracy is done with very slight variances (a tenth of a grain of powder at a time). More often than not, it's the middle of the road cartridge (not the fastest, not the slowest, not the highest pressure, and not the lowest) that yields the best results.

Before determining best results, one needs to qualify the goal. Minimal recoil? Minimal flash? Most accurate? Highest velocity? Most reliable feeding? Biggest bullet? Lightest bullet? And so forth.

Bullet loads (reloading data) put out by Hornady, Lee, etc, has been done with one or several test handguns or rifles, but the potential range of firearms that might use a given load make the end result a variable. It is possible to say that for a given rifle and chambering, a certain twist, bullet weight, powder, and velocity will achieve a certain result, but the result will be specific to that rifle. When I say that rifle, I mean that specific serial number, that one solitary rifle. In a handgun, knowing twist rate means very little. The barrel just isn't that long, the velocity not that high, the range not that great.

Seating depth depends on the specific firearm. The biggest concern is minimum overall length; cartridge pressure (and associated danger) climbs rapidly when too short an overall length (bullet seating depth too great) is used. Likewise, the nature of the crimp in a given cartridge makes a difference, too, and can affect pressure, accuracy, feeding, and other aspects of ammunition use.
 
Posts: 611 | Registered: September 13, 2006Reply With QuoteReport This Post
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Many thanks. You have made the case for experimentation.
You are spot-on about rifle. Friend and I developed a rifle/ammo for 1000 yard competition. Fireform Norma cases, use VV powder that is little affected by changes in temperature, best/sorted bullets, and a charge weight right at the point where more or less would lower the impact point. Those were good days.

Thanks again, Mac


Mac in Michigan
 
Posts: 175 | Location: Below the Bridge in Michigan | Registered: July 04, 2015Reply With QuoteReport This Post
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Originally posted by P320Mac:
That is interesting. Clearly, Del, you found something better when using 147 RN. What did you find was better? What pistol are you shooting them in? Thanks.

There really isnt a better, just diff. For most,the 147gr running 900fos offer really soft recoil & enough vel for good accuracy in most guns. Buy some your next order & shoot them alongside your 115gr & 124gr. For punching paper they all make the same hole. For accuracy at high soeed most prefer the 147gr.


IF YOU AREN'T HANDLOADING, YOU AREN'T SHOOTING ENOUGH!
NRA Instruc: Basic Pistol & Met Reloading
 
Posts: 7525 | Location: ca, usa | Registered: February 17, 2004Reply With QuoteReport This Post
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Thanks for your observations.
My impression, subject to correction after experimentation, is that lighter bullets provide softer recoil. Thanks for the push to try heavy bullets.

One very experienced bullseye shooter found for sure that using "slow" powder softened recoil and left a good deal of un-burned powder on the bench.

Mac


Mac in Michigan
 
Posts: 175 | Location: Below the Bridge in Michigan | Registered: July 04, 2015Reply With QuoteReport This Post
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For me, 9mm bullet weight is all about the recoil impulse (sharp/soft/short/long) perceived when shooting primarily Steel Challenge-type events at speed. Nine months out of the year, I shoot a match every week, only using 9mm, in both pistol and carbine.
As other have mentioned, the relationship (in handguns) between overall length of the cartridge can be tailored to specific guns, and you can vary powder charge in order to find a soft-shooting (read: recoil impulse) round.
Changing recoil springs (different rates) further tailors the load/overall length to that specific gun. With enough patience and work...you can really find a sweet spot that works well.
147 grain works best in my situation(s), but I will shoot 124s if pressed by need.
A lot of shooters use 115 grain bullets in 9mm at our matches, due to overall lower cost. I have converted quite a few over to 147s just by letting them shoot and feel the difference.
YMMV.
 
Posts: 2600 | Location: WV | Registered: January 30, 2010Reply With QuoteReport This Post
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Use of 147 is counter intuitive to me. But experience is very important. Now have heard from several people about 147, which I thought only to be used with sound attenuaters.

Thanks, Mac


Mac in Michigan
 
Posts: 175 | Location: Below the Bridge in Michigan | Registered: July 04, 2015Reply With QuoteReport This Post
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