Different bullet weights - different performance

[Dahak]

Did some testing and determined that my M&P 2.0C 9mm hates 115 and does really well with 147 grain. 124 grain lands below point of aim, but does not have the left-right variance that 115 produces. Okay, easy reaction - use 147 grain pills.

My P365 hates 147 grain, performed better with 124 grain, and is waiting for some 115 grain to come in to see if the trend continues. Use lighter weight bullets - check.

I can't just stop at the easy answers though. I reload (today's rounds were cast bullets with Unique, but W231 and Titegroup are my go-tos for 9mm), Its not a big deal to make what each gun likes; in fact that's part of the reason why I reload and am just getting started on the customization path. I think I understand why there is vertical variance with the different bullet weights, but I am at a loss for why there would be left-right variance that is noticeable at 3 yards (Dot torture targets (2.5 inch circles), impacts not leaving the circle but grouping at different places while holding at the same aim point).

Can anyone explain why? Would a faster burning powder tend to make the L-R variance better or worse, all things being equal?

Thanks!

 

[rwsmith]

It's possible....

It's possible that you are getting some torque from the bullet spin, especially with a lighter gun.

I REALLY like 147 grain bullet in 9mm for target shooting.

 

[rockquarry]

Few loads and few shooters do poorly at three yards. I'd start over and vary the powder charge and maybe powders, shooting groups with each change and do it at twenty-five yards if you have good benchrest shooting skills and have a good rest. If you don't shoot well, you can try this at fifteen yards, but the results won't tell you nearly as much as shooting at the longer distance.

Keep in mid all the time that some bullets simply don't shoot well in some guns. However, I've always been able to find a handgun load that will do well in multiple guns, but it takes some experimentation.

Torque? I don't know anything about that and probably wouldn't recognize it if I did have a "torque" problem. Slim possibility, maybe, but I'd look elsewhere first.

 

[Ron IL]

If you watch slo-mo video of someone shooting you will see the torque he is talking about. In 3 yards the bullet may not be stabilized yet. The 115 grain is a short bullet and the 147 grain is a lot longer with much more bullet to barrel contact. On my 9 I messed with all kinds of tests. I have settled on the 147 gr with Unique powder. I totally quit Titegroup with 115 bullets because of leading. The longer bullet with a slower powder looks like I just cleaned the barrel after shooting 100 rounds. I also have them sized to .358. It is for a Baretta 92x. They have been known to have a slightly larger bore. I usually shoot at the 25 yard stuff.

 

[stansdds]

I cannot say that I have ever had great success with 115 grain FMJ loads in the 9x19. I have found better accuracy with 115 grain JHP bullets as they have a longer bearing surface. 124 grain FMJ bullets tend to do better, again, longer bearing surface. I have found best accuracy with 124 grain JHP bullets and both FMJ and JHP 147 grain bullets. Lead bullets in the 9x19? Some people have good luck with them, I have not.

 

[PPCSHOOTER]

WIDENERS HAS 115GR FMJ IN STOCK . CHEAP AS YOUR GOING TO GET THEM TODAY. JP
9mm Bullets for Sale - Widener's Reloading Supply

 

[rockquarry]

Most people give up with cast bullets in the 9mm before they are successful. As with all handgun chamberings I've worked with so far, they will shoot the right cast bullet that "fits" well at least as accurately as a jacketed bullet, often more accurately. Granted, it takes some work and experimentation.

The best 9mm bullet I've found to date has been a 150 grain round nose design cast from an obsolete Lyman .38 Special mould (#358212) and sized in a .358" die. This bullet functions with 100% reliability in three 9mm pistols, is accurate, and doesn't lead the bore.

However, I tried about a dozen other designs, many powders, different alloy mixes, and bullet diameters before I found what really works well.

 

[rct269]

One constant you have in shooting any firearm with a rifled barrel is the rifling rate-----one turn of the bullet in yea many inches of barrel length------and that rate is what it is, is somewhere between damn close and identical from one manufacturer to the other for any given caliber, and there is clearly nothing you can do about changing it. The only reason it's there is to stabilize the bullet in flight---a necessity if your objective is to hit your target (at ranges considerably beyond three yards). And at this point let me suggest any testing at a range of three yards might tell you something about the marks made by different brands of unburned powder, and not much else.

Another constant you have is the diameter of the bullet---essentially the same for any and all of any caliber (but you'll find worthwhile differences in performance from any given gun by varying the diameter a thousandth or two or three).

So what's different that makes a difference? The length of the bullet---more particularly the length of the bearing surface of the bullet. Your gun likes one length better than another. Your job is to find out which---and unless you want to spend a lot of time learning very little, get a machine rest. It'll cost you less than you paid for any decent gun in your stable, and it'll give back information you're not going to get anyplace else.

Ralph Tremaine

 

[__steve__]

I wonder if the velocities would show a similar variation within each load

 

[Nevada Ed]

That is just the way it is.
Every pistol, due to it's specs and how it was put together and broke in,
will usually like a certain weight bullet or a certain target or maximum speed, with the pressures that go with the loads makeup.

Very seldom do I get tiny groups out of the same bullet at sub-sonic and +P speeds and great accuracy takes time to find, in most cases.

I also found that barrel length also plays a big part in accuracy and fps,
in my 38.357 and 9mm loadings.
A 2 or 3" barrel and short sight picture, is very hard to master, if you have
bad mechanics and tech. use with the weapon.

With a 6" barrel, I can have six cups of coffee and still have a good day,shooting.

Hang in there.

 

[rockquarry]

One constant you have in shooting any firearm with a rifled barrel is the rifling rate-----one turn of the bullet in yea many inches of barrel length------and that rate is what it is, is somewhere between damn close and identical from one manufacturer to the other for any given caliber, and there is clearly nothing you can do about changing it. The only reason it's there is to stabilize the bullet in flight---a necessity if your objective is to hit your target (at ranges considerably beyond three yards). And at this point let me suggest any testing at a range of three yards might tell you something about the marks made by different brands of unburned powder, and not much else.

Another constant you have is the diameter of the bullet---essentially the same for any and all of any caliber (but you'll find worthwhile differences in performance from any given gun by varying the diameter a thousandth or two or three).

So what's different that makes a difference? The length of the bullet---more particularly the length of the bearing surface of the bullet. Your gun likes one length better than another. Your job is to find out which---and unless you want to spend a lot of time learning very little, get a machine rest. It'll cost you less than you paid for any decent gun in your stable, and it'll give back information you're not going to get anyplace else.

Ralph Tremaine

I'll assume you've used a Ramsom rest considerably and am always interested in what someone has to say about their experiences with it.

I bought one new, with a windage base and several inserts years ago. They work well, but, according to some, a few rounds must be fired for the gun's grip to "settle in". I don't recall this happening to me, but it may have.

Along about the same time, I began learning to shoot from a good solid rest using sandbags and finally found no need for the Ransom rest. I sold it.

The late and long-time editor of HANDLOADER and RIFLE magazines, Al Miller once remarked that a good shooter should be able to consistently shoot groups from a rest at 25 yards that will equal the group sizes fired with a Ransom rest at 50 yards. Generally, I think this statement is very true. Unless you're looking for accuracy differentiations to the quarter-inch, learning to shoot well from a rest will satisfy the needs of most accuracy enthusiasts.

If you have a need to know about 50-or 100- yard accuracy potential with a handgun, get a Ramsom rest unless you're an exceptional shooter.

A big advantage of the Ransom is that it is unaffected by shooter fatigue, but none of us should shoot so long at one time that our groups enlarge. If they do, it's time to quit.

 

[DeplorabusUnum]

I would echo what others have said. When I'm trying to find an accurate load, I always shoot at 25 yards from a rest. The more still you can keep the pistol, the better the information you get about each load. It just removes some of the human variable from the equation. Once I've found an accurate load, then it's time to move on to shooting without the rest, and working on aim and trigger control. Best of luck.

 

[rockquarry]

If you watch slo-mo video of someone shooting you will see the torque he is talking about. In 3 yards the bullet may not be stabilized yet. The 115 grain is a short bullet and the 147 grain is a lot longer with much more bullet to barrel contact. On my 9 I messed with all kinds of tests. I have settled on the 147 gr with Unique powder. I totally quit Titegroup with 115 bullets because of leading. The longer bullet with a slower powder looks like I just cleaned the barrel after shooting 100 rounds. I also have them sized to .358. It is for a Baretta 92x. They have been known to have a slightly larger bore. I usually shoot at the 25 yard stuff.

A skilled shooter should have no problem overcoming this "torque", if that's the only problem. You may have a poor bullet for the gun and torque is the least of the problems to overcome, if there really is such a thing. This sounds a bit YouTubish, but I won't criticize because I'm not familiar with it. I'm also unfamiliar with the type of gun the original poster is using. My experience has been with traditional 9mm DA/SA pistols, made with aluminum alloy and steel, a variety of them.

 

[geekeye]

i've heard folks talking about working up rifle loads say that horizontal shift tends to be related to barrel harmonics, but i really don't know if that's a factor in shorter pistol length barrels or not. if you are reloading it couldn't hurt to test different powder charges with the same bullet weight to see if that helps.

 

[rct269]

I'll assume you've used a Ramsom rest considerably and am always interested in what someone has to say about their experiences with it.

I bought one new, with a windage base and several inserts years ago. They work well, but, according to some, a few rounds must be fired for the gun's grip to "settle in". I don't recall this happening to me, but it may have.

Along about the same time, I began learning to shoot from a good solid rest using sandbags and finally found no need for the Ransom rest. I sold it.

The late and long-time editor of HANDLOADER and RIFLE magazines, Al Miller once remarked that a good shooter should be able to consistently shoot groups from a rest at 25 yards that will equal the group sizes fired with a Ransom rest at 50 yards. Generally, I think this statement is very true. Unless you're looking for accuracy differentiations to the quarter-inch, learning to shoot well from a rest will satisfy the needs of most accuracy enthusiasts.

If you have a need to know about 50-or 100- yard accuracy potential with a handgun, get a Ramsom rest unless you're an exceptional shooter.

A big advantage of the Ransom is that it is unaffected by shooter fatigue, but none of us should shoot so long at one time that our groups enlarge. If they do, it's time to quit.

My experiences are likely unremarkable-------and more than dated. I set out handloading seeking the ultimate in accuracy. This was a good long time ago, and accomplishing my first objective---to be better than factory was achieved so quickly, I figured there had to be more to it than simply the consistency touted in all the How-To magazines. I also decided there was less to it than the picayune fiddling with different powders, primers, case capacities, crimps, and the like. I figured it was about bullets being launched through a tube, and seeing as how there wasn't much I could do about the tube I'd best concentrate on the bullets. Which ones produce superior results----and why. I figured the whys would make for a pretty short list----the particular alloy, the dimensions (diameter and length), and the lubricant. I also figured I'd probably be dealing with rather small variances, and I better be able to believe them----every time----all the time. That let me out as the shooter.

Enter the machine rest. It was love at first sight! My definition of ultimate accuracy was/is group size. It was truly amazing to see how well the gun shot----compared to how well I shot it. I wasn't out to reinvent the wheel, so my work was done with one caliber (.38 Special) and one gun (K-38). Later on (and without the machine rest) I messed with a .44---at 100 yards and beyond. The gun was an 8 3/8" .44 Magnum----the loads were decidedly less than factory---having decided any and everybody who shot full-house .44 Magnum loads was nuts!!

As to the inserts and the gun getting cozy, it was never a problem. I'll suggest attaching the fasteners in the appropriate pattern with measured torque gets the credit for that.

Ralph Tremaine

 

[terry_tr6]

I sporterized a spanish .308 mauser and the thing was pretty accurate(after I wacked off the last inch of barrel and got to some good rifling). But hornady 125gr SP and 150 gr SP produced nice groups but with about a 5" horizontal difference. you could alternate shots and get 2 nice groups, about 5" apart.

I was having real bad leading issues with coated bullets loading with a pretty fast powder (AA#2) . on advice of Brazos the maker, I swapped to a slow powder(AA#7) and leading GONE. We think the fast powder was getting around the bullet before it was solidly in the bore and melting the lead. Unfortunately no more #7, 231 and unique are what i have. neither bad on leading but darn that #7 left a clean barrel