Handgun "Precision" Reloading

[mbruce]

Just curious on "precision" reloading for handguns...one of those beloved "Why" posts....


What makes some powders more accurate than others? -- is it really the pressures that they build behind the accuracy? If so then in theory all powders are as accurate as each other if you can safely match pressure for pressure? Or is it...who cares just use the cheapest stuff b\c you aren't that good of a shot anyways!

Does a longer COL in 10-25yds handgun shooting really make a noticeable difference? -- When tweaking for better accuracy does anyone play with the COL?

Is a gun really going to prefer one bullet weight over another? I often read members posting "my gun is more accurate with a 124gr bullet than a 115gr bullet" -- is the bullet weight really the reason behind the better accuracy or is it a combination of things and the shooter just so happened to dial in the right pressure/bullet weight combination for his/her gun?

Thanks!

 

[Yarddog]

"[Is a gun really going to prefer one bullet weight over another?]"

YES & Yes ; )
Y/D

 

[Grumulkin]

What makes some powders more accurate than others? -- is it really the pressures that they build behind the accuracy? If so then in theory all powders are as accurate as each other if you can safely match pressure for pressure? Or is it...who cares just use the cheapest stuff b\c you aren't that good of a shot anyways!

I have no good idea why, but for some reason different handgun cartridges do better with different powders. Though not so true with handgun powders, some powders have a larger range of load weights where good accuracy is maintained while with others, less than half a grain can make a significant change in accuracy. Another part of it is that with some powders, pressure becomes excessive before bullet velocity is adequate to stabilize the bullet. And yes; if you're not a good shot, it doesn't matter so much.

Does a longer COL in 10-25yds handgun shooting really make a noticeable difference? -- When tweaking for better accuracy does anyone play with the COL?

For 10 to 25 yard shooting especially with a semiauto or revolver, COAL probably makes little difference.

Is a gun really going to prefer one bullet weight over another?

Very definitely especially with scoped single shot handguns. Part of it has to do with barrel twist and bullet stabilization and part with obtainable velocity with the powder used.

A 1.5 inch 3 shot group shot at 200 yards with an Encore 460 S&W handgun.

A 1.6 inch 3 shot group shot at 200 yards with a scoped Encore in 375 H&H Magnum.

 

[LiveLife]

Published load data with indicated PSI or CUP pressure measurements are "maximum peak pressure" recorded. The max pressure numbers don't tell you how smooth or brief the pressures were achieved and maintained.

Accuracy is best achieved through start to max load data range if this pressure map is smooth and not spikey. Yes, accuracy comes from consistent powder burn producing even chamber pressure, not just peak max pressure attained for a brief moment during powder burn.

So, two different powders may list the same pressures, but how it achieved the same may be very different (gradual build up vs wham/bang detonation).

Also, some powders have "sweet" spot for particular bullet caliber/weight combination that happens to produce more consistent powder burn/chamber pressure - this is the holy grail for us reloaders looking for "the load" for said caliber/bullet type/bullet weight/barrel length.

Depending on barrel diameter, rifling type, length and recoil spring type, material and spring rate, with subsequent OAL used, powder burn rate/chamber pressure will also be affected. In general, longer the OAL the sooner the bullet bearing surface will engage the rifling resistance to start to build chamber pressure to result in more consistent powder burn and greater accuracy.

Shuffling/factoring all these variables is what makes reloading fun/challenging.

 

[rfwobbly]

1) To me it's several things. How the burn rate works with the bullet weight. How the case fill effects the ignition. How the powder meters and its ability to get the same fill on each cartridge. How temperature affects the velocity. Etc. There are maybe 10 "important" things going on, and in truth there are probably 5+ powders that could fill the same roll as the one I now use. So will the sky open and trumpets sound when you get the right powder? Hasn't happened for me. Will your scores go up? Yes.

2) The thing about OAL for me is avoiding the things that could cause my gun to have a mishap in the middle of competition. I want a round to feed flawlessly despite having a staggered position within the mag. I want all external case dimensions to be spot-on. I do NOT want bullets getting stuck in the rifling when I go to clear my weapon.

So to me the OAL is more of a place to avoid screw-ups rather than a place to gain accuracy.

3) Yes, the rate of twist mostly determines that. But it also plays a part in "barrel flip" and "felt recoil", 2 things I try to reduce/control when competing.

 

[1SOW]

I agree with the above.

Many of the "Bullseye" guys are big on crimp vs pressures attained and accuracy.

Your finding of 124gr being more accurate in your 9mm handgun at 25 yds or less leads to a question:
Are you testing that from a rigid Ransom Rest or shooting off-hand. The reason I ask, is I believe the 124 is "easier" to shoot accurately, but not necessarily "more accurate".
By the way, I'm more accurate and faster with 124/125gr than 115gr.

 

[mbruce]

The accuracy claims were hypothetical but I do read posts where such claims are made. So why mold the 115gr bullet I wonder? I have only shot 115gr lrn but I have on order mbc 124gr lrn...With those I'll be shooting thru the same hole in no time...ha

I ordered a pistol rest from the only company that popped up when I googled pistol vise...right now I'm using a plastic one which is cool if no height adjustments are needed in the back...

 

[918v]

What makes some powders more accurate than others?

Voodoo

Does a longer COL in 10-25yds handgun shooting really make a noticeable difference?

50% group reduction in my experience. No, not from 3" to 1.5", but from 1" to .5".

Is a gun really going to prefer one bullet weight over another?

Yes, and not only that, it may prefer one brand of bullet over another even if the two are identical in weight and profile. I have found the softer the alloy and the thinner the jacket, the more easy it is to develop a tack driving handload. Maybe it is the way they conform to the rifling. I dunno.

 

[1SOW]

50% group reduction in my experience. No, not from 3" to 1.5", but from 1" to .5".

At 64 yrs old, I couldn't do that off-hand if someone strapped me to a steel target stand.

When I group my CZ 9mm 3" at 25yds, I square up my shoulders and pretend that happens every time.

 

[918v]

Nobody can do that off hand.

 

[mbruce]

I like steel reactive targets -- ya don't have to mess with this grouping stuff -- ha....

I found myself flinching and anticipating the shot yesterday when I was shooting from a vise...even shooting from a vise takes practice, at least for me -- i need a few more rounds with it to find my "tack driving vise grip" -- i tried all kinds of weird grips

 

[UnknownGunMan]

Did you try with your "mouse" hand? That would be your left

 

[GLOOB]

My overall general impressions, just from reading stuff:

Bullet weights: Any given weight bullet has an ideal twist rate. Some bullets will stabilize better than others, for a given barrel's twist rate.

Powder: Each powder has different burn characteristics. In general, you need to reach a certain pressure threshold for optimum burn. This reduces the variation in muzzle velocity. Adding more powder beyond that optimum, and things may start to go the other way. This is why fast powders are often wrongly considered more accurate. They are often more accurate at LOWER levels of recoil and velocity, because they reach higher pressures with lighter loads. When you start using slower powders, you generally need to use higher charge weights, which will get you into higher velocity and recoil levels, before the standard deviation comes down. So they "aren't as accurate" because they have more recoil than the faster powders by the time you reach their ideal pressures.

 

[Hangingrock]

From spitting distance to 50yds how much accuracy do you really need? Three factors shooter, ammunition, and firearm are involved along with climate/environment. I don’t do my best shooting at minus 20°F. I operate under good enough theory.

The load employed in the following photograph consisted of Win-231 – WLP – mixed cases & cast bullets loaded on a Dillon 550 progressive press.

I’m a stand up and shoot type of person. The target pictured represents traditional offhand at 50yds. Do I shoot groups like this every shooting session no but often enough that it’s not a fluke happenstance. Within reason there are going to be more related shooter and firearm issues than ammunition issues unless the ammunition is total garbage.

Example there is commercial loads that shoot extremely accurately when used in a broad spectrum of firearms. The commercial ammunition is not being tailored to a particular/individual firearm.

I simply don’t tweak the ammunition for one particular firearm as I own several of that caliber and require functionally for all as opposed to one. I’m not a handloader but a reloader the difference is of importance.

 

[918v]

It's not a question of need.

My philosophical frustration with firearms is they do not shoot where I point them. The bullets impact here and there, everywhere. The goal is to get them to impact through the same hole at the point of aim.

All guns are incapable of this, although some come very close. A teeny group at a great distance is pure joy. That is why I reload.

 

[mbruce]

Accurate enough to where my wife can knock down steel reactive targets....so i need a smart bullet -- a bullet so smart that it knows to go to metal even if it's aimed to miss -- maybe i need a magnetic bullet.

 

[rfwobbly]

Accurate enough to where my wife can knock down steel reactive targets....so i need a smart bullet....

In 9x19, I've gotten my very best accuracy by loading Precision Delta 124gr RN over N320 and kissing each bullet before it's seated.

 

[918v]

Have you tried any other 124gr RN's with N320?

 

[1SOW]

918v:

All guns are incapable of this, although some come very close. A teeny group at a great distance is pure joy. That is why I reload.

I understand, and reload 'partly' for the same reason.

I have an experiment with my 9mm CZ "in progress". I decided to load 50 rds, as close to being as uniform as possible using range brass and chrono them and measure for group at 25 yds.

I measured (a lot of) MG 124gr FMJ and found 50 bullets as close to same length as I could.
I sized & measured (a lot of ) WIN cases and found 50 as close to .75" as I could find.
I tightened my crimps to .356 +/- .0005" (Mostly right on)
I loaded them to an OAL of 1.14" +/- .0005" (MOSTLY right on)
I carefully checked the n320 loads for consistency.
I used Fed SPPs from the same box of 1K
I labelled the 50-rd box "MATCH LOADS"

AND NOW...and now....I haven't shot them yet. They've been on my reloading bench for over a month. Do I want to shoot them off-hand or from a rest? What if "I" have a bad day?

Anyone have a spare 250# Ransom Rest handy?

One of these days, I'll feel froggy and go chrono and group my "purrrfect" loads.

It was fun to see how close to standards I could get, and it really wasn't 'that' tough to do. At 25 yds I doub't there is much change from my reguklar loads. Maybe at 50yds, but I don't have a 50 yd range convenient to try them.

 

[918v]

The problem is the other part of the equation- whether the gun will like the load.

Accuracy and consistency are not necessarily a result of uniformity. You could have 50 identical rounds, in every respect, and they may group like crap just because the gun does not like them.

You can have a load your gun likes, then try to improve it by weighing your brass, cullets, powder, etc. and the accuracy will be no better.

Or you may stumble upon a magic load that does everything you want. Those are few and far between.

 

[1SOW]

This is a load I've fired over 2K times. and it's pretty consistent I know how it shoots and groups.

You can have a load your gun likes, then try to improve it by weighing your brass, cullets, powder, etc. and the accuracy will be no better.

I agree with that likelyhood within 25yds, but it might matter out a 50yds.

My son loads WAAAAY looser than I do, but when I shoot his gun and ammo, it makes no noticeable difference on the results inside 25 yds. He whips my butt in USPSA---usually.

 

[rfwobbly]

Have you tried any other 124gr RN's with N320?

Oh yes. Winchester, Montana Gold, Zero, Precision, Hornady... to name a few. The issue is that I shoot a CZ, and the CZ chamber doesn't "like" all bullets. And all these with N330, N340 and N350 too.

 

[Captal_de_Buch]

If precision means accurate then try lead bullets, at least in 38, 357, 40 and 45acp.

The extra .001" diameter certainly seems to help.

 

[918v]

Oh yes. Winchester, Montana Gold, Zero, Precision, Hornady... to name a few. The issue is that I shoot a CZ, and the CZ chamber doesn't "like" all bullets. And all these with N330, N340 and N350 too.

How's the accuracy of Precision and Zero in comparison to the Hornady? I tested Hornady against RP and some cheapo bulk stuff and Hornady delivered groups half the size. The others strung horizontally even with OAL and powder charge adjustment.