What is powder accuracy

I see people discussing how accurate this or that powder is, and I'm a bit confused. Of the things I would assign accuracy to, barrels and bullets would be easy picks. Do people just mean it's easy to find a good load for. Even my least favorite powders like true blue and power pistol make accurate loads, so what gives????

 

Can’t wait to learn something new.

 

I don't have a full answer, but I do have some examples. Here's one: in MY 10mms, for a given projectile, (so far) I have always found Blue Dot results in more accurate loads when compared to Longshot, the only variable being charge wt.

 

When i different grouping test between powders. You can see what load is more accurate.

 

My signature "Holes on target speak volumes" is how, by comparing group size using same/similar reloading variables to "most accurate" to "most accurate" loads achieved for the powders.

Side-by-side comparative load development, powder work up and range testing with incremental reduction of OAL to squeeze out bit more accuracy, especially for lighter target loads, are what some articles use like this bullseye match load powder comparison - https://www.shootingtimes.com/editorial/loads-for-the-bullseye-shooter/99418

Over the decades, as I conducted load development and range testing, "most accurate" loads identified at 10-15 yards were tested at 25 yards (25/50 yards for PCC loads) and smaller groups of 2" or less achieved over multiple range trips get noted.

To rule out "bad range day" shooter input and range conditions, two or more "most accurate" powder loads can be shot side-by-side on same range day using same firearm and if one powder consistently produced smaller groups than other powders, it becomes "more accurate" powder.

 

For me a good example would be something like Varget vs CFE223 in 308. The Varget will outshoot the CFE 95% of the time, or at least it will for me. There are other similar comparisons that can be made across different burn rate powders, but Ive pretty much found that extruded powders that are temperature stable are generally more accurate than a ball powder that is not.

 

Beats me. I don’t think I’ve ever used the phrase myself. I do know about hot powders and cool powders - single-base vs. double-base vs. triple-base, and so on - and I do know there are some loads that have a reputation for good accuracy in almost any serviceable firearm - 47gr of IMR4895 in .30-06Spg under a 168gr SMK or 2.8gr of Bullseye in .38Spl under a 148gr wadcutter as examples - but those numbers float a little depending on the shooter and gun. Sometimes by as much as a grain (rifles) or 1/2 grain (pistols) but they’re good, well-known, traditionally accepted “sweet spots.”
Other than that, I’m going to pop some corn and sit back and watch the replies come in along with you and everybody else.

 

Would the more accurate statement be my gun prefers. If I were to take bullets as a like example, often sierra and Hornaday are tested together, back to back and compared. If a guys gun prefers the Hornaday 68 over the sierra 69 does that person say the 68 is an accurate bullet. I'm all about professing ones success, but it would be equally fair to say Bullseye and wadcutters is an accurate combination. I've just not seen in my testing any special powder that I would deem accurate.

 

Well, as with any blanket statement or sweeping generalization, sometimes you just have to consider the source. If the source is, “Some really popular guy on YouTube...” I’d be skeptical.

 

I would suspect the biggest factor here is how well the powder meters.
I can’t imagine there is a whit’s difference for any given powder from the top of the container to the bottom.

 

I had not even considered the question being inferred that way but by any reasonable assessment, it's logical to make that a criteria. This question came from the current green dot discussion, but I don't immage they are discussing its fabulous metering. I shoot and prefer a lot of powders that people hate the metering on because my belief is they are more consistent across the temperature spectrum.

 

Some powders seem to offer easier tuning and wider nodes (greater forgiveness) than others, across a wider span of cartridges, expansion ratios, relative bullet weights, etc. Some powders are just less “spikey” than others, and it can feel like load development is impossible, because picking multiple charge weights will shoot exceptionally small. Varget is an example - the list of cartridges for which Varget is a very reliably small shooting powder is huge, and it offers very stable behavior, often with wide nodes.

As we’ve also discussed recently some powders are less temperature sensitive, and will stay in their groove much better than others - again, Varget is a King in that domain.

Alternatively, some powders take a lot more work to find a sweet spot, and find itty bitty groups. Does that mean they’re absolutely terrible and spray bullets every which way? No. But it does mean I’ll need a little more time in load development, and have a narrower node, and my groups might be 3/4-1moa instead of 1/2-3/4.

But in general, I do agree, most folks which actually know what they’re saying WON’T say something like, “oh I love H335, it’s a super acccurate powder…” Rather, they might say instead, “I have a really small shooting H335 load in my 223, really happy with it.”

 

I knew varget would pop up and based on the wide success by many people in many different cartridges that could easily be accepted as true. I think AR comp and h4350 also have a very strong following.

 

For autopistols I prefer pistol powders that give tight standard deviations and extreme spreads. This is for function reliability. But coincidentally, the 45 ACP pistol powders with the tightest SD's & ES's are also the favorites of 2700 Bullseye shooters. And they are fast: Bullseye pistol powder and Titegroup. This could be a coincidence or an artifact of the reason that pistols with very light loads will malfunction more often with powders with wide velocity spreads.

When it comes to rifles, the long range guys want low ES's and SD's as it shows up in vertical stringing. I was a sling shooter and never saw what the F Class guys are seeing off their bench rests. My F Class buds have powder preferences, but those preferences move back and forth. At one time Varget was a favorite of the 308 class, now I hear H4895 is the leader. For the 6.5 mm crowd it seems H4350 has been the staple for a long time.

With hand held rifles, the human is the limiting factor on accuracy. My accuracy with hunting rifles more or less plateau's in the one to two MOA range at distance. From there, I look for the rifle powder that gives the highest velocity without blowing primers or creating sticky extraction.

And, combinations hit sweet spots, where there should be none.

Why this rifle shot so well with this bullet, and at these powder charges, is a mystery to me. Ten shot groups.







this was above average for ball



this is what I expect for ball







kinda shows that the bullet makes a difference too. Military bullets have lots of weight and I assume, center of gravity variations. So flyers show up.

 

BE will probably be the most common on light target handgun ammo. Or some other fast powder like WST

 

I have to agree with you. Some bullets are just inherently accurate, regardless of caliber.

powder??

Versatile yes. And as someone said, some powders MAY be easier to get an accurate load than others but for me, everything I do is too small of a sample size to make that statement.

In both my .338 and 7 Rem Mag, RL22 significantly outperforms IMR4381. But I wouldn’t say RL22 is an accurate powder, or IMR 4381 isn’t an accurate powder. Some people would say RL22 is too temperature sensitive to be accurate. But I haven’t had that experience.

I recently tried IMR 4381 in my .243. It didn’t shoot as well as other powders. I still wouldn’t say it’s an inaccurate powder, just haven’t gotten it to work for me……yet.

 

My interpretation or definition would be in a powder test when all other components are alike. As in all the same brass, primers, bullets fired thru the same barrel with the only change being the powder to find which one produces the most consistent and accurate group.

But then that only proves which powder is most accurate for that combination.

 

I've never given a lot of thought to this, but this seems most likely to me. I shoot a lot of 308 and have found it to be very easy to find a good load for. Basically, every powder I've tried gave me groups that were acceptable for my needs. My preferred powder choices are based on getting the speed I want and temperature resistance.

I had a 7mm Rem mag for a while and was never able to get a load I liked even after trying several powders. Most of them were not only mediocre accurate but were close to 150 fps slower than what I was looking for. I finally tried Reloder 25 and got the speed I was looking for, but even worse accuracy. I'm sure that if I'd kept experimenting, I would have found what I was looking for, but I have better ways to spend my time and money so that rifle was sold.

And I also had a 300 WSM. I found a very accurate load of H4350 that was pushing a 180 gr bullet to 2950 fps. That made it easier to sell the 7 mag. After reading that others were getting closer to 3050 fps using Reloder 17 I decided to give it a try. I don't recall the exact charge weights, but I was about 2 gr below max and had already reached over 3000 fps. Accuracy was poor. Only 1/2 gr less resulted in the same 2950 fps and accuracy I was getting with H4350. Had I gone to a max book load I'm sure it would have been an overload in my rifle. I decided to just stay with H4350.

 

It is very possible that the belted magnums had very long throats, given the sort of people who buy the things, are looking for maximum velocity, not maximum accuracy.



I have one 270 Win that has a match grade barrel and a match chamber. It shoots very well. My FN Deluxe in 270 Win, with its commercial chamber and throat, shoots looser groups than the rifle with the match chamber. I believe the tighter throat reduces bullet wobble, but, I can push bullets faster in rifles with longer throats before the primers pop. Thems the trade off's. I am certain the more recoil a cartridge produces, the larger the groups will be in a hand held rifle.

It was well known, back in the day, that very accurate ammunition was easy to create inthe 308 Win. With good bullets from 125 grain to 175 grain, if you used IMR 3031, IMR 4895, or IMR 4064, and your rifle did not shoot MOA or less, it was not the fault of the bullet, powder, or rifle.

A 308 Win is a positive pop gun compared to the recoil from the big belted magnum. I can say, this month I took my 300 Win Magnum out, and around shot three, I was squeaking after each shot with 150 grain bullets. And squeaking loudly after shooting 190's. Regardless of the mechanical perfection of your thunderstick, recoil is not conducive to accuracy when a human is pulling the trigger! I quit shooting after 30-35 rounds as all the fun had gone.

Just last week, I got to shoot a Colt 22lr ACE pistol.




This conversion unit was designed to simulate 45 ACP recoil with a 22lr. I told the owner I thought the whole idea was stupid. Firstly, I don't like recoil, and secondly, if you want the pain of a 45 ACP, just fire a standard 22lr, and have a buddy hit you with a canoe paddle after each shot!

 

I agree. I pick the powders I want to use but if they fail. I go to my old faithful.
I should have learned to chase the tortoise instead of the hair. Now I had 30 powders in my cabinet. 3/4 of my rifles use 2 powders. IMR4064 and H1000.
They aren't always the best. But they are easy to find a load with.

 

Or someone on a internet forum with anecdotal information. There are just so many variables involved it would take a whole lot of statistically valid testing to prove one powder is more "accurate" than another,
Just a little butter on my popcorn please.

 

I always thought it was just a component of a potentially accurate cartridge. One that gave the right burn rate and pressure in a particular arrangement to create a harmonious arrangement thereby sending the projectile down range in a consistent stable manor. Like @GeoDudeFlorida mentioned loads like 30-06 and 148 grain Wadcutters are classic and known for their accuracy. I don’t know if any scientific predictor of accuracy. It has always been trial and error for me, there is no one particular pressure range that I shoot for other than below max. So my scientific answer is “magic”!

 

Like mentioned in this thread, some powders shoot a particular combo in a any given firearm better than others.
When I first started loading for my 338-06, I pretty much used IMR4350. It was what I had on hand at the time, and I could get the rifle to shoot 3/4- 1 inch with the Hornady 225s. In Hornadys manual, they mentioned VV N150 as a powder that gave them the most accurate results. I found a pound of it and decided to give it a whirl. In this case, it did turn out to be better, as it shrank the groups to 1/2". I could never get that rifle to do any better with the IMR, and believe me, those results were more than acceptable, but I definitely bought another couple pounds of the N150.
Not too long ago I reformed some cases for that rifle. Seeing Varget on the recipe list and having 8# in the cabinet, I decided to do my fire form with that. Well wouldn't ya know with the consistency I was getting from the mid load, I decided to play around with it a bit. I found it to be right there with the 150 in accuracy. So when the 150 is gone, I'll be switching to Varget.
All firearms are different, and you can have 3, for that matter, 10, of the same exact rifle/handgun. This one will like this combo, that one likes that, and another will like something else entirely. Rocket science can be very interesting and a whole lot of fun

 

If I could make rounds that worked well in every rifle as often as I could make them that fail across the board I'd be a lot happier.