Accuracy vs Velocity vs Bullet deceleration

M

Metal god

New member
The other day I was at the range and the know it all SRO was telling guys in my group that the higher the velocity the less accurate the round "PERIOD" He was not putting any caveats on anything . He kept saying it's been proven a slower velocity bullet will ALWAYS be more accurate . I knew there were so many things wrong with his statements but he is the type that talks louder when you disagree or moves on to some other thing that although is or could be correct he uses it as a blanket statement and that then makes what he was saying incorrect .

When he did listen he would add something to the equation that was never in the discussion in order to help his point . Like one of the things I said was that more velocity helps with is wind drift . If you have less wind drift the bullet can be shot more accurately . He then would say no because "IF" you have a heavier bullet ---NO NO NO I stopped him right there and told him you don't get to add things to this equation . We are talking about wind drift and velocity . . Same bullet same rifle same wind same everything but one bullet is traveling 1000fps faster then the other . Your telling me the bullet traveling slower will have less wind drift and be more accurate . He says yes because it has to do with what bullet decelerates more by % of it's max velocity .

That's when He lost me and quickly moved to asking me what bullet I was using to shoot at are 300yd max range . I told him 175gr smk . He then went on a 5 min rant on how I was waisting my time shooting boat tailed bullets at 300yds and less . Although I do understand that the BT bullet shines best at longer distances . It's not a waist of time to use them at 2 and 3 hundred yards . The 168gr smk has a boat tail and was designed to shoot 300yds . It's to bad Sierra did not have this guy working for them before they waisted all that time making and selling the 168gr MK .

I was getting more upset by each sentence this guy spoke . Not because he was 100% wrong but because he was not clarifying his point and stating these things as fact blanket statements . The people I brought with me were hanging on his every word and I had to explain later to them how half of what he was saying was not accurate . That took much more time and detail then I think any of them was ready to hear or take in .

I think I finally get what some of you meant when you said that you don't like people coming up and telling you how to do things or what works best . :mad: Not so much for me because I knew what he meant but having to explain what he was saying was only half true at best to people that were not ready for that much info was a pain .

end rant :rolleyes:

Question . is a slower bullet always more accurate ??

Is shooting a BT bullet at 300yds or less a waist of time ?? Oh the best part , I asked if my BT smk were useless what was the best short range match bullet to use . ??? His answer in a snotty way , I don't know
 
Last edited:
In a stable atmosphere, slow bullets are as accurate as fast ones. Their drift is the same for each shot. They have the same accuracy in a constant speed crosswind, too. Only in a changing crosswind is the faster one more accurate because it drifts less per yard of flight for each mph change in wind.

Benchresters get a couple hundredths MOA better accuracy up to 200 yards with handmade flat based bullets. At 300 yards, it's a tie. Past 300 yards the advantage goes to boattails.

Unless you have the rifle and ammo to see the difference, forget about it.

Meanwhile, ask that dude to explain how Sierra got their 30 caliber boattail HPMK's to shoot in the ones (under 2/10 inch) and often in the zeros (under 1/10 inch) in their 100 yard range in California.
 
Last edited:
What about SD . If you have the same type of bullets one traveling at 3500fps and the other at 2500fps but both have the same SD of 100fps . Id think the faster bullet would have less vertical stringing ( if thats the right term ) then the slower velocity bullet , especially at longer ranges . I'd also think that would make the higher velocity bullet more accurate .

Thanks for clarifying the wind must be changing down range for the higher velocity bullet to be more accurate . I did know this but was not thinking clearly on the matter .
 
Question . is a slower bullet always more accurate ??
Click to expand...

Answer - No.

Different rifles have different optimal accuracy loads for a given combination of bullet, powder, case, primer, seating depth etc. The probability that the lowest minimum load would be the most accurate is way lower than it would not be.

The statement 'slower is always more accurate' is a bit nonsensical in itself. Slower to what minimum velocity? If that was the case, target shooters would aim to find loads that would barely have the bullet reach the target, since that would be the 'slowest bullet' at that given distance...

Is shooting a BT bullet at 300yds or less a waist of time ??
Click to expand...

Answer - If they shoot well in your rifle, then no.
 
Last edited:
Unless having to listen to the RSO is a requirement, other than for range safety reasons, I would politely tell him to bother someone else since I came to the range to shoot and not listen to him. Life is too short to waste time on people like that.
 
Metal God said:
end rant
Click to expand...

Simply put, a lot of folks are long on opinion and short on facts. This is the case with your guy.

Clueless and proud of it.

In his case, it's better to open his mouth and remove all doubt than to be silent and thought a fool.

Most of us would generally rather the opposite.;)
 
If the guy had some State, Regional, National Championship wins, he might have some credibility.

Till then, it is just another case of "too incompetent to know he is incompetent".
 
Most of the time when people make statements like this there is an element of truth to it. I think that is the case here. Slower loads are USUALLY a bit more accurate than loads right at max. And BT bullets don't really start to show any measurable advantage until they are used at longer ranges. I sure wouldn't call them a waste of time at closer ranges. It is better I think to have a load suitable for long range, and use it at closer ranges, than have to develop 2 different loads. One for short range and another for long range.

They say that a little knowledge can be a dangerous thing. Without being there it is hard to say if this guy knew just enough to be a jerk or not.
 
Quite a few times over the last forty or fifty years, I've read claims that best accuracy comes from loads about a grain or so under max. I've never tested that. However, the velocity difference between book max and one grain under wouldn't seem to me to be worth talking about.

I figure the deal has more to do with harmonics than velocity. But that's just a guess.
 
What some of you last posters have said is my point . He was not using any caveats or ifs of any sort . It was , slower velocity is more accurate every time . BT is a waist , period at this range

If he had said , Max pressure loads and highest velocity loads tend not to be your most accurate . I'd say your right . He never explained what he was saying . I agree he was speaking some truth but the fact he did not clarify or expand on his comments . That made what he was saying wrong . In some ways it was funny because he was saying so much stuff I knew was not right my head was being over whelmed by my own thoughts I had a hard time coming up with a rebuttal

One of the people I was with was my dad . My dad comes over and says , That guy said this , that and the other thing . :rolleyes: I say , well he's wrong because of this , that and these other things . My dad :confused: I'm just telling you what he said . Me :( I know but --- aahhh here he comes to chime in because he heard me say he was wrong . Thats when he said so many inaccurate things he confused me :o .

Slower is ALWAYS more accurate :rolleyes: Ok I'll take that Marlin 30-30 over there instead of the 308 scout .
 
Last edited:
Sub-sonic rounds tend to be more accurate for some cartridges out of some guns.

That's the only "slower is better" statement I think it is safe to make.
 
Quite often, accuracy loads are a few grains lower than the max powder charge, using the same components. Considerably smaller charges than that may again not shoot as well as the accuracy load, due to poorer ignition, resulting from inadequate load density.

Some powders are more tolerant of light loads than others...IMR 4895 for one.

For hunting, it's really great when your top load happens to be your most accurate with a particular bullet and powder. I have one for my .270 Win, using 130 grain bullets and Reloder 22 that produces 3,250+ fps on my chronograph. I use magnum primers in that load, for better cold weather ignition.
 
Now I do not agree with this guy, but in all my rifles I do find that they do shoot more accurate at mid range speeds as compared to max. For wind drift and such the faster bullet will drift less,but that is mearley a adjustment on the scope to correct. Also as another posted stated, It has a lot to do with the bullet you are shooting. As for boattails at less than 300 yards?? I shoot 168 and 175 SMK's all the time and from 100 to 1000 yards they seem to work good for me.
 
Only thing he said that made a bit of sense is about the boattail bullets, but I've always read it's more like 200 yards where flat-base bullets cease to be more accurate. No practical experience as all our shooting is long range so we never use them.

The rest is garbage as everyone's said. In practical experience, ours is that max load is not usually best accuracy- although last weekend we appear to have found the exception working up a new .260.

I think your RSO needs to spend more time driving a rifle and less time telling everyone else how to do it. He might learn something.
 
I've always been amused by this notion that accuracy loads are "quite often" or "usually" below max loads, as if it's some sort of physical property.

For one, "max loads" are an arbitrary designation submitted by the cartridges designer and approved as by SAAMI if the cartridge is submitted for their voluntary standards. It has little to do with any true design limits. Some cartridges are rated ABOVE the real brass design limit and will cause loose primer pockets at SAAMI max loads. Other times, you've got 4 or 5 or 6 cartridges all designed on the same case (.338Fed, .308Win, 7-08, .260Rem, .243Win, .243AI et al) that all have different max pressures.

Here's the thing. The most accurate load being below max depends on one simple thing, that is, if we ignore the biggest problems in the system which is whether or not the shooter, gun, bullets, etc are even capable of telling "most accurate"... it's statistics.

"Max load" is only one point on the line.

If we assume a 10% reduced starting load and load increments of 1%, which is fairly typical, there's a 90% chance that the "most accurate" load will be at less than max... because there are 10 loads and only one is "max". If we assume a theoretical increment of 0.1gr, for illustrative purposes, a cartridge like the .243Win will have 4.5-5.0gr span between starting and max. That's as many as 50 increments... only one of which is max. All else being equal, there's a 2% chance that max load will be "most accurate".

This has nothing to do with any physical property or condition that exists that makes max loads inherently less accurate. It's simply a matter of chance.

This entirely leaves out the fact that published "max loads" are very often no where near true Maximum Average Pressure in a commercial rifle. Testing for official data is almost always done in SAAMI minimum chambers and real guns are almost always made near SAAMI max chamber dimensions. That means our theoretical "max" is only max in our minds.... but we have no way of telling, unless we have a certain expertise and some expensive equipment, which eliminates 99.9% of us.
 
If you're shooting someone else's bullets(you didn't make them)......then you're a bottom feeder.And am not saying that the least bit "ugly".Think about it.....and "it" can be bullets,barrels,stocks,etc,etc.You are simply at the end of the supply chain.

Because most of us fit into the above category,we "manage"......so making patent statements that this bullet likes "X" amt. of pressure...or "this" barrel"...or "this" anything,loses something because there's no way it can take in all the variables.

Get a solid,fr/rr rest.....snag a chrono...and start testing.Nothing new under the Sun.For the fortunate few(although casting cut's to the chase pretty durn quick).....we'll obsess over making what we can,and manage(bttm feed)what we don't.
 
Brian- I think what is trying to be said is.
Say Min FPS is 2800 and Max is 3500, Somewhere in that 3000 to 3200 is where most are finding the accuracy node. For me anyhow I find it a upper side of middle line. If that makes any sence. I did try to push my 308 when I took it out to 1-Mile. I can tell you a 308 is not a One Mile rifle. Failed bad for me any how. Best I could get from a 24 inch barrel and 175 SMK's was 2790's. Accuracy was very spotty at that speed. I did drop it to 2640's and she will hold Quarter size groups at 300 yards. I am sure lot's of people get accuracy at high speeds,but it seems most go for mid range and do very well there.

I do need to say- I know min and max FPS is a hard one to put a number on since all loads can be loaded down,but I am refering to just your normal min ,max loads.
 
Wind deflection is a consideration when discussing accuracy. The amount of deflection is tied to velocity, but also to loss in velocity over the distance shot. Bullets with a higher BC lose velocity a slower rate than those with lower BC, so tend to deflect less in the wind.

We're constantly trading factors among various caliber, cartridge, velocity, bullet weight, and grouping ability when it comes to hunting/varmint cartridges. Light bullets pushed to very high velocities give dramatic explosive effects, but are not necessarily as stable in the wind. Heavier bullets may provide greater energy at longer ranges and on larger game, but drop is greater, especially within the first few hundred yards because velocity is not as high.

For hunting cartridges, I tend to pick the flatter-shooting loads that have sufficient energy to kill the game I hunt...within the longest range that is reasonable for me to shoot from a decent rest under reasonable atmospheric conditions. Life used to be simpler when I only owned a .30-06. Today, I choose an appropriate cartridge for my hunting based on game/varmint, max range, proximity to the house, etc....from the following: .22LR, .22 WMR, .223 Rem (2); .243 Win (2), and .270 Win. (The .223 Rem LV tends to be chosen more than the others, because it's a newer rifle and the cartridge works for varmint types/distances around here.) Most shots have been under 300 yards. Bullets weighing 50-53 grains seem to work well, so far.
 
4runnerman said:
Brian- I think what is trying to be said is.

Say Min FPS is 2800 and Max is 3500, Somewhere in that 3000 to 3200 is where most are finding the accuracy node. For me anyhow I find it a upper side of middle line. If that makes any sence. I did try to push my 308 when I took it out to 1-Mile. I can tell you a 308 is not a One Mile rifle. Failed bad for me any how. Best I could get from a 24 inch barrel and 175 SMK's was 2790's. Accuracy was very spotty at that speed. I did drop it to 2640's and she will hold Quarter size groups at 300 yards. I am sure lot's of people get accuracy at high speeds,but it seems most go for mid range and do very well there.



I do need to say- I know min and max FPS is a hard one to put a number on since all loads can be loaded down,but I am refering to just your normal min ,max loads.
Click to expand...


Doesn't matter if you're talking PSI or FPS. "Max" is a singular data point with 9 or more points below it. At best, it's a 10% chance of being most accurate.

For several reasons, I simply don't believe the whole premise.

1)The whole statistics thing I just explained.

2)There are too many variables. A load that's most accurate in a 24" barrel should not be most accurate in a 26, 28, 30, etc inch barrel nor from one chamber size, brass capacity, brass hardness, bore diameter, etc to the next.

3)Most shooters are the weakest link in the system and few shoot statistically valid sample sizes. They could pick "most accurate" loads with a higher probability by rolling dice.

4)When I read what's written by winning competition shooters in disciplines that allow for fully custom loads, I see many of them running HOT loads, well above SAAMI max in most cases. They use custom barrels, typically with tight chambers and loads beyond anything published.

5)I have never found it to be true in any of my guns. As I've said before, I almost never even bother LOOKING for an "accuracy load" because I can't tell the difference in group sizes in a typical work up. 3 (or 5) shot groups are statistically invalid. I'm not going to shoot 30 shots at each of 10 different increments to figure out which one is 0.1MOA better than the other 9. If someone eliminates a potential load based on the outcome of a 3 (or 5) shot group and then picks 2 or 3 "potential" accuracy loads based on the outcome of other 3 (or 5) shot groups, they'd have just as much success simply writing down the charge weights and eliminating them with dice rolls.
 
Very true Brian. Barrel length will make a difference. I have to voice on your 3 to 5 shot group though. To me it is ( and always has been ) more than enough to judge a load work up by. I do the normal step ladder test. I find my best load, Make a few changes here and there one at a time. Tweak it so to say and I am done. That load is accurate every time I go out to the range whether I shoot 5 or 50 rounds. If you shoot a 5 shot group and all 5 make 1 hole,If next time out they do not,That is the shooters fault. Now temp will play into this very much.
The shooters that run max loads or over, I think if you look deeper,the only ones that do that a Bench Rest shooters. Which is true,but the F-Class open and FTR Class,very seldom if ever do that. Im sorry that those are the only 3 classes I know anything about,so - Again you might be right,Just saying.
When I retest loads for the first time after work up and tweaks. I will take a 4 ft by 2 ft target. I place 20 - 1/2 inch dots on target going straight across the target . One shot at each dot. When all 20 are inside that dot I am done.
Maybe my loads are not upper mid range?.
all rifles are 24 " barrels

223- 25.5 Varget-60 gn bullet
243-38.3 4064-87 gn bllet
308-42.3-RL-15- 175 gn bullet
6MMBR-28.6 Varget-107 gn bullet

All those loads shoot way under sub MOA.
 
You must log in or register to reply here.
Back
Top