velocity vs accuracy

pete evans

Well-Known Member
just working up a load for my 270. imr 4831 and Sierra 130 pro hunter. first group was the tightest at about 7mm which is more than accurate enough for my needs. it was 53 grains of 4831 so towards the lighter end of the range. I forgot to take my chrony so unsure of velocity. I'm going to load up some more and re shoot with chrony. just thinking if the velocity is low do i get a faster loading and mess about with seating depths or do I just say accuracy trumps speed and leave it as it is.
 

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caorach

Well-Known Member
Statistically your groups probably don't mean much - i.e. if you shot those same loads at the same targets such that you'd 100 rounds in each target then it may be all the groups would be exactly the same size.

However, my bet is that if you shot the "slow" load at a deer the bullet would probably exit and so it has more energy than it needs anyhow. Given that I'd go with whatever you have confidence in and if the small group helps (and I've gone down the same road myself despite knowing it was pretty much a house built on sand) with the confidence they go for it and don't worry about the velocity.
 

pete evans

Well-Known Member
yes one group means very little, i agree. I'll probably redo and go for something that falls in the middle of a group range of acceptable groups. I generally don't reload for pleasure so not too fussed about chasing the ultimate.
 

mallettn

Well-Known Member
I agree that all the groups look good so there isn't any real evidence that going hotter is leading to a deterioration. There is no need to do more development, but I think you could probably get a faster load that groups as well with a bit more time and the .270 is meant to be a fast flat shooting calibre. Agree you need to take the chrony next time!
 

8x57

Distinguished Member
just working up a load for my 270. imr 4831 and Sierra 130 pro hunter. first group was the tightest at about 7mm which is more than accurate enough for my needs. it was 53 grains of 4831 so towards the lighter end of the range. I forgot to take my chrony so unsure of velocity. I'm going to load up some more and re shoot with chrony. just thinking if the velocity is low do i get a faster loading and mess about with seating depths or do I just say accuracy trumps speed and leave it as it is.
One is no good without the other. As with most things in life it's all a matter of balance. What you are looking for is a load with sufficient accuracy and velocity to do the job.
Set your parameters of what you are looking for and aim to match these and don't go looking for some super duper velocity or superb accuracy at the cost of he other.
 

CarlW

Well-Known Member
Velocity is vanity; accuracy is sanity. Didn't someone clever on here say that at some point? Probably @Woodsmoke or some other pedant...:p

Anyway, despite this, I do care about velocity (maybe I have got a small winkle or something).

I therefore tend to set myself a minimum velocity with which I am happy, then start chasing accuracy properly once I have passed that velocity threshold (obviously, with pressure and safety as my first priority).

Kind regards,,

Carl
 

Woodsmoke

Well-Known Member
Velocity is vanity; accuracy is sanity. Didn't someone clever on here say that at some point? Probably @Woodsmoke or some other pedant...:p
Don't think it was me, but it sounds like something I'd say. I'm very wise :lol::lol::lol:

Try doing groups at 300 yrds on a still day, all with same point of aim.
I use a very similar load the one the OP describes, but with H4831 and 54 grains. It groups well enough at 280 to shatter a standard clay pigeon time and again. Not entirely sure what the velocity is, but I'd hazard an estimate that it's around the 2800fps mark
 

8x57

Distinguished Member
I therefore tend to set myself a minimum velocity with which I am happy, then start chasing accuracy properly once I have passed that velocity threshold (obviously, with pressure and safety as my first priority).

Kind regards,,

Carl
:thumb::thumb::thumb:
 

bobjs

Well-Known Member
Accuracy with a lower powder content will always win for me, I have NEVER run any rifle on hot loads,

the day a fox or target out runs my ammo I will pack it in,

bob.
 

Flash

Well-Known Member
Velocity is important but id always go eith accuracy
As long as your projectile has ample energy to dispacth its target at range and msjes for sn ethical kill
 

MACKY

Well-Known Member
I shoot a .20 VT and I can get it going at just under 3750fps using 17.5gr of N-120 but it's only giving me about 1" at 100m.
Quite quick for a little round but if I use 18.5gr of N-130 I'm getting 3550fps but this will get me 1/2" or less using 32gr V-max.
So not always about how fast you can get it going. Accuracy always wins for me.

John
 
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Heym SR20

Well-Known Member
Accuracy is always useful. But you need to consider what the target is and choice of bullet and energy at target.

First Accuracy. In normal hunting ranges 1” is more than good enough for most purposes. To use an extreme example - a solid target bullet at 2,000 FPS May give a .25” Group. Whilst accurate, would useless for deer stalking. Much better to should a well constructed expanding bullet at say 2,800 FPS that gives a1.5” group.

For my 7*65r I have loaded up the biggest bullets I can use and loaded faster than the best group. These are 173gn H Mantles at 2650 and I am using them on driven boar. I want penetration and killing power on big tough animals at 50 yards and every bit of extra weight and velocity helps. I am not worried about trying to shoot a fox at 300 so accuracy is secondary.

When working up this load I did a test from starting load upwards and shot them all to the same point of aim. They all went into a 2” group,so simply 50gr of IMR 4350 and loaded them up. Not supper accurate. But two from top barrel and two from bottom go into an 1”
 

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Muir

Well-Known Member
I'm guessing tht you are tickled to death with the grouping of your rifle and don't want to risk changing anything that will break the magic spell. My data shows you are just under 2700 fps for that bullet. If that will suit your needs then don't change the powder charge. It will certainly kill deer because I am using a 123 grain 6.5 bullet at 2450 fps and killing deer with it, handily. Your choice. Upping the charge a bit can't hurt much and Pro Hunters, in general, don't seem to mind throttling up.~Muir
 

captdavid

Well-Known Member
Both, to a point, my 60+ yo FNs are in 7x57 and 30-06 are on the low saami pressure side. I start three grains below max and work up using three shot groups. then I repeat myself. which ever is the best group, I play with a little 1/4 below and above. which ever is the bes,t, as long as the group is acceptable, the speed should be no more than 100fps lower than factory specs, I stop there. In my case, both shoot 1.25" groups @ 100yds. Same thing with my semi-custom 280 produced .90 groups. capt david
 

PKL

Well-Known Member
I've found with almost all reloads as a general rule...seat bullet 1 caliber deep and load to 96% of max recommended with the best performing propellant tested, and you'll have the best outcome in terms of velocity to grouping..at least, in 99.9% of circumstances it has always held true for me... it also saves a million hours or work and £££'s in testing...a blimming ballache of epic proportions....which is why I'm very much starting to just bite the bullet (no pun intended) and buy good Norma factory ammo despite of costs.
 

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