How conistent of a speed for accurate long range?

[Spitz]

I've been working at getting better at long range shooting for a while now. I practice shooting out to 500 yeards but seeing as I live in the desert, would like to try reaching out a little farther.

Big Fin impressed me with his CDS system on his scope and I'm planning on having it added to my VX3.

I've found factory ammo that shoots very well out of my rifle. It's a .300 win mag shooting 180 grain bullets. So . . . I've been out chronographing some rounds. They're all from the same box. 5 shots, here are the numbers:

3140
3149
3180
3080
3090

Is that ok? I was a bit surprised that the there was a change of up to 100 fps but realy don't know if that is to be expected or not. Figured I'd have a few of you smart guys help a brotha out.

 

[174in]

Yea factory ammo is like that the hornady superformance is the most consistant velocity ammo I have found.It may help to make sure you start with a clean gun.You should notice the velocity going up as the barrel gets more fowled.Also try to let the barrel cool down for 10 min in between shots and see if the consistancy gets any better

 

[schmalts]

that is a lot of spread. How long between shots? But all things aside, how is the group? The bullet drop for 100fps shouldn't be that drastic and i would worry more that the group is tight.
You need to start reloading bro.

 

[justdada]

100 fps... yea, you gotta start reloading.
Past 500 that is going to make a real difference.

 

[Spitz]

I am shooting the hornady superperformance and the goup is.75" or less on each 3 shot group. Figure I can't expect much better and would spend a lot of money trying. I tried teaching myself reloading and after reading and reading and trying and trying I determined I was one step short of retarded.

I started with a clean barrel but only waited a couple minutes between each shot. I'll give it another go next week. If I were to order CDS dials, would one want to average the speeds or go with the median?

 

[idnative1948]

Gentlemen, here I have to disagree with you all.
Of course, I am older than 99% of you all. I was always taught that it is hunting, not shooting. And this was from mine and my brother's mentor. The chances of a bad shot from 300+ yds increases. We would rather not take a chance at 300+ and wound an animal instead of a bang flop. Just something that was instilled in us. Be it right or wrong, just how we were taught. Just my thoughts so have at me.

 

[schmalts]

Gentlemen, here I have to disagree with you all.
Of course, I am older than 99% of you all. I was always taught that it is hunting, not shooting. And this was from mine and my brother's mentor. The chances of a bad shot from 300+ yds increases. We would rather not take a chance at 300+ and wound an animal instead of a bang flop. Just something that was instilled in us. Be it right or wrong, just how we were taught. Just my thoughts so have at me.

If your not a good shot or do not practice at longer range your thoughts are good in my book. But no matter what happens at the end of the day he still has to shoot, beit 100 or 500yrds he is doing the right thing and making sure his equipment and skills are up to the task.

 

[174in]

I am shooting the hornady superperformance and the goup is.75" or less on each 3 shot group. Figure I can't expect much better and would spend a lot of money trying. I tried teaching myself reloading and after reading and reading and trying and trying I determined I was one step short of retarded.

I started with a clean barrel but only waited a couple minutes between each shot. I'll give it another go next week. If I were to order CDS dials, would one want to average the speeds or go with the median?

Wow I am suprised that you had that much diferance in velocity with that ammo,but I belive you.If it was me I would try a box of the fed premium with a simalr bullet and see how that work for accuracy and consistantcy if not I would just average the speeds.sounds like you are getting good groups.keep us up to date on your results.

 

[174in]

How good of groups are you getting at 500yds?

 

[Carl]

How far do you want to shoot Spitz? 100 fps spread should only cause ~3" of vertical at 500, with your load. Not great, but workable. At 700, it's more like 7", which is getting to be too much for my taste. And if you get a CDS built with that data, use the middle of the spread (3130 for you).

100 fps extreme spreads aren't ideal, but happen often enough. Unless you're getting a good deal on factory ammo, if you start shooting much you'll want to check out reloading anyways.

 

[thecrittergitter]

based on what i've experienced myself and more so beign around some very experienced long range shooters, 20 fps difference is ok, 50 is about max that you really want to be. That being said, most of that is based on shooting 1000 yards.

Your best bet is to not worry about those velocities at this point. You should go out, set up a target at 500 yards. if your shooting under 5" group, your wasting your time checking velocities At least if your going to keep it around 500 yard max.

I'm a fanatic about trying to get it all perfect too, and find most of it is a waste of time. Most of the animals that i have hit 4" off the mark are still dead as a doornail

 

[wgiles]

Always question things. First off, is your chronometer giving you good readings? If you are getting good groups, don't worry too much about the velocity spread. I only use my chronometer when I'm working up loads, but when I get consistent velocities, I usually get good groups.

 

[Drake4]

I'd do what Critter suggested. Shoot it at 500 and see what happens. If you are under 5" then leave it alone (if that is as far as you want to shoot). 100fps is pretty extreme over 400-500 yards.

Just curious...were those velocity readings in order? If so, I would guess that you are losing velocity with a fouled barrel. Every barrel is different though. Could be your chrony too....most are only accurate to +/- 2%. That is a spread of 120fps @ 3000fps.

It's fun isn't it!

 

[gundog]

An extreme spread of 120 fps is not unusual for run of the mill of the shelf ammo. If you buy the cheaper ammo you'll typically find extreme spreads of 100 fps or considerably more.

 

[Spitz]

Thanks for the thoughts guys. I've got the next few months to keep tinkering. The barrel was clean before the first shot. I'd probably question the accuracy of the chronometer as much as everything else when it really comes down to it. I don't know much about them and I don't think my buddy spent much on this one.

Going to head out sometime in the next couple weeks when there's no wind to shoot some groups at 400 and 500. I'll let you know how things are looking.

 

[174in]

sounds good that will be interesting to here how it goes. Maybee you will have a chance to try a different chrono too.

 

[gundog]

To get good results from any chrono you've got to set it up correctly. It's got to be mounted rock solid. Typical tripods are too flimsy and create poor readings. A good surveyor's tripod will provide good stability.
Futher, the chrono must be perfectly level and the gun barrel needs to be level to the chrono. Any angle to the shot will add about a 10fps error in the reading. Sunlight from above can also kill an accurate reading. The chrono needs to be shaded as much as possible. Since your in the desert shooting over sand, the light bounce off the sand can produce errors. A dark towel placed under the chrono will stop the bounce. Try shooting through two chronos and compare readings.

As others have said, if you want to be accurate beyond 400 yds. you really need to handload. A good handloader should be able to hold extreme spread to around 20 fps provided the gun has a good bore and chamber.