BULLET VELOCITY

[banus02]

hi all just hoping for some good advice,trying to go longer range but am pi..ing in the wind as I do not know the velocity of my rounds,they are,.223rem,cz 527 varmint,24inch barrel 1in9 twist 53gr vmax loaded with 24.2grs n133.col 2260 and rem 7.5 primer.i was hoping one of you technical chaps would/could run this in a ballistic calculator for me,thank you

[Scotch_egg]

Seriously buy or get access to a chronograph.

 

Crap in = Crap out

[Missed]

I would agree. The money spent on a chrono will be saved many times over, especially when working on loads.

[gbal]

Hi Banus-While it is true that a good chronometer is very useful-velocity is a good guide to pressure,which is otherwise very hard to measure-and helpful in fine tuning loads,not everyone can readily afford one-the one to consider is the magneto,for accuracy and sheer ease of use in allconditions.However,what you can do is use manufacturers published data-a relaoding manual,maybe,but these are often biased to US powders.Not so Vihtavuori's.But it's all on the net-google vihtavuori 133 eg,and you will access this:

 

52g sierra V133 22.5 g 3110 fps; 25g 3389 fps (lo/hi recommendations). 55g 24.1 gives 3215 fps

 

With just a little care you can extrapolate-your 24.2 is certainly well within the recommended window,and is probably giving about 3200 fps(it's not quite pro rata,as increasing powder does not give equally increasing fps,but you have a ball park,and could nudge up carefully,if you want to try.

(the 'need for speed' is overdone,as it does not neccessarily lead to more accuracy-hence 'nodes'-powder/velocity points that give best accuracy,and for all normal purposes ,going over the recommended maximum loadings ,is just an exercise in pressure and barrel wear.The gains in performance are rather small- it might trim a 52g 3400 fps (200zero) drop/drift at 400y to 21.2/23.6 inches,compared to a quite moderate 52@ 3250 giving 23.5/24.8 -and even less 'gain' at 300-and in any case all such shots are going to need accurate dialing in...so difference is another 2 clicks....

A good ballistic program will help,so long as accurate data for your rifle load goes in-and the chron is needed here,really,but it's easy enough to get the ball park effects as above ,from sources like Accurate shooter etc-and judge for yourself just what gains if any might be squeezed out. Better by far an more accurate load,for most purposes.(1000y with most shootable cartridges needs every fps you can get,and no,the 223 isn't the tool-but there the issues ( bullet goes transonic)are quite different from eg fox shooting at much shorter range,or targets to 600 or so.

Sorry to go on a bit,but not everyone can buy all the kit ideally helpful,and not everyone needs to,at least initially. For most,the evidence is the holes in the paper,not what the chrono says-given that you have a good idea of what fps that load is doing in your rifle,and there are no pressure signs-which are very unlikely within the manufacturers published data.

What you really need is a good backstop that allows you to see bullet splash,and a good reading of the wind (see figures above).Velocity nibbles at that,within a cartridge,but nothing is flat,and nothing bucks the wind completely. I'd have a laser rangefinder and a wind measure before a chrono,for most field shooting,but the chrono for target load development-sighters do the 'need to adjust' bit!

Good shooting.

Gbal

[banus02]

THANK YOU ,for all your replies.i am very fortunate to have had a reply from rabbit fingers with the offer to try his chronograph and hopefully this will take away the velocity questions and so will give me one less thing to worry about.much more to longer range< past 200 yards>shooting than point and shoot.have a lot to learn but recieveing great help on this site,again thank you all.

[banus02]

THANK YOU ,for all your replies.i am very fortunate to have had a reply from rabbit fingers with the offer to try his chronograph and hopefully this will take away the velocity questions and so will give me one less thing to worry about.much more to longer range< past 200 yards>shooting than point and shoot.have a lot to learn but recieveing great help on this site,again thank you all.

[gbal]

THANK YOU ,for all your replies.i am very fortunate to have had a reply from rabbit fingers with the offer to try his chronograph and hopefully this will take away the velocity questions and so will give me one less thing to worry about.much more to longer range< past 200 yards>shooting than point and shoot.have a lot to learn but recieveing great help on this site,again thank you all.

Good-use of a chrono will help-at least it will sort out your optimum velocity/accuracy trade off.

For 'point and shoot'-ie very limited/no time to adjust scopes,you are in a =/- 2 inches ball park for eg fox.(4 inch fatal hit zone-stretch it to six if you like,doesn't really change things that much...)

Your guide drop figures are (52g) /200 zero in inches are : (at 100,200,300,400 yards are:

 

3250 fps +1.5 0 -7.5 -23.5

3400 +1.3 0 -6.8 -21.2

 

so a 250 zero might bring the 300y closer to "p@s" but you need a little hold over,whatever zero is used.

Just for comparison,here's what a really hot 22 might give (NOT a 223 rem- a 223 WSSM:

 

52@ 4000fps +.7 0 -4.4 -13.6 ,so still not into "p and s" at 300y. (a 243 55g @ 3950 would be very similar),but note you need 4000 fps to keep your 300 drop (200 zero) within 4",unless you have a 250 zero.... and 10 mph wind is too much...8 inches at 300 at ,though 3.5 at 300- might be manageable,and 5mph-half-should be).

 

So velocity is not THE answer-as I suggested,it nibbles at drop/drift,but even 600fps more won't deliver 'p&s' beyond 300y,and you won't get anywhere near that in a 223rem,as you know-it's a reality check to look at the data!

But by all means get what you can,safely-and don't fret over what is unobtainable!

Gbal