FPS with 20" Barrel

[steveff1353 7]

Hi all

 

Can anyone tell me what FPS i'm getting with the following load:

 

56.8gr Varget - 65gr Hornaday V-max

 

Tikka t3 .243 with 20" Barrel

 

Also where i can find out this kind of information without having to buy a chronograph

 

Thanks All

 

Steve

[SNAP SHOT 194]

Simply put mate you cant really find out he info unless you buy a chrony...

 

for the small investment they are they give a wealth of information.....

 

i'd strongly recommend one even just for doing drop charts at extended ranges....

 

they also can tell how consistant your loads are,

 

 

ATB.

 

 

Snap.

[Mr_Logic 5]

Echo 100%.

[HUnter_zero 58]

Hi all

 

Can anyone tell me what FPS i'm getting with the following load:

 

56.8gr Varget - 65gr Hornaday V-max

 

Tikka t3 .243 with 20" Barrel

 

Also where i can find out this kind of information without having to buy a chronograph

 

Thanks All

 

Steve

 

Steve, it's going to be around 4468 +/- 10% fps BUT will also be high pressure at around 857 bar (taken on a COAL of 2.680"). 56.8grains will give a compressed charge of 35% are you sure your numbers are correct?You can not get 100% accurate MV unless you spend £1000's on a top notch chronograph. The cheaper ones have an error of +/- 5% IIRC. You can obtain a mathematical model of your load using "Quick load" which is surprisingly very accurate.

 

John

Edited September 29, 2009 by HUnter_zero

[Spangle 0]

Can you get 56.8gr of Varget in a .243 case?

[steveff1353 7]

Hi all

 

Can anyone tell me what FPS i'm getting with the following load:

 

56.8gr Varget - 65gr Hornaday V-max

 

Tikka t3 .243 with 20" Barrel

 

Also where i can find out this kind of information without having to buy a chronograph

 

Thanks All

 

Steve

 

Steve, it's going to be around 4468 +/- 10% fps BUT will also be high pressure at around 857 bar (taken on a COAL of 2.680"). 56.8grains will give a compressed charge of 35% are you sure your numbers are correct?You can not get 100% accurate MV unless you spend £1000's on a top notch chronograph. The cheaper ones have an error of +/- 5% IIRC. You can obtain a mathematical model of your load using "Quick load" which is surprisingly very accurate.

 

John

 

Oops, sorry all, not 56.8 it should have been 46.8gr.

[steveff1353 7]

Can you get 56.8gr of Varget in a .243 case?

 

No you cant mate, my mistake. should read 46.8gr.

[SNAP SHOT 194]

even if you the right loading, different components such as brass, primer, seating depth, will vary the velocity,

 

you are still over the max loading too, So if you want trouble, keep on doing what your doing....!!!!

 

get someone to show you the ropes mate....

 

 

ATB

 

 

Snap.

[steveff1353 7]

even if you the right loading, different components such as brass, primer, seating depth, will vary the velocity,

 

you are still over the max loading too, So if you want trouble, keep on doing what your doing....!!!!

 

get someone to show you the ropes mate....

 

 

ATB

 

 

Snap.

 

Right Ok. Lets see if i can get it right this time:

 

.243

22" barrel

Varget powder 36.8gr (way less than the max in the Hornaday Manual)

Lapua Brass

Hornaday 65gr V-Max

Federal Primers

COL 2.250 measured to ogive (working on 2.210 after shooting various groups)

 

Apologies for the mistakes guys, less haste, more speed springs to mind!!

 

Thanks

[SNAP SHOT 194]

Can you get 56.8gr of Varget in a .243 case?

 

No you cant mate, my mistake. should read 46.8gr.

 

 

 

 

[SNAP SHOT 194]

Right now that i'm outta bed and fed,

 

looking at the spec you give, for a 24 inch barrel in .243 shooting 65g, your looking at a velocity of around 3200- 3300 fps

 

now seeing as you have a 20 inch barrel you can knock off about 30 to 50 fps per inch loss,

 

so in theory you should be getting around 3000 to 3100 fps, IN THEORY,

 

but the only way you will ever tell is to shoot a 10 round string through a chronograph.... to get the average velocity...

 

 

i'd say you'd be on the lower limits of 3000 fps personally......

 

hope this helps you out.

 

Snap.

[steveff1353 7]

Right now that i'm outta bed and fed,

 

looking at the spec you give, for a 24 inch barrel in .243 shooting 65g, your looking at a velocity of around 3200- 3300 fps

 

now seeing as you have a 20 inch barrel you can knock off about 30 to 50 fps per inch loss,

 

so in theory you should be getting around 3000 to 3100 fps, IN THEORY,

 

but the only way you will ever tell is to shoot a 10 round string through a chronograph.... to get the average velocity...

 

 

i'd say you'd be on the lower limits of 3000 fps personally......

 

hope this helps you out.

 

Snap.

 

Thanks for that mate appreciate it.

[SNAP SHOT 194]

No worries mate.....

 

 

if you could get a chrony to fire 10 rounds through it would be intresting to see the Actual velocity achieved....

 

 

Snap.

[HUnter_zero 58]

Right Ok. Lets see if i can get it right this time:

 

.243

22" barrel

Varget powder 36.8gr (way less than the max in the Hornaday Manual)

Lapua Brass

Hornaday 65gr V-Max

Federal Primers

COL 2.250 measured to ogive (working on 2.210 after shooting various groups)

 

Apologies for the mistakes guys, less haste, more speed springs to mind!!

 

Thanks

 

That would be a very light load producing about 3000 fps.

Steve, you seem to be just guessing at what you are doing? Very dangerous indeed, get your self a good reloading manual.

 

John