FT/LBS data for shortened rifles required please

[reelme]

Hello all i don't have a chrono yet so I was wondering if anyone out there might be able to help?
my 243 has a 17 1/2" barrel and shoots 65gr vmax with 40gr varget and 90gr speer hot-cor with 34gr Rel15
my .223 has a 14 1/2 barrel and shoots 55gr vmax with 25gr of varget
my 308 has a 18 1/2 barrel and shoots 125gr nosler bt with 47 gr varget and hornady 130 sp with 44gr of h4895
all these loads shoot excellent but as i don't have a chrono or ballistics data chart(yet!! i'm on the vino at the minute so they might be purchased after a couple more glasses) could anyone advise what fps and lbs/ft these loads would be doing??
cheers

 

[Muir]

Not really. Conjecture would be the best anyone could offer. If you can guess at the speed, this formula has always worked for me:

WT x Velocity (Squared) x .000002215 = Ft/lb ME.
~Muir

 

[reelme]

cheers Muir done a few guesstimates will use your formula tomorrow had one too many vinos to do it at the mo
thanks again
~Reelme

 

[Dalua]

I multiply fps squared by grains and divide by 450240

 

[reelme]

thanks for the formulas chaps
are the ballistic calculators any good for giving me the info on my shortened barrels or should i just get a chrono and use your formulas?:?:
cheers again
reelme

 

[patjack]

And another way also
VELOCITY×VELOCITY÷450240×BULLET WEIGHT =FT LBS.

 

[lister]

buy or borrow a chrono

 

[.25-06]

Of course you'll notice both formulae require the velocity..... your going to have to shoot some rounds over a chrono. to get speeds for your load/rifle combinations.

+1 with Lister Chrono. a must.

 

[Penyard]

No substitute for chrono to get truly accurate data but Quick Load program is pretty good for getting a fairly good idea of how a load is likely to perform and takes in to account barrel length. Suggest you invest in both when funds permit. I have an 18" barrel .308 and quick load data very close to reality over chrono.

 

[j0e_bl0ggs]

A chrono will be a far more useful tool than QuickLoad.
Just to put into context if one does not know how to calculate muzzle energy what use will QuickLoad be if basics are not understood?
This is not meant as a slight, just pointing out that £150 could be better spent elsewhere.

 

[Sharpie]

You do need to shoot those rifles over a chrono. Particularly the .243 90 grain load, if you intend to shoot deer with it.

I'd also be surprised if you exceed 1000 fpe with the .223 with such a short barrel.

Reloading without a chrono is just guesswork, particularly if you have such short barrels.

Compared with a lot of unnecessary shooting stuff, nevermind a few tubs of powder and boxes of bullets, £125 for a chrono isn't much.

Once you have chronoed your loads you are much better placed to use a ballistics calculator to work out your drops, and choose the best zeroing distance for MPBR for your particular setup.

This is what I'd buy, I borrow one and it works very well, much better than the slightly cheaper folding one.

PROCHRONO DIGITAL CHRONOGRAPH: Amazon.co.uk: Sports Outdoors

 

[reelme]

thanks for the advice guys
joe bloggs -one does know how to calculate muzzle energy etc but if one read my original question one was asking if anyone could advise on what ones guns would be doing fps and ft/lbs, so to assume one doesn't understand the basics is in ones opinion very much is a slight. i do believe this forum is for offering help and advice and not for making assumptions on ones academic skills! by the way i have a HND in mechanical engineeering

 

[reelme]

sharpie cheers for the advice on which chrono to buy .i'm just off to order it now
cheers again

 

[j0e_bl0ggs]

thanks for the advice guys
joe bloggs -one does know how to calculate muzzle energy etc but if one read my original question one was asking if anyone could advise on what ones guns would be doing fps and ft/lbs, so to assume one doesn't understand the basics is in ones opinion very much is a slight. i do believe this forum is for offering help and advice and not for making assumptions on ones academic skills! by the way i have a HND in mechanical engineeering

You asked if someone could help without supplying the required data.

I do not need to make assumptions, your question patently shows the depth of knowledge.
Bottom line why ask in the first place if you know it all already?

 

[reelme]

I believe the relevant data was in my original question but was asking if anyone could advise for example if they had similar guns and loads!! so I' m sorry if my question and request for advice seems substandard for yourself but the world would be a very sad place if we were all budding Einstein's like yourself! so let's get back on topic now and the next time I'm struggling with quantum physics and the theory of relativity I know who to ask

 

[splash]

Quickload results ( Not all data supplied or used so use at your own risk !)

.243 65gr 2953 fps 1258 ftlb
90gr 3402 fps 1491 ftlb Danger over pressure

.223 55gr 2687fps 882 ftlb


.308 125 gr 2768 fps 2126 ftlb
130 gr 2598fps 1949 ftlb


Hope this helps BUT WORK UP your loads while checking for signs of danger !

 

[reelme]

Splash thanks for the info
i got the load data from the hornady,speer and nosler manuals so i'm bit concerned with the 90grain speer over pressure? so will have to check them out when i get my chrony!
thanks again
is the 90 and 65 grain data the wrong way round?

 

[8x57]

Quickload results ( Not all data supplied or used so use at your own risk !)

.243 65gr 2953 fps 1258 ftlb
90gr 3402 fps 1491 ftlb Danger over pressure

.223 55gr 2687fps 882 ftlb


.308 125 gr 2768 fps 2126 ftlb
130 gr 2598fps 1949 ftlb


Hope this helps BUT WORK UP your loads while checking for signs of danger !

I thought that with such short barrels the energy levels would be low but I didn't appreciate that they would be so low. Yes I realise that this is only the predicted figures from quickload. It will certainly be interesting to see what the actual figures are when run over a chronagraph which is the only way you will ever know. Rather limits their use for deer stalking and staying within the law doesn't it.

 

[reelme]

yes quite a surprise but i nearly always use the 308 for deer! the 223 is purely a foxing gun and until i get the chrono and check the data so is the 243! maybe i shouldn't have listened to the wife when she said size doesn't matter!

i wonder what load was developed for the rpa woodland stalker with the 16inch barrel in 243 to achieve the legal dose??

 

[bobjs]

buy or borrow a chrono

a big + on this,

with respect to peoples/other shooters info and what they say they get is not worth taking as true.

the crono if set up correctly will never lie,

use it trust it.............and get creditable results,

bob.


woodland stalker info here.(but not the info you need me thinks)

http://www.google.co.uk/url?sa=t&rc...OvmM5lBEcQskufLDA&sig2=kbpXhRKztNTTiLTpwAn-mg