Hi All
I ‘m hunting with a .303 BR Rifle and reload my ammo.
I have a concern about the landing of the projectile.
I do not know how to calculate this.

Question:
Could some one please assist me in calculating the projectile landing ?

Choices:
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?

 

Are you talking about where the bullet hits at different ranges when sighted to be right at a closer range? To calculate that, people would probably want to know scope or not, bullet weight, & velosity. Then some reloading books have tables in them, or there is computer software also.

Hi
No Bullet or projectile landing is when you chamber the round - the projectile does not seat 100% in the barrel - there wil be some bullet jump - now that distance can differ - between 6mm - 1mm.

Take a case that has been fired in that rifle, using some needle nose pliers crimp the case in very lightly (you have to experiment) just behind the case mouth. Sometimes I just catch the case between a raised shellholder and die (case laying on it's side) and lightly crush the case so it will hold a bullet fairly snugly when you push it into the mouth. Just barely start the bullet into the case and slip it into the chamber. Now close the bolt. Remove and measure. Do this multiple times until you are sure you have a reliable reading. If you make the case fit tight enough you can also drop the bullet into the rifle then insert the case and close the bolt. If the case isn't snug enough on the bullet it can lodge the bullet into the rifling and then leave it there when you open the bolt. If this happens drop a smaller caliber (6mm, 25, ect) bullet down the muzzle with the rifle vertical. It will knock it loose.
If you have a Lee Collet die you can vary the neck pressure to any degree you like. Just make sure you bevel the mouth of the case so it doesn't gouge the bullet base and mess up your reading. If you are handy with the crimp portion of your seater die you can usually add just enough crimp (no bullet in case) to hold the bullet securely when you insert it by hand. You can also make it tighter and bevel the mouth good then use the seating die to just start the bullet. Whichever method you use to get a firm but not too tight grip on the bullet you then insert it into the chamber and then measure with a calliper to see what loaded length has you touching the lands.
Keep in mind on many guns the magazine will determine length and not your chamber unless you want to single load rounds. Also some rifles have enough room depending on what bullet you are using that your bullet won't touch the rifling no matter how far you seat it out. I have a 7mm that I load 100gr Sierra HPs in at times and they will fall out of the case before touching.
Hope my rambling suggestions and information help and don't just leave you confused.

OR....... simply purchase a Hornady (formerly Stoney Point) OAL (over-all length) gauge from Midway with the appropriate caliber modified case. It will tell you exactly how deep to seat your bullets without contacting the lands.

I'm pretty sure they ship Down Under.

Raven,

If you are using a "standard" .311" diameter bullet weight between 150 and 220 grains in your 303 British, then you ought to be able to use the commonly accepted Minimum O.A.L. (Overall Length) cartridge length of 2.195" to 3.075" Maximum as a guideline. Specific individual bullet lengths, weights and magazine length in a particular rifle will determine +/- what is your best fit for FUNCTION.

Unless you've got a custom rifle I doubt whether or not adjusting the length of the bullet/loads to the Leade or Freebore in a military chambering/rifle will help improve accuracy much. Especially in most (read:all) old military 303's the Leade is normally so long as to be of little use for tinkering with load length. Each rifle can be a mystery unto itself though.

My expereince with 303's is that the best reloading effort is spent attempting as best you can to match the reloading Dies & Brass to the chamber since every 303 British ex-military rifle I ever fiddled with had notorious headspace. With ensuing short case life and other potential reloading issues.

If you want to know where the Leade starts in your rifle; without using other tools - like Sburd mentions is to very slightly re-size a case (without a primer & just the first 1/10th of an inch of the case neck) insert one of your bullets (flat-based) BACKWARDS into the case and then attmept to chamber it. That will tell you where the Leade starts and in most old military chamberings you'll notice will allow for a very-y-y-y long cartridge; most probably way past what the magazine length of the rifle can accomodate. Personally, I'd stick to function over load tweaking when reloading for such a rifle.

If your bullet of choice has a cannelur, you will be limited in the amount of fore/aft movement. In short you crimp on the provided cannelur, or risk core separation damaging the bullet jacket.

Hi Gerry
I thank you for the advice – I will do as you described – Will keep you informed – we are going to do load development this weekend.
To the other peeps that replayed to the post I thank you as well- It is nice to know that there still are peeps in this world that can help some one else.

Raven,

Cool, I'd enjoy hearing how things work out for you this weekend.