303 Loads For Whitetail & Coyotes???

[jmoore]

I won't give out my load data because I don't believe my own entries until I have checked them against the manual(s) - again! and once more with feeling!

I also tend to use multiple scales just to double check them against each other. Its a wonder anything ever gets loaded!

[Alfred]

For the 150 grain Hornady .312 bullets I use 43.5 grains of 4320.
I get sub MOA out to 300 yards with this load.
As always start a couple of grains below this suggested charge weight and work your charge up to suit your individual rifle.

I recently bought a fresh supply of 4320 and haven't used it yet. Theres always a possibility of the characteristics of a powder changing over the years especially when the trademark changes hands.

[Pattern14]

I know many reloaders (and I'm using the word loosely) tend to crank their loads up to the maximum but actually I have found that the best performance is achieved somewhere in a middle range between the minimum and maximum published load. I use 150 grain Hornady SP bullets with IMR3031 and load on the lower side. I've always been happy with the results.

[gunner]

Thats right Pattern14, i found my best loads between the 60 and 75% range.


Regards

Gunner

[rmckeon]

well, I thought I'd share my results...

I started with 41gr of IMR4895 and worked my way down to 40gr of the same. I found that my groups became considerably tighter by the time I worked my way down to 40gr.

I never would have thought that reduced loads could generate better accuracy, and only tried it based on input by members such as Gunner and Pattern14 - and I'm obviously pleased that I did, based on the results. Next time out I'm going to try to reduce my loads a bit more.

Thanks to you folks that shared your load data and expertise.

[gunner]

Thank you rmckeon ! That`s for me the sense of this great forum, we all can learn from each other and help each other

Best Regards

Gunner

[Pattern14]

Not only will reduced charges help your accuracy but you'll save on powder and every little bit helps especially in the last several months of empty shelves. Good luck.

[Alfred]

Lighter loads showed very poor accuracy in the Enfields i've tried them with. Those rifles had bores on the loose end of the spread.
My 1915 has a much tighter bore, the only one I've seen that mikes at .311 exactly, the nominal bore size rather than the looser bore most often encountered, so I'll be using much lighter loads and .311 bullets rather than the stout loads and .312 bullets I use with my two groove Savage.
Light loads can also result in the front sight offset being too great, the lighter loads don't usually flex the receiver as much, and can allow the bullet to leave the muzzle on the back swing of the vibration, throwing bullets to the right of center rather than left of center as the service loads do.

I'll also be trying cast bullets with the 1915, 185 gr Lyman gas checked and sized .311.
I replaced the damaged rear sight with the correct windage adjustable sight I got rather cheaply from APEX, so adjusting for altered bullet drill or throw should be no problem.
I also obtained a PH5A for long range shooting with full power loads.

IMR 4007 SSC powder shows some promise, offering loads that duplicate the MkVII at far lower pressures than other powders. Unfortunately not available locally as of yet.
I'd like to find a source for affordable pull down MkVII bullets of a quality manufacture. POF bullets aren't worth the trouble, I've tried those before pulled from dud rounds.
I'll be using Match Kings till a bullet that better duplicates the MkVII can be found.

Older barrels subjected to double base powders can develop a slight constriction just ahead of the throat. This is caused by pressure and heat expanding the fissures of heat checking surface fractures (not craze cracking though often mis identified as such), the hard baked carbon and some metal fouling infiltrates the fissures raising its suface, the fissures prevent solvents from doing their job in removing this fouling.
When the bullet encounters such a constriction it is micro swaged and if pressures are not high enough to continue the upsetting effect beyond this point there will be some gas blowby inducing variation in velocity and softening the bullet jacket or damaging the base.
Long Range shooters discovered this effect in comparing barrels set back at rechambered. Moving the constricted section back even a fraction of an inch put in within the zone where pressures remained high enough to overcome the swaging effect.

In worst case scenario constriction can reach a level where bullet jackets become gas washed and overheated enough to cause jacket seperation and blow through in the bore.

On the opposite end of the spectrum the raised thermal/gas checked surface can end up being washed away in clumps causing much worse blowby effects.
The higher the operating temperature of the propellant the more pronounced the effect.
Barrel metalurgy can be a deciding factor.


PS
The 150 gr bullet loads may not respond as well to the compensation factor that allows the MkVII load to give better long range grouping than short range groups would indicate.
Varying the velocity till the compensation factor kicks in may result in wider 100 yard groups but over all smaller groups MOA wise at longer ranges.
My 300 yard groups are usuall less than 1/2 inch horizontal, but near three inches vertical when using the 150 grain bullet loads.
I'll experiment with reducing velocity a hair and see if the vertical spread shrinks at longer ranges.

[lucky dog]

Sunday I was hitting clay birds on the backstop of the 100 yd range using the 150gr Privi bullets in front of 40 grains of Varget. This was with my 1918 BSA. The '44 Longbranch likes the load to.

[blacksan]

I always enjoy the varied responses to a thread like this. It is my experience that some rifles like higher velocities and some rifles don't. I never take responses as gospel but do look for common results that allow me to explore a starting point.