.303 Load Data Needed

Well this is insane. I have found about 3 different load data sets.

One says Hornady 174 RN, IMR 4350 Min 37.0 Max 44.6

Two says Sierra HPBT 174, H4350, 43.0 Grn Min, Max 48.0C

Three says 174-180 Grn, IMR4350 Min 42.0 Max 46.0

Why the insane variations? I was going to just load for 42.5 grains with a scale and call it a day.
 
Keep in mind, IMR and H are not directly interchangeable.


Equipment used to test has many variables.


There can be up to a 15% difference from one batch of powder to the next.


Some books (like LEE's) are incredibly conservative.
 
Well - Its not insane. Last time I checked there was about a two grain difference between IMR and H4350. The rest just illustrates the natural variation from test to test....
In your case, you havent mentioned the brass you're using. If its military spec, then you need some additional margin, as 42 grains would be closer to max than min.
 
I think this is one of those situations where you can't put enough of that slow burning powder (either H or IMR 4350) into the case to blow yourself up with a 174/180. It's really just a bit too slow for the 303... but... that makes it a bit safer to load with.

I load H4831SC in my 30-06 and can't get enough in to blow myself up either. But if I switched to 4350 in that same case (bit faster than 4831) I'd do some serious damage with a full case.
 
Thank you all. I have opted, as I am using a mix of Winchester, IVI, and Dominion brass, to load 41 grains of IMR 4350 behind my 180 and 174 grain. I will see how that goes. It should be sufficient for plinking I would think. It states that 42.0 is the minimum though for IMR 4350 from 2 sources, yet according to another, it is in the middle. Perhaps a 42.0grain would be better? I am trying to settle on a good round number. I would think 42.0 is good, if not 42.5?
 
Drachenblut said:
Thank you all. I have opted, as I am using a mix of Winchester, IVI, and Dominion brass, to load 41 grains of IMR 4350 behind my 180 and 174 grain. I will see how that goes. It should be sufficient for plinking I would think. It states that 42.0 is the minimum though for IMR 4350 from 2 sources, yet according to another, it is in the middle. Perhaps a 42.0grain would be better? I am trying to settle on a good round number. I would think 42.0 is good, if not 42.5?
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Well, I've put quite a bit of effort into this to try and help a new reloader, so might as well give some more.
The brass you have is all commercial, except check the IVI, to see if it may be military. With the light load you are proposing it won't make any difference anyway.
The selection of 4350 powder is actually ideal for you to start out on. A powder a bit slow for the cartridge is safer than a faster powder.
The light load you propose may be accurate, but maybe a heavier charge is required to make it shoot well, as 4350 requires a fair bit of pressure to be accurate.
Shoot the light load for a while, then you may want to gradually creep up. However, with a slow powder like 4350, don't change the charge by anything less than ½ grain at a time.
 
H4831, thank you for your help. I will try 42.5 Grns, being a new reloader, I may load some of another batch of 20 with 43 - 43.5 and see how that works.
 
H4831 said:
Well, I've put quite a bit of effort into this to try and help a new reloader, so might as well give some more.
The brass you have is all commercial, except check the IVI, to see if it may be military. With the light load you are proposing it won't make any difference anyway.
The selection of 4350 powder is actually ideal for you to start out on. A powder a bit slow for the cartridge is safer than a faster powder.
The light load you propose may be accurate, but maybe a heavier charge is required to make it shoot well, as 4350 requires a fair bit of pressure to be accurate.
Shoot the light load for a while, then you may want to gradually creep up. However, with a slow powder like 4350, don't change the charge by anything less than ½ grain at a time.
Click to expand...

Just in case you are unsure, I will say right now YOU NEED TO LISTEN TO THIS GUY!!!!!!

Has helped me out in the past and if anyone know what they are talking about its him.
 
I will be loading:

Hornady 174 Grain Round Nose, mix of IVI, Dominion, Winchester Brass, IMR 4350 powder at 43.0 Grains even, using a scale measure. I will be using Winchester Large Rifle primers.

Give me the OK and go ahead H4831 if you think that's good!
 
Hello, I will be using a Lee Auto-Prime Manual hand-loader, as I have heard of ram-prime issues. How do you know? Besides, I need to know if that's a safe load. Think so?
 
You will be fine with the autoprime. Sorry - thought you were pounding 'em the old fashion way. The "lee classic loader" is a fun little tool for inserting primers and keeping you on your toes as they can sometimes go off - but you aren't doing it that way so WLR will be great. Enjoy!
 
Personally, I think you've got the wrong powder if you're trying to get the best performance/accuracy out of your rifle.
To answer your question, you shouldnt rely upon any advice from the internet as a substitute for prudent reloading practice. Use a starting load that you're comfortable with, shoot a round and check for overpressure, increase and test accordingly.Developing this regimen is one of the most important aspects of reloading.
 
Well, it's the powder I have. I'm not made of money so. What would you reccommend for a powder? Oh did I mention I live in Southern Ontario, land of the reloader's hell to get anything? *smile* I called 10 gun shops and only ONE had lee auto prime shell holders, not to mention anything Lee. Shocking.

In any event, I have settled on a loading of 43 grains of IMR 4350 in my .303, and will work around that. I know it can handle 46 as I had it loaded to that before with Accurate Arms 4350.

I have also settled on 47.5 grains in my 7.62X54R. The slow rate of powder should burn nicely in the long Mosin barrel.

Cheers,
D
 
As mentioned before 4350 is slow for this calibre, and likely the russian calibre as well. Re 15, Varget, 4064 or 4895 are preferred for 303. If you're just plinking, it likely doesnt matter. If you're trying to get the most out of the rifle and yourself, one could argue that using 4350 is a waste of money...
 
I've had good results with all of the following in the .303; IMR 4895, IMR 4064IMR 4320 , IMR 4350, W760, H414, Varget, and RE 15. My first choice when I started reloading for this ctg some 40 yrs ago was IMR 4064, and it's still a good one.:) If a person wants to reload for a variety of MILSURP ctgs and wants to rationalize his powder supply, IMR 4064 works well in just about any that I can think of. I agree that IMR 4350 is a bit on the slow burning side, but it still works well enough with a 174/180gr bullet.
 
Let me add BL-C(2), H380, IMR3031 and H335.
Don't be shy using magnum primers for winter ignition (pre-test it, of course) with ball powders. My own favourite is BL-C(2).
 
Winchester-Western loaded millions of rds of .303 for the Brits in ww2 using a ball powder which was later morphed into BLC2. It was well thought of by them. On the topic of ball powder, I've gotten some great accuracy with both W760 and H414 and 174/180gr bullets. Yup,use magnum primers for cold weather hunting loads.
 
My test load for Lee-Enfield rifles is 37 to 38 grains of 4895 (either IMR or H) with a Sierra 180 flatbase bullet. Gives about 2250ft/sec from Lee rifles, 2325 from a full-length Ross.

NOT a nasty load, very accurate, about 200 ft/sec below milspec and just happens to be the known most accurate velocity by Enfield/Woolwich test for the .303, 1910.

To make good even better, I get 180+ loads to the pound of powder. Being that I am a True Scot by ancestry, this is a Vurra Guid Thing.
 
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