Powders for 303 Brit

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I Dont Care About You

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Tried my first reloads for the No4 Mk2 today. I tried W748, BL-C2 and IMR 4046.

W748 seemed to have crap consistency with an ES over 200.

4046 might be an option but it seemed to produce lower velocities and the published pressures are typically higher.

BL-C2 seems to be the winner so far. It produces the best velocities, has the lowest published pressures and has very low ES and SD values.
 
I Dont Care About You said:
Tried my first reloads for the No4 Mk2 today. I tried W748, BL-C2 and IMR 4046.

W748 seemed to have crap consistency with an ES over 200.

4046 might be an option but it seemed to produce lower velocities and the published pressures are typically higher.

BL-C2 seems to be the winner so far. It produces the best velocities, has the lowest published pressures and has very low ES and SD values.
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I only use 4320 in my Ross, which is the only 303 I own at the current time. That's mostly because I have a ton of it from when they couldn't give it away, and I'm pretty sure they don't make it anymore anyway. That probably doesn't help you much.

The real reason that I'm weighing in at all is that you talk about published pressures. The only reasons why a published source with pressure testing equipment stops under the standard pressure for a cartridge are either they ran out of room in the case or the pressure variation puts a certain percentage of shots over a certain over pressure point. There's some serious protocol and math involved. Remember that the number they throw out there is an average pressure, not a range of every shot they measured. They never quit because they wanted to; they quit because they had to. Even the maximum SAAMI specs themselves are an average pressure with a built in overage of a certain margin a certain about of the time.

Just in case your head is hurting, the simple translation is that the loads with published pressures that are low aren't safer than those that are higher. They're actually the same kind of safe. the higher loads are more consistent which allows them to go higher.
 
LordEvilPepper said:
I load blc2... makes for vety consistent groups.
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Based on the velocity variations I saw today, I'm willing to believe this. I'm gonna try a few more loads w BL-C2 to get the right velocity range and then try it for accuracy.



Dogleg said:
I only use 4320 in my Ross, which is the only 303 I own at the current time. That's mostly because I have a ton of it from when they couldn't give it away, and I'm pretty sure they don't make it anymore anyway. That probably doesn't help you much.
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Not really ... unless you want to sell me a couple pounds of it.


The real reason that I'm weighing in at all is that you talk about published pressures. The only reasons why a published source with pressure testing equipment stops under the standard pressure for a cartridge are either they ran out of room in the case or the pressure variation puts a certain percentage of shots over a certain over pressure point. There's some serious protocol and math involved. Remember that the number they throw out there is an average pressure, not a range of every shot they measured. They never quit because they wanted to; they quit because they had to. Even the maximum SAAMI specs themselves are an average pressure with a built in overage of a certain margin a certain about of the time.

Just in case your head is hurting, the simple translation is that the loads with published pressures that are low aren't safer than those that are higher. They're actually the same kind of safe. the higher loads are more consistent which allows them to go higher.
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Except I found BL-C2 velocities (which are a function of pressure) to be very consistent. Whereas 4064, which has the higher published pressure, had absolutely terrible velocity variation.
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Ive been using 42.3 grains for my p14 for years... tossing a 180ge hornady round nose sp. 1.25 to 1.75 moa groups

Unforchently they have discontinued that projectile, or at leaste forgone doing a run of them for like 10 years lol. i have about 150 loaded rounds left.

I have about 200 174gr fmjs loaded still. But they are closer to 3moa... my gun doesn't like the 174 anything for some reason. Ive tried factory, ppu projectiles, hornady and campro(?)
 
I'm close to 40 grains of imr 4895. According to load data, around 2300fps with a 180 pill. Not sure about groups though. It stays on the 16 inch steel at 200 for my scoped ph supreme. Still working up a bit to get close to service load...maybe. ill check groups in spring with paper when I can get to my target board.
 
I'm driving the 174/180 grain bullets from my M10 Ross [McGowen 26" barrel] at 2650 fps.
Most accurate "hunting" bullet is the 180 Sierra Pro-Hunter, but several other bullets also
shoot moa or better. Dave. [FWIW, you will probably not reach these speeds safely in a LE]
 
I Dont Care About You said:
Tried my first reloads for the No4 Mk2 today. I tried W748, BL-C2 and IMR 4046.

W748 seemed to have crap consistency with an ES over 200.

4046 might be an option but it seemed to produce lower velocities and the published pressures are typically higher.

BL-C2 seems to be the winner so far. It produces the best velocities, has the lowest published pressures and has very low ES and SD values.
Click to expand...

Both 748 and BLC2 are ball powders. They are harder to ignite than extruded powders. One of the indications is poor ES and SD. Best results are with a magnum primer or the standard Winchester. The lighter the bullet, the better the result with a switch to a hotter primer.
 
Ganderite said:
Both 748 and BLC2 are ball powders. They are harder to ignite than extruded powders. One of the indications is poor ES and SD. Best results are with a magnum primer or the standard Winchester. The lighter the bullet, the better the result with a switch to a hotter primer.
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This is an excellent theory ..........

However ...... W748 produced crap ES / SD while BL-C2 produced excellent ES / SD, while both were using the same primer. In fact BL-C2 did better ES / SD. numbers than IMR 4064.
 
Good old IMR 3031 worked well for over 80 years, why fix what isn't broken.

If you have a 303 Brit chambered rifle with a median diameter bore, that shoots well, it's quite expedient to usu one of the old tried and true powders, such as IMR3031 or IMR4064, BLC2,IMR4320,IMR4350 and for heavier bullets 175-200+grains H4831 all work very well.

If your particular rifle has a large bore, over .312 it's not likely going to make much difference which powder you use if you aren't shooting bullets that have a proportional bore diameter.
 
I Dont Care About You said:
Load?
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41.2gr IMR 4064

The Sierra manual indicates a max load of 40.7gr, and I don't have the crony results written down, but I want to say they were running roughly 2450 fps. No signs of overpressure and "good" brass life, as good as you'd hope for 303 British anyway. The batch I have on the go right now are on their 4 firing, neck sized only, and no evidence of incipient head case failure.

Greg
 
Eagleye said:
I'm driving the 174/180 grain bullets from my M10 Ross [McGowen 26" barrel] at 2650 fps.
Most accurate "hunting" bullet is the 180 Sierra Pro-Hunter, but several other bullets also
shoot moa or better. Dave. [FWIW, you will probably not reach these speeds safely in a LE]
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Once of my 174gr test loads went almost 2670 fps. The case looked fine but the primer is slightly flattened ... not massively so .... but slightly, enough to say that load is a wee bit too hot. The book velocity for that load is 2615 fps so I'll back it down 0.5gr to get closer to the book velocity. Weirdly my test load was 1.5gr less than the max book load.
 
Klondiker said:
41.2gr IMR 4064

The Sierra manual indicates a max load of 40.7gr, and I don't have the crony results written down, but I want to say they were running roughly 2450 fps. No signs of overpressure and "good" brass life, as good as you'd hope for 303 British anyway. The batch I have on the go right now are on their 4 firing, neck sized only, and no evidence of incipient head case failure.

Greg
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Thank you. I'll consider giving it a try.

I have several different manuals but the only load I could find for 4064 under a 174gr bullet came from Hornady #7. It says max 39.3gr at 2400fps, which didn't make sense compared to the 4064 loads I. found for 150gr and 180gr bullets, both of which were 1.0 to 1.7gr hotter.

Hodgdon and IMR list 41.1 as max for 180gr bullet so your 41.2 for a slightly lighter bullet seems pretty reasonable.
 
I Dont Care About You said:
This is an excellent theory ..........

However ...... W748 produced crap ES / SD while BL-C2 produced excellent ES / SD, while both were using the same primer. In fact BL-C2 did better ES / SD. numbers than IMR 4064.
Click to expand...

Not a theory. A fact. That is why I shared it. You loading manual probably makes the same recommendation.

If you don't want to see if the 748 and BLC2 do better with a magnum or Winchester primer, don't try.
 
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Ganderite said:
Not a theory. A fact. That is why I shared it. You loading manual probably makes the same recommendation.

If you don't want to see of the 748 and BLC2 do better with a magnum or Winchester primer, don't try.
Click to expand...

The BLC2 load I tried is in the single digits SD and ES was something like 13 fps. Not certain it could get better than that.
 
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