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Velocities with 300win mag 180gr BT

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Old 01-07-2007 | 10:26 PM
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bigcountry
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Default Velocities with 300win mag 180gr BT

What kinda velocities are you guys getting with 180gr. With RL22, and 75gr I was getting 3020fps but starting to get heavy bolt lift with 77gr at 3100 (I believe). With 5-10MPH variable winds, I was getting 1.1MOA also, not bad, I think I could do better on a calm day.

Chrony did something else funny tonight.

I started with 74gr and getting 2990fps, and then with 75gr around 3020fps,76gr averaged 3050fpsand 77gr, it stayed flat. With 77gr velocities varyed from 3016 to 3100fps. It was getting dark. Maybe light had something to do with it. Can't wait until Mossy gets his ProChrony. I kept putting off buying a Oehler 35P, now too late.
 
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Old 01-08-2007 | 12:08 PM
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Default RE: Velocities with 300win mag 180gr BT

With the .300 Winnie, any loadat or above 3,000 fps with a 180 gr. bullet is giving you your money's worth. Some barrels can get into the 3100's without pressure issues.Several huntersI knowhave noted that many non-premium 180 grain bullets are about optimum, in terms of expansion and penetration, at somewhere in the upper 2900's to about 3,000 fps.I wouldn't be concerned, particularly if the accuracy is adequate.
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Old 01-08-2007 | 12:53 PM
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bigcountry
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Default RE: Velocities with 300win mag 180gr BT

Thanks Roskoe, I started getting heavy bolt lift at 77gr of RL22. But I am loading out to the rifling at 3.58".

Just shocked I can get almost RUM velocities with my win mag.
 
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Old 01-08-2007 | 01:52 PM
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Default RE: Velocities with 300win mag 180gr BT

I got my pro chrony today big boy.......so the next trip out we can double check stuff!!!!
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Old 01-08-2007 | 01:58 PM
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bigcountry
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Default RE: Velocities with 300win mag 180gr BT

ORIGINAL: mossy33oak

I got my pro chrony today big boy.......so the next trip out we can double check stuff!!!!
Hey if it sucks, blame JamesB
 
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Old 01-09-2007 | 05:33 AM
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Default RE: Velocities with 300win mag 180gr BT

ORIGINAL: bigcountry

What kinda velocities are you guys getting with 180gr. With RL22, and 75gr I was getting 3020fps but starting to get heavy bolt lift with 77gr at 3100 (I believe). With 5-10MPH variable winds, I was getting 1.1MOA also, not bad, I think I could do better on a calm day.

Chrony did something else funny tonight.

I started with 74gr and getting 2990fps, and then with 75gr around 3020fps,76gr averaged 3050fpsand 77gr, it stayed flat. With 77gr velocities varyed from 3016 to 3100fps. It was getting dark. Maybe light had something to do with it. Can't wait until Mossy gets his ProChrony. I kept putting off buying a Oehler 35P, now too late.
Sounds like you crossed the "point of diminishing returns" at around 75-76 grains, andany additional powderis pretty much wasted, unless the 77 grain load is more accurate! In this velocity range, I would stick with the MOST ACCURATE load.

I suspect that your Chrony was telling you the truth, and some other brand will just confirm what you already know....
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Old 01-09-2007 | 06:14 AM
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Default RE: Velocities with 300win mag 180gr BT

I use 75 gr of IMR 4831 ang get sub 1" groups , my best 3 shot group was 0.5" my velocity is 3010 fps. using a 180 rem corelok. If I step it up to 77 grains I get 3080 fps but the groups open up to just over an inch 1.1"-1.3"
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Old 01-09-2007 | 08:20 AM
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bigcountry
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Default RE: Velocities with 300win mag 180gr BT

ORIGINAL: eldeguello

ORIGINAL: bigcountry

What kinda velocities are you guys getting with 180gr. With RL22, and 75gr I was getting 3020fps but starting to get heavy bolt lift with 77gr at 3100 (I believe). With 5-10MPH variable winds, I was getting 1.1MOA also, not bad, I think I could do better on a calm day.

Chrony did something else funny tonight.

I started with 74gr and getting 2990fps, and then with 75gr around 3020fps,76gr averaged 3050fpsand 77gr, it stayed flat. With 77gr velocities varyed from 3016 to 3100fps. It was getting dark. Maybe light had something to do with it. Can't wait until Mossy gets his ProChrony. I kept putting off buying a Oehler 35P, now too late.
Sounds like you crossed the "point of diminishing returns" at around 75-76 grains, andany additional powderis pretty much wasted, unless the 77 grain load is more accurate! In this velocity range, I would stick with the MOST ACCURATE load.

I suspect that your Chrony was telling you the truth, and some other brand will just confirm what you already know....
You know I have heard this before eld, but never saw this. When I go up 1 to 2 gr past max, I usually see a sharp rise in velocity, along with hard extraction.

So are you saying that this "null" in velocity is real? I don't know. I just heard with slow powders you can get to a point where more powder is just not burnt well or used well
 
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Old 01-09-2007 | 09:58 AM
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Default RE: Velocities with 300win mag 180gr BT

Mark - have you ever thought about how much simpler your life would be if you didn't own a chronograph?
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Old 01-09-2007 | 11:40 AM
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bigcountry
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Default RE: Velocities with 300win mag 180gr BT

ORIGINAL: Roskoe

Mark - have you ever thought about how much simpler your life would be if you didn't own a chronograph?
Man, I love this stuff. I love the gadgets, I love tinkering, and playing with the loads.

I have a 7mm08 that is a true sub.5MOA gun. I am bored to death with it.

Reloading as you know is different for many people. I think thats the reason I trade alot. I like building the different loads.

When I first started reloading, I went after it like crazy, but only to find ok loads for each gun. I took a break for several years, and all the sudden, I had a 600 yard field in the spring to shoot at, and started this accuracy craze. And lost the field 2 years ago. Laid off for a year, and now back at it with some new guns.
 
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