| DeishuAK |
| (.224 member) |
| 29/06/05 10:27 AM |
Velocity - Barrel Length 458 Win Mag
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Without the aid of a chronograph I'm wondering what sort of velocity loss I'm getting with my 22" barrel 458 Win Mag as opposed to the "standard" 24" barrel readings you typically get from factory loading data. Some sources say as little as 10 fps per inch. What's the real deal?
| 475Guy |
| (.400 member) |
| 29/06/05 11:07 AM |
Re: Velocity - Barrel Length 458 Win Mag
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This has been a topic of discussion since guys started to play around with their toys. There are a lot of variables in checking your velocity loss in regard to only your gun. The only way to really check is to have a 28" barrel, shoot it for group and chrono. Then, in increments of 1" only, you cut off the barrel til it's a nubbin. Remember, you're shooting everytime you cut the barrel.
Now, when comparing apples to oranges, one make with a 22' barrel may have a tighter chamber than the 24" or 25". That 22"'er will come up with higher velocities or may just match the longer barrels. Conversely, you can have tight chambers in the longer barrels and pat yourself on the back everytime you reload and chrono the load because of the chamber. Like I said, it all depends.
Damn that made me much more fatigued than normal.
| mickey |
| (.416 member) |
| 30/06/05 12:28 PM |
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Re: Velocity - Barrel Length 458 Win Mag
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I think you will find that the 458 suffers very little from a shorter barrel. In my experiance the bigger and slower you start the less effected the velocity loss is by shortening the barrel.
Sort of like old men eh?
I think a 22 inch barrel is perfect for a bolt in 458.
| Oldsarge |
| (.300 member) |
| 30/06/05 12:48 PM |
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Re: Velocity - Barrel Length 458 Win Mag
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It's an interesting question and would be nice if there was an interesting answer! One of the factors that drove the .458 Win into disrepute was the shorting of the barrel from the original 24" to the current 22" version. Admittedly, we all know that Olin/Winchester down-loaded the cartridge as well because of the problems with caked ball powder in the heat of Africa but if the "rule of thumb" that you loose 26 fps for each inch of barrel holds true with the Win as much as it does with other cartridges (and I don't know that it does, having never owned one) then the loss is 52 fps. That isn't much most of the time but when your bullet weighs 500 grains, it makes a significant difference. Like .475 says, the only way to tell is to start with a long tube and cut it down, chrono-ing all the way. That's an expensive way to find out and when you get down to 22" and find you aren't happy, you can't put it back!
| Will |
| (.333 member) |
| 30/06/05 03:16 PM |
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Re: Velocity - Barrel Length 458 Win Mag
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I am not a ballistician but I doubt adding 2" to a 458 over the 22" will matter much at all. The case is powder limited, so no matter what the barrel length its peak velocity is also limited.
I speculate that this is also true with my 416 Taylor. I get the same velocity out of my 22" barrel that others get from their 24" barrels. The case can only hold so much powder and hence in a relative sense can only achieve a certain limiting velocity regardless of the barrel length.
Velocity in a 458 is probably more dependent upon powder choice than barrel length.
| 475Guy |
| (.400 member) |
| 01/07/05 12:45 PM |
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Re: Velocity - Barrel Length 458 Win Mag
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Damn, Dude, you posted something I wholeheartedly agree with. It be a FLUKE!!
| DeishuAK |
| (.224 member) |
| 01/07/05 01:38 PM |
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Re: Velocity - Barrel Length 458 Win Mag
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I'm using the 400 grain Trophy Bonded Bear Claws with my 458 WM rifle, my brown bear loads. I've used the 300 grain TBBC's in the 375 H&H and 225 in 338 WinMag, both with outstanding results in bear and lesser game. Our shots are almost always at closer range (100 yards or less), so this 22 inch will only be an asset in the thick alders and willows, with MV not being a major issue. I was just curious to hear from those who have compared their chronographed loads with the factory/loading manuals using a 22 inch barrel.
| hcroveda |
| (.224 member) |
| 13/07/05 10:47 AM |
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Re: Velocity - Barrel Length 458 Win Mag
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I have a Mauser with 26" Douglass Premium barrell in .458 WM.
Only for example of velocity with this long barrell, this is my own reloads with Hornady 500 FMJ:
WW cases, Fed 210, IMR 3031 # 72.5 gr. 2.221 fts.
WW cases, Fed 210, IMR 4895 # 72 gr. 2.182 fts.
WW cases, Fed 215, WW 748 # 79 gr. 2.057 fts.
Hector
| 458RugerNo1 |
| (.224 member) |
| 18/07/05 06:25 AM |
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Re: Velocity - Barrel Length 458 Win Mag
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With a 500gr bullet I'd say no more than 50fps loss with 2" of bbl...