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One of Us |
I am considering a 270 Win and am wondering how much velocity you lose with a 22" barrel from the published loading data (with a 24" barrel). What kind of velocity are you guys getting with 130 and 140 grain bullets from your 270's with 22" tubes? | ||
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one of us |
The rule of thumb is 25-35 fps loss per 1" of barrel. I think a good max target is 3050-3100 fps with 130s and 2950-3000 fps with 140s (assuming appropriate powders) given 22" of barrel. Some guns and bullet types will will be a bit slower, some a bit faster, but I'd bet this is the average. I'm actually pretty happy running my .270 w/ a 24" barrel at these velocities. Regards, -Lou | |||
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One of Us |
I shoot a Model 70 Featherweight with a 22"er and get 2820 with Nosler Partition 160's behind 59ish grains of RL25 A little warm in my gun, so be careful and work up! friar Our liberties we prize, and our rights we will maintain. | |||
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One of Us |
I think the 270 is one of those rounds that loses a bit more than the traditional "25-35" fps per inch... I believe it's more in the 50 fps neighborhood under 24"... Still, the 270 works handily with a 22" tube. With H4831sc I got 3,100 with 130's. | |||
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one of us |
I get 3080 or so with 130gr TSX's and RL-22 in a 20" barreled Sako Finnlite. 3100 should be easily doable with a 22" barrel and a few different powders.........DJ ....Remember that this is all supposed to be for fun!.................. | |||
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<9.3x62> |
You should be able to get 3050-3100 with 130 and still within or at the SAAMI pressure limit. | ||
One of Us |
Elkhunter I have a 22" Sako 270. Checked my spreadsheet and I have loaded 60 different loads. The max velocity and the best accuracy for the 130 grain came from the Barnes TSX with a velocity of 3313 using 60.5 grains IMR 4831. That was MAX in my rifle and started to shine up the extractor grooves. For 140 grain, the best accuracy and highest velocity was with........you guessed it, the Barnes TSX and I'm getting 3175 with either 59.4 grains of IMR 4831 or 57 grains IMR 4350. These loads were worked up to slowly and carefully as I would recommend anyone do. The TSX's are a little faster than other bullets and the velocity increases as copper builds up in your barrel. Short answer 130 grain - 3250 fps, 140 grain - 3150 fps. ____________________________________ There are those who would misteach us that to stick in a rut is consistency - and a virtue, and that to climb out of the rut is inconsistency - and a vice. - Mark Twain | Chinese Proverb: When someone shares something of value with you and you benefit from it, you have a moral obligation to share it with others. ___________________________________ | |||
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one of us |
I can get 3150fps using a case stuffed with H4831SC and 130gr flat-base Interlocks. Gun's more accurate at 3000-3050 however. All of my 270 loads regardless of bullet weight work best at about a grain under book max. I have made a few loads that push the envelope. Those loads were not as accurate as a proper book load within proper pressure limits. I Think the 22" tube works fine in a 270. Going to a 24" tube woukdn't make a noticable difference except when using a chrono. Game won't know the difference. ZM | |||
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one of us |
Woods, your loads are a good bit over max pressure. You are pushing them way to hard if your shooting 130gr bullets at over 3300fps in a 22" barrel. Your rifle may be tight enough that you are not getting pressure signs other the velocity. Velocity is a pressure sign!. If you are getting 200fps faster than anyone else it's because you are running at higher pressure. In a 22" barrel over 3150 with 130gr bullets or 3100 with 140's is most likely over pressure. There's not such a thing as magic barrels that will allow you to shoot 200fps faster than everone else. If you need to go that fast buy a 270 WSM or 270 Weatherby. Please reload safely......DJ ....Remember that this is all supposed to be for fun!.................. | |||
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One of Us |
I'd like to thank everyone for their replies. I recently purchased a 25-06 from a friend for a very good price and am no longer working on the 270. Thanks again for taking time to post. | |||
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one of us |
I have no trouble getting 3150 with a 130 and 3000 with a 150, 295 with a 160 with some of the old surplus 4831 I have in a 22" barre....the same stuff that O'connor used..I still have about 40 lbs. of that good stuff...I save it for the 270 only...I cannot get that with todays IMR or H 4831 as I cannot get the same number of grains in the case..I have not tried SC, so that might be a good route to explore... Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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one of us |
I have not tried it myself, but I understand that IMR 7828 is now available in SC, and that, using 7828 SC, you can get a few more grains in the case than is possible with regular 7828. I also think that today's 7828 may be very close to the old surplus 4831 that O'Connor used and that Atkinson still has. So, maybe with the new IMR 7828 SC, we may finally be able to get the velocities out of the .270 that people claimed to get 30 or 40 years ago. "How's that whole 'hopey-changey' thing working out for ya?" | |||
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