GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: Friar on June 29, 2019, 01:11:17 PM
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I just received a new 45 Cal from Extreme Big Bore Airguns. It's awesome. I'm getting 940fps with Mr. hollow points 280 grain pills on air and 1360 on helium. It's awesome. It was even $200 off!
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I have one of Brents .408 with a Titanium Air Tube I traded for and it is a Beast. I can only Imagine the 45 cal on helium.
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Nice Kevin, that baby is packing one heck of a punch!
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I have one of Brents .408 with a Titanium Air Tube I traded for and it is a Beast. I can only Imagine the 45 cal on helium.
I've gotten my 45 around 1360 with 280 gr on helium. It's got the thump of one of the old black powder 45-70s. I haven't choreographed any of the bullets in the 250 range on helium yet (due to a lack of helium), but I'm sure they will thump! On air it will shoot through a 4x4 with no problems. I killed a 13 point with my other Extreme 45 a couple of years ago with a 350 gr bullet, but I think the 250 - 280 gr range is ideal.
I've got one of the booster pumps which is really nice because I can fill my gun up to 4600psi even if my tank itself is down to 1800 psi. That's the lowest I've tried it.
Where is your air gun only hunting ranch and what critters do you have on it to hunt?
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Sounds like on Helium you need a MUCH heavier bullet.... JMO....
Bob
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Sounds like on Helium you need a MUCH heavier bullet.... JMO....
Bob
Would you explain why you think that?
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Well if he is getting 1360 fps with the 280 gr. on Helium, I would think slowing it down would have two advantages.... more FPE and less drift in wind....
Bob
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Interesting points you make
But I don't think a deer within 100 yards will care about FPE too much with a .45 bullet of either 280gr or 350gr 😄
Quick trip to Chairgun
85 yard zero, 8 MPH crosswind @ 90 degrees
100 yd drop 100 yd drift
280 @ 1360. -1.41. 3.65
350 @ 1050. -2.32. 2.61
So you trade less drop for more drift
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I have one of Brents .408 with a Titanium Air Tube I traded for and it is a Beast. I can only Imagine the 45 cal on helium.
Where is your air gun only hunting ranch and what critters do you have on it to hunt?
https://www.t3pranchags.com/contact-us/ (https://www.t3pranchags.com/contact-us/)
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Maybe so.... but if he's getting 1150 FPE at 1360 fps, he would get at least that at 1050 fps (and likely more).... which would mean a 470 gr. bullet, not a 350 gr. (and quite possibly a 500 gr. @ 1050)... That has a 68% higher SD than a 280 gr., so the BC should be at least that much better, and likely it would be about double the BC of the 280 gr. (because the longer bullet should have a better FF).... Try those numbers and see what you get....
Not to mention the lack of supersonic "crack"....
Bob
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Sure, same parameters except I changed the BC to .250
470gr @ 1050 gives -2.17 drop and 1.68 drift at 100 yards.
Used a BC of .18 for the 280gr and .21 for the 350gr
Note: When I'm using He I fine tune for just under supersonic based on that seasons expected temperature to keep the crack down to get under the twitch response of the deer, besides the transsonic accuracy issues too so agreed on your point
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Using a BC of 0.30 (67% higher than 0.18) would reduce the drop and drift even further (drift to 1.4" instead of 3.65").... Are you more likely to miss with a drop difference of about 1/2" (which is consistent).... or a drift difference of 2.25"? (which varies with windspeed).... Double the windspeed, now the drift difference increases to 4.5".... Just sayin'....
Bob