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Old January 19, 2012, 06:49 PM   #1
cbhester
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220 Swift Ballistic Coefficients

Is there anyone out there who has studied several different bullet manufacturers version of the 220 swift and can tell me who makes the highest ballistic coefficient in the 22 caliber bullet?
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Old January 19, 2012, 06:55 PM   #2
Brian Pfleuger
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The highest BC bullet is basically going to be the heaviest bullet. You will be limited in terms of bullet weight by the twist rate of your barrel.
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Old January 19, 2012, 07:30 PM   #3
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For Swift purposes I'd suggest the Sierra 50gr BlitzKing

.248 @ 3300 fps and above
.243 between 2650 and 3300 fps
.232 between 2050 and 2650 fps
.222 between 1800 and 2050 fps
.203 @ 1800 fps and below

The 55gr BlitzKing is slightly better, but at the high end of the Swift box and you are trading off velocity

.271 @ 3100 fps and above
.264 between 2550 and 3100 fps
.250 between 2050 and 2550 fps
.236 between 1800 and 2050 fps
.224 @ 1800 fps and belo
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Old January 19, 2012, 08:36 PM   #4
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http://www.midwayusa.com/product/256...ail-box-of-100

You'll never get them to stabilize in a standard Swift twist though.
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Old January 19, 2012, 09:27 PM   #5
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As with my Swift, most have a 1:14 twist which will limit your bullets to 55 grains or less. I have good results with Sierra 50gr BK and Berger 50 gr FB.
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Old January 19, 2012, 10:26 PM   #6
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I can't speak for all 220 Swifts, but mine (with the 20 inch barrel) is not limited to 55 grain bullets and smaller. I shot the 60 grain Nosler Solid Base Boattail for years and loaded and shot the 63 grain Sierra semipoint bullet, and both were extremely accurate. Starting soon, due to my need for a heavier bullet for my heavier ranch varmints, I plan to load and test the 65 gr Sierra Gamekings in the Swift. Sierra says that the bearing surface of the 63 grain and the 65 grain are the same, so I'm hoping that the 65 grain will work out fine. Also, I've been told by several folks on this forum that their Swifts are real tackdrivers with the Winchester 64 grain Powerpoint. So...nope...you are not limited to 55 grains or less.
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Old January 20, 2012, 01:43 AM   #7
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A "Swift" with a 20-inch barrel?
Who made/built it?
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Old January 20, 2012, 07:38 AM   #8
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Thanks alot, I have a Ruger M77 with a 24" (I think) barrel, I'm not sure what the twist in that barrel is though, but intend to try and look it up.

Anyone know what it would cost and where I could find someone to custom make a long barrel with a more suitable twist for the 90 grain berger bthp? And does anyone know what the optimum length and twist might be for this particular bullet?
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Old January 20, 2012, 08:59 PM   #9
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Mehavey, back in the early 80's I wanted a 220, so I prowled the gun shows. I knew that Ruger had made some heavy barreled varmint guns in the mid to late 70's and they got rave reviews regarding accuracy. I found one, but the heavy barrel had been cut to something less than 20 inches. The guy that sold it said he wanted a 220 that would fit on the dash of his old truck (for coyote shooting), so he had the barrel shortened. I think I paid $200 for it and the old 10 power scope (Lyman, I think). Man, that thing would shoot. I had never had a rifle that shot that good. Well, the barrel finally needed replacing, so I found a gunsmith near the house and told him I wanted a new barrel, but I wanted it to be 20 inches and more of a sporter weight size. He tried to talk me out of it, but I was determined. As it turned out, he put a 21 inch barrel (Douglas) on it and I didn't catch on to that extra inch for years. I also had him tune up anything and everything, float the barrel and bed the action. Turns out that the gunsmith was a top of the line guy that specialized in ultra light rifles, but I didn't know that back then. The rifle is a real tackdriver.
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Old January 20, 2012, 09:06 PM   #10
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cbhester, your Ruger probably has a 1 in 14 twist. I'm sure that plenty of barrel makers can give you what you want, and I'll guess that what you want is something like a 1 in 7 inch twist (the long range guys on the forum will give you a more precise answer on that and the approximate cost).
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Old January 20, 2012, 09:27 PM   #11
mehavey
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Comparing the 223 & the Swift velocities give you a glimpse of the req'd twist for (really) heavy bullets at Swift design speeds.

223Rem:
90grSMK/2,600fps ~ 6.5 twist for 288,000 RPM (Generally accepted twist for this bullet)

Swift (QL predicts using 26" barrel/full case of N560 powder at 55,000psi)
90grSMK/3,200fps ~ (3200/2600 * 6.5) = 8 twist for same 288,000 RPM
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Old January 20, 2012, 09:35 PM   #12
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Quote:
I'm not sure what the twist in that barrel is though, but intend to try and look it up.
Measure it yourself: Put a correctly sized borebrush on a cleaning rod and run it into the bore. After it begins to turn (with the rifling) stop. Take a Sharpie and make a mark on the top of the rod back by the handle, and one at a specific point (like where the tang ends or at the bolt handle cut in the stock). Push the brush in ..... advance it until the mark back at the handle is back at the top (having made one full turn). Make a second mark on the rod at the same reference point you used before. Push the rod all the way through the bore (reversing bore brush direction inside the bore is bad ju-ju). Pull rod back through and measure distance between the two reference marks.

Voila'! Your twist rate is 1(turn in): x" (x being the distance between the two marks).
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Old January 21, 2012, 07:04 PM   #13
cbhester
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Quote:
Swift (QL predicts using 26" barrel/full case of N560 powder at 55,000psi)
90grSMK/3,200fps ~ (3200/2600 * 6.5) = 8 twist for same 288,000 RPM
Thanks a lot for the info, if those calculations are based on a 26" barrel will a longer barrel just make it better, worse or neither?
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Old January 21, 2012, 10:05 PM   #14
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I ran the 90 gr SMK at 3200 ft/sec and an 8" twist in JBM and got a stability factor of 1.330 which tells us that the bullet will be marginally stable. Dropping the velocity to 3000 ft/sec gives a stability factor of 1.301.

Chances are that the bullet will do OK.

Berger recommends a 7 twist for their 90 gr bullet.

If you aren't looking for the last bit of accuracy, a 1 - 7" twist will give you more assurance of stability. Berger likes to run their bullets at marginal stability because faster twists cause some drop off in accuracy. Going with their recommendation gives you that margin.
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Old January 21, 2012, 10:54 PM   #15
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Thanks again for more good info, I am looking at ordering a custom 30" barrel with 1:8 twist, I pretty much know nothing about the barrel contour but need to know before ordering. Can anyone recommend what contour to go with for the use of long range target shooting and using primarily the 90 grain berger target bullets?
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Old January 22, 2012, 12:47 AM   #16
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In a couple weeks I'll be ordering a Shilen for 1000yd shooting and I went with #7 contour.

Just have to get on the manufacturer's site and figure out what you want.

What one manufacturer considers a varmint contour, another might call it light varmint.

The Shilen #7 is the standard Remington varmint contour..870" OD at the muzzle.
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Old January 22, 2012, 11:00 PM   #17
will99
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Did a good bit of reloading this past summer. My 1:14 barreled Swift shoots best with Hornady VMax 55gr. The 50gr. weren't as accurate in Speer or Hornady. The 45gr. even less so. IMR 4064 undoubtedly the best powder. Just my 2 cents.
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Old January 23, 2012, 07:10 AM   #18
cbhester
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Quote:
My 1:14 barreled Swift shoots best with Hornady VMax 55gr
Hey will, did you ever try shooting the sierra match king 52gr bthp's? I have had lot of success inside 300 yards with them killing hawks, groundhogs etc, using H380 powder 5% shy of the max load, just an idea you might try if you haven't already.
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