220 Swift & 90gr Bergers...

[ISS]

I want to build a live varmint rifle in 220 Swift using a bolt action. I ended up somehow with about 300 of the Berger 90gr VLDs.
My Rockchuck hunts are at 3500ft or a bit higher.
We have much greater choices these days, any thoughts about a 7 vs 8 inch twist?

thanks,

Rich

 

[ELR LVR]

I know my 220 Sw Ack handles the Berger 85.5 with great accuracy in an 8 twist
I would find the OAL of the Bullet and get on Bergers site to use their bullet stability calculator
anything above a 1.4 and you will be fine
my SG Factor is approx 1.42 - 1.46 and you can see my 600 yd accuracy in the pics
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With something as fast as a Swift, I would be reluctant going anything faster than an 8 twist
due to risk of bullet failure
----------------------
It's a big catch 22
We want to drive the heavies fast
but by driving the heavies fast, we risk blowing them up in a fast twist also
----------------------
I just looked - Berger List their 90 VLD with an OAL of 1.254 ; BC of .534
Now I was going to say, with the BC and accuracy I get from an 85.5 Berger
I have seen no need to try anything heavier
And if we compare the length of the 90VLD 1.254" to the 85.5 of 1.167"
We can see that the 90 VLD is QUITE a bit longer
for not much more BC
90 VLD BC .534
85.5 BC .524
----------------------
With the length of the 90 VLD, I'd be more willing to bet it actually needs the recommended 1:7 twist
which, might mean you would have to load down your swift in order to use them so they don't come apart due to the RPM's a Swift will generate in a 7 twist barrel.
I would honestly sell them off and buy the 85.5 instead
I know for a fact the 85.5 can handle Swift Velocities in an 8 twist
since it handles my Swift Ackley Velocities just fine.
Most of the guys using the 90's and 95 SMK's are doing so with 223's and 22 BR's in 7 twists
but only driving them up to maybe 3200 fps, which is SLOW compared to a Swift cartridge
---------------------
IE: I don't see anybody else driving these heavy .224 Cal bullets to Swift Cartridge Velocities
of over 3500 fps
and using 7 twist barrels
and living to brag about it

 

[cb186]

I assume this is going to be a long range(600-1000yard) varmit gun?
I think I'd go 7ish twist, because I doubt your going to get to 3400, and an 8 twist would be marginal even at that speed.
I'd also make sure I'd get a .219" bore barrel.

 

[ELR LVR]

I assume this is going to be a long range(600-1000yard) varmit gun?
I think I'd go 7ish twist, because I doubt your going to get to 3400, and an 8 twist would be marginal even at that speed.
I'd also make sure I'd get a .219" bore barrel.

Im getting 3650 with 85.5's
I dont think 3400 with a standard Swift is out of the realm
Of course as I mentioned a person could load down until it works if bullet failures are a result
of using a 7 Twist
but that would negate the very purpose of using a Swift
a Guy may as well use a 22 BR by then if it came down to that
----------
It may work in a 7.5 twist
I know my recommended twist is 7.7, but------------
I'm fine with approx 1 inch groups at 600 and using an 8 tw.
I have enough Berger bullet failures in 6mm 8 twist going 3400 fps
I could not imagine what would happen if I went tighter and the limited bullet selection I would be down to
I use to use a 9 twist in 6mm, just so bullets would stay together
there is a ragged edge of going tighter twist and having bullets survive,
finding it usually means adjusting velocity
and it sucks being forced to load down just because bullets won't reach the target
when a cartridge is capable of so much more
-----------
It's like having a Pumped 327, and having to retard the timing so much just to survive on todays gas lol

 

[Charlie-NY]

I'd get an 8 twist and trade away the 90VLDs which aren't needed for your intended use. 7 twist barrels are blowing up a lot of good bullets.

 

[cb186]

Im getting 3650 with 85.5's
I dont think 3400 with a standard Swift is out of the realm
Of course as I mentioned a person could load down until it works if bullet failures are a result
of using a 7 Twist
but that would negate the very purpose of using a Swift
a Guy may as well use a 22 BR by then if it came down to that
----------
It may work in a 7.5 twist
I know my recommended twist is 7.7, but------------
I'm fine with approx 1 inch groups at 600 and using an 8 tw.
I have enough Berger bullet failures in 6mm 8 twist going 3400 fps
I could not imagine what would happen if I went tighter and the limited bullet selection I would be down to
I use to use a 9 twist in 6mm, just so bullets would stay together
there is a ragged edge of going tighter twist and having bullets survive,
finding it usually means adjusting velocity
and it sucks being forced to load down just because bullets won't reach the target
when a cartridge is capable of so much more
-----------
It's like having a Pumped 327, and having to retard the timing so much just to survive on todays gas lol

Dang, you must REALLY be stomping on that thing. I think I was at 3550ish(from memory) on my 22creed with 75eldm's out of a 26" prairie dog gun.

 

[ELR LVR]

Dang, you must REALLY be stomping on that thing. I think I was at 3550ish(from memory) on my 22creed with 75eldm's out of a 26" prairie dog gun.

Actually, that is very respectable, considering the 22 Creed is basically an improved 22-250.
I will say I am using slow powder and a 30 inch barrel, so there is some free FPS there.
But my bolt lift is easy and I get no pressure signs.
I haven't tried to push it yet

 

[20 TAC]

Reading this thread with great interest. I was just thinking about an 8 twist Swift or Swift Ackley the other day and the prospects of shooting the 62 ELD-VT. I wonder what the ballistics to 500 yds and beyond would look like on that.

 

[357Mag]

I want to build a live varmint rifle in 220 Swift using a bolt action. I ended up somehow with about 300 of the Berger 90gr VLDs.
My Rockchuck hunts are at 3500ft or a bit higher.
We have much greater choices these days, any thoughts about a 7 vs 8 inch twist?

thanks,

Rich

ISS-

Howdy !

Wondering how far out your typical rockchuck shots are, and what amount of wind you typically encounter ?

What do you bias towards the front, in your cartridge / bullet selection(s)….
Flatness in trajectory, minimizing windage, ulltimately deliverable energy; tightest possible grouping ?

Doing internal and external ballistics comparisons, how does say…the 62ELD-VT
measure up to your terminal performance needs; compared to the heavy/longer
.224” cal VLD target bullets ?

Charlie-NY and TAC 20 brought up a couple of different approaches.…
Maybe the twist you can be happy with is “ slower “ than 1-7, 1-8; etc ?


With regards,
357Mag

 

[6MMsteve]

Primer pockets hold ok with that velocity, I always lost primer pockets maybe the brass is better these days been a long time

 

[Steel Mover]

I have a 22-250 AI with a 1-7 twist 26" that I built to shoot the 80 grain SMKs. It is actually more accurate at about 3:200 fps. I also have a 240 Laser with a 1-7 twist barrel that holds to right at 4,000 fps with 115 VLDs but will only shoot two bullets, the Berger VLDs of Noslers, the others just come apart due too the rpms. The Laser is a blown out 280 Remington with a 40 degree shoulder, shoulder length is .100 longer than the 240 Gibbs. Is formed with one shot, at a full charge, using a false shoulder.
If I was to build them again I would do a 1-8 twist so I might get more bullets to use and more powders to use.
Frankly I do believe the 6mm is a better choice than the .224 for distance, BC and velocity. The 240 Laser tied the world record for group size at 1,000 yards. It has a wicked muzzle blast from its 30"barrel. The creator, John Bass, shot it in CA at the LASC range to tie the record. I bought the rifle from John.
John said the Baby Laser is a better choice, yet, is a blown out 6 mm Rem with a 40 degree in a long action. Made by running a 243 reamer in until the bolt closes on a 6/rem go guage closes, then running a 243 AI reamer in. One day, I will do an old 700 action up like that with a Lothar Walther 1-8 twist 26" barrel.

 

[cb186]

Reading this thread with great interest. I was just thinking about an 8 twist Swift or Swift Ackley the other day and the prospects of shooting the 62 ELD-VT. I wonder what the ballistics to 500 yds and beyond would look like on that.

I switched to the 62vt out of my creed.
Here is my ballistic chart.

 

[20 TAC]

I switched to the 62vt out of my creed.
Here is my ballistic chart.

Thank you sir! Crazy how flat that thing shoots. Now to tell myself I don’t need another chambering….

 

[ISS]

I just got the itch for another Swift. My last ones were an OM70 and then a Savage BV12. I got enough input to go 1:8" twist.

thanks,

Rich

 

[Gary in MD]

Good choice, now if we could just get Lapua or one of the other premium brass makers to do a run of quality brass for the mighty Swift!

 

[danny]

I assume this is going to be a long range(600-1000yard) varmint gun?
I think I'd go 7ish twist, because I doubt your going to get to 3400, and an 8 twist would be marginal even at that speed.
I'd also make sure I'd get a .219" bore barrel.

Even if he does not use this only as a long range VARMINT rifle, he should probably be ok with extra twist if he elects to go short range with lighter bullets.

Danny

 

[medicineman]

What's the matter Rich...don't you have any more barrels for your 22-284 ?

 

[ELR LVR]

I have a 22-250 AI with a 1-7 twist 26" that I built to shoot the 80 grain SMKs. It is actually more accurate at about 3:200 fps. I also have a 240 Laser with a 1-7 twist barrel that holds to right at 4,000 fps with 115 VLDs but will only shoot two bullets, the Berger VLDs of Noslers, the others just come apart due too the rpms. The Laser is a blown out 280 Remington with a 40 degree shoulder, shoulder length is .100 longer than the 240 Gibbs. Is formed with one shot, at a full charge, using a false shoulder.
If I was to build them again I would do a 1-8 twist so I might get more bullets to use and more powders to use.
Frankly I do believe the 6mm is a better choice than the .224 for distance, BC and velocity. The 240 Laser tied the world record for group size at 1,000 yards. It has a wicked muzzle blast from its 30"barrel. The creator, John Bass, shot it in CA at the LASC range to tie the record. I bought the rifle from John.
John said the Baby Laser is a better choice, yet, is a blown out 6 mm Rem with a 40 degree in a long action. Made by running a 243 reamer in until the bolt closes on a 6/rem go guage closes, then running a 243 AI reamer in. One day, I will do an old 700 action up like that with a Lothar Walther 1-8 twist 26" barrel

Let me see if I have this right?
a 7 twist
6mm
shooting 115's at 4000 fps???
Were these Berger 115's the older stuff made by Walt or their newer offering?
---------
I've had plenty of 115 Bergers blow up on me at 3400 fps, so just wondering