PDA

View Full Version : Cast in the 220 Swift.



andym79
08-23-2014, 09:16 PM
Hi Guys, can anyone here tell me if they have had success shooting cast in the 220 Swift specifically in the 2000-2500fps range.

I am looking at a Ruger No1 single shot in 220 swift. 1:14" RH 26.00" barrel.

Bullshop
08-23-2014, 09:36 PM
I don't have a Swift but do pretty good work with a 22/250 with 1/14" twist at even a little bit higher velocity than 2500.
Most recently I have been shooting the NOE 55gn copy of the RCBS design with 31.5gn of IMR 7383 for a bit over 2700 fps for about 2 moa at 100 yards. Not the best accuracy the gun will do but certainly usable within about 200 yards.
It sure works to rid my pasture of small pests.

andym79
08-23-2014, 09:47 PM
Most recently I have been shooting the NOE 55gn copy of the RCBS design with 31.5gn of IMR 7383 for a bit over 2700 fps for about 2 moa at 100 yards.

Is reasonably accurate 3000fps possible with a 1:14 twist?

114335

I think this could be a nice bullet, though I would prefer a rounded nose!

runfiverun
08-23-2014, 10:47 PM
I think getting near 3-k is possible, and if any cartridge will do it it's the swift. [you'll be at 3/4 throttle]
I use the same loads in my 220 as I do in my 22-250 and they both shoot to the guns potential.

I just picked up a savage 112 single shot in 220 swift and have put only 20 rounds of j words through it so far.
it was super accurate with my standard 220/250 load and the only change I made was to seat out to the max oal
which is about .005 off the lands.

the rcbs 055s would surely be a good one to get to 3-k with I have pushed it near 2800 with very acceptable accuracy.
the HM-2 mold is very close but with more nose support and a little more body diameter to work with so it has potential, and the saeco 60 gr rn is super similar to both of them it should do well also.
I'd pick one of those and get started with a slower powder and focus on making the boolit have good contact with the ball seat area, and line up with the centerline of the barrel.

Bullshop
08-24-2014, 12:17 AM
Another trick to push the velocity envelope is to use a powder that is too slow for maximum velocity for the cartridge.
By that I mean lets say that for a 60gn bullet max velocity with optimum powder burn rate is lets just say 3600 fps.
Now if you go beyond optimum burn rate to still slower powders and find one that with 100 % density only gives 3000 fps you have the most likely candidate for powder that will give good accuracy at the intended velocity, 3000 fps.
The reason I believe is the gentler start of the slow burning powder is less damaging to the boolit and the longer push builds to the higher velocity.
The powder I am using IMR 7383 I believe has a burn rate somewhere between the two 4831 powders from IMR and Hodgdons. If you consult any reputable load data source you will see that this burn rate is beyond optimum for highest velocity with a 60 gn bullet/boolit.
The NOE design I am using was to be a copy of the RCBS 55 gn but boolits from my NOE mold sized, lubed, and checked weigh 62/63 gn.

Bullshop
08-24-2014, 12:31 AM
Is reasonably accurate 3000fps possible with a 1:14 twist?

114335

I think this could be a nice bullet, though I would prefer a rounded nose!
I think a 1/14" twist may be too slow for that boolit.

303Guy
08-24-2014, 01:16 AM
How long is that boolit? I've shot 60gr Hornady spire points in my 16 twist hornet with very good accuracy. I would guess the velocity to be around 2650 fps. A 14 twist might just work with that boolit. Then again it might not but I suspect it has a fair chance. It's a bit hard to choose to buy a rifle with the hope the boolit will work.

andym79
08-24-2014, 02:37 AM
Bullet is .690" long. From the calculator I used a 1:16 will not stabilise it, a 1:14 should however start to meet stabilisation at 2800fps.

I always let the twist get the better of me, glad I sounded this one out first!

So no its not a wise choice for a 1:14 twist (unless you drive it at 3000fps, but then there would be no guarantee of accuracy), perhaps a 1:12 twist.

I am looking at the rifle not the bullet. It just has lots of support.

Would be better to go for a 55 grain design, thanks for the suggestions runfiverun. The Lyman 225415 and similar projectiles should start to stabilise at 1500-1600fps!

The 1:14 twist however should be kinder on cast, though I suspect 2700fps would be the upper limit!

303Guy
08-24-2014, 05:07 AM
a 1:14 should however start to meet stabilisation at 2800fps. There was an online software for a while that allowed the bullet profile to be changed and it showed the stability over a wide velocity range. Some profiles were more stable at lower velocity while others (spitzers) became more stable at higher velocity. Some were less stable at subsonic while some about the same. Then there was transonic speeds and again some profiles were better than others. Then they publishers took it offline - pity. It also allowed the change of the stability factor giving the required twist or gave the stability factor for a given twist as selected.

Iron Whittler
08-24-2014, 05:59 AM
A grand old cartridge for sure. I managed to acquire a Ruger 77 Tanger in like new condition. Am looking forward to working with it(cast, swaged, & jacketed). Iron Whittler

Bullshop
08-24-2014, 11:18 AM
I have the RCBS and Lyman 55gn designs and the NOE copy of the RCBS design. All are good shooters in a 1/14" twist.
I rate the NOE as outstanding for a couple reasons. First and foremost it drops a slighter larger diameter both in body and nose. I lube them in a .228" die and it does not touch the body but is close enough the lube will not go past the boolit. I think they drop at about .2267" on the bands.
Second is that my NOE mold is a 5 cavity so the same amount of time spent casting produces many more boolits.
Still I can make a lot of boolits in an hour using a two cavity. With a well tuned up two cavity 22 cal mold I run at very close to five cycles per minute so an hour can produce about 300 boolits.
I have developed a special fondness for the NOE design but its likely not that it is a better design but just because I shoot so many of them compared to the others and that is most likely due to the fact that it is a five cavity and so when I need more boolits is the one I go for.
Truth is for a 1/14" twist any of the three mentioned designs will do well assuming the mold drops a large enough diameter for the particular rifle being used.
There are others available that will also work and I have quite a number of other 22 cal designs but these are the ones I have the most experience with used in a 1/14" twist.

runfiverun
08-24-2014, 11:58 AM
the main reasons I mentioned the ones I did is I have used them to push the 22's to higher velocity,
and the rifle is a ruger.
in my experience with the rugers boolit shapes like the rcbs 055sp and the saeco #245 for the 358 win have held up to near jaxketed velocity's.
and have maintained accuracy very well because they are pretty good imitators of the ruger throats.