220 Swift AI neck size?

[Raider1v1]

Right now i am building a slow-er fast .22. I landed on the 220 swift AI as it appeared to be a decent balance between the speed and barrel life etc. vs the 22-243, 22-6mm etc. It will be a 1:12 shooting the 53gr hornady's. The barrel will be a 26" finished, full profile.

I dont want to have to turn necks on the norma cases that i bought, but im stuck on the diameter of the neck. I called PTG and their neck reamers are tapered a bit. They are .2625 at the "base" and .2610 at the top. Is this standard, or how should i go about picking the neck diameter? I want to go with whats standard for this 220 swift case.

 

[357Mag]

Raider -

Howdy !

FWIW -

The 4D Reamer rentals website lists a .220 Swift AI available for rental.
The print for that reamer shows .261" OD for the neck @ the shoulder juncture. and also for the case mouth.

https://4drentals.com/product/220-swift-ackley/

I DK whether that helps any ?


With regards,
357Mag

 

[Raider1v1]

interesting!

I looked at the standard 220 swift and its .2615 / .2600. Then the AI is .2610 .2610. I wonder why there is a difference. Is there a recommended range of clearance that i should follow? this is my first time building something to this spec, normally i just call up and order a standard chambering.

 

[357Mag]

Raider -

Howdy !

I am wondering about the 1-12....

Slower twist:
53's will shoot just great from a slower 1-14, as will the other common .224's like 55gr; and even some 60s.

Faster twist:
Living in SD as you are, perhaps you have some PD work in mind ?
If so, and given the case capacity you'll have; why not set the rifle up for potential application out as-far-as 1,000yd ?

Why I say that:
While living in NE Indiana, I shot groundhogs w/ my " .22-35 Remington " wildcat.
It has case capacity between than of a .22-250, and a .22-250 AI.
I used the .22-35 and prototype 55"V"-Max to get into the 500yd club on a 510yd groundhog kill.
That was about as-far-as I wanted to push a 55, and expect a predictable outcome.

Afterward.... I had my Wichita WBR1375 action rebarrelled from a 24" SS 1-14 Hart .224" cal to a 28" SS 1-8 K & P .224" cal 5-groove. My thought was to go for a 1,000yd groundhog kill.
I did load work-up using Hornady 75 "A"-Max exclusively.

Ideally, I wanted to have 450 ft lb available @ 1,000yd, but my choice of a 28" ( to allow gun to fit an AirGlide ) held me just short of that energy threshold. I found out that a 29" would have fit, and that length would have put me right in the desired energy sweet spot.

I moved from NE Indiana w/o ever getting to take that 1,000yd shot.
But, that did not in any way prevent the rifle from being capable of making such a shot.

My point:
Take a clear eyed look @ what distances you might want to shoot in future.
The .220AI has a lot of performance capability. Why not position yourself to exploit that ?


With regards,
357Mag

 

[Raider1v1]

Yes, this will be for prairie dogs! The reason i chose the 1:12 is thats what hornady reccomended, well really 1:11, but i cant get that from shilen.

I have a fast twist 243 that shoots the 105 amaxs. My longest confirmed pd kill is 928 with that. The 220 swift will replace my 204 ruger.

So you think the ptg neck specs are ok?

 

[fredo]

Right now i am building a slow-er fast .22. I landed on the 220 swift AI as it appeared to be a decent balance between the speed and barrel life etc. vs the 22-243, 22-6mm etc. It will be a 1:12 shooting the 53gr hornady's. The barrel will be a 26" finished, full profile.

I dont want to have to turn necks on the norma cases that i bought, but im stuck on the diameter of the neck. I called PTG and their neck reamers are tapered a bit. They are .2625 at the "base" and .2610 at the top. Is this standard, or how should i go about picking the neck diameter? I want to go with whats standard for this 220 swift case.

Only one way to know for sure...
Seat a bullet in one of those Norma cases, then measure loaded rd. neck diameter. As long as it measures under .259, you will be fine to use that .2625-.2610" reamer.

You can also look at another way. That being, to 'solve' for max. neck diameter, which is very simple:

Chamber neck diameter = .261
.22 cal. bullet diameter = .224

.261 - .224 = .037
.037" represents the remaining 'space' left over in that (.261") chamber

With that value established, you'll want to subtract .002-3". That is to allow room in the neck for your brass to expand and release the bullet upon firing...VERY IMPORTANT!!!

So, .037 - .003 (to be safe) = .034" This value is the total 'thickness' allowed of your brass neck.

That said, you must now that divide .034 value by 2, to represent both 'sides' of the cartridge neck.
.034 / 2 = .017"

.017" then equals the MAX. neck thickness that your brass can be, in order to "safely" work in a .261" nk. chamber.

Considering that, I'm not aware of any .224 cal. brass that has necks as thick as .017" (not even .223WSSM brass)

Long story, long... you should be just fine with a .261" neck for your .220Swift AI
(but again, check & verify for yourself!!!)


As a comparison, the loaded rd. nk. dia. on my .22-243AI (using necked down Lapua .243 brass) measures ~.254". And I use a .251" bushing for resizing...

Have fun!

 

[mikecr]

I dont want to have to turn necks on the norma cases that i bought, but im stuck on the diameter of the neck.

Measure your neck thickness & go from there.

 

[Raider1v1]

so i measured 15 cases, they are all mainly 0.15 thick. there was a couple that were 0.17 and one that was 0.18. with a .224 bullet that puts me well under both reamers size.

you think i should go for .260? or do .261?