Cast in 220 Rimmed 'Swift' or 22-303 Brit

[303Guy]

Yup. The 220 Swift is almost a rimless 22-303 Brit. I have a 22rf barrel or two with their 1-in-16 twist barrels and I want to build a dedicated cast 22-303 centre-fire rifle on a Lee Enfield action. The chamber will be screwed onto the barrel. The question is, can such a twist stabilize a decent cast boolit weight with such a large case? (The 22 hornet can).

An alternative is to use the 30-30 case instead.

I won't be paper patching this round. It's just too small! So plain cast it will be. I do of course plan on getting substantial velocities with this thing.:Fire:

[runfiverun]

i have done quite well with my 12 twist 223 at 2750 fps. with the rcbs 55 sp, similar to the saeco 248 which my ruger 358 win likes.
i hopefully will have time to work with my 14 twist 22-250 maybe this summer [doubt it]

a short boolit could help with your slow twist.
i have to inspect and weight sort each boolit carefully, and use a harder alloy 4/6/90 which i waterdrop.
i was using straight linotype but have been getting better accuracy with the 4/6.
but i really have to hustle with the casting and re heat the mold frequently to keep any mold consistency.

[HARRYMPOPE]

Crandall in Canada made the 303 -B 22 Varmint-R on the 303 Brit case back in the 1940's Meredith also did a 22-303.Elliot up north also played necking down the 303,he did a 25 but i cant remember if he did a .22.

A 1-16 Hornet i had did the 225415 1600 OK but the 225438 shot a bit better.You will be driving them faster so it may work fine.Should be a fun project.

HMP

[Bret4207]

Are the RF barrels intended for the LE action? If so it's worth a try. If they're run of the mill RF barrels I'm not sure there's enough meat there to chamber them.

[6.5 mike]

Lyman's cast book lists loads for the swift, might be a place to start looking. I just looked in my Ackley book, he shows two shortened 22/303 cartridges, .22 Varmint-R & 22/303(Sprinter), this one was made up be an Australian gunsmith. Both show a standard twist of 1 in 14", & a special twist of 1 in 16". The other was developed in Canada.

Another is the .22/303(.22 rocket or .22/4000). This one is not shortened, & was designed in Australia. Same twists are used. :drinks:. Their is some cast data for the Sprinter & the Rocket.

[enfield]

I did the 22 hornet conversion with a #1 mk3 using a 22 RF barrel and it wont shoot the Lyman 55 gr boolit at all. If I cut about 10gr off the nose or cut off the gas check portion of the boolit it makes a big difference ( I didn't check the barrel twist before but i think its 1-18) and almost all the 22's I have seem to be the same .

[Mk42gunner]

It also depends on what the 22 barrels are made of, or maybe when they were made. I read an article by Roy Dunlap about the Hornet, he said that a lot of the older Hornets made from 22 barrels had soft steel and were easy to shoot out.

I do not know if modern barrels are made of the same steel that centerfire barrels are or not. Shooting cast it may not make a difference.

Robert

[303Guy]

Bret, these are ordinary 22rf barrels. The idea is to screw the barrel with throat to the chamber portion to make up the complete barrel.

I would be quite happy with a 22 Varmint-R but case forming would be more complex hence the desire to simply neck the 303 down to 22.

I'm unsure of the steels used in iether of my two barrels but I do believe my Tozz has a 4140 barrel and with a 1-in-14 twist! The barrel I would like to use is a long Cooey Mod 75. It does not 'sound' like soft steel. More like a higher grade carbon or alloy steel. I believe it was a Canadian military training rifle.

I was surprized that my 1-in-16 twist hornet stabilized 60gr Hornady spire point j-words and it did it with good accuracy and punch. I settled on the 55gr spire point because it was much cheaper and had a slightly flatter trajectory. No ferral goat I ever shot at with it lived. (I had a loading technique that produced around 2720fps with those 55 grainers using compressed Lil'Gun and R-P cases). .224 bullets down a .223 barrel - worked just fine!

But - the hornet has a miniscule muzzle blast compared to a 22-303 although this Cooey barrel is rather long.

[1Shirt]

I would question any but the shortest of blts for that twist.
1Shirt!:coffee:

[303Guy]

The hornet it seems, will stabilize 55 and 60gr j-words with a flat base or very short chamfer with the 1-in-16 twist because of the low muzzle blast. Starting the bullet off absolutely straight into the bore is part of it. The fact that those bullets are .224 with the hornet bore being .223 may also play a role. The spire-point might also be slightly more stable than other profiles.

In conclusion, the 1-in-16 twist barrels I have may not be viable for cast.:-? Unless I look at round nose boolits

[paul edward]

The idea is to screw the barrel with throat to the chamber portion to make up the complete barrel.

Have you built two piece barrels like this before?

How well do they handle pressure?

Photos or drawing would help clarify how this goes together.

Intriguing concept.

[303Guy]

Have you built two piece barrels like this before?No I haven't. I'll polish up my drawing and post it.