Tikka M55 project

[kickinback]

Hi Jethro, where are you at with this at the moment?

[Jethro]

G,day Kickin,
The rifle is at the smiths awaitin the arrival of a barrel to be chambered and fitted.
In the meantime I have to get my finger out and get hold of a form die and a set of sizing and seating dies and send them to the smith to have them adjusted to suit the case. I just need to email sinclairs for some more info before I go ahead and order.

Jethro again

[Jethro]

G,day all
Sorry to restart an old post but I thought Id let you know where I'm up to with the Tikka 55 project.
I recieved the rifle back from the smiths with the new barrel fitted and chambered about a month and a half ago. Funds have been a bit scarce so I had to wait awhile to order a scope for it. I was going to give a Leopold mkII a try but I couldn't find one to look through. I was however very impressed with the Bushnell 4200 6-24 x40 P side focus Mildot so when they came on special at NVT I grabbed one.
Ive only just mounted it on the rifle today, thankfully with no mishaps this time. (I dropped the last scope I bought for this rifle while mounting it and f*#@&!d it).
This is how it looks to date.

Sorry about the Picture quality.
I haven't shot it yet as I'm waiting on some gear to get here from sinclairs so that I can finish making cases for it. It is 20cal based on a 222rem blown out to fit a shortened 204rug chamber.
The 3 groove 1 in 10 twist barrel is stamped 204 SH/1. The SH could mean either Shit hot or shithouse. depending on how it shoots.
Ive been forming a few cases. So I thought I would post a pic of the steps involved.

From Left to Right; 1, new 222rem case, 2, 222case annealed, 3, necked up to 6mm, 4, necked back down to 204 in one pass. And 5, fireformed and full length sized.

The only thing I need to do ( I hope) is determine the overall chamber length and then trim the fireformed case to the correct length.
Hopeful my trimmer will arrive from sinclairs and it will all fall into place this week. Then I can go

Jethro Again.

[MISSED]

Looking good Jethro,be intrested to see how the combination goes

Cheers

[ogre6br]

nice work there

Can I ask why when you are going from .224 to .204 you are going Via .243??

The guys who I have talked to in the states who are doing something similar are all necking down 222 (or 223) to .20 cal in one pass- without anneal or anything.
It's such a small change that there thinking is that it wont work harden the brass much at all.

You could creat a false shoulder in the 222 neck to get you good neck engagement so you cases are held and blow out well.

just asking

later
p

[dave]

nice work there

Can I ask why when you are going from .224 to .204 you are going Via .243??

Im no expert but that made no sense to me either, im sure theres a reason just hasnt come to me i guess......

[Jethro]

The original plan was to go straight from 222 down to 204, but when I sent the dies and some cases to the smith he advised me to go up to 6mm first as there wasn't enough false shoulder to reliably headspace from. I tried annealing a couple of cases and found that they ran over the expander and then through the sizing die a lot easier with better concentricity & less force required. Im using winchester brass ATM as its relatively cheap.

Jethro again

[Ned Kelly]

G'Day all,
i'm curious too. But I'll take a stab........

By annealing the case you can do a great deal of work to it before it work hardens too much. By expanding to 6mm them back to 20cal means you get a real good shoulder to ensure the case head spaces correctly in the chamber so you do not have head separations during fire forming or in the future.

But still wanting to know for sure

Cheerio Ned

[Jethro]

Yep, yer pretty much on the money there Ned.
Ive found winchester brass to be pretty hard straight out of the bag, so thought Id try annealing.
I just had another look at the pic of the case with the smoked shoulder and it doesnt really show the datum line that is around the false shoulder. I'll see if I can find another pic that shows the datum/headspace mark a bit better.
This project is as much about playing with cases as it is about building & shooting accurate rifles. It also keeps me out of the pub.

Jethro again

[Ned Kelly]

G'Day Jethro,
Thought so; thanks for that
Cheerio Ned

[Cranky Bugga]

Looking good Jethro What load did you use for the fireform?
I can confirm that necking 222 to 204 didn't really give a good false shoulder for positive headspace. By annealing the necks you also reduce the chance of cases splitting when they are blown out and you get a well formed case first up.
Cheers

[woob614271]

Top rig, mate. Look out bunnies, cats, foxes and whatever else takes your fancy...

[Mevo2230]

Thanks for updating the thread mate, it was very informative.

I am starting to think of starting a project rifle myself, it will be a 22, either an old lithgow or brno.

[ogre6br]

So who has load info on the 20/222??

Its one of my options for my .20 cal project
I'm leaning towards a 20/223- but will seriously consider the 20/222.

Whichever I choose will be a variety based on a shortened 204R chamber

SC- has told me my barrel is not close so I have some time before the decision needs to be made.

Thanks
later
P

[Jethro]

Ogre,
Starting loads can be worked out from Andy Montgomery's article on the 204-222 sprinter in the April -June Guns & Game. The sprinter is the standard 222 case necked down to .20cal with no shoulder improvement.
Cranky, I dont know what the load was for the fireformed case as the smithy did it when he test fired the rifle.
As soon as I get some loads worked up I'll let you know.

Jethro agian