Hi folks. What problems might I expect necking a 303 Brit down to 224? Will I be routinely turning necks? Should I be planning on a thicker than 'normal' neck (and designing the chamber to suite)?

quote:

Originally posted by 303Guy:
Hi folks. What problems might I expect necking a 303 Brit down to 224? Will I be routinely turning necks? YES Should I be planning on a thicker than 'normal' neck (and designing the chamber to suite)?NO

It would be prudent IMHO to have your neck wall thickness no greater than .013" and no less than .010" with the optimum around .011". This will allow you good griping , adequate expansion to seal the gas and controlled brass fatique.

If you are serious about wildcating you might consider getting a set of Butch,s bushings if he has any left. roger

Thanks for that bartsche. You say no to the custom chamber. Does that mean the thickness you recommend will fit a standard chamber? I fellow at work had a 270 which he said did not require neck sizing - the neck had enough tension after firing to hold the bullet. He claims very tight groupings. It must have been a 'sniper' rifle! (Actually, he bought it as a target rifle).

Not "problems" but "steps."

One pass will probably cost you about 100% ruined brass. Half dozen dies and it should work o.k.

BUT!!!: Anneal, anneal, anneal. I am guessing at least twice. You will be work hardening A LOT. Dip neck (worked area) in molten pure lead is good. (Alloys not hot enough. Better than nothing, but pure lead hotter, better.) Hold case rim in fingers, dip neck --Unprimed or Fired Primer, please-- and drop in water when it begins to hurt fingers... the other, more time consuming has you use propane to light pink in a dark room or templac, lacquor or grease crayon, with melts at desired temp... base of case in water. Knock over when neck hits temp to quench/anneal.

.303 body is a bit smaller than most rimless Mauser so you could go 7mm as in 7/08, 6.5 as in .260 Rem. or 6.5 Swede or 6.5 Dutch or ???; 25?? .257 Roberts? .250 Savage...; .24? .243 probably... then... .22/250? (Got your wildcat dies as yet? Epps might have some used for sale.) Self abusive? You could start with a .308 die since the neck is starts at .303... (ha, ha).

I have assumed you have not blown out the shoulder, not yet anyway. Used die sets and single dies are common and cheap at gun shows up here. If necessary, you can cut the die in two with a carbide saw. Hacksaws might and might not. Hard, hard, hard...

With the price of fuel, you might want to save this for the basement during the cold season. Not Xmas there as I recall from an Aussie exchange student I knew a bit in school, many, many yrs. ago. luck.

Taking a 303British to 25cal is a one step operation, 22cal will be another. I'd personally turn necks. I've considered rebarreling my P14 303/25 to an old hellcat 303/22Improved to build an 'old World varminter' ... see if it'll give the Swift a run for its money with a fast twist barrel. Keith Bridgeman at Sprinter in Sth Australia has all these old reamers.
Cheers...
Con

quote:

Originally posted by 303Guy:
Thanks for that bartsche. You say no to the custom chamber. Does that mean the thickness you recommend will fit a standard chamber? I fellow at work had a 270 which he said did not require neck sizing - the neck had enough tension after firing to hold the bullet. He claims very tight groupings. It must have been a 'sniper' rifle! (Actually, he bought it as a target rifle).

If your equipment will give you great alignment and concentricity than you can go with tight necks just as I have known some bench rest guys attest to. I've heard numbers like .001" clearance.

Some dies have produced wall thickness variations on necked down brass from .019" to .012". This was on the same piece of brass from side to. Neck turning sure helps in a case like this.

Here are some wall thickness measurements just taken. You can draw yuor own conclusions on chamber neck demensions needed to make these all tight.
.222-

w-w cases, .006" to .010"

F.C. cases .007" to .095"

.223-

Lc-04 cases .0075 to .0105"

Lc-03 ni case .0075" to .0095"

F.C. cases .008" to .0095"

.22-250-

F.C. cases .011" to .0122"

Win. cases .0105" to ..0125"

PRVI. cases .010" to .0125"

Frontier Cases .0102" to .0112"

SL-53 formed with no neck turning .016"
to.017"

.243 WSSM F.C.case .016"

.30-06 win. .015"**KA73 .012"

30-30 Peters case .010"

.303 Savage UMC case .014"

7.62x54 win case .009" to .011" same case

.270 WSM .014" to .016" same case

.303 Brit. .009" to .012"same case

If you PM me your E-mail Address I'll send you some interesting forming photos.

FYI--I just finished neck turning 150 cases for one of my wildcats.

As to your referece to a std. chamber? I'm not sure what that is when talking wildcats or specialized chamber tools.

The suggested anealing process; well, there have been some good threads on AR you can look up and glean a lot of good info. roger

Thank you bartsche. I'll PM you my e-mail address.

I intend turning a split chamber/barrel, mainly to be able to do the work on a lathe without reamers and also I have a barrel that is too small for a chamber (other than a hornet chamber).

Thanks iiranger. I was wondering whether I could anneal that way! (I have batch of loaded rounds I want to unload to aneal but that would mean de-priming! Better to just shoot them off and suffer a few split necks).

I did consider the 257 Roberts and the 6.5 Swede. I would rather go 6.5x57 (or is that 6.5x58? - the 6.5 Portugese?) Then I thought I could 'improve' the 303 case to get similar capacities. I have located a barrel in either 6mm or 6.5mm. But I already have the 223 barrel so I thought it would be a good place to start and once I get that right I can start spending money. Besides, the thicker neck seems like a good idea from a neck turning point.

Oh... We don't sit around waiting for spring - we go hunting! It only rains in my parts. Actually, it really rains! We walk around in slush! But it is fun! Wet and cold, but fun. And steep and slippery! I have had mud jammed up my rifle muzzle. We all did that day.

quote:

... old hellcat 303/22Improved to build an 'old World varminter' ...

Well, Con, the 303 case is 'almost' a rimmed Swift. Now, that is exacly my thinking - well, almost - since I have to keep pressure to 303 level which is why I want the 303/22Improved - to get Swift performance at 303 pressure. Do you have the cartridge dimensions for the 'hellcat'? Maybe I can contact Keith Bridgeman. Would he mind if I e-mailed him?

By the way, how hard will a medium pressure, large case cartridge be on a barrel? I suspect the barrel I have is of ordinance steel. It has a 1 in 15 twist.

quote:

Originally posted by 303Guy:

quote:

... old hellcat 303/22Improved to build an 'old World varminter' ...

Well, Con, the 303 case is 'almost' a rimmed Swift. Now, that is exacly my thinking - well, almost - since I have to keep pressure to 303 level which is why I want the 303/22Improved - to get Swift performance at 303 pressure. .

In order for you to achieve Swift performance your PV will have to be close to that of the Swift or 3.2 cc x 63000psi. If your working max. pressure will be 45000 psi. You will need a cartridge with a useable capcity of close to 4.5cc. The .303 brit has a usefull capacity of around 3.3 cc. It would appear that you are talking about a 36% capacity increase with your intended improved case. That is more than the capacity of the 30-06 case.
There is no intent here to rain on your parade. your project is interesting and your direction is sensible. Your expectations may just be a little high, but I've been wrong more than once. roger

quote:

There is no intent here to rain on your parade. your project is interesting and your direction is sensible. Your expectations may just be a little high, but I've been wrong more than once. roger

Thank you bartsche, that is exactly what I was wanting to hear! Any idea what my expectations should be when doing an Ackley improvement on the 303 case? I will, of course, accept reality and live it. I am guessing I should be able to drive a 60gr bullet to 3300fps or a 55gr bullet to 3400fps - max, depending on suitable powders. (Long barrel, remember).

My rough calculations show you will get about 3.65cc max and a 3170fps velocity with the 60 gr. bullet. These are really broad brush calculations; your 3300 fps may be closer. I doubt if you erver burn that barrel out in this life time. rogerroger

303Guy,
The 'hellcat' was my description. There was a full-length blown out 303/22 variant that was said to run with the 220Swift in a P14 or M98 action and at similiar high pressures. Whether the old timers actually chronographed it is another matter. I've only had experience from a mates No4 in 'standard' 303/22 and it was a 'hot 223Rem equivalent'. You'd need the P14 action to start getting significant speed gains, plus have all the taper blown out.
There was also a rimless 303/25 and 303/270 ... not sure if they ever necked that case down to 22cal. Keith Bridgeman is the one to talk with, I'm pretty sure his father had something to do with designing the rimless versions and the reamers are probably still in his (Sprinter's) workshop.
Cheers...
Con

I have a .303/22 on a No4 action, a .303/25 on a SMLE action and a .303/270 also on a SMLE action. I don't have forming dies (obtainable from Jansa Arms in Australia) but use the Redding bushings in a Redding die to reduce yhe neck diameter - and at least two anneals. It takes me 3 passes with different bushings to get to .303/25 - I'd love to do it in one. As to .303/22, until I got the sequence - including one pass through a .303FL die to set the shoulder back - right, I lost 2 out of 5 cases, but now I can do a run of 20 without loss.

My .303/22 was made by Canterbury Gunworks - they have the reamer - using a large diameter .22LR BSA barrel with a 1/16 twist. In deference to the barrels .223 diameter and twist, I have only used 40gr .223 Hornet projectiles driven at 3100 fps - a Super Hornet so to speak - under 1" at 100 yds. Oddly enough, I put the .303/22 up on Trademe with cases and .303/22 dies - No takers. I'll try again in a few months.

Thanks for the replies Guys.

Interesting that Canterbury Gunworks used a 22lr barrel. That means the BSA barrel is of tough enough steel. I'm not sure what steel my barrel is but it is 22lr and has a 1/15 twist. (Odd for a 22lr but then my Toz barrel has 1/14). I shoot 224 bullets in my 223 bore hornet. It stabilizes 60gr bullets with it's 1/16 twist, so....

A 'hot 223Rem equivalent' sounds good. The velocity I am hoping to get would be equal to or less than the starting loads for a Swift which would be about a 'hot 223'. So, bartsche, you would be correct.

Thanks for the run down on sizing. Not quite a walk in the park but do-able!

303Guy,
Just be aware that some of the barrel burning stories floated about the 220Swift may have been due to the use of 22RF barrels. At the time of the Swifts introduction, it would have been mighty tempting for backyard 'smiths to use 22RF barrels if available.
Cheers...
Con

Stuart Elliott in Queensland sells my 9 die case forming set. It should solve your problems.
Butch

Thanks for that butchlambert. I will keep that in mind!

Con, that makes sense. It's what I want to do. I was comparing the 22-250 to the Swift and could not figure out how the Swift could be any hotter! My problem is to figure out what steel my barrel is. It look’s tougher than 'normal' 22lr steel (some 22lr's use 4140 barrel steel anyway but this one is too old for that). If it turns out to be less than ordinance steel, I will use it to re-barrel my hornet or build something a lot milder. (I don't have a 22 magnum in my safe). It's just that my 'needs' call for a long-range varminter and I have the No.4 and this barrel and I like experimenting and doing things myself!
So, from the help from you guys, I look’s like I shall opt for a straight walled 303, necked down to 22, keeping pressure to normal 303 for the sake of barrel life. I intend to neck turn. I also intend to make a set of forming dies and loading dies - just for the sake of experimenting and knowing that they were mine!
I have already done the scope mount base - made from alloy bicycle crank arm, and keyed into the charger bridge. This has already passed the drop test - I dropped it onto concrete, scope first! Both scope and mount survived with no damage! After cleaning the imbedded sand from the rubber eye-ring, the rubber slowly regained it's smoothness. The base is screwed and glued and there is no cracking of the glue. So, for once my overkill paid off!

I have mentioned before that I intend having a switch barrel system for this rifle. Nothing more sophisticated than a custom barrel wrench and receiver clamp and two scopes! I should be starting on the clamp next week.


I have just acquired a rear drive shaft, which I might use for the chamber! If too tough to machine then I will use some 4140 I have kept for the purpose.

I sure whish I had your energy! roger

Aahh... well ... actually ... ummmm ...
No, I don't have energy. It takes me like forever to do things! But it does keep me stimulated! Just today I subsided into doing just one simple project - an expander plug to open sized case necks to to take a paper patched bullet. (I got it just slightly too big but it will work for now).


Oh, this is where I got my estimation from;

quote:

60 GR. NOS PART Hodgdon Varget .224" 2.680" 33.0 3242 40,000 CUP 36.0 3473 49,000 CUP
60 GR. NOS PART Hodgdon H4831 .224" 2.680" 41.5 3252 41,600 CUP 46.0C 3556 51,800 CUP
55 GR. HDY SP Hodgdon Varget .224" 2.680" 34.0 3516 47,000 CUP 36.0 3645 51,900 CUP
55 GR. HDY SP Hodgdon H4831 .224" 2.680" 41.5 3194 36,600 CUP 46.0 3616 46,600 CUP

Both those powders are available to me but I will regard those figures as guides only. I do not see myself running at pressures above 45 000 CUP.

bartsche,
Being down under causes the blood to pool in our heads ... we do crazy things. Like the wildcatter with a 17/22-250 with 52" barrel (two barrels welded together) who also almost straight-walled a 50cal Browning to do a 0.729" beast.
Cheers...
Con

quote:

... two barrels welded together ...

Welded or sleaved with a press fit? The rifling could quite easily be properly aligned. Mmmmm .... Do-able!

No, not kidding!

I have a crazy idea of my own. It's to build a 22 BB Cap rifle using a piece of barrel someone cut off, by bringing it up to length with an integral silencer. The motivation is that we have rabbits on small holdings where using a 22lr is a bit risky and I couldn't be bothered with an air rifle. That one is two or three projects down the line. It will take a while as it is going to be a repeater!

quote:

Originally posted by 303Guy:
I do not see myself running at pressures above 45 000 CUP.

My error I was holding the 303 to 45000 psi and don't have the foggiest what that relates to in cup. Just a hole in my knowledge bank.
?? roger

If you go to this link
http://kwk.us/powley.html

hold your cursor over "pressure", near the box with psi beside it and a graph giving you an approximate conversion from CUP to PSI should appear

quote:

I was holding the 303 to 45000 psi and don't have the foggiest what that relates to in cup.

That would be about 40,000 CUP and might well be a more realistic pressure.

Thanks for the link tbolt, I notice that the CUP reading is higher for a larger case with the same piezo pressure reading! That would be due to the copper crusher reacting to mean pressure.