UPDATE - 303.35 - Any and all advice thankyou !!

[Jacko]

G/Day folks, This is my first Wildcat cartridge. It is simply a .303 British necked up to .358.   I'm using a No1 Mk3 Lee Enfield action. I anticipate it will drive a 250 gr bullet at about 2200fps. Sure there is factory cartridges that are less effort, cheaper and more powerful etc but I have had this project in the back of my mind for a very long time.

I have a soft spot for the No1 Mk3. Until recently I owned an outstanding original No1 Mk3 1943 Lithgow. I sold it to a mate who will cherish it. The 303.35 goes back many decades in Australia and New Zealand. It's been reinvented many times but never made factory status like the 303.22 or 303.25 did

The rifle build is very early days and I anticipate it will take until late this year early next year to complete

I have received advice and most of it seems very good, some concerns me and I wish to confirm it here and ask for any more advice experienced Wildcatters are willing to offer

I have zero experience with fire forming, necking up or annealing brass but have been hand loading for my pistol caliber Levers for quite a while. Is annealing 100% necessary, I'm told no often and unless it's done right detrimental. I've researched this and feel if needed I could anneal with little trouble if needed - thoughts

I have bought Remington cases to learn how to neck up on. It's well priced and commonly available. I have been considering having the rifle head spaced 0.006 off the thickness of the rim - idea is to use tighter tolerances than the military spec to prolong case life, case life is important to me - thoughts

Best way to go about necking up the brass - I've been advised to use a tapered expander from a .358 Winchester die. On this advice I've ordered a set. Also to simply fire off .303 cartridges in the 303.35 chamber. I'm also aware of loading a mild charge, filling the case with a suitable filler , topping off with molten wax and fire forming. I'm an inpatient bugger and want to start playing with forming these cases before I get the completed rifle so this only leaves me with necking up. Gotta learn patience  - thoughts

I'm advised to have my Gunsmith ream a .303 Lee RGB resizing die as the case hardening is thinner than other brands to match my chamber as a cheaper alternative/ faster alternative than having RCBS or Hornady make a custom 2 die set, seems there's a 3 month wait. I have sent emails and received replies from them. Of coarse both want chamber specs and several fired cases first. Gotta remember postage, exchange rate , Obama can make exports from the USA very very expensive. I'm told just about any seating die will work, remembering I have a .358 Win seating die on order - thoughts

Full length resizing - some differing advice makes sense to me to full length re-size after necking up the case then neck sizing thereafter unless the case needs to be re-sized again? I've yet to research neck sizing dies and have had Super Simplex dies recommended. I have bought a Lyman Universal case trimmer and have a set of digital calipers

I have found some old load data , been advised of load data another couple of fella's are using, and reasoned?? my own data that all seem to match. Seems the 303.35 will fit somewhere between the 35 Remington and .358 Winchester in  terms of performance

Appreciate any further advice

regards Jacko

[trotterlg]

If I were to make one of these up this is what I would do:  First have the headspace set to .002 or a tiny bit more, it seats on the rim so you will have very little differences between cartridges, no reason to have more headspace than you need.  For dies, I would just take a set of 303 dies and run a proper sized carbide reamer through them for the neck, put a 35 expander ball in and you are done.  One pass through the die and you will have brass.  Same thing for cutting the chamber, a 303 reamer with the pilot bushed up to 35 and then just neck ream for the 35 neck.  You could probably use a .357 Mag reamer to do the chamber neck with.  This should be a dead easy project.  Larry

[Jacko]

Thank you for your advice Larry. My initial thoughts in my ignorance where it should be an easy project. My barrel will not arrive at the Smiths for another  couple of weeks so no real work will begin before then. I have printed off your reply and will speak to my Gunsmith.

This question probably highlights my lack of understanding of the workings of a rifles chamber - One point you made was that a .357 mag reamer may be the go for the chamber neck. I plan on using a 1 in 12 twist barrel and 225gn to 250 gr bullets for the majority of my shooting/hunting with this rifle, It will be a case of seeing which bullet shoots best. Is there any neck/ throat considerations I need to keep in mind.

275gn and 310gr bullets are also available and being a tinkerer by nature just know I'll get around to trying some out.

regards Jacko

[trotterlg]

There are always easy ways to do things, If you go with a .303 reamer, just press a undersized aluminum or brass tube over the pilot and then turn it to the diameter needed for your bore, that will keep the chamber centered on the bore, then any 38 reamer will cut the neck and lead as long as it is a rifle barrel reamer not for a revolver.  There are lots of really cheap 303 dies on Ebay, and you can find reamers there also, just figure out what you need for the resizing neck size and get one, I would guess about .370 or so, they should not cost you more than about $10.00, guess you will need to open up the bullet seating die also, but you can probably find a drill bit (either inch or metric) that will do that job, then just use a 38 cal bullet seater plug or make one up.  I made up a set of 20-06 dies from a 30-06 dies just by using some inserts in the neck of the dies.  Good luck, post some pictures and tell us how it shoots.  Larry

P.S.  A size "U" or a 9.4mm Drill would probably do for the sizer, a good one should be able to get through a die neck at least once. 

[Catfish]

Boy Jacko am I glad you ask that question. I just bought a lathe to do some chambering with and threading with and being into wildcat I now know where to post my questions for good advice. I always said it`s not what you know, but who you know. 

[Bull45cal]

Very true Catfish.  Larry really knows his stuff.

[Shortgun]

Lots of fellows have been making the 35 Remington RIMMED out of 303 brass for a long time. It is however not full length. It must be trimmed slightly. Use standard 35 rem dies, We are getting 2200 plus FPS out od 14 in contender barrels with 180 gr bullets. Quite effective on whitetails and such

[Jacko]

Thanks for the info Shortgun. Interesting you can reform 303 brass into 35 Rem. Last year when I bought my Marlin .44 mag I did consider the .35 Remington calibre Marlin. I had looked at load data for the .35 Rem a while ago and compared it against the .358 Win figuring the 303.35 would be somewhere in the middle. I since found a couple of fella's that have 303.35 and have supplied me with load data and I have also found a load from decades past that uses 41gr IMR 3031 powder for a 208gr cast bullet at 2150fps. I realise the powders formula may have evolved but it still compares favourably with the modern load data I've sourced.

Most promicing powder appears to be ADI AR 2208. I should be able to safely acheive 2100fps with 225 gr bullets and about 42gr of powder. Of coarse I will be starting my load development about 10% less then this. By comparision ADI list 39.5 gr AR2208 215gr proj at 2265 fps in .303 British calibre. I figure a bit less AR2208 than this is a good place to start due to the bigger bore of the 303.35 and corresponding lower pressures.

I am still waiting for the rifle. Finally received the Recknagel sights today and I'll drop them off to the Gunsmith tomorrow. Last I heard the barrel is still coming. I have sorted out the die's, necked up some brass just need something to shoot it in now. I'm not a patient man at any time but I just gotta accept it could be another couple of months before I get the completed rifle if I'm lucky.

regards Jacko

[bill439]

Why not use a 35 remington chambering reamer and use 35 remington dies with a 303 shellholder for the reloading part?

[Catfish]

1 think on loading dies, it might pay you to get a Bushing die set because when to neck out that muc your case necks will be relitively thin and you can get the bushing you need and not have to use an expander plug makeing your brass last longer.

[briannmilewis]

Any pix of the formed brass?

What game are you planning on shooting with it?

[Jacko]

Evening folks, been chipping away getting my 35.303 sorted this last few months. Here how she  looks at the moment and what I've been up too with it



Until recently I had settled on a very accurate load of 44 grains of AR2208 [ Varget for our US friends ] under a 225gr Sierra Gameking. The Rifle is capable of 3/4 MOA if I do my part, not bad for a SMLE !!!! This is a mild load, approx 4 grains under a max load that just seemed to find a sweet spot, recoil is mild and even though I'm guessing judging from other chaps I've tracked down that shoot 35.303's the 44 gr load is giving me about 2150 fps

Upon firing my case neck expands 4 thou. Too date I am up to my fourth reload with the Remington brass. I have neck sized only with a .358 Winchester die. I have a Lee RGB .303 British die that I had reamed so I could full length resize my brass as required but have only used it when necking up cases. I have found no need to anneal my Cases.

Gamekings are just about the cheapest .358 J word proj on the market here in Australia but at nearly $1 per projectile are now off my shopping list. I have decided to go with cast projectiles and to date have shot a Lyman 358315, a gas checked 208 grain Cast projectile with excellent potential. I was keeping velocity down to approx 1900 fps using 38 grains of AR2208. I have not got around to pushing it any faster as yet.

The ballistics with the 208 gr projectile defeats the purpose of the Rifle as it closely replicates my 1894 Marlin .44 mag's ballistics with Cast bullets. Also they are quite a short projectile and I worry about how reliably they will feed. I have decided to go to a 250 gr to 270 gr Gas Checked Cast Projectile with a view to driving them at around 2100 fps. Should make a respectable 200 metre thumper for Game too the size of Red Deer. Should be a capable 100 yard cartridge for larger game like Scrub Bulls, Camels etc if I ever gert the chance to hunt them

This is a photo of a Cast Bullet Engineering 358250 projectile seated in a case I have not fireformed yet. Cast using wheel weights, with lube and Gas Check it comes in a tad under 260 grains and a 225 gr Sierra Gameking in a fireformed case. Note the one calibre long case neck and the sharper shoulder.

The CBE 358250 projectiles will not chamber, my Rifles throat is too short.



After some consideration, research and several discussions with knowledable folks my Rifle is now at the Gunsmiths having the throat lengthened so that the longer heavier Cast projectiles will chamber. I hope to have the Rifle back for this weekend to test out some loads with the CBE 358250 proj.

I understand the possibility that the lighter shorter Lyman 358315 Cast and the 225 gr Gameking Jacketed proj may not shoot as well as they did, then again the extra jump may not hurt accuracy at all. Either way once the batch of Sierra Gamekings are gone I won't be shooting Jacketed again. There is potential for lower pressures to be generated with the longer throat and Cast projectiles and I'm confident I'm on the right path with these heavier Cast projectiles.

regards Jacko

[BBF]

Jacko:
Besides the price difference between jacket and self cast bullets, there is that sense of pride you get with making your own.

[Jacko]

Thats actually the greatest thing I've gained from this project scatterbrain. I may not have assembled the Rifle but it was assembled from parts I chose. Sure there is a few other 35.303's out there, but I had wanted this Wildcat for many years and the simple act of forming the cases, Casting projectiles, load development etc has given me a great sence of satisfaction as well as teaching me a hell of a lot in the process.

regards Jacko