My project has begun! I shall be boring out that old 303 barrel and cutting the rifling myself! The target is a 375/303 for reasons of not wanting too much recoil but having a 'straight' walled case keeping the original body taper. Bigger is tempting because it would be easier to make a bigger rifling cutter! My first step will be to build a rifling attachment for one of our lathes. Because I want to shoot cast lead bullets, I shall be giving it four grooves. I have been thinking of the two-groove Lee Enfield type bore which swages the bullet to bore diameter with rifling 'ridges'. We'll see when it comes to cutter time! My thinking here is that this method removes the least amount of material, making it that much easier to cut.

Have fun!
Post lots of pics of the stages please...
Those 225 grain 375 projectiles will be good for this one..

Just a question: Boom Stick , why don't you get that political shit off your signature? roger

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Originally posted by bartsche:
Just a question: Boom Stick , why don't you get that political shit off your signature? roger

Because I like using my 1st and 2nd amendments

You could put one in yours...

what are you building it on ? I have ap14 in 303 epps that i am considering rechambering to a 300 win case firing a 215 grn 303 projectile.

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what are you building it on ? I have ap14 in 303 epps that i am considering rechambering to a 300 win case firing a 215 grn 303 projectile.

I plan on using an old Lee Enfield - a Long Tom. Oh, I am not looking for high performance, just dead pigs and deer!

If you already have a 303 Epps on a P14, you are pretty close to 'enough' performance already! Have you tried loading the Epp's to higher working pressure? If you lube the cases and headspace on the shoulder your case life should be quite good. Just wondering. The P14 is such a strong action! But 303 Win Mag does make sense! It's just that a hot 303 Epp's could be fun too. You would be able to get that bullet to around 2500fps I should imagine. I have a few 215gr projectiles.

Any tips on boring and reaming the barrel out prior to cutting the rifling?

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Originally posted by 303Guy:
Any tips on boring ?

No, but why do you have an avatar of Bruce Willis?

My question, how do you rifle a barrel with a normal lathe?! I didn't know that was possible. Cool project you got going here though! Seems to be a lot of .375 cartridges popping up recently

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No, but why do you have an avatar of Bruce Willis?

You want to see me clean shaven and with short hair! I didn't think that picture looked like him, though.

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how do you rifle a barrel with a normal lathe?! I didn't know that was possible.

Not normally no, but the idea is to use the lathe to drive the rifling cutter. What I have to do is make up a geared drive to rotate the head while the cutter is being drawn through. Ideas given to me are to use a fixed chain to rotate the input shaft of a worm drive. The only one I have that would work at the moment would have to be geared up quite a bit. That's an indexing head for a mill. Perfect but for the gear ratio. But you have given me an idea to drive the indexing head shaft via the auto feed shaft. Mmmmm.... thanks!

Say, would I be correct in thinking I could use 38-55 Winchester load data for cast bullets in my 375/303?

The .38/55 is about the same length and the case is a little smaller in diameter. Pressure for the .38-55 is way lower than the .303.

I think your cartridge will be the same as the 37 Rimmed. I'm not sure where you'd find loading data but I'd guess that high end 375 Winchester loads would be a good starting place.

Ray

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I think your cartridge will be the same as the 37 Rimmed.

Thanks for that. The 37 Rimmed turns out to be a 30-40 Krag case for-runner or spin-off. For all intents and purposes the same. Interesting!

My cartridge will not have the 'shoulder' as shown in the 37 Rimmed drawing.

I can't understand why the 30-40 Krag hasn't retained a place with cast bullet shooters - it just seems to be an ideal case design for that.

quote:

Originally posted by 303Guy:
My cartridge will not have the 'shoulder' as shown in the 37 Rimmed drawing. Roger


I can't understand why the 30-40 Krag hasn't retained a place with cast bullet shooters - it just seems to be an ideal case design for that.

Propably for many of the same resons I can't understand why every cast gas checked bullet shooter don't own at least three short barreled, slide action 35 Remingtons. OK that problem is solved.

Gun sales were and are marketing driven and it's supporters are fickel and easily lead. roger

bartsche, I haven't been able to open the file you sent me on barrel length and stuff. I am at the point on deciding how long (or short, really) to make my barrel. I have cut the barrel down t0 20 1/2 inches. I don't want to have to bore and ream and rifle more than necessary. I cannot help thinking I might have to cut down the last bit of muzzle after rifling. This thing is likely to have a 50mm (2 inch) extension of the barrel for the suppressor/muzzle break which will be a overbarrel type. That will take care of recoil and muzzle blast. I am wanting to achieve around 2200fps with a 250gr bullet and perhaps 1800fps with 300gr cast or 250gr cast. Pressure limit is 43,000 CUP. (For cast, that would be more like 35,000 CUP I should think). Would an 18 inch or shorter barrel give me that?

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... three short barreled, slide action 35 Remingtons ...

You have three of those? My Dad hunted Cape Buffalo with one of those! He loved it! Do you have any pics you could share? I would love to see what he hunted with looked like.

quote:

Originally posted by 303Guy:
bartsche, I haven't been able to open the file you sent me on barrel length and stuff. I am at the point on deciding how long (or short, really) to make my barrel. I have cut the barrel down t0 20 1/2 inches. I don't want to have to bore and ream and rifle more than necessary. I cannot help thinking I might have to cut down the last bit of muzzle after rifling. This thing is likely to have a 50mm (2 inch) extension of the barrel for the suppressor/muzzle break which will be a overbarrel type. That will take care of recoil and muzzle blast. I am wanting to achieve around 2200fps with a 250gr bullet and perhaps 1800fps with 300gr cast or 250gr cast. Pressure limit is 43,000 CUP. (For cast, that would be more like 35,000 CUP I should think). Would an 18 inch or shorter barrel give me that?

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... three short barreled, slide action 35 Remingtons ...

You have three of those?

Sorry "Kiwi"(term of endearment)I didn't say I even had one. Read again.Actually the implication was that in a 35 cal the capacity of the 35 Rem.is just about optimum for driving a 300 gr. gas checked bullet at its max. velocity.That that cartridge made its fame in a slide action in part is just a big plus.
I'll check what I sent you but off hand there are no bells ringing. It seems reasonable that a 20" light barrel should get the job done nicely in a walk around modified Enfield. roger

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I didn't say I even had one.

I was just making sure (and hoping!)

I am planning on going down to 18 inches then adding 2 inches with the suppressor overhang. Thanks! (I have done a trial boring out using the off-cut piece of barrel. I have the means now to set the twist rate using our mill. I hope to do the boring next week if other projects don't intervene.)

Well folks, the recession is biting hard! I could be next! This means my 375/303 project will get shelved untill things pick up. Pity! Oh well, at least I still have my other rifles to hunt and play with.

I may have to move if I lose my position but I'm sure I'll get back on line eventually. (I'll be finding out on Tuesday who gets axed).

quote:

Originally posted by 303Guy:
Well folks, the recession is biting hard! I could be next! This means my 375/303 project will get shelved untill things pick up. Pity! Oh well, at least I still have my other rifles to hunt and play with.

I may have to move if I lose my position but I'm sure I'll get back on line eventually. (I'll be finding out on Tuesday who gets axed).

My prayers go with you. roger

Thank you bartsche. Of course there is an upside - none of my guns are actually worth much so I won't be selling them off!

I took one of my workmates out on a hunt yesterday - he is new to hunting and I have just helped him find a rifle (a nicely sporterised No4 Lee Enfield) and both he and I were very pleased with our No4's. He had shortened his barrel and this proved to be a great advantage in our bush. He only got mut in the muzzle once. Mine did well with zero mud - my muzzle device did it's job splendidly! But, I did collect a whole lot of gunk in my action. I now want to complete my project one way or the other as it is a MkI which means it has a bolt cover. Maybe I can lap the bore out to 8mm and get it to shoot straight at bush ranges. (Think of Rambo in the jungle or the old Tarzan in the jungle movies - in the rain! It's fun and cold and wet).

Hey, you know, thinking about it, I am still an good terms with my employers so maybe they would let me come in and complete my projects. Mmmm ..... worth asking!

quote:

Originally posted by Cheechako:
I think your cartridge will be the same as the 37 Rimmed ...... Ray

Thinking about this, would it be an idea to use this principle to allow for the 'dough-nut' that inevitably forms when opening out a 303 Brit case to 375? That way, I would not have to worry about it's presence as it would be in the new 'shoulder'.

Mate watching with interest, just recently i finished a 303-35 (.35 territorian), 20" barrel with 1-16 twist (to aid in shooting GC cast), built on a No4 savage action.

The 303-375 was a close second as far as calibre choice though.

Paz