Building a "308 British" No.4?

[LeeEnfieldNo.4_mk1]

everyone who shoots the .303 knows that finding .303 ammo that's affordable is hard to do these days. Reloading is the option that most go for, however unless you shoot cast (which I also do) finding good .303 bullets can be just as hard. I understand that some poeple have had decent luck shooting .308 bullets out of a standard .303 barrel, but that is hit or miss and I would like some consistency.

I have the parts for a .308 Win build with a stripped action and a take off DCRA barrel, and while that will be a great rifle it will lose a little but of it "charm" not being in .303.

So, how about a .303 chambered barrel with a .308 bore? I would allow you to use standard and common ,308 bullets and is modern rifleing was used would be able to take advantage of a larger selection of bullets since the Enfield rifleing seems to prefer flat base bullets only.

I remember some people doing this for a sporter but would like a military spec rifle.

How difficult would it be to get a barrel made up? I imagine the tricky part would be the front mounting point for the front sight.

Also, for reloading dies, would it be as simple as using a .308 expander in a .303 die?

As for cost, a few hundred all said and done is not a big deal for me. I could probably find a sportered No.4 for very cheap. The barrel and mounting said barrel is probably all I will need done professionally.

Thanks for any info.

 

[kawicrash]

My only concern would be somebody shooting a standard .303 cartridge out of it at some point. It would probably just swage the bullet down, but you never know...

 

[leebuilder]

Seen it done on another fourm. 308/303 you need a reamer with interchangeable pilots and a custom die so it is right. You could get by with an 308 expander but you casing wall thickness will have to allow for it. Front sights can be solder on.
I built two one in 22 and the other in 17HMR, was the easiest at the time learning for scatch on my own.
Be safe

 

[burnt_servo]

I've thought about this too .

for anyone with concerns about the bore being too tight , 7.62x39 rifles are built with 308 bores all the time .

if you compare 303brit to 30-40 krag , they are extremely similar .... similar enough that a person could use a krag reamer to cut a 303 brit chamber .
what you would end up with is the cases would be slightly larger . , they would have a longer neck and the throat would be cut deeper for heavier bullets .

the only downside I see is the long throat , in terms of accuracy with lighter bullets unable to be seated close to the rifling .

the slightly larger case capacity would lend its self to reducing pressures if standard 303 was fired in the chamber , the longer throat would also help keep the pressures down .

maybe this was the original intention of the dimensions of the krag , to be able to safely fire 303 british from the same rifle through a 308 bore.


green mountain barrels make inexpensive barrel blanks , if a guy has a lathe and time he could make a really nice project for himself

 

[Ganderite]

I have built as couple 308 Brit rifles. And plan on building a 308 Brit sporter on a #1 action.

I use a 303 Brit reamer, with no throat. Then throat the chamber with a 308 throater. Throat matches the 155 match bullet, which I have a lot of.

It will digest a regular 303, but the tight throat makes you try real hard to close the bolt.

I use old 308 target barrels. We cut 2" off the chamber end, so the chamber and throat is almost like new.

Here is a full wood one, complete with fake bayonet lugs milled into the barrel. It is pictured with a real 303 for comparison.

I prefer the 308 Brit because the rounds go into the regular magazine and feed with no problem.

 

[Cdn303]

everyone who shoots the .303 knows that finding .303 ammo that's affordable is hard to do these days. Reloading is the option that most go for, however unless you shoot cast (which I also do) finding good .303 bullets can be just as hard. I understand that some poeple have had decent luck shooting .308 bullets out of a standard .303 barrel, but that is hit or miss and I would like some consistency.

I have the parts for a .308 Win build with a stripped action and a take off DCRA barrel, and while that will be a great rifle it will lose a little but of it "charm" not being in .303.

So, how about a .303 chambered barrel with a .308 bore? I would allow you to use standard and common ,308 bullets and is modern rifleing was used would be able to take advantage of a larger selection of bullets since the Enfield rifleing seems to prefer flat base bullets only.

I remember some people doing this for a sporter but would like a military spec rifle.

How difficult would it be to get a barrel made up? I imagine the tricky part would be the front mounting point for the front sight.

Also, for reloading dies, would it be as simple as using a .308 expander in a .303 die?

As for cost, a few hundred all said and done is not a big deal for me. I could probably find a sportered No.4 for very cheap. The barrel and mounting said barrel is probably all I will need done professionally.

Thanks for any info.

I recall a thread last year that someone posted about ordering a run of No4 barrels with .308 bores. I cant recall the barrel manufacturer though.