Brit 303 SMLE

[ourflat]

My neighbor gave me a Mosin and a Brit 303 SMLE. He’s a great guy! I want to shoot the 303 in the near future. My serviceability inspection went well. I slugged the Brit 303 SMLE bore with cerrosafe and measured the case, case neck, bullet, etc. with my digital calipers of the internal bore of the barrel.

My numbers are displayed in the attachment. I would like to build a few loads since buying ammunition for this gun is outrageously priced right now.

What do you recommend for a bullet size based on my barrel chamber measurements?

Frank

[Bloodman14]

Try a standard .316 diameter boolit first. NOE's 316299 and Accurate's 316215B are what I would recommend. If you don't have molds, PM me your address, and I will send some to you, ready to load.

[ourflat]

Try a standard .316 diameter boolit first. NOE's 316299 and Accurate's 316215B are what I would recommend. If you don't have molds, PM me your address, and I will send some to you, ready to load.

Thanks BM but let me pay you for them. I appreciate you quick response. I’ll PM you….

Frank

[Eddie1971]

I agree the NOE .316 is the way to go. My SMLE loves this head and my Mosin 91/30 too. Only issue is you got to catch NOE when they have these in stock. It's a hot seller. I have the brass mold I attached here. It's also used on my 7.65x53 Argentine loads as well.

https://noebulletmolds.com/site/shop...-brass-316299/

[ourflat]

Thanks Eddie…. Where did you find your GCs?

Frank

[Eddie1971]

Thanks Eddie…. Where did you find your GCs?

Frank

Sage's outdoors, they are great!

[Adam Helmer]

Frank,

What model SMLE do you have? I have many and all like my Lee 185 grain RN cast boolit. I size .311" for all arms and load specifically each box of ammo for a specific arm. Many people over size the .303 cartridge. Size cases for each arm to a slight "crunch" fit and label the boxes so.

I never needed a boolit larger than .311". I tried many Lyman cast boolits in the 170-185 grain range in my many SMLEs and the Lee 185 works best for me. I drop my boolits from the mould into a bucket of water. My powders are Unique, 2400 and IMR4198. I hope this helps.

Adam

[ourflat]

Thanks Adam for the advice. BM is sending some of his stock in which I will give it a whirl and start in your direction if needed. I shot some test rounds this morning from a friend who gave me a few to try the gun out. Well it shot like a dream up to 200 yards. Very impressive gun this 303. It’s a No 1 Mark 3.

Frank

[ourflat]

Guys, what are you using for primers? My reloading books call For Federal 210, 215?

Frank

[Bloodman14]

I use Winchester LRP's and CCI 200's. As I recall, the ignition characteristics are the same.

[ourflat]

Thanks BM…..

Frank

[Bad Ass Wallace]

Keyboard shooters always take me to task, when they say "slug" the bore to determine the correct size cast bullet to use.

I say, all that determines is the size of the tightest spot in the barrel, better to start a bullet into the muzzle and make sure the rifling at that point (the last point of contact before exiting) contacts both the top and bottom of the lands. Then size your projectile to that dimension.

You see the barrel of a No.4 will be either a 2 groove or a 5 groove and measuring the "slug" of a 5 groove, the micrometer will be on top of the land on one side and between 2 lands on the other 0(i.e. inaccurate).

Take the humble SMLE 303;

According to the Small Arms Identification Series by Ian Skennerton "Magazine Lee-Enfield Rifle" Page 29

1) Lee Metford and Lee-Enfield Mk1:
Barrel Specification:
Barrel Length - 30.5"
Rifling Metford - 7 groove L.H. 1 turn on 10"
Rifling Enfield - 5 groove L.H. 1 turn in 10"
Bore Dia - 0.303"
Metford Rifling Depth - 0.004"
Enfield Rifling Depth - 0.0055
Metford Land Width - 0.023"
Enfield Land Width - 0.0936

From book "The British Service Lee" by Ian Skennerton Page 86
2) Short Magazine Lee Enfield Mk 3:
Barrel Specification:
Barrel Length 25.2"
Rifling Enfield - 5 groove L.H. 1 turn in 10"
Bore Dia - 0.303"
Enfield Rifling Depth at muzzle - 0.0065
Enfield Rifling Depth at breech and to within 14" of the muzzle - .005
Enfield Land Width - 0.0936

From book "The British Service Lee" by Ian Skennerton Page 158
3) Short Magazine Lee Enfield Mk 4 & 5:
Barrel Specification:
Barrel Length 25.2"
Rifling Enfield - 5 groove L.H. 1 turn in 10"
Bore Dia - 0.303"
Enfield Rifling Depth at breech - .005
Enfield Land Width - 0.0936

It would seem from this data that an Enfield 303 could be .303" over lands and a bore of up to 0.314" at the breech and up to 0.316 at the muzzle.

My Martini 303's shoot best with a .314 dia projectile which would seem to fit with the above specifications and bore diameter of .313"

A lot of folk don't realize there are two chamber specifications for the 303; Martini Enfields, LE & SMLE Mk1 all have a chamber suited to Mk6 ammo with a 215gn cupro-nickle, While the Latter No.1 Mk3*, No4's and No5's are chambered to suit Mk7 with a 174gn bullet.

When it comes to cast bullets, this is important to choose the right bullet to limit bullet jump into the rifling, normally about 0.010" - 0.020"

My starting load is 28gn IMR3031 and bullets are approx 15BNH

Start by tapping a bullet into the muzzle and see where the rifling bites into the bullet. If the barrel is in good condition that 220gn bullet should see rifling touching the nose.

This group fired with my 1896 Martini Enfield and the CBE 220gn bullet duplicating the MK6 ammunition.



Cast boolits 220gn (LH) and 192gn (RH)

[ourflat]

Goodday mate,

I lived in Woomera and worked @ JDFN for many years before they closed it down. I absolutely loved living in the donga and going dingo, fox, and rabbit hunting with the old spotie.

Thanks for your insights on the SMLE!

Cheers,
Frank

[Fishman]

I will second Adam Helmer's advice to not oversize your brass. Since you only have one SMLE, you are golden. Adjust your sizer until the brass "just" allows the bolt to close with a little force to cam it in and you won't wear out your brass nearly as quickly.

[Adam Helmer]

I will second Adam Helmer's advice to not oversize your brass. Since you only have one SMLE, you are golden. Adjust your sizer until the brass "just" allows the bolt to close with a little force to cam it in and you won't wear out your brass nearly as quickly.

Fishman,

Thank you for the kind endorsement about sizing .303 brass. The same goes for my .30/40 Krags. Rimmed cases should be fire formed on first firing and kept that way to ensure long brass life.

Wallace had the right advice on checking cast boolit size by the Muzzle Test. As he said, "the muzzle is the last contact a boolit has with a rifle." I shove a boolit point first into the muzzle and see how far it enters. Be guided accordingly.

Adam

[Bigslug]

Ourflat,

I've got the NOE 311299, 314299, and 316299 molds. On first look at your casting, I'd say reach for the .316 version, BUT. . .

it helps to know the BORE diameter as well (what you've listed is actually the groove). The nose section on those 299 bullets increases as the base diameter increases, and that can get you into sticky terrritory when you it comes to chambering. After a number of adventures with bizarre dimensions it was concluded that a set of pin gauges for accurately determining hole diameters was a necessissity. Once you've got bore, groove, and a good chamber cast to see what your "funnel" is cut like, making the call is easier.

And like B.A.W. says, 5-groove Enfields (or a lot of S&W's) have offset lands and grooves, so measuring your bore slugs properly requires a V-anvil micrometer - I can't remember the flute number because I ended up with both

[Bloodman14]

I was looking at V-anvil mike's, and I am not sure what is indicated by the number of 'flutes'?

[ulav8r]

Flutes refers to the number of cutting edges of a reamer or other multi-toothed cutter.

[Eddie1971]

If you have an SMLE made during WW1 you need a fat .30 Boolit, .314-.316, due to the use of cordite wearing out the bore. If you have a like new .303, like a #4 or an unissued SMLE from Lithgow, yes a .311-.312 will work.