no.1 mk 3 tight bore

[c141b]

I have a G.R b.s.a.c 1917 SHT. L.E 3 with 5 grove barrel and a bore of .308. I have lee bullet moles tl 312-160-2r, c 312-185-1r, c 309-120-r and c 309-170-f also lee sizing die of .309,.311,314. what is my best option on casting a bullet that will fit correctly. I slug the bore then rapped a Shem around it and subtracted the shem and got .308

[Der Gebirgsjager]

I like your measuring technique! Looks like you've got a great rifle with a great bore and can expect great results. But--to answer your question is not so simple. I would just start with boolits sized to .308 and work upward depending on the results. An educated guess would be that you'll find .311 to be about right, but you won't know if you don't start with the .308 size. Anyway, great find. I'm sure you'll enjoy it.

[Ballistics in Scotland]

I'd push a .309 bullet through the bore, as gently as possible, first, just to make sure that that method of measuring has worked out all right, but the chances are that it has. I'd say the 185gr. is likely to be the best for a .303, as I believe every British-made one was throated to accept the 215gr. round-nose which went out before the First World War.

That would be a tight bore for a .303, but not unheard-of. At the time the rifling would be cut in numerous very shallow scrapings, so there was no real incentive to cut the rifling too deep. It might happen if they got it a little rough and wanted to improve it, like trying to even up the legs of a table till you get a coffee table. Excessive diameters mainly came with the No4 Lee-Enfield, which was usually rifled in one pass of a multi-pointed broach. This was a very expensive tool, which would be sharpened, reducing its diameter, several times in its life. So they used to start out with it oversized, to make it last.

While it isn't possible to get a really accurate measurement of either bore or slug by measuring directly, without your shim, in practice corner to corner of lands or grooves is close enough to give you a good idea whether you have a problem bore.

If it really is .308 and you want to use jacketed bullets, they can be .308, which are probably easier to find in great variety. You just might or mightn't find the case neck isn't as tight on those as you would like. If so spinning the expander button in a drill, between folds of fine abrasive paper, should reduce it enough to work well.

[Der Gebirgsjager]

Some really interesting and poignant information by BIS. I recall my first ever high powered rifle, a No. I Mk. III 1918 BSA. The first box of cartridges I owned for it were Peters 215 gr. Round Nose Soft Point. Very impressive. I did manage to kill my first large 4-point buck with it at around age 15 or 16 shooting off our back deck down into a creek about 75-100 yards distant. But other than that, the entire box was fired away here and there without memorable results. A local reloader reloaded the original cases for me, but used 180 gr. RN cast boolits, explaining to me that he didn't have the proper sized boolit, but these were close. Shot them all up also, often at game, withoug anything good to report. Then I eventually got into reloading and tried out 174 gr. Hornady RNSP. What a difference. They were, and are, .311 in diameter. My rifle (still have it) had pretty good bluing, but the wood had seen some pretty rough usage. Over the years many other nicer specimens have come my way. That 174 gr. Hornady works well in all of them.

[Scharfschuetze]

Lucky you to have such a tightly bored Lee Enfield. Two of mine push .316" and I have a 316299 mould from NOE to cater to them.


I recall my first ever high powered rifle, a No. I Mk. III 1918 BSA.

Ditto for me. Wish I still had it. Cost me $19 and my Dad mail ordered it for me from an add in the back of American Rifleman in the mid 60s.

[JeffinNZ]

Forget the bore and fit the bullet to the throat. It may have a tight bore but the throat for sure will be standard. If you use too small a bullet it will cant going through the throat. I would suggest .314 to begin with.

[Bad Ass Wallace]

Sorry to be a disbeliever but I think you 1917 SMLE wouls be unlikely to have the bore dimensions you measured.

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


BSA made factory bore gauges in sizes .3025, .303, .3035, .304, .3045, .305. .305 being considered worn out!

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 to 0.316 at the muzzle.

To be 0.308" your rifling would be only 0.0025" deep?

[c141b]

Here are two pictures 1 shows .314, 2 shows .006 .314 -.006 = .308 With a 5 grove barrel using a shem is the only way i know to do it. Am i in the ball park with this method? If i am right,how should i proceed with the bullet moles and sizers i have?

[Der Gebirgsjager]

I'd try the 312-185 sized to .311.

[Scharfschuetze]

Sorry to be a disbeliever but I think you 1917 SMLE wouls be unlikely to have the bore dimensions you measured.

Lee Enfield bores are all over the map. I would hesitate to bet on what's in the book v. what's out in the field. My LEs go from .310" to almost .317" so I generally have to segregate reloads for each rifle.

With the aggressive 5 groove Enfield rifling, they all shoot jacketed bullets fairly well. I just have to be careful with the cast boolits to optimize the accuracy of each one.

My tightest LE is a NO 4 T and my largest bore is a No I MIII* Lithgow rifle. Both have virtually new bores, so wear isn't a factor regarding the diameter of the Lithgow rifle.

I like der Gebirgsjaeger's suggestion to start at .311" for your initial attempt.

Hardly a single bore diameter in this gaggle of the Queen's rifles.

[Multigunner]

Cupro-nickel fouling in the grooves can reduce slugged major diameter by .002 or more. I've slugged Enfield bores before and after through metal fouling removal and found the bore sizes to be much larger than the first attempt suggested.

That said wartime barrels , especially if from subcontractors, could vary wildly. Bores as tight as .306 have been reported.

My 1915 Enfield lock has a true .311 bore, the only one I've seen so far.
It would probably have not passed prewar gauging since specs called for a minimum major diameter of .313.

[c141b]

the 312-185 sized to .311 sounds like the way to go. Thanks