LE Mark No.1 Mk 3 - A true .303 bore!

OEM

OEM

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Hello folks: Some of you may remember when I nursed an old No1 Mk3 that was given to me as a rusted heap, back to life. Well, since then, I've shot it quite a bit and of late, have been experimenting with reduced loads and cast boolits.

Now I've always had poor accuracy in the thing, and I attributed it to many things, the damned crack being one, and my poor eyesight being the other. Then, with my reduced loads, I was not even hitting the target at 50m. And I thought, dang, my eyes have really lost it!! But I could make 3 inch groups with my 30-30...granted it had peep sights.

Anyway, a friend suggested that I slug my bore. At one of our casting sessions, where he was making shotgun slugs using pure lead, we made some 9mm boolits which, well, with the LE known to have a huge bore and all, would be perfect right? Well, the results are interesting to say the least.

100_2756.jpg

irst pic here is an average width measurement with my calipers. I saw a low of .297 and a high of .303/.304!:eek: No wonder we were having so much difficulty getting the lead through the bore. Man I broke tons of little poplar dowels! :rolleyes:
100_2761.jpg

Then we tried pushing a .305 jacketed bullet (the smallest usable bullet I have) through the chamber out to the muzzle and I couldn't generate enough force to push it even two inches. See the lengthwise abrasions? I've never heard of this with a Lee-Enfield. Maybe I reall need .303 bullets... lol. We had to ram it back out the chamber.
100_2762.jpg

Here's another pic of the jacketed bullet, turned to show some more scrapes/abrasions.
So it appears my throat/chamber area is actually less than 305??:eek:

Perhaps this then is what's affecting my accuracy (besides the one eye going bad)? I've been shooting jacketed .311 bullets with 38 Gr varget with so so accuracy at 100. But currently, all I'm shooting are boolits I cast from the Lee CTL-312-160-2R mould. This drops a boolit of 313 quite consistently, but obviously its too large for the gun!

So has anyone ever heard of a 303 this tight? What boolit should I use? I tried charges ranging for 6.5 Grs of Bullseye to 8.5 Grs with no appreciable increase in accuracy. My Marlin 336 in 30-30 shoots pretty good at 7 Grs BE over either the Lee 170Gr Flat or the Le 113Gr Soupcan mould.

Thoughts anyone?
 
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Hi there, OEM!

Wartime production standards were somewhat relaxed, even on bores, with allowable bore diameters (before rifling) being allowed as big as .304". Peacetime standard was an absolute low of .301, but the occasional wartime barrel would slip through as low as .300. It appears that you have found one which is even smaller!!!!!!

Learn something new every day!

Have you tried ordinary .308 bullets hrough the old girl? Once in a while you will run into an SMLE that likes them.

Too bad we're 1400 miles apart; this could be good fun.

Good luck.
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Hi Smellie!

Nice to hear back from you! I'm surprised at the lack of response to this thread. As you say, its something new for you too and that's what I figured too!

I never knew they came this small...in most cases, I read that I should size to .312 and above. I never thought of shooting my 30-30 boolits through her. That's a pretty good idea which I will try soon. The boolits I have drop out at about .309 so might be a good fit. If it is, I might get a .309 sizer and size ALL my 30 cal boolits to that size and call it good!

Yes, pity we're that far apart...I don't know of any LE experts around my neck of the woods who can tell me more about this one. Make sure to contact me if you're ever around here!
 
"...broke tons of little poplar dowels!..." Wood isn't the right tool. Use a 1/4" Al or brass rod.
The land diameter isn't the bore diameter. The hole drilled through the barrel blank before it gets rifled is the bore.
A cast 9mm is far too big. They're a nominal .355". Something about that 9mm casting of your's isn't right. Suspect you've left some lead in the barrel. Use a cast .30 cal bullet or a suitably sized lead fishing sinker. Those .313" cast bullets will do nicely. Forget jacketed bullets altogether.
 
Thanks for your thoughts sunray. I will clean out the bore first...to make sure no lead is left in there. Then use my cast 313 boolit to slug. The land and bore always gets me mixed up.

From my pix, it appears that my lands is .299 and my bore is .297. I can't imagine how it can come out so small.
 
If you are measuring land to groove, then .303 is bang on.

Sunray raises a good point, which I was also thinking of when I saw your pictures. First, .355 is WAY too big, and second: Ensure you are measuring groove to groove and not land to groove. It's tricky to do with a 5 groove barrel, but an easy way to get a rough idea of your grove to groove diameter is to measure from one extreme edge of the groove to the extreme edge of the opposite side. Take a head on look at your casting and you'll see what I mean. Do this all around and you can average it out.

Enfield Bore

I'm having a very hard time believing that a .311's barrel is only .300's of an inch. Stranger things have happened, I'm sure, but still.

When cleaning the bore, a good foaming bore cleaner followed up with a nylon bore brush is the bee's knees.
 
If you can't accurately caliper an object ; try inserting into a known size of ring, say .320. Push it against one side then make a note of the gap remaining.
Thats how we measure the OD of 3 bladed fluted reamers. A Caliper won't work and an OD tape won't work. Slide a gauge ring over it and measure the gap. Divide the gap by 3 and that should tell you the OD ( If I recall correctly ).
I don't know if this helps or not, but it's how we measure the OD of odd sided circular equiptment. Mind you the stuff we work with is much larger, but the principal should still be sound.
Good luck
 
"...Slide a gauge ring over it..." Involves having one and being able to measure a wee gap.
"...The land and bore always gets me mixed up..." Land to land is the bore. You want groove to groove. Rifle into a padded vise, then hammer your cast bullet through the barrel, preferably from the chamber end, with the 1/4" brass or Al rod and a plastic mallet. Then measure the widest part of the .313 cast bullet.
Lee-Enfield barrels, even wartime production barrels, can measure from .311" to .315" and still be considered ok. A .3105" barrel appears occasionally, but not a .299". Military ball ammo used a .311" bullet. .299 is 12 thou too small.
 
Measuring 5 groove barrels

The way you show the .299 measurement in the picture is giving you a false reading. The SMLE No.1 Mark III has a five groove barrel. With the calipres positioned as shown, you are measuring from land diameter on one side to groove diameter on the other side.

A very accurate bore diameter can be made, but it involves using a precision V block to do so with an odd number of rifling grooves. A barrel with an even number of rifling grooves is easy, because it measures from groove to groove ON A LEAD SLUG, giving a true bore diameter.

As SMELLIE suggests, try some .308 calibre bullets and see how they shoot. You might get lucky.

As far as tight bores on the .303 British, early Ross Rifles before 1910 had .300 and .309 as the standard measurements.

Really clean your barrel. If it does not shoot reasonably after that, I would suspect other causes of inaccuracy.
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