Replacing a #4 Enfield

[Midnitemo]

The Mossberg is here but it just didn 't wow me in the flesh , CZ 527 carbine is a possibility now it's got a 1 in 9 twist instead of the previous 1 in 12 but the 5 round mag and positive feed put me off a little , i'm liking the Sako to my eyes it's almost a clone of the gunsight scout but probably better built

[CharlesHarris]

I recently obtained in a gun auction site a Cdn. Long Branch No. 4 Mk1* in original, as-issued, near pristine condition. The price was $600US shipped to my FFL.

This rifle was made in 1943 and a 2 groove barrel, typical of its type. Cast bullets from my NOE #314299 cast in wheelweights + 2% tin at .315,” are just a wee bit smaller than ideal for this rifle, but gaschecked and firing ¾ of a full-charge load with 30 grains of IMR4064 it is acceptably utilitarian.

My barrel is .304" on the lands and .316 in the grooves. The chamber neck diameter is .346”, generous enough that I can load a throat-diameter bullet which “fits,” being .317 on the bands and .306” on the nose, as-cast from my latest NOE .316-202 plain-based “299 clone” mold.

Getting a mold which casts bullets which “fit” is the first goal of the .303 owner. The easiest way to do a “pound cast” of a .303 chamber is to take a .38 Special soft lead, factory round-nosed bullet, drop it into the chamber, and then use the Brownell’s .38/9mm Squibb Rod to pound it into the chamber neck until the .35” diameter squib rod comes to a hard stop against the shoulder of the chamber. Tapping the slug back out you will then will capture the neck diameter, case mouth transition, throat diameter and origin of rifling, which is everything that you need to know to order your new custom mold.

In my Longbranch rifle the width of grooves is .115." This means that about ¾ of the bullet circumference is displaced by the lands and is either distorted into the grooves, or extruded longitudinally towards the base as the bullet travels down the bore. This can result in ill-fitting plain, bullet bases emerging out the muzzle out-of-square. GC type bullets when used without the gas-check, or bevel-based bullets are more forgiving. Hornady GCs don’t crimp-on sizing in a .316 sizer. Their diameter maxes out at about .314,” which is too small to seal the throat of my No.4, so I got NOE and Accurate to cut plainbased molds drop their bullets .316+” as-cast, no sizing required.

Lee Enfield 2-groove barrels are quite different from US Remington 03A3s. Typical two-groove 03A3s are 5/8 (62% circumference) land and 3/8 (38%) groove with bore and groove being .300 bore x.308 with .311” diameter cylindrical throat to guide the bullet's initial shot-start. Lee Enfield 2-groove barrels are a 75%/25% land/groove ratio, normally .304 bore with two .110-.115” wide grooves of .006 depth, and conical chamber throats having the major diameter of groove diameter +0.002/-0.000. I have never measured a throat slug from a 2-groove .303 of less than .315 and found a few as large as .320”!

Jeff Brown in NZ says this agrees with his experience.

My WRA 1942 flat-based and Rem-UMC 174-gr. MkVIIz Lend-Lease bullets are .312” diameter. The soft gilding metal jacket and lead core upset and provide reasonable accuracy even in worn bores showing erosion from use of Cordite ammunition, as correct MkVII ammo should.

According to the Johnson Method of Musketry Coaching, adopted by the Canadian Army, the No.4 rifle during WW2 was zeroed to center the group relative to point of aim at 300 yards, firing with the elevation ladder of the stamped, (vs. millled) Mk3 battlesight folded down and sighting in using the large ghost ring peep. At 30 yards the shot group should be 2.25 inches above the aiming point on the Cdn. 9C target. At 100 yards it should be 8.5 inches above the auxiliary aiming mark on the Cdn. Army 4x4 half-bull target.

Eight different heights of foresights were available for armorers to exchange if necessary to adjust elevation. A one increment (0.015”) change in front sight height changes the elevation by about 1 mil, about 3.6” at 100 yards or 11 inches at 300 yards. Windage adjustment does not require use of special spanner or other tools. Simply insert a 3/8" brass drift through the side hole in the sight guard and gently tap against the sight base with a light hammer.

Drifting the front sight ¼ of the width of the front sight blade (again, about 0.015”) changes windage about 1 mil. Setting the correct, textbook, battle sight zero with MkVII ammunition on your No.4 also gives you a thoroughly practical utilitarian zero for shooting at 50 to 100 yards with our typical cast bullet loads from 1300-2000 fps. In most .303s the largest diameter bore-ride bullet which chambers and extracts easily without producing a “tight neck” condition, thus maintaining safe release clearance, is the way to go.

The Lee-Enfield's rear-locking action is blamed for poor case life by re-loaders. It is adequately strong for its intended working pressures which should not to exceed 45,000 copper units. Case failures result from excessive cold-working of fired cartridge brass from military chambers having generous clearances, intended to function under "trench warfare conditions." Neck resizing only improves reloading case life. Keeping pressures below max., more like Krag levels, not exceeding 2400 f.p.s. with 174 grain jacketed bullets, does too.

Typical .303 cartridges have about 1/16" clearance of the case shoulder in the chamber. This ensures rifles will function under combat conditions of mud, sand, or dust. Because the .303 British headspaces on the rim, this clearance is inconsequential to headspace. But it results in the case shoulder being blown forward upon firing. When fired brass is repeatedly reloaded and full-length resized, cold working and fire-forming elongates the case body ahead of the solid web, causing case head separations by the second or third reload.

Best case life in reloading the .303 British requires that fired brass be partially sized. I back off the full-length resizing die so that a US 10-cent coin is pinched between the press ram at the top of its stroke and the sizing die, to avoid setting back the case shoulder. US jacketed bullets used in modern sporting .303 ammunition are .311-.312" diameter. Component bullets for the 7.62x39 give good results in new barrels if a .309-.309 expander plug is used to ensure adequate neck tension with the smaller diameter .310” bullets. Hornady and Speer 123-grain spitzer soft-point 7.62x39 bullets obtain 2700 f.p.s. with published loads from Speer manuals 13 and later. They are more accurate than milsurp ammo, with mild recoil, flat trajectory and good varmint performance, but at .303 velocities their construction is a bit fragile for hunting deer, and meat damage may be excessive.

Issue-grade .303s, firing common milsurp ammunition are "at best" 4-m.o.a. groupers. You can improve on this using good sporting ammunition or hand loads with quality bullets. RWS, Sako, Norma and Privi-Partisan ammo are uniformly good. MEN and HXP military are good.

If the barrel on your No.4 has seen better days, new replacement barrels machined to the original military contour with milled front sight base and bayonet lug are available in the US and Canada from Criterion. These are .311” groove diameter, chambered in SAAMI dimensions for .303 British, six grooves with a 1-10 LH twist rate and made from gun barrel quality 4140 chrome moly steel with a 0.010-short chamber, which can be headspaced via bolt-head replacement. Barrels are available either Parkerized or in the white.

The best US powders to approximate service ammunition or factory soft-points are IMR4064, RL-15 and Varget. Sierra, Hornady and Speer .303 sporting bullets are all good. Sierra 175 MK and 180 Speer Hot-Cor soft points are most accurate. In a properly bedded No. 4 rifle with using 40 grs. of Varget, RL-15 or IMR-4064, 4 to 5-inch ten-shot groups at 200 yards are possible with the Sierra Matchking in carefully adjusted service-grade rifles having correct stock bedding.

DCRA and British NRA competitors were always careful to dry Lee-Enfield chambers with mineral spirits or acetone after cleaning. Otherwise the cartridge case will not grip the chamber walls upon firing. This causes additional thrust against the bolt face by the case “pistoning” in the lubricated chamber, springing the action with respect to the vertical buttstock socket, causing vertical stringing on target until the rifle settles into a round group.

Grouping improves about 30% when the handguards and fore-stock of the No. 1 MkIII* are relieved so the only barrel contact with wood is under the chamber and at the spring-tensioned V-block behind the nose-cap.

Best accuracy in the No. 4 comes when the barrel is solidly bedded under the chamber, with the rest of the barrel free of contact except for upward pressure at its midpoint near the lower band. An alternate method common in Australia and New Zealand is completely free floating the barrel entirely from its lower band to the muzzle, or if this doesn’t work, trying 4-6 lbs. of up-pressure against the barrel at the nose-cap. It takes only 10 minutes with a scraper to relieve the hand guards, cut sheet metal shims, and cement them in place with Acraglas gel.

Normal .303 headspace measurements are (0.064" / 0.074") in British military specifications. A new No. 4 normally is fitted with a 0 (Zero) size bolt head, but if it has a size 1 that’s OK. After firing 3500-5000 rounds, continued firing compresses the locking lugs, bolt, and the bolt head, shortening the assembly and increasing headspace. Armorers then fit the next size "up" bolt head and you are good to go until the barrel is shot out. When the rifle goes "Factory Through Repair" (FTR) a new bolt head the next size "up" is fitted with the new barrel. No. 4 Bolt heads were made in 4 sizes (0, 1, 2, & 3). Only a very few number size 4 were made for wartime use only. If a number 3 would not correct headspace, a new bolt would be tried with bolt head 0, 1, 2, or 3. If the headspace still cannot be corrected it means that the lug seats in the receiver were buggered. Such rifles were then scrapped and marked for Drill Purpose.

To confuse matters bolt head size 'numbers' are almost meaningless, due to tolerance overlap. It is necessary to use a headspace gage and to try several bolt heads. This is because it is necessary to measure the headspace DIMENSION and not to simply change a bolt head marked SIZE.

Jeff In NZ explains here proper bedding of the Lee Enfield, which is seldom understood in the US, so please pay attention and you will learn, as I did:

"My No4 Mk2 is bedded with its barrel exerting downward pressure against the wood at the muzzle. After much experimenting I settled on an epoxy bedded action, neat fitting, inch wide oiled felt top and bottom under the barrel band such that the wood work is SNUG and the same felt under the top wood at the muzzle ON TOP ONLY pushing down on the barrel. For MY rifle it works great. Also the fore-end should be free contact with the front of the butt socket.

"Starting with an unknown No.4 , be aware that as wood ages and dries out, it shrinks away from what is previously in contact. First make sure the fore-end is correct - if it’s a Mk2 forend on a Mk1* rifle, has the rear been filled and reinforced to replicate Mk1 wood?

"If the wood is replacement, then it is likely that it wasn't fitted correctly. So, dust the inside of the fore-end with talcum powder, and wipe over the metal with an oily rag. Reassemble and screw everything up tight. Then dissemble the rifle. You should be able to see at a glance where the problem is. Some possibilities:

"1. The king screw sleeve is too long, and the action is not seating correctly. This is revealed if there are no oil marks under the chamber and around the ledges inside the fore-end. The quick check is to repeat the talcum powder test without the bushing being included. You then may find that correct barrel down-pressure suddenly re-appears, in which case it is corrected by shortening the bushing to fit.

"2. If the receiver appears properly bedded, but there is not a central bedding surface under the chamber, gently scrape the receiver bedding surfaces from front to rear until you have removed enough to allow the chamber to make firm contact with the fore-end. Re-check contact at the muzzle end - this may give the required down-pressure.

"3. If you have good fitting all around the receiver and under the chamber, but no barrel down-pressure, this means that you have to remove the receiver bedding surfaces as in (2), but in such a way that you "tilt" the whole barrel receiver group downwards. If necessary scrape from under the chamber and the forward bearing surfaces. This tightens the bearing of the recoil lugs and the butt socket, due to their angle with the fore-end which is better than shimming, because it permits evening the butt socket bearing left-to-right.

"You should only scrape away wood surfaces in small increments, and repeat the talcum powder/ oily metal test after every adjustment. As I guide, I assemble/ dissemble a No4 at least 10-15 times when fitting a fore-end, and up to 30 times when working on a No1! Patience, Grasshopper, Wax On, Wax Off!"

While it is true that load data for the .303 British cartridge is plentiful in the Lyman handbooks and other sources, common published “starting” loads usually produce velocities exceeding 1400 fps, which require using gaschecks. Gaschecks cost over $30 per thousand in the US, MUCH more overseas, an expense which for recreational shooting is an unnecessary and costly absurdity.

Once you have identified a bullet which “fits” when cast of common, soft, scrap alloy, your first milestone is to determine the minimum powder charge which will reliably expel a soft lead, lubricated bullet from the bore every time, without fail. Avoiding alchemy, weird science and the frustration of knocking out stuck bullets, let’s just cut to the chase!

It just so happens that in the .303 British the standard pressure charge recommended for the same weight of lead bullet when loaded in the .45 ACP, using that same powder charge in the .303 defines “cat sneeze,” about 4 to 5 grains of Bullseye. Increase the charge gradually only until best grouping is obtained and stop there. I found 7 grains of Bullseye a “sweet” spot for my rifle. Indeed the idea of getting 1000 rounds per pound of powder has a rather nice “ring” to it.

The upper velocity limit for successful plain-based bullet utility is defined by the performance of black powder rifle cartridges firing the same weight of bullet. It makes little difference whether your black powder rifle was a .32-40 or a .44-40, because 40 grains of black powder drove a soft 170- to 200 bullet in those cartridges about 1300-1400 fps accurately and without a gas-check. This level is below “starting” .303 cast loads published in Lyman handbooks, so we must again improvise. But fear not.

“Starting” charges in the Lyman Cast Bullet Handbook, 4th Edition (2010) p.174 for the .32-40 Winchester, with the same weight bullet, are exactly what we would have wished for in the .303 as our practical plain-based loads. It also just so happens that when using common “rifle” powders such as 4198, RL7, 3031, etc. this works about to be about ½ of a full charge for that powder using a jacketed bullet of the same weight in our .303 rifle. Extruded, tubular rifle powders such as 3031, 4895, 4064, RL15 or Varget ordinarily tolerate charge reduction to about 75% of a full jacketed load when using gas-checked bullets of the same weight and give very good results.

When a 1-grain tuft of Dacron is loosely inserted into the case neck, to take up most of the free airspace in the case – NOT pushed down on the powder – ballistic uniformity and acceptable ignition can be obtained with cast bullets down to about 50% of the full jacketed bullet charge. In actual practice this defines an upper charge limit for our plain-based bullet, being about 1300-1400 fps.

[Straight Shooter]

A very comprehensive post Charles, even i enjoyed reading it ...and no nothing about guns ...good post !