Ongoing SMLE Saga

[oksmle]

A while back we had several different threads discussing the longevity of .303 brass fired thru SMLEs, favorite loads, fillers, etc. I had made a couple of comments & several of you PM'd me for additional information. I told each of you privately that after I was satisfied with the tests I was running that I would post the results here for everyone to see.

First the rifle: It's a #1 Mk III that I assembled from parts accumulated over a period of a couple of years. The barrel is a "new surplus" that had no loose spots in it & has been fire lapped. One turn was taken off the breech end & a .303 Brit. SAMI finish reamer was used to cut a minimum SAMI chamber. After reaming I eased the throat just a tad for cast bullets. The rest of the rifle is pretty much the way it would be issued to a British recruit except the trigger breaks right at four pounds & the military slack is very smooth. The wood is properly inletted & the butt stock is tight & square to the action.

The Bullet: NEI #72 - 185.5 grains, cast of straight WW (no tin added). The body casts .313" & the nose at .304". Hornady gas checks are seated with a Lee .314" push thru die.

Cases: Remington cases which have been turned & reamed & the flash hole has been prepped. The cases were indexed on the first firing & have not been sized since then. They are still indexed for each shot. Remington 9 1/2 Primers.

Load: 23.0 grains Surplus 4895 (dropped), no lube, 1.6cc PSB filler, OAL 2.936",
light Lee crimp to kinda' hold everything together.

I fired the equivalent of twelve matches of sixty rounds each in ten shot groups. That's a total of 720 rounds for record (with no lube). The largest group was 2.772" & the smallest was 1.211" (it's hanging on my garage wall). But what I was attempting to proove to myself was that properly handled the SMLE cases would give good service life (12 reloadings & still going strong) & the use of lube for this rifle & load was not needed. Cleanup consisted of one clean patch thru the barrel & no leading has occured at any time during the tests. The next step is to use the same fireformed cases at a higher velocity (2000 fps) to see how long they will last.

oksmle

[mike in co]

oksmle...
the boolits......air cooled, water dropped , heat treated ??

[oksmle]

The boolits were air cooled. I forgot to mention the velocity: 1585 fps with an ES of 12 fps. When I start looking for 2000 fps my intent is to add the same powder in one grain increments & reduce the PBS until/unless accuracy falls off or leading developes. My goal being to reach this velocity with air cooled boolits & without using lube.

oksmle

[curator]

I have used PSB as a filler in my cast boolet .303 loads with similar results. It appears to leave a light coating in the bore that acts as a lubricant. Of course, its best attribute is preventing any blow-by from melting small amounts of lead off the bullet and blowing it up the bore. This is the cause of most leading, not friction as most think. Bullet lubricant on cast boolets works more as a sealant than lubricant. I found Veral Smith's book "Jacketed bullet performance with cast bullets" very helpful in developing full power cast loads that shot accurately. My best high power load for my CNo4Mk1* is 48 grains of AA8700 and Lyman's #314299 made from wheel weight alloy. It is a lightly compressed load that gives around 2200fps and good accuracy without a trace of leading.

[StarMetal]

Curator,

You said: This is the cause of most leading, not friction as most think. Bullet lubricant on cast boolets works more as a sealant than lubricant.

Most means NOT ALL. So in that case explain the other reasons for leading if friction isn't one.

The sole purpose of a filler is not just to help seal gases getting around the base of the bullet, but also to position the powder back against the flash hole.

Lube is multifunctional and one of it's purposes is indeed to LUBRICANT the bullet and bore.

Dacron and Kapok are also good fillers and alot cheaper.

Joe

[oksmle]

Joe .... I have used Dacron, Kapok, COW (instant type), Grits, Cornmeal & PSB. They all work as a filler to a degree. But I found that I needed the additional protection of lube when using anything other than COW or PSB. After about 1800 fps the COW required lube. If I want to continue to use lube, I suppose any of them would work just fine. Unfortunately, I'm comparing several different rifles & calibers when I make that statement. With different barrel conditions & boolit fits.

oksmle

[Frank46]

Would anyone know if a bren gun bbl would fit either a #1MKIII or MK4. With the ban on importing bbls now I was just thinking. The gas port can be plugged with a set screw so thats not an issue. Since I have never seen one of these puppies in the flesh maybe someone who may have one could maybe measure the shank to see what the diameter is. Thanks, Frank

[grumpy one]

Frank, I've never handled a BREN (it's supposed to be all capitals - first two letters of "Brno", the designers, and "Enfield", the Royal Military Establishment where they modified the Brno design to work with the rimmed 303 British round). However a key feature of the gun is that it has an instantly changeable barrel, instead of providing cooling for it. The BREN team always carried at least one spare, and hot-swapped them when it started to heat up. It only rotated something like 90 degrees before it could be pulled forward - I've only seen it done in a movie though. So, even if the BREN barrel is large enough diameter at the socket end to take a Lee Enfield thread, you'd have a fair amount of machining to do. It would be cute to have a Lee Enfield with that handle on its barrel though. The main purpose of the handle was to twist off the hot barrel, to swap them.

[Frank46]

grumpy one, just an idea I had bouncing around the few remaining functioning brain cells I have. That and maybe getting a BREDA (spelling??) mg bbl in 8mm and having it on a 98 mauser. Course the cooling fins might look wierd but you can bet no one else has one. Problem is finding either in good enough shape to make the job worthwhile. Of course the handle may have to come off. Anyway it was just an idea. IMA has the breda bbls and according to them they weigh about twenty pounds. Sure wouldn't have much recoil. frank

[castalott]

OKSMLE...
I have heard of Enfields desribed by where they were made..."Fazakerly" for example.My old friend Pat ( long gone ) would describe yours as a "Bitsa".....Bits of this and bits of that made into something good.....

Those old Enfields are wonderful guns......have fun...

[grumpy one]

grumpy one, just an idea I had bouncing around the few remaining functioning brain cells I have. That and maybe getting a BREDA (spelling??) mg bbl in 8mm and having it on a 98 mauser. Course the cooling fins might look wierd but you can bet no one else has one. Problem is finding either in good enough shape to make the job worthwhile. Of course the handle may have to come off. Anyway it was just an idea. IMA has the breda bbls and according to them they weigh about twenty pounds. Sure wouldn't have much recoil. frank

There were two common Bredas (a guy's name in this case, not an acronym). One was a BREN-like light bipod machine gun, the Modello 30. However it was 6.5 mm delayed blow-back design, and was therefore not the one you're talking about. It seems to have also been one of the worst guns imaginable. The other was an 8 mm gas operated medium gun, tripod mounted, the Modello 1937. Unlike the Modello 30 it had no cooling fins on the barrel. Both guns had quick-change barrels like the BREN. The Modello 37 had the remarkable feature of putting the empty cases back into the 20 round clip after firing, then dropping the refilled clip out the bottom when they were all used up. I've never seen either Breda, but the Modello 37 seems to have been a (barely) acceptable product, unlike the Modello 30 which was a bad joke. I don't know what the quick-change barrel mounting looked like. Bear in mind that there were two versions of the Modello 37 - the one for use in tanks etc. had a much heavier barrel. It sounds as if that might be the one you've found, if it weighs so much. The lighter barrels were 26.75" long and parallel, not tapered. I don't know the outside diameter. You also shouldn't assume that the 8 mm Italian round used the same bore and groove diameters as anyone else's 8 mm.

[BruceB]

The Bren barrel is much larger in diameter than that of the #4 rifle.

The flash suppressor and gas regulator are part of the barrel assembly, along with a substantial carrying handle, all of which would have to be removed for use in a rifle, followed by very extensive lathe work.

The barrel also has a number of heavy helical-cut lugs around the chamber area to engage the barrel locking nut, which is a large component with a handle attached, and which mounts in the receiver of the gun. In use, the locking-nut handle is lifted to disengage the barrel, which is then pulled straight forward out of the receiver and also out of its engagement with the gas system at the forward end of the receiver. The barrel itself does not turn for removal.

Any raw recruit could change the barrel on the Bren in about ten seconds or less, and a trained #2 man can do it in about three seconds. The gun itself can be field-stripped or re-assembled in under thirty seconds...blindfolded. Changing a firing pin or extractor (or both) can be done in less than a minute, but I have never seen either component fail in service. Spares were carried as a routine precaution, but were very rarely needed.

Through WW II, the .303 Brens were issued with a fitted spare barrel. When later Marks (Mk3, and Mk 4) were converted to L-series guns in 7.62 NATO, they were eventually equipped with just one chrome-lined barrel. This was due both to changing evaluations of expected tactics, and the better resistance of the chromed barrels to heat and erosion. The gun and its barrel still contained sufficient mass to tolerate a great deal of heat.

With the earlier non-chromed barrels, it was "recommended" that the barrels be swapped after 200 rounds at the "rapid rate" of 100 rounds per minute (about four magazines). However, I've personally fired over 400 continuous rounds at more than the rapid rate and the gun was still running fine and didn't seem excessively hot.

Although the barrels issued for service were fitted to the individual gun and serial-numbered to the weapon, in practice the barrels were almost completely interchangeable. I've never seen a Bren fail to function with a barrel NOT numbered to the particular gun, including four different barrels on my personal Bren...NONE of which match the gun's numbers. A factor which CAN make a difference from barrel to barrel is that both barrels were also ZEROED to the gun. When field-expediency demanded the carrying of a non-matching barrel, the primary (properly-numbered) barrel was mounted on the gun and the second barrel taken along for emergencies. Any gunner worth his salt would surely test-fire such a spare to see what he was getting for point-of-impact; I know I certainly would!

The offset sights of the Bren. arranged that way to avoid the top-mounted magazine, are exactly one inch to the left of the bore. When zeroing the gun, it is also zeroed so that the mean point of impact is ALWAYS one inch to the right of the point of aim, and in this way there is no tendency for crossfiring, or having the impacts anywhere except nominally one inch to the right of the sights, at any range. The standard zeroing targets, fired from 25 yards, had a bold-printed aiming mark and rings, and identical-but-shadow-printed aiming mark and rings centered one inch to the right of the bold features. This made it very easy to obtain the correct relationship between sights and bore. Armorers made all adjustments in zeroing, interchanging various heights of front sights and setting the windage as well. The gunner could only adjust the elevation when the gun was in service. KISS....

[grumpy one]

Thanks Bruce. Aside from having corrected a long-held misconception of mine (that the BREN barrel was twisted loose rather than unlocked from the back) you referred to the 7.62 NATO barrels having had chromed bores. In 1980 when the Lithgow plant was still set up to make the FN SLR I had a tour of the plant. I asked the section superintendent of the barrel-making part of the plant (after seeing their rifling cutting machine) whether they had given any thought to button swaging instead of cutting. He said that button swaging isn't acceptable for military rifling because it is too shallow, and this is especially so when you are going to chrome the bore, which was done with all Lithgow SLRs. This surprised me considerably - I hadn't heard that the rifle had a chrome bore. Do all SLRs have chrome bores, or only Lithgow ones, or was this guy confused? The last option seems unlikely - he seemed to know his stuff like an old time craftsman.

After making enough SLRs to last forever back in I guess the early 1950s when that rifle replaced the Lee Enfield Mk III* in Australian service, the plant was switched to a readiness status that involved just keeping the superintendents and retrenching everyone else. From then on, whenever a regimental armourer classified a rifle as too difficult for him to fix, he sent it back to the plant. These guys in the plant would then rebuild it, having the capability to pretty much make whatever parts might be needed. They sure had some nice-looking SLRs in their finished-and-ready-for-despatch area. Just glancing at them in the rack I couldn't tell them from new.

Geoff