.318'' groove No.4 Enfield, what bullet to use?

Own a early N0.4 Mk1 Fazakerley Enfield rifle that I am getting ready to load for. The bore is a near mint 2 groove. Thought I would start by slugging the barrel before ordering up some bullets. Lubed the bore & a lead .314'' diameter pistol bullet, and ran it down the bore. The bullet measured .304"+(not quite .3045") by .318"+(again not quite .3185"). Measured with a good vernier caliper and a micrometer. To be sure I read the bullet 5 times. And just for good measure, ran a second bullet down the barrel and measured it. The results were the same. I have yet to shoot this rifle, though I have owned it for over 5 years, so do not know how military or commercial ammo would preform from it. The question I have is should I use a bullet like a jacketed 'J' bore 8mm Mauser bullet .318"diameter? What size cast bullet would be best? Thinking a 175 jacketed 'J' bore bullet would be best weight wise, so as to keep the load in the same weight category. Any advice would really be appreciated.

Man that’s a big bore on an Enfield even my worn out ones slug better than that. .318 J Mauser bullets would be where I start. Cast would probably take a custom mould of your choice in the .319 to .320 range. Weight in cast is not as big a deal to me because you can’t match the velocity. I’d ask if your confident on your measurement but it sounds like you are.

I would be very careful using the Woodleigh .318 bullet . A long groove diameter bullet with your very deep rifling will cause massive pressure spike . Also with a big cast bullet the rifling will cut the bullet deeply and affect accuracy , depending on what you are looking for in accuracy . I would try a Hornady .312 174 round nose bullet at a medium velocity . It should grab your .304 lands and should stay straight due to its long cylinder shape . Speer did make [ a long time ago when Speer KNEW how to make bullets for military rifles ] a .313 215 grain round nose that does work great . They can still be found here and there .

a .318" bullet in a .303" chamber will be a jam fit and can cause high pressure since the case neck cannot release the bullet.

A .318" groove diameter isn't really all that uncommon. If the attached engineering drawing (source?) is credible, it's actually within specs. Before venturing into oversize jacketed bullets, it would be worthwhile to try normal .311" to .313" projectiles. You might be pleasantly surprised.

As for cast, I've tried unsized bullets dropping ~.316" in my 2-groove Savage that goes about .304"x.318". Accuracy isn't great but OK for short-range plinking and practice.

https://www.milsurps.com/images/impo.../2qjycqs-1.jpg

A .318 bullet in a .303 chamber would only be a problem if you could not close the bolt cleanly . It may , that would depend on the dia of the chamber neck . The neck having to " expand to release the bullet " is BS . It does not expand when you pull the bullet out with pliers by hand .

BS? Now that is a technical acronym I am not familiar with. Please explain in more detail.
"Close the bolt cleanly". Please explain.
As to the neck not releasing the bullet and running up pressure it is discussed in "Hatcher's Notebook" and was determined to cause high pressure.

Hatcher's jamming a case mouth into a bullet is not the same as the neck having to expand to release a bullet . It was all explained in an earlier post . Maybe someone will link to it for you .

Good morning everyone.

I think there is a lot of great information out there on reloading, lot of ideas and lots of opinions. That said, I would certainly hope we all could look at each and take what we want and disregard the rest but do it in a respectful manner. With those ideas and opinions there are also lots of personalities and we need to take that into consideration when we make our posted replies.

So, please everyone be respectful of others and let’s all enjoy the wonderful abundance of information available here.

Enjoy you day folks ;)

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Originally Posted by green

BS? Now that is a technical acronym I am not familiar with. Please explain in more detail.

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Ballistically Suspect ?:madsmile:

I wonder if he just shot it with some factory ammo first to see...probably shoots great as he says the bore is near mint.

This link provides good information from someone who has "been there, done that"

Replacing a #4 Enfield

The problem is similar to that in the 6.5mm Carcanos ( a 91/41 in my case), where a groove diameter bullet would enlarge the case mouth so much that the round would be impossible to chamber - a create a horrible pressure spike if it could!

Hornady makes (made?) "oversize" bullets for the Carcano, but various investigations warn of excessive pressure if one doesn't keep to a rather tight-tolerance powder charge.

When I made a careful measurement of some original Carcano bullets, I found that they were not seriously oversized, but the jacket had an open base. I think this is part of the answer, as an open base should allow easier upsetting of the base of the bullet to create a driving ring to fill the bore. Ok, the upset may only be 0.001" or so, but that makes the difference!

So, my tip is: use open-base bullets - if you can find them - but do NOT try anything as large as a .318 diameter.

I was the one who put out the testing on the Hornady .268 bullets , and posted warnings . I fired over 400 of them in 15 different Carcanos with many different loads . They were made wrong . It does not matter what powder or charge you use . Yes original Carcano bullets were .266 dia with an open base [ with a first type bore with a .270+ groove ] , just like every other military bullet of the period . They all used " bore riding " . Higher velocity and less pressure due to less bearing surface . The 91/41 has the last [ and smallest bore area ] used in Carcanos . The main problem is the land size [ a tight one will have more problems ] and the gain twist . I never had a round loaded with a .268 not clear a chamber neck .

Bob, could you please post a link to the results of you're tests. I don't seem to be able to find them anywhere and I'm really interested in reading more about how you came to the conclusion that Hornady got it wrong in designing the Carcano bullet.

It was like 7 years ago . I am not a pc type guy and would have no idea how to find it again . The main problem was the Carcano has very deep rifling , some have gain twist rifling , the original bullets were smaller than groove and there were different land groove combinations used from the 1890's to the 1940's . The guy at Hornady did not seems to know these things and tried to make the bullet for a shallow rifiled , groove dia bullet type modern rifle . By making the bullet close to groove dia he keep tearing up jackets , so he made the jackets very thick . This combined with a long bearing surface made for a lot of pressure as the bullet was engraved by the rifling , and it got worse as the twist changed and tried to re-engrave the thick jacket . We had some where the jacket actually stuck in the last bit of rifling and some of the lead core came out . Now go to the smaller bore area Model 91/41 with no gain twist , but the smaller groove [ some as small as .267 ] would grab the bullet . That with the small differences in land and groove dia on the 50 years of rifles is why the bullet will work ok with some Carcano's . A bullet of .266 with a hollow [ or cupped ] base would have worked fine in ALL Carcano rifles . Maybe the Italians did know what they were doing in the first place when they made THEIR bullet like that .

---------- Post added at 05:10 PM ---------- Previous post was at 05:07 PM ----------

I would not use the .268 bullet in any of My Carcano's . But it does work great in my very early Type-38 Arisaka rifles with .270 + grooves . The difference is .002 + groove clearance , shallower rifling , and NO gain twist .

I've never had any problems whatsoever shooting the .268 Hornady bullets in my carcanos. My favorites being a Tiro a Segno Nazionale marked M41 and a 1918 dated M91 Truppe Special. I read Dave Emary's article on the carcano bullet and chose to follow his advice to only use the components listed. Perhaps this is why I had no problems.
Early Hornady bullets measured .268 and had no cannelure, shortly after their introduction the diameter changed to .267"(actual diameter measures .2667") and a cannelure was added.
Length, diameter and bearing surface compare favorably with original military bullets. However, the thick jacket does not allow for any expansion in soft tissue and they do not yaw easily so they're all but worthless for hunting.
PRVI is now making .267" carcano bullets in 140 and 160 grain. Perhaps they might expand. We'll see if ever I get interested in hunting again.

hi i have a bsa smle with a lithgow barrel that measures .318# the barrel is in very good condition i have been told to try paper patching a cast projectile i have the gear to do it just need the time i will use onion skin paper i will still gas check

hi found a bullet mould that i lapped out to 321” i have made a dummy round and it chambers so i will load them up and see how they go 15 gr ar2205 should be a good starting load

Stop trying to fix what isn't broken! There is more than enough displacement in a conventional lead-cored .312" bullet to completely fill the .318" groove. Just shoot it!

hi i tested my cast bullets today they worked a treat ,i have shot the bsa with ex mil ammo and it wasn’t as accurate as my cast loads

The .303 was DESIGNED as a black-powder cartridge, at about the same time the French were introducing smokeless powder.

The design of the Enfield rifling as shown in that drawing extract, is correct. Remember that in the late nineteenth century, boring and reaming a nice straight, mostly parallel hole was not much of an engineering challenge. Cutting FIVE, equally-spaced grooves of EQUAL depth with a zillion passes of a single-point hook cutter was another matter.

Furthermore, the "spirit" of the BP muzzle-loader was still hanging about. In the classic P-53 Enfield, the bullet, developed from the French Minie Ball, was BORE sized at the point of loading and tamping down on the powder charge. The pressure from the black powder ignition pushed into the large hollow base and expanded the soft LEAD skirt into the grooves. This expansion served two purposes; it sealed the bore and thus enabled more efficient use of the propellant gases AND, as each bullet whizzed up the barrel, the expanded skirt scraped out some of the fouling from the previous shot.

The bullets designed for the .303 in MILITARY service all have open bases. The jacket is relatively thin and soft-ish, the inner lead core is very soft. So, when you kick the bullet in the rear with twenty thousand PSI, not only will the bullet be persuaded to move forward, it will tend to bulge a little at the rear. So, the front half of the bullet "rides" the lands whilst the very rear expands a few thou and acts as a gas-seal / piston. The fast burning rate and consequent "early" peak in the pressure curve of Cordite help in this process.

HOWEVER, Mk7 ball or a close commercial facsimile are somewhat elusive commodities, so most reloaders use a bullet of approximate weight and hope for the best.

Sadly, MOST of the commercial bullet offerings are WRONG for this cartridge and rifle combination. Closed-end, flat-base bullets tend to not "bump-up" to the same extent, even with relatively fast-burning powders. Boat-tailed SP / HP bullets are even worse, as the boat-tail tends to divert the propellant gases around the bullet and into the tiny gap between the bullet body and the major diameter of the grooves. This high-pressure gas acts as a cushion against bullet expansion at peak pressure and also causes gas-cutting in the barrel throat / leade.

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Originally Posted by Bruce_in_Oz

The .303 was DESIGNED as a black-powder cartridge, at about the same time the French were introducing smokeless powder.

The design of the Enfield rifling as shown in that drawing extract, is correct. Remember that in the late nineteenth century, boring and reaming a nice straight, mostly parallel hole was not much of an engineering challenge. Cutting FIVE, equally-spaced grooves of EQUAL depth with a zillion passes of a single-point hook cutter was another matter.

Furthermore, the "spirit" of the BP muzzle-loader was still hanging about. In the classic P-53 Enfield, the bullet, developed from the French Minie Ball, was BORE sized at the point of loading and tamping down on the powder charge. The pressure from the black powder ignition pushed into the large hollow base and expanded the soft LEAD skirt into the grooves. This expansion served two purposes; it sealed the bore and thus enabled more efficient use of the propellant gases AND, as each bullet whizzed up the barrel, the expanded skirt scraped out some of the fouling from the previous shot.

The bullets designed for the .303 in MILITARY service all have open bases. The jacket is relatively thin and soft-ish, the inner lead core is very soft. So, when you kick the bullet in the rear with twenty thousand PSI, not only will the bullet be persuaded to move forward, it will tend to bulge a little at the rear. So, the front half of the bullet "rides" the lands whilst the very rear expands a few thou and acts as a gas-seal / piston. The fast burning rate and consequent "early" peak in the pressure curve of Cordite help in this process.

HOWEVER, Mk7 ball or a close commercial facsimile are somewhat elusive commodities, so most reloaders use a bullet of approximate weight and hope for the best.

Sadly, MOST of the commercial bullet offerings are WRONG for this cartridge and rifle combination. Closed-end, flat-base bullets tend to not "bump-up" to the same extent, even with relatively fast-burning powders. Boat-tailed SP / HP bullets are even worse, as the boat-tail tends to divert the propellant gases around the bullet and into the tiny gap between the bullet body and the major diameter of the grooves. This high-pressure gas acts as a cushion against bullet expansion at peak pressure and also causes gas-cutting in the barrel throat / leade.

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Well said Bruce, spot on. Can't agree more with you. :thup: