303 British / .308 / 30-06 Discovery???

R*d Dawg said: Hey guys. I have baffling information to discuss with you guys. I've been reloading 30-06 for a little while and 303 british longer. However, I added .308 to this thread because it also takes a .30 cal bullet. I purchased a lot of tracer bullets (projectile only), some boat tails, and AP bullets as well during a gunshow I attended in Ontario recently. I went to measure a few of each with a digital caliper to see what the actual diameters were and they all came to either .308 or .309. However, I had some pulled .303 bullets from 1944 that were duds (yes I am sure), both copper jacket and nickle, and decided to measure them and they came to .308 as well. So, from previous understanding .303 bullets should be slightly larger and decided to measure some bullets in factory cartridges from modern and past. Modern came to .308 and past came to .304. My question is: Am I losing my mind or is it true I can use .30 cal bullets in all 3 calibers???? Thanks!

B*bby Ironsights said: You can, and will usually get good results, but you should have a .311 diameter from the .303 british, it`s bizarre that you got .308 bullets from them.

m*ple_leaf_eh said: .303 BR uses a .311 cal bullet. Don't ask why. No one really knows the reason for the difference.

G*bbs505 said: .303 BR uses a .311 cal bullet. Don't ask why. No one really knows the reason for the difference. It is because that is what the british picked as they were impressed by the swiss 7.5.

R*jamB21 said: American made and british made ........plain and simple

H4831 said: Hey guys. I have baffling information to discuss with you guys. I've been reloading 30-06 for a little while and 303 british longer. However, I added .308 to this thread because it also takes a .30 cal bullet. I purchased a lot of tracer bullets (projectile only), some boat tails, and AP bullets as well during a gunshow I attended in Ontario recently. I went to measure a few of each with a digital caliper to see what the actual diameters were and they all came to either .308 or .309. However, I had some pulled .303 bullets from 1944 that were duds (yes I am sure), both copper jacket and nickle, and decided to measure them and they came to .308 as well. So, from previous understanding .303 bullets should be slightly larger and decided to measure some bullets in factory cartridges from modern and past. Modern came to .308 and past came to .304. My question is: Am I losing my mind or is it true I can use .30 cal bullets in all 3 calibers???? Thanks! Now that is real information! Can't wait to get measuring. Some one said maybe US made accounts for it. I have lots of different cartridges, both commercial and military, including some Winchester made military from WW2.

tjh*ile said: It is because that is what the british picked as they were impressed by the swiss 7.5. The 7.5 Swiss uses standard .308" bullets and is the only European rifle cartridge I know of that does so. .311" calibre seems to be much more common among European cartridge designs: -7.65x53mm Mauser -7.62x54Rmm -.303 British -7.62x39mm M43 -7.62x45mm Czech

k*mzter said: The origional 7.5 swiss used .304 bullets. If I remember correctly they didn't change to the .308 until the 1911 model. Kimzter

D*NCESWITHEMPTIES said: Not to question your reloading methods or experience, but could your calipers be goofed? Had a set of digital calipers go south on me a few years back by a few thou. Didn't realize it until a fresh set of known reloads wouldn't group any longer... But I have heard of some Enfield bores varying from .309 to .312 when measured with strong to new rifling. Probably wasn't a big issue to the manufacture of combat rifles of that time. 2 m.o.a. was quite acceptable & probably could be achieved with the slight variances in both bores & calibers. Desperate times!

tjh*ile said: Yes, that's correct. GP1890 is .304" and GP11 is .308". Come to think of it, the French 7.5x54mm also uses a .308" bullet.

*agleye said: The actual nominal bullet diameter for most old SMLE's and P14's is right at .313" [Bore is 303, groove depth is .005(x2)= .313"] However, most North American made barrels are at .311" As for bullets, I have a slew of pulled Military bullets from 303 Cartridges back to the 20's. The diameter varies from .3085" right up to a few at .314" [AP rounds] Sierra and Speer bullets for the 303 usually mike up at .3106-.3112", while Hornady offerings are about .001" larger. I have some Winchester Power points here that mike .3102" I also have some 180 grain Norma bullets that mike .3125" This diameter also works with the 7.65 Mauser rifles, and the 7.7 Japanese offerings. Not much consistency here, but the best way to determine what to use is to slug your barrel. I have 2 303's in P14 rifles, one is a 303 Epps. Both groove diameters are close to .313" However, I once slugged a SMLE barrel for a friend that looked quite good inside, but did not shoot well with anything. Imagine our surprise to find that the groove diameter was .317" Regards, Eagleye

Why n*t? said: Yessirree Bob, and I know more than one guy who has loaded the 220 gr Sierra .308" round nose in his Lee-Enfield when there were no more 215 gr .311" bullets available. :) Ted

303c*rbine said: Yessirree Bob, and I know more than one guy who has loaded the 220 gr Sierra .308" round nose in his Lee-Enfield when there were no more 215 gr .311" bullets available. :) Ted That's true Ted, I regularly use 220 Hornady (.308 diameter) bullets in my Enfields. Some show better accuracy than others due to the different internal sizes of the barrels.

V*my Ridge said: .303 BR uses a .311 cal bullet. Don't ask why. No one really knows the reason for the difference. It is because that is what the british picked as they were impressed by the swiss 7.5. 303 just has a nice ring to no? :D

mb*go3 said: Just paper patch the .308 bullets for the .303..................................Harold

R*d Dawg said: Hey guys. Well seems there are mixed feelings - I am still confused myself as I know that .303 br should be around .311-.312 (atleast from what more experienced guys have told me) - also about the caliper being out - I actually did have to replace it recently because I know it was giving me messed up readings, but since I know the .30 cal bullets were pulled from 30-06 and .308, the measurements were obviously coming out right.... a while back I also got the same measurements with my last caliper (but didn't think much of it). Strange too since I got similar readings from both war time and commercial .30 cal/303 br. The only one like I said before that measured different was a round nosed .303 round from 1905 measured at .304.

sl*shee said: Yup, ask any old enfield fan and they will tell u of the .308-.312ish varience and to slug ur bore. What surprised me is that nobody has yet mentioned that .308Win is a shortened .30-06 and thus the same bullet diameter. Why winchester decided to shorten the case can probably be found in wiki somewhere

cycl*ne said: Why winchester decided to shorten the case can probably be found in wiki somewhere It was the only concession from the .30-06 the Americans were willing to make....:rolleyes:

rnbr*-shooter said: What surprised me is that nobody has yet mentioned that .308Win is a shortened .30-06 and thus the same bullet diameter. Why winchester decided to shorten the case can probably be found in wiki somewhere Winchester didn't do it, the US Army did (Springfield Armory, actually). Winchester "civilianified" the military round. As to why - a case that is half an inch shorter, will allow a rifle that is one inch shorter (from the M1 came the M-14). There are actually a few other differences between the .30-06 and the .308: - the ejector groove is different (wider for the .308) - the neck is shorter for the .308 - the case body taper for the .308 is less.

tjh*ile said: The .308/7.62x51 was developed because improvements in powder since the .30-06 was developed made it possible to get the same ballistics as service .30-06 ammo in a smaller case.

N*rthman999 said: Yessirree Bob, and I know more than one guy who has loaded the 220 gr Sierra .308" round nose in his Lee-Enfield when there were no more 215 gr .311" bullets available. :) Ted I do that for my dad for his trapline. At 50 yards they're deadly accurate and they hit as hard as anything I can find in 303 British.

b*arhunter said: CIL used to make bullets for the 303Brit that were packed in nice little, red plastic, partitioned trays and were in green/red cartons, 50/carton. The late Les Viel, of Vernon, BC used to stock them in various weights and diameters. They were available in weights from 150grn to 225grn and from .310 to .314 diameter. Les loved the 303 British. I have several north American loaded 303 cartridges that were loaded by different manufacturers, including red striped boxes of Defence Industries Ltd. out of Montreal. All of the US makers bullet diameters measure .308, while the DIL measure out at .312. Supposedly the DIL ammunition is loaded to tighter standards and is regulated for special purposes. That's the popular rumor anyway. I can understand the US makers loading with .308 diameter bullets for the plain simple reason being that is what they were set up for and just didn't want to mix things up on their own end when they switched over to 30-06 production. Definitely a huge saving in time and hassle for very little difference in down range performance. As far as barrel diameters go, I recently picked up a Pakistani No4 MkII. It has a .310 bore and will shoot either .308 or Hornady .312 diameter bullets equally well. It prompted me to check out a couple of other bore diameters in different marks of Lee Enfields. I measured a Lee Speed, with gain twist rifling, .311, a No1 MkIII 1911, .310, No1 MkIII*, 1918, .315, a No1 MkIII* 1922, .312, a No1 MkIII* 1942 Lithgow, .317, a 1950 Long Branch, .310 and last, a 1943 Savage, 2 groove, .309. My measuring instruments are made by Starrett and have zeroing pieces included in the set. I used Cerrosafe to cast the bores. Nothing new here at all from what others tell me and nothing unusual either. The diameters are all within specs, give or take a thou, and I really doubt there is a company in the world, now or earlier that would scrap a run of barrels for .001 out of spec, especially during war time conditions. The same can be said for the manufacture of bullets. It definitely shows why some 303 rifles digest .308 diameter bullets and perform so well with them. The fact that Savage and Long Branch barrels were shipped in large quantities to the UK during WWII would also explain the smaller diameters found on many UK built No 4 rifles as well. One other thing, the barrel on the Lithgow was replaced during an FTR and is as new, even though it has the largest bore diameter.

d*wnwindtracker2 said: Enfield rifling has lands the same size as the grooves so the average diameter is less than a more standard rifling. The British did that so as to have longer lasting barrel accuracy.It might help with the 308 bullets as well. just a thought

c*gar_man said: I have been shooting .308 bullets in Enfields for years. :eek: Going back to my DCRA days (Dominion of Canada Rifle Association), it was done all the time. Many team members of the NRA, British NRA that is, shot the same at Bisley. Nosler 165 grn Ballistic tips, wow, those suckers worked flawless @ 600 yds. The trick, which is no trick, use a .303 die set with .308 neck expander in the F/L or Neck size die. We experimented with 2 up to 6 groove barrels, all shot excellent.

N*rthman999 said: I tried some .308 dia, 180gr winchester bulk bullets in my No4 Mk1* recently and it was shooting at least as well as 180gr .311 Sierra's at 100 yards.

W*rkin Man said: I have an old surplus round I saved for display. It's headstamped GB1943 VII(British manufacturer, Mark 7 ball) with a cupro-nickle jacketed bullet. This thread got me curious, so I measured it. It's 0.308" in diameter. I suppose it's possible the bullet was made in the US, then shipped to the UK and loaded there. Jim

Sly *ld Fox said: 303 just has a nice ring to no? :D Answer from Breaker "By the law of .303, Sir"

TGC said: Hmm so than could russian 7.62, 306 work just as well than?

Tw*Tone said: Answer from Breaker "By the law of .303, Sir" ...under Rule 303...

10x said: Not to question your reloading methods or experience, but could your calipers be goofed? Had a set of digital calipers go south on me a few years back by a few thou. Didn't realize it until a fresh set of known reloads wouldn't group any longer... But I have heard of some Enfield bores varying from .309 to .312 when measured with strong to new rifling. Probably wasn't a big issue to the manufacture of combat rifles of that time. 2 m.o.a. was quite acceptable & probably could be achieved with the slight variances in both bores & calibers. Desperate times! I would check the calipers as well. If you are measuring bullet diameters a simple micrometer usually gives a more accurate measurement. I have measured several hundred .303 bullets and come up with diameters of .311 to .312. I have also slugged and measured the bore on a number of .303 rifles and have found several that are .314 and one that was .315. If you are slugging a bore that has an odd number of lands you will need a calibrated " V " block to get the true groove diameter.

10x said: Yup, ask any old enfield fan and they will tell u of the .308-.312ish varience and to slug ur bore. What surprised me is that nobody has yet mentioned that .308Win is a shortened .30-06 and thus the same bullet diameter. Why winchester decided to shorten the case can probably be found in wiki somewhere There is some serious debate on the .308 win and it's origin. I suspect the U.S. military and Winchester looked at the 300 Savage and said " Lets give it a longer neck, load it up to bolt action pressures with a modern powder and see what happens".

b*arhunter said: The diameter of the 7.62x54R, 7.7 Jap and 303Brit should all be .311 for bullet diameter.

10x said: The diameter of the 7.62x54R, 7.7 Jap and 303Brit should all be .311 for bullet diameter. Not if you cast bullets. the .303 British needs a cast bullet with the nose riding the rifling and 0.001" or 0.002" over the bore diameter. This means some guns like my martini shoot best with a bullet that is 0.316" in diameter

b*arhunter said: Good to know 10X

Th* Queens Medalist 86,87 said: I always advise to use 30 cals, hunting, survivor, military applications and target. 303,30.06, 7.62x51,7.62x54,7.7 jap,7.62 russian short. You can shoot a lot of collectables in those 30 cal/roughly 30 cals that have some interchangeability. Probably a couple others out there as well. It will save you a lot of $ too!

TGC said: I asked in a post in GNzs once if 308 civilai, 7.62x51 and 7,62x54 was interchange able for relaoding, and got a few answers back saying it was not comparable at all, especiallly nato and soviet, not i read its ok, what ever is a guy to do, i only go by what i am told by those in the know, and when i repeat it, i look like a foll, oh well thats life

TCBF said: - This is a very good thread. - I have a 1943 long Branch with a mis-matched bolt. I took it in to have it checked. they headspaced it, re-crowned the muzzle and slugged the bore. They said they had seen bores from .307 to .317. Mine came out at .319! They said, basically, just shoot it and see what it likes. My unscientific experiments thus far with WW1 and WW2 ball and various dominion/CIL/Igman stuff is that we (the rifle and I), at 100 yards, group an ES 4 between just under 4" to about 6", and an ES 5 (counts the most outside shot of a five-round group) at 5" to 8". If you are of the school that believes that a service rifle is just a war club with a rifled hole in it, then this is adequate accuracy, and on par with a lot of FN C1 groups (and C7A2 as well!!) that I have seen in my time. I am having fun experimenting, though. - For the Canadian Rangers, IVI has produced 215 grain KKSP type nosed cartridges. Probably to stop the stories of seals being taken with 174 grain Mk 7 ball. Has anyone had a chance to mic any of these projectiles?

10x said: - This is a very good thread. - I have a 1943 long Branch with a mis-matched bolt. I took it in to have it checked. they headspaced it, re-crowned the muzzle and slugged the bore. They said they had seen bores from .307 to .317. Mine came out at .319! snip Sounds like the perfect rifle to shoot cast bullets designed for the 8x57....

sc*anna54 said: I always advise to use 30 cals, hunting, survivor, military applications and target. 303,30.06, 7.62x51,7.62x54,7.7 jap,7.62 russian short. You can shoot a lot of collectables in those 30 cal/roughly 30 cals that have some interchangeability. Probably a couple others out there as well. It will save you a lot of $ too! Are you talking about bullets or rounds? Thanks. ./

b*arhunter said: 10x, you have a thing for cast bullets. Admit it now. No one will give you a hard time about it. You're right though. I have a Lithgow No1 with a .318 bore and the only bullets it will shoot well are cast. I tried some .318 diameter 8mm bullets but they didn't shoot much better than the regular .312 jacketed bullets.

*legs69 said: I wonder what the variances would be if people measured the same bullet several times over several days?

10x said: 10x, you have a thing for cast bullets. Admit it now. No one will give you a hard time about it. You're right though. I have a Lithgow No1 with a .318 bore and the only bullets it will shoot well are cast. I tried some .318 diameter 8mm bullets but they didn't shoot much better than the regular .312 jacketed bullets. I do have a thing for cast bullets. I have gotten cast bullets to shoot accurately out of some guns that will not shoot a jacketed bullet consistently.

sn*per767 said: I may be wrong but here's my take on this bullet dia. thing: the .303 caliber is a european caliber (and japanese) the 0.303 dia. is equal to 7.7 mm exactly ( 7.7mm / 25.4 mm per inch = 0.303 inch exactly or 0.30315 which is close enough for the girls I shoot with) now a .308 bullet has grooves of 0.300 which gives .004 inch of interference between the groove bottoms and lands. now if you apply the same .004 inch all around the .303 caliber you need a .311 bullet. It's as simple as that! 0.300" lands + 2 x .004" for the groove depth = 0.308" bullet 0.303" lands + 2 x .004 for the groove depth = 0.311" bullet I hope everyone knows a bullet diameter is equal to the bottom of the grooves so the rifle bullet can be extruded thru the barrel which permits the powder pressure to build up and deliver maximum muzzle velocity as opposed to a muzzle loader bullet which do not have a lot of interference in the rifled bore. Snippy PS: the big lines of life are driven by simple principles (excuse my french)

*agleye said: I may be wrong but here's my take on this bullet dia. thing: the .303 caliber is a european caliber (and japanese) the 0.303 dia. is equal to 7.7 mm exactly ( 7.7mm / 25.4 mm per inch = 0.303 inch exactly or 0.30315 which is close enough for the girls I shoot with) now a .308 bullet has grooves of 0.300 which gives .004 inch of interference between the groove bottoms and lands. now if you apply the same .004 inch all around the .303 caliber you need a .311 bullet. It's as simple as that! 0.300" lands + 2 x .004" for the groove depth = 0.308" bullet 0.303" lands + 2 x .004 for the groove depth = 0.311" bullet I hope everyone knows a bullet diameter is equal to the bottom of the grooves so the rifle bullet can be extruded thru the barrel which permits the powder pressure to build up and deliver maximum muzzle velocity as opposed to a muzzle loader bullet which do not have a lot of interference in the rifled bore. Snippy The problem with your deduction is that the 303 rifles tend to have a slightly greater groove "depth" than do the 308/30-06, etc. The groove depth is usually from .0045" to .005" making the total groove diameter .312" to .313" I have two P14's in 303 [one is rechambered to the Epps] and they are both very close to .313" groove diameter, while having a true .303 bore diameter. If you buy a North American made aftermarket barrel, they usually have a .311" groove diameter, but the offerings from Europe are seldom that small, but are often much larger. Regards, Eagleye

jm*x857 said: i used to have some cast bullets, they were .314 dia. they shot probably the best of my batches of cast bullets out of my enfield mk.4 , but i never had very satsifying results with cast bullets anyways.

10x said: i used to have some cast bullets, they were .314 dia. they shot probably the best of my batches of cast bullets out of my enfield mk.4 , but i never had very satsifying results with cast bullets anyways. I have some Lee enfields that are incredibly accurate with cast bullets and others that give them a fast tumble so they "buzz" after they leave the muzzle. I have no idea why some guns will shoot jacketed 303 (.312") accurately but tumble 0.314" cast bullets.

G*nderite said: "I asked in a post in GNzs once if 308 civilai, 7.62x51 and 7,62x54 was interchange able for relaoding, and got a few answers back saying it was not comparable at all, especiallly nato and soviet, not i read its ok, what ever is a guy to do, i only go by what i am told by those in the know, and when i repeat it, i look like a foll, oh well thats life." The problem with a fuzzy question is that precise answers may not be for the question you thought you were asking. 308 Wincehster and 7.62x51 are very similar rimmless calibers and funtionally interchangble. That is, the rounds will fit and safely go BANG! 7.62x54 is a Russian rimmed cartridge that looks more like a 303 Brit. It shoots the same .310 - 3.12 bullet as the Brit. Nothing about it is really interchangeble with a 308Win or 7.62x51.

tjh*ile said: I hope everyone knows a bullet diameter is equal to the bottom of the grooves so the rifle bullet can be extruded thru the barrel which permits the powder pressure to build up and deliver maximum muzzle velocity as opposed to a muzzle loader bullet which do not have a lot of interference in the rifled bore. Muzzleloading rifles still need to have the projectile (or patch/sabot) large enough to fill the grooves. The exception is with hollow base bullets, such as the Minie, which expand on firing to fill the grooves.

jm*x857 said: I have some Lee enfields that are incredibly accurate with cast bullets and others that give them a fast tumble so they "buzz" after they leave the muzzle. I have no idea why some guns will shoot jacketed 303 (.312") accurately but tumble 0.314" cast bullets. i found that i really had to use a fast burning load to get them not to tumble, which i believe couldn''t produce consistant enough velocities to get the accuracy of what i was looking for.

10x said: i found that i really had to use a fast burning load to get them not to tumble, which i believe couldn''t produce consistant enough velocities to get the accuracy of what i was looking for. Ooohhh! You have an off square crown or unevenly worn rifling at the muzzle..... I cured a couple of tumbling Lee enfields by truing up the crown. I have a couple that tumble cast bullets no matter what I do. They shoot jacketed bullets o.k.




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