Reloading the Carcano

Many who reload the Carcano use the Hornady "0.268"" bullet (in fact it measures 0.267"), and are aware of the strange loading requirements prescribed by Hornady for their use, e.g. magnum primers and specific powders and charges. This is the first time anyone has explained why, and it's good enough for me. Take varying groove sizes, deep rifling and gain twist and you can get a very special situation. It appears that using 0.264" bullets, while not necessarily accurate, is safe, and requires no special loading restrictions. The same would go for cast bullets, except that they could be sized appropriately, and would be accurate (at least they are for me).

Thanks to "mag" from Gunboards. With so much rumour, hearsay and just plain nonsense, it's nice to see some real research and informed conclusions.

06-20-2008, 08:51 PM
mag
Senior Member


A friend and I have shot 1000's of the "big" Hornady .267 dia 160 rn bullets, A lot of testing in over 50 different carcano rifles and carbines of all models. We did this as soon as the bullets came out. Both of us have found that there is a problem with this bullet . Here is what we have found, and why it is a problem . We did find that sometimes you could get 30 or 40 rounds fired with no problem before something bad happened. Since we were firing over 100 rounds per day at times, it was much more likely for us to see it compared to a guy that only fires 20 rounds every month or so. The designer of the bullet did not seem to understand some things about the way most European military bores [ and Carcanos ]were made to shoot. They did not use groove size bullets for a reason . The Carcano has very deep rifling and this is the cause of some of the problem. Also the Carcano's bore size [ land and groove ] did change over the years. The early rifles had a larger groove [ about .272 ] and the groove size did get smaller to about .266 [ with shallower rifling ]with the M-41's . So any pressure data produced from one size bore with not be the same as what was made from another. The land size is what is causing the Hornady bullet to have problems. We have found that the rifles with the smaller lands are more likely to have problems with the bullet, and that it can be a size differance as small as .001 [ .002 total of both sides ] . The deep rifling of the Carcano was cutting through the jacket on the original "big" bullet. To fix this the jacket was made thicker , this caused another problem, that was made worse by the gain twist rifling. It was very hard for the rifling to engrave the thick jacket so deep into the bullet [ this slows the bullet down and causes pressures to go up. Then when the bullet has to "re-engrave" when the twist changes the perssure goes up some more. The " recomended" powders did help with this on some of the less tight bore [ their test rifles ? ] , but it still did not fix the problem on real tight bores [ that they did not have to test ? , but other's could be shooting ] . There was a reason the Italians made their bullets .265 to .266 and used the material that they did for the bullet jacket . The long undersized bullet [ open at the base ] would still ride straight down the bore, the base would seal, and the "extra" bullet material that was displaced by the deep rifling would have the extra groove depth to go into,, and there was also room for the rifling cut "wings" to shift to as the twist changed . To see why this is a problem all you have to do is figure the bore area of a .253 land - .268 groove barrel and compare it to the area of a .267 dia bullet. Where is all that extra displaced bullet material going to go ? It is not going to displace exactly the same each shot. That is why pressures can spike .
I have seen the big bullet [ shot with the recomended load ] have the jacket get stuck in the bore ,way into the gain twist, as the lead core exited. This could also be another cause of over pressure if a shooter fired another round into the stuck jacket. Between the two of us we have had many case faliures with this bullet. We will not use it in Carcanos any more. So the bottom line is they made a bullet that will only work in some of the rifles, needs the load to be matched to each rifle, is not for non-expert reloaders [ or "custom reloaders" that have no idea what size bore rifle their ammo will be used in ] and has a very narrow reloading spec . I knew the bullet would be pulled from the market after a while from the problems I knew it was going to cause. So I bought several 1000 extra right after we did our testing. The bullet does work well and shoot well in some OTHER types of " 6.5mm " rifles, many times it is the only one that will . This is what I have found, some may find it interesting . I do feel the big bullet will get you [ in many of the rifles ] if you shoot it enough. I had a M-91 lr that was shooting it pretty well, over 80 rounds in testing with no problems at all and good accuracy . I shot the rifle in a match and the 14 shot blew the case apart. So number 94 shot in THAT rifle got me. mag

Sorry, Double Post...Could not delete Posting Completely...no "Delete Post " Function visible

Doc AV

Just like the Interaction between Bore, Groove and Bullet diameter as occurs in the Austrian Mannlicher series of rifles ( and also the French Lebel and Berthier, the Portuguese Kropatschek, and the Type 45 Siamese)...all users of Long, cylindrical Bullets with potentially Large bearing surfaces, the Italians obviously had a similar Interaction in their 6,5 calibre.

The basis of all this was the "undersized" (WRT groove depth) Bullet using "Base Upswage Obturation ( in artillery terms, a "driving Band") to give the bullet the necessary engagement in the rifling together with obturation of the groove depth, to allow for full utilization of the gas pressure in Propelling the Bullet.
The rest of the Bullet cylinder (jacketed) was lightly engraved, or in the case of "two diameter" bullets, not engraved at all; as it travelled down the bore...only the Upswaging of the (Hollow) base (of a FMJ) would grip the lands and groFves.

NOTE that this principle works BEST with Open base FMJ projectiles (Both cylindrical RN and to a lesser extent, short Spirepointed FMJs with Flat bases (such as the 1905 German "S" projectile (154 grains) when "cross used" in Barrels with Groove diameters larger than .324"" (say French .326 or Austrian .329).

The relationship between Bullet diameter ("say" .318-319) in a Commision 88, having Bore of .311 and grooves from.320-322 ( "z" type freshened rifling) is a case in Point.
The same applies to the M95 Austrian Mannlicher, a "True" 8mm Bore .315, Groove .329, M90/93 Cylindrical steel jacket bullet, .324 +/- .0005. Thus the problem in 1930, with the upgrading to a FMJBT Spire point, they had to increase the diameter of the bullet to .329-.330, as there was insufficent base to upswage, and thye actual contact area of the jacket was much reduced by the Spire and BT shape. So Gas obtruation was achieved by the use of the full diameter(Groove) Bullet.

Now all these rifles(Carcano included) were developed at about the same time (1888-1895) and the Theory of Bullet to Rifling relationships had already been well thrashed out by both Theoreticians such as Hebler, Lorenz, and Rubin in Switzerland, and practically by Baron Von Mannlicher in Austria: The French and the Italians also had information from the Scientific Publications of the Swiss in this regard.
The Germans, of course, developing a rifle And cartridge by a "Kommission" ended up with a "Camel" with certain problems (the original Kom.88 Bullet was .318, and the rifling was also .318...leading to excessive friction, pressure spikes , and barrel wear...this combuined with some Poor barrel steel, led to the "JudenFlinte" scandal ( more imagination than fact) and the subsequent change in both barrel steel material ("neue materiale" or "n.m." markings, and the "z" deepening of the grooves from 318-319 to .321-322, whilst leaving the Bore at the original 7.9mm (.311). These modifications solved all the problems.

This is my simplification of information from mostly German sources of the time...there has been much (English) language controversy on this whole ".318" controversy.

I had not heard that the Italians suffered similar problems;
I have found in reloading for my Carcano rifles (I use Pulled Military projectiles, or FMJs from other sources, such as Norma, which does(did) make a 6,5 139 grain FMJBT, with a fairly large base. I have found these do function reasonably well, although a bit undersized ( .264.)
the 6,5 Swedish FMJ with flat base ( 100 grain) training bullet made by Norma works well in Carcano rifling, as the base expands well to "engage" the grooves.

Where I found problems was in the use of Soft Points and hollow points, Flat based or not, because the bases were completely sealed by jacket, and did not "swage up" as much. This, as well as the diameter differences, could explain the inconsistencies in performance.

The same could appply to the .267 Hornady projectiles developed by a couple of Keen shooters within the Hornady organisation, whom I have had the pleasure of E-conversing at the time of the Carcano Bullet's development.

BTW, the Carcano 162 grain RNFMJ, is also a type of "Two diameter" Bullet, with only the rear end section being .267-8; most of the cylinder is actually more like .263, from the ogive down.
This may not be noticeable on some of the Wartime production projectiles, as dies wore out,... but the same principle is used on several French Bullets, which had "double diameters" even though they were Spire and BT (Balle D and Balle N).

It seems that if the Italian designers of the Carcano system had problesm with the Bullet vis-a-vis the rifling, it was minor, because all research has failed to allude to this; other problems such as Soft case heads,(fixed by "Working the brass" a bit more with the added "ring" in the head) Primers Popping out in rifles ( fixed by recutting the bolt face to allow the actual contact surface to "peen" the primer Pocket shut, using the "ring" formed by the previous "heading " operation in the cartridge case; this groove around the bolt face also acted as a gas escape route, if a primer did "fail".

Crimps were added to the neck of the case (triangular stab crimps) to prevent soldiers "improving" their cartridge powder loads; and so on. Nothing in the trials and Unit proving exercises during 1892 and 1900 showed any major "bullet" problems.
Perhaps the only problem encountered was in Africa, where the long pencil like bullet tended to go straight through Native Rebels, and hardly affect them...so much so that even during the 1936-41 Italian occupation of AOI (East Africa), Spent 6,5 FMJs were routinely " picked up" by the natives for reloading ( they did it with 8x50R projectiles as well, from the War Booty M95s issued to the Askari ( Italian native Troops) and the Dubats (Native Irregulars under Italian officers). It was infact this "penetration and not Lethality" problem that led to the development in 1937-38 of the 7,35 cartridge, with a "fibre pointed" Bullet copying the British Mark VII design, to increase deformability of the projectile at close range (M38s were sighted at 300 metres or so, fixed).

Getting back to the Carcano reloading problem, I hope you guys in the US and Canada can get to the bottom of this...In Australia, we are stuck with factory 6,5 with .264 Bullets,(Norma and Prvi-Partizan,) and no supply of Hornady .268 Bullets in sight.
Some use Pulled Military bullets --a lot of the Italian Milsurp ammo is now "dead", so Bullet and Powder is Pulled, loaded into new cases (Boxer primed) and shoots quite well.

Regards,
Doc AV
AV ballistics.
Brisbane Down Under.

Quote:

---

Originally Posted by Andy

Many who reload the Carcano use the Hornady "0.268"" bullet (in fact it measures 0.267"), and are aware of the strange loading requirements prescribed by Hornady for their use, e.g. magnum primers and specific powders and charges. This is the first time anyone has explained why, and it's good enough for me. Take varying groove sizes, deep rifling and gain twist and you can get a very special situation. It appears that using 0.264" bullets, while not necessarily accurate, is safe, and requires no special loading restrictions. The same would go for cast bullets, except that they could be sized appropriately, and would be accurate (at least they are for me).

Thanks to "mag" from Gunboards. With so much rumour, hearsay and just plain nonsense, it's nice to see some real research and informed conclusions.

06-20-2008, 08:51 PM
mag
Senior Member


A friend and I have shot 1000's of the "big" Hornady .267 dia 160 rn bullets, A lot of testing in over 50 different carcano rifles and carbines of all models. We did this as soon as the bullets came out. Both of us have found that there is a problem with this bullet . Here is what we have found, and why it is a problem . We did find that sometimes you could get 30 or 40 rounds fired with no problem before something bad happened. Since we were firing over 100 rounds per day at times, it was much more likely for us to see it compared to a guy that only fires 20 rounds every month or so. The designer of the bullet did not seem to understand some things about the way most European military bores [ and Carcanos ]were made to shoot. They did not use groove size bullets for a reason . The Carcano has very deep rifling and this is the cause of some of the problem. Also the Carcano's bore size [ land and groove ] did change over the years. The early rifles had a larger groove [ about .272 ] and the groove size did get smaller to about .266 [ with shallower rifling ]with the M-41's . So any pressure data produced from one size bore with not be the same as what was made from another. The land size is what is causing the Hornady bullet to have problems. We have found that the rifles with the smaller lands are more likely to have problems with the bullet, and that it can be a size differance as small as .001 [ .002 total of both sides ] . The deep rifling of the Carcano was cutting through the jacket on the original "big" bullet. To fix this the jacket was made thicker , this caused another problem, that was made worse by the gain twist rifling. It was very hard for the rifling to engrave the thick jacket so deep into the bullet [ this slows the bullet down and causes pressures to go up. Then when the bullet has to "re-engrave" when the twist changes the perssure goes up some more. The " recomended" powders did help with this on some of the less tight bore [ their test rifles ? ] , but it still did not fix the problem on real tight bores [ that they did not have to test ? , but other's could be shooting ] . There was a reason the Italians made their bullets .265 to .266 and used the material that they did for the bullet jacket . The long undersized bullet [ open at the base ] would still ride straight down the bore, the base would seal, and the "extra" bullet material that was displaced by the deep rifling would have the extra groove depth to go into,, and there was also room for the rifling cut "wings" to shift to as the twist changed . To see why this is a problem all you have to do is figure the bore area of a .253 land - .268 groove barrel and compare it to the area of a .267 dia bullet. Where is all that extra displaced bullet material going to go ? It is not going to displace exactly the same each shot. That is why pressures can spike .
I have seen the big bullet [ shot with the recomended load ] have the jacket get stuck in the bore ,way into the gain twist, as the lead core exited. This could also be another cause of over pressure if a shooter fired another round into the stuck jacket. Between the two of us we have had many case faliures with this bullet. We will not use it in Carcanos any more. So the bottom line is they made a bullet that will only work in some of the rifles, needs the load to be matched to each rifle, is not for non-expert reloaders [ or "custom reloaders" that have no idea what size bore rifle their ammo will be used in ] and has a very narrow reloading spec . I knew the bullet would be pulled from the market after a while from the problems I knew it was going to cause. So I bought several 1000 extra right after we did our testing. The bullet does work well and shoot well in some OTHER types of " 6.5mm " rifles, many times it is the only one that will . This is what I have found, some may find it interesting . I do feel the big bullet will get you [ in many of the rifles ] if you shoot it enough. I had a M-91 lr that was shooting it pretty well, over 80 rounds in testing with no problems at all and good accuracy . I shot the rifle in a match and the 14 shot blew the case apart. So number 94 shot in THAT rifle got me. mag

---

Agree Sir,what I still can,t understand is why Hornady didn,t just copy the original Italian round or the WCC round (an exact copy itself) !

---------- Post added at 10:24 PM ---------- Previous post was at 10:16 PM ----------

[QUOTE=DocAV;15070]Just like the Interaction between Bore, Groove and Bullet diameter as occurs in the Austrian Mannlicher series of rifles ( and also the French Lebel and Berthier, the Portuguese Kropatschek, and the Type 45 Siamese)...all users of Long, cylindrical Bullets with potentially Large bearing surfaces, the Italians obviously had a similar Interaction in their 6,5 calibre.

The basis of all this was the "undersized" (WRT groove depth) Bullet using "Base Upswage Obturation ( in artillery terms, a "driving Band") to give the bullet the necessary engagement in the rifling together with obturation of the groove depth, to allow for full utilization of the gas pressure in Propelling the Bullet.
The rest of the Bullet cylinder (jacketed) was lightly engraved, or in the case of "two diameter" bullets, not engraved at all; as it travelled down the bore...only the Upswaging of the (Hollow) base (of a FMJ) would grip the lands and groFves.

NOTE that this principle works BEST with Open base FMJ projectiles (Both cylindrical RN and to a lesser extent, short Spirepointed FMJs with Flat bases (such as the 1905 German "S" projectile (154 grains) when "cross used" in Barrels with Groove diameters larger than .324"" (say French .326 or Austrian .329).

The relationship between Bullet diameter ("say" .318-319) in a Commision 88, having Bore of .311 and grooves from.320-322 ( "z" type freshened rifling) is a case in Point.
The same applies to the M95 Austrian Mannlicher, a "True" 8mm Bore .315, Groove .329, M90/93 Cylindrical steel jacket bullet, .324 +/- .0005. Thus the problem in 1930, with the upgrading to a FMJBT Spire point, they had to increase the diameter of the bullet to .329-.330, as there was insufficent base to upswage, and thye actual contact area of the jacket was much reduced by the Spire and BT shape. So Gas obtruation was achieved by the use of the full diameter(Groove) Bullet.

Now all these rifles(Carcano included) were developed at about the same time (1888-1895) and the Theory of Bullet to Rifling relationships had already been well thrashed out by both Theoreticians such as Hebler, Lorenz, and Rubin in Switzerland, and practically by Baron Von Mannlicher in Austria: The French and the Italians also had information from the Scientific Publications of the Swiss in this regard.
The Germans, of course, developing a rifle And cartridge by a "Kommission" ended up with a "Camel" with certain problems (the original Kom.88 Bullet was .318, and the rifling was also .318...leading to excessive friction, pressure spikes , and barrel wear...this combuined with some Poor barrel steel, led to the "JudenFlinte" scandal ( more imagination than fact) and the subsequent change in both barrel steel material ("neue materiale" or "n.m." markings, and the "z" deepening of the grooves from 318-319 to .321-322, whilst leaving the Bore at the original 7.9mm (.311). These modifications solved all the problems.

This is my simplification of information from mostly German sources of the time...there has been much (English) language controversy on this whole ".318" controversy.

I had not heard that the Italians suffered similar problems;
I have found in reloading for my Carcano rifles (I use Pulled Military projectiles, or FMJs from other sources, such as Norma, which does(did) make a 6,5 139 grain FMJBT, with a fairly large base. I have found these do function reasonably well, although a bit undersized ( .264.)
the 6,5 Swedish FMJ with flat base ( 100 grain) training bullet made by Norma works well in Carcano rifling, as the base expands well to "engage" the grooves.

Where I found problems was in the use of Soft Points and hollow points, Flat based or not, because the bases were completely sealed by jacket, and did not "swage up" as much. This, as well as the diameter differences, could explain the inconsistencies in performance.

The same could appply to the .267 Hornady projectiles developed by a couple of Keen shooters within the Hornady organisation, whom I have had the pleasure of E-conversing at the time of the Carcano Bullet's development.

BTW, the Carcano 162 grain RNFMJ, is also a type of "Two diameter" Bullet, with only the rear end section being .267-8; most of the cylinder is actually more like .263, from the ogive down.
This may not be noticeable on some of the Wartime production projectiles, as dies wore out,... but the same principle is used on several French Bullets, which had "double diameters" even though they were Spire and BT (Balle D and Balle N).

It seems that if the Italian designers of the Carcano system had problesm with the Bullet vis-a-vis the rifling, it was minor, because all research has failed to allude to this; other problems such as Soft case heads,(fixed by "Working the brass" a bit more with the added "ring" in the head) Primers Popping out in rifles ( fixed by recutting the bolt face to allow the actual contact surface to "peen" the primer Pocket shut, using the "ring" formed by the previous "heading " operation in the cartridge case; this groove around the bolt face also acted as a gas escape route, if a primer did "fail".

Crimps were added to the neck of the case (triangular stab crimps) to prevent soldiers "improving" their cartridge powder loads; and so on. Nothing in the trials and Unit proving exercises during 1892 and 1900 showed any major "bullet" problems.
Perhaps the only problem encountered was in Africa, where the long pencil like bullet tended to go straight through Native Rebels, and hardly affect them...so much so that even during the 1936-41 Italian occupation of AOI (East Africa), Spent 6,5 FMJs were routinely " picked up" by the natives for reloading ( they did it with 8x50R projectiles as well, from the War Booty M95s issued to the Askari ( Italian native Troops) and the Dubats (Native Irregulars under Italian officers). It was infact this "penetration and not Lethality" problem that led to the development in 1937-38 of the 7,35 cartridge, with a "fibre pointed" Bullet copying the British Mark VII design, to increase deformability of the projectile at close range (M38s were sighted at 300 metres or so, fixed).

Getting back to the Carcano reloading problem, I hope you guys in the US and Canada can get to the bottom of this...In Australia, we are stuck with factory 6,5 with .264 Bullets,(Norma and Prvi-Partizan,) and no supply of Hornady .268 Bullets in sight.
Some use Pulled Military bullets --a lot of the Italian Milsurp ammo is now "dead", so Bullet and Powder is Pulled, loaded into new cases (Boxer primed) and shoots quite well.

Regards,
Doc AV
AV ballistics.
Brisbane Down Under.[/QUOTE
Sir, at what distance do you shoot your Carcano reloads ?
Thanks, IAC.

I see old Doc is still putting out all the old Gew-88 miss-information . He still does not know the original German bore size or what the Z rifling was or when it was used . Even though it is very clear in any German documents . He should go and buy a Gew-88 rifle , or maybe 50 that will prove everything he says is wrong .