drewwizard
Airman
- 41
- Dec 31, 2016
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The difference in ballistics at fighter ranges is very large. Look at a ballistic table, and see what a 500 yard drop is like between the two cartridges. We are likely talking 10s of feet. requires a little better ballistic compensator for the slower round. The deal breaker is the energy left at 500 yards. You either need speed and weight (14.5mm Russian), or explosive head (20mm and above) to deliver damage.The British 7mm was as mature as it was going to get in 1913-14, It had already been through a number of variations.
Altering the shape of the case does little or nothing despite some peoples claim to the contrary. It may make the cases harder to form.
Lowering the powder charge does work, but then "underpowering" the cartridge seems to be defeating the purpose. Making the velocity difference between the .303 and the .276 closer means a closer trajectory path and less difference to justify the change.
The difference in trajectory for long range rifle shooting has little application in air to air combat where the effective distances are much shorter. A few inches difference in impact on an aircraft fuselage?
The Japanese may have been happy with much less than eight .303s, the Italians were not, shifting to a pair of 12.7mm machine guns in the early/mid 30s, before the Hurricane and Spitfire first flew. The 12.7 was roughly 3 times more powerful on a round to round comparison.
The Italians failed to increase the rate of fire as time went on, although they did try using HE ammunition. The pair of synchronized machine guns might be equal to 3-4 synchronized .303. When mounted in the wing one 12.7 might be equal to two .303s. Yes less than eight .303s but the Itialians weren't happy" about it, they simply didn't have the engine power to carry any more. Their primary fighter engine, the Fiat AR 74, made roughly the same amount of power as the Bristol Mercury in the Gloster Gladiator.
They also tried fitting additional 7.7 machine guns at times.
Here is a bit of internal ballistics (what happens inside the gun) information. It is a bit simplified but bullet velocity is dependent on the pressure applied to the base of the bullet vs the weight of the bullet per unit of area (sectional density).
What this means is that using similar powders (to keep the burning curve the same) is that, due to the difference in diameter, you can accelerate a 145 grain 7mm bullet to the same speed as a 174 grain .303 bullet using the same pressure. If you want to use a 165 grain bullet in the 7mm you need more pressure, if you want higher velocity you need more pressure.
The smaller diameter bullet will have less room inside for incendiary materiel and it's AP qualities may be suspect, especially at anything other than a 90 degree impact. Long skinny bullets not doing so well at oblique impacts or penetrating after intermediate barriers. The US .50 having trouble with that one for instance.
The British, after the BoB, moving to a mix of 50% AP and 50% incendiary ammunition as fast as production would allow.
The difference in ballistics at fighter ranges is very large. Look at a ballistic table, and see what a 500 yard drop is like between the two cartridges. We are likely talking 10s of feet. requires a little better ballistic compensator for the slower round. The deal breaker is the energy left at 500 yards. You either need speed and weight (14.5mm Russian), or explosive head (20mm and above) to deliver damage.
Is the top one an Anchutz?BTW these are two of the rifles I own.
View attachment 470541
View attachment 470542
The bottom one is a converted No 4 Enfield and will make anybody who claims that "rear locking lug rifles won't shoot" a liar.
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The No.4(T) was considered the "best" sniper rifle of the war because they were bedded and accurized by H&H, not because of the cartridge. The .303 comes up short against the 7.92x57mm and .30-06 in ballistics.which is why many people considered it to be the best sniper rifle of the war.
The .303 cartridge was obsolescent prior to WWI, and straight up obsolete by WWII. It only remained in service so long because a couple pesky world wars popped up and interfered with the re-tooling. The Boers out-shot the Imperial troops, at least as far as I have understood, primarily because of the rapid reloading from 5 round stripper clips. The Lee-Metfords of the era were issued with magazines, tethered to the rifle, and required single feeding to reload. combined with the fact that the rifles were poorly zeroed with respect to the ammunition used. As a result, the Boers were able to maintain a higher volume of fire, and more accurately at distance.
I assume, perhaps erroneously, that HAD the 303 been replaced, the British would have explored the .50 Vickers as a possible aircraft armament.
top rifle is an RPA 2000 quad lock. (four locking lugs at the front of the bolt) It is a single shot action and the only opening in the tube that forms the receiver is the loading/ejection port on the right hand side. I did use this rifle twice at the Canadian National matches about 17-18 years ago and such custom rifles had all but displaced the converted military rifles.Is the top one an Anchutz?
I have used a civilian version of the Lee Enfield L42A1 on the long ranges at Bisley a couple of times and I did better than I expected up to 800 yards. I cannot tell you why, but the rifle gave me confidence that it would do well. I hope yours is as good
To be honest the 303 was a very good round and when matched with the Lee Enfield was at least as good as any other bolt action rifle. The round was an almost perfect match for the Lee Enfield which is why many people considered it to be the best sniper rifle of the war.
I can only go from my own experience, but I hadn't shot a full bore rifle for many years and at 800 yards scored 86 which was a group of about 26 inches. Most of the others were a lot better than me but they were regular shooters. I had to score 80 at 300 yards before I was allowed to shoot at 800 yards. I don't know the score it was a pass or fail test.
Another fact which may be of interest but I like you used peep not telescopic sights. Some used the telescopic sights but I didn't as I was used to peep sights on my 0.22 target rifle
Very true, the charger bridge was added shortly thereafter, but the rimmed cases never functioned perfectly well in the clips. It was an improvement, no doubt, but the Mauser's worked better. Wartime manufactured ammunition had slightly beveled rims, to help with the rim-lock issue, so soldiers could force a round into the chamber. But try that with modern factory brass, and the rifle will lock up solid.The Lee Metford may have been loaded with single rounds from the top but that was changed to using 5 round stripper clips in the top.
Unless you are very careful stacking the magazine, a rimmed case will grab the rim of the cartridge below it and lock up the rifle. A decidedly poor turn of events.I don't see any problem with a rimmed cartridge.