Bullets - same part number but different shape

[G.S.]

Your call, then maybe is more to the story

[rf2]

I finally got the chance to shoot 2 groups with the old bullet and the new bullet. The 3 shot group with the old bullet was 0.62" at 100 yards. The 3 shot group with the new bullets was 0.86" at the same distance. There was also a small offset in the POI of about 0.5" in elevation and 0.25" in windage. Good enough for 100 yard shooting.
I'll have to rework the load a bit to bring the group size down to where it was before. I think in this case it could be an issue with the OAL - even though they are the same OAL, the distance to the lands is different due to the different ogive shape. Alternatively, I suppose it could be due to the fact that the second batch of brass was full length sized, whereas the first batch was neck sized. Oh well, I guess more experimentation will be required.

30-06 hunting loads feb 2019.jpg

[Gun Nut]

I finally got the chance to shoot 2 groups with the old bullet and the new bullet. The 3 shot group with the old bullet was 0.62" at 100 yards. The 3 shot group with the new bullets was 0.86" at the same distance. There was also a small offset in the POI of about 0.5" in elevation and 0.25" in windage. Good enough for 100 yard shooting.
I'll have to rework the load a bit to bring the group size down to where it was before. I think in this case it could be an issue with the OAL - even though they are the same OAL, the distance to the lands is different due to the different ogive shape. Alternatively, I suppose it could be due to the fact that the second batch of brass was full length sized, whereas the first batch was neck sized. Oh well, I guess more experimentation will be required.

30-06 hunting loads feb 2019.jpg

There can be quite a variation in brass depending on who manufacture it and when. You might even want to weigh your brass. Sometimes there can be quite a bit of variation in wall thickness. In the first world war the .303 Ross functioned well with Canadian made brass, but when the troops were issued the British brass it was lighter walled and over expanded causing the rifle to jam. Thicker walled brass might also account for the effect on the powder capacity of the cases.

You don't stop hunting because you grow old. You grow old because you stop hunting.
- Gun Nut

[Fox]

There can be quite a variation in brass depending on who manufacture it and when. You might even want to weigh your brass. Sometimes there can be quite a bit of variation in wall thickness. In the first world war the .303 Ross functioned well with Canadian made brass, but when the troops were issued the British brass it was lighter walled and over expanded causing the rifle to jam. Thicker walled brass might also account for the effect on the powder capacity of the cases.

You don't stop hunting because you grow old. You grow old because you stop hunting.
- Gun Nut

The 303 Brit ammo in the ross shot best with Canadian ammo not because of the brass thickness but rather the tolerances held in manufacturing. The Commonwealth ammo would not chamber in many cases, this was not a concern for the Lee Enfield rifles because they built in massive chambers to be able to chamber dented and dirty cases, this was designed around the problems found when fighting the Zulus, the .577/450 cartridge with its foil case.

[Gun Nut]

The 303 Brit ammo in the ross shot best with Canadian ammo not because of the brass thickness but rather the tolerances held in manufacturing. The Commonwealth ammo would not chamber in many cases, this was not a concern for the Lee Enfield rifles because they built in massive chambers to be able to chamber dented and dirty cases, this was designed around the problems found when fighting the Zulus, the .577/450 cartridge with its foil case.

As a bit of follow up on this:

• From: The G.O.C. 2nd Can. Inf. Brigade.
• To: D.O.O. 1st Can. Division.

[COLOR=rgba(0, 0, 0, 0.7)]Ammunition:
[COLOR=rgba(0, 0, 0, 0.7)]With reference to your letter dated 12th instant, asking for a report on the ammunition, etc., at present in use, the Officers Commanding Battalions of this Brigade have reported that the Small Arm Ammunition of British Manufacture (Kinoch) does not work as well in the Ross Rifle as the ammunition of Canadian manufacture. They find, after firing a few rounds, that the shells seem to stick in the bore and are not easily extracted, in fact, more than the ordinary pressure must be applied. It seems that the cartridge case is slightly smaller than those of Canadian manufacture and on expansion fits the bore so tightly that the difficulty mentioned above takes place. This seems to me to be a point where the most rigid investigation is necessary, as a serious interference with rapid firing may prove fatal on occasions.
[COLOR=rgba(0, 0, 0, 0.7)]A.W. CURRIE, Brigadier-General. G.O.C., 2nd Can. Inf. Brigade.

You don't stop hunting because you grow old. You grow old because you stop hunting.
- Gun Nut

[Fox]

As a bit of follow up on this:

• From: The G.O.C. 2nd Can. Inf. Brigade.
• To: D.O.O. 1st Can. Division.

[COLOR=rgba(0, 0, 0, 0.7)]Ammunition:
[COLOR=rgba(0, 0, 0, 0.7)]With reference to your letter dated 12th instant, asking for a report on the ammunition, etc., at present in use, the Officers Commanding Battalions of this Brigade have reported that the Small Arm Ammunition of British Manufacture (Kinoch) does not work as well in the Ross Rifle as the ammunition of Canadian manufacture. They find, after firing a few rounds, that the shells seem to stick in the bore and are not easily extracted, in fact, more than the ordinary pressure must be applied. It seems that the cartridge case is slightly smaller than those of Canadian manufacture and on expansion fits the bore so tightly that the difficulty mentioned above takes place. This seems to me to be a point where the most rigid investigation is necessary, as a serious interference with rapid firing may prove fatal on occasions.
[COLOR=rgba(0, 0, 0, 0.7)]A.W. CURRIE, Brigadier-General. G.O.C., 2nd Can. Inf. Brigade.

You don't stop hunting because you grow old. You grow old because you stop hunting.
- Gun Nut

I never heard that before, it does not really make sense either, if they are small and fired in a larger chamber they are just being fire formed, the only reason they would not relax and be able to be extracted is if the pressure were higher or if you had a chamber that was rough and would catch the brass. I know that the No 1 rifles had massive chambers, what most people consider a "headspace" problem but those people do not understand what headspace is on a rimmed cartridge.

I have a bunch of different military cartridges, I think most of them are Canadian though so they would all be good for the Ross.

Really taking this off topic though.