Author Topic: 2F to 3F Powder Conversion  (Read 17652 times)

Daryl

  • Guest
Re: 2F to 3F Powder Conversion
« Reply #25 on: August 18, 2009, 06:04:02 PM »
My findings as well at the chronograph, DP - 3F giving higher shot to shot velocity swings than 2F.  Over the years, I've found 2f to be more consistently accurate than 3F as well. It fouls more in the vent area of the flinter, but this is easily addressed by pricking the vent now and then. In a cap gun, I notice nothing other than improved accuracy AND less demand for an extremely tight ball/patch combination - due to the lower/slower pressures of 2F.

In the .58 and .69, my shot to show velocity spreads fell to below 10fps on 10 shot strings with select accuracy loads when using spit for lube. Using grease/oil for lube, ie: bear grease or mink oil would double the shot to shot variations.  I also noted that the heavier loads in both .58 and .69 gave the mallest variations shot to shot in velocity spreads. The light loads generally gave the largest spreads - same ball and patch.

Wiping between shotsalso  increased the shot to shot spreads, while shooting 'dirty' reduced shot to shot spreads.  That indicates a more consistant bore without wiping.  At 50 yards, the first shot is usually an inch out of the group, but is fairly consistently placed - no problem while hunting large game.

Daryl

  • Guest
Re: 2F to 3F Powder Conversion
« Reply #26 on: August 18, 2009, 06:14:44 PM »
Jim- seems to me, memory being a fleeting thing as it sometimes is, the Whitworth 'target' charge was 70gr. of fine English Powder only. It was a long time ago ;D.  I also think the military charge was 60gr. as that was the charge used with similar weight in the Enfield rifled Musker and rifel that Whitworth was trying to replace.  With a bullet of approximately 500gr. (480 to 530) 60gr. was deemed to give about max. recoil from a 9 1/2 pound rifle that the average solider could handle accurately.  I might be all wet about this- Oh well.

The additonal friction as well as increased weight of projectile is the recoil and pressure rasing demon.

I have a Lyman Minnie mould for my .69 - original-Civil War era at 730gr. - so far, I've resisted firinga single one and probably won't - ever. The 480gr. ball kicks quite enough, thanks.  I'm getting over 1,500fps with heavy loads and round ball coupled with relatviely flat trajectory with round ball, & complete penetration with pure lead balls which smashes moose. I see no reason to accept 800 to 1,000fps with it's very arched trajectorya nd increased pressure for no gain whatsoever.

jmforge

  • Guest
Re: 2F to 3F Powder Conversion
« Reply #27 on: August 18, 2009, 09:38:57 PM »
Jim- seems to me, memory being a fleeting thing as it sometimes is, the Whitworth 'target' charge was 70gr. of fine English Powder only. It was a long time ago ;D.  I also think the military charge was 60gr. as that was the charge used with similar weight in the Enfield rifled Musker and rifel that Whitworth was trying to replace.  With a bullet of approximately 500gr. (480 to 530) 60gr. was deemed to give about max. recoil from a 9 1/2 pound rifle that the average solider could handle accurately.  I might be all wet about this- Oh well.

The additonal friction as well as increased weight of projectile is the recoil and pressure rasing demon.

I have a Lyman Minnie mould for my .69 - original-Civil War era at 730gr. - so far, I've resisted firinga single one and probably won't - ever. The 480gr. ball kicks quite enough, thanks.  I'm getting over 1,500fps with heavy loads and round ball coupled with relatviely flat trajectory with round ball, & complete penetration with pure lead balls which smashes moose. I see no reason to accept 800 to 1,000fps with it's very arched trajectorya nd increased pressure for no gain whatsoever.
The British hunting rifles of the day oft times used rather lightweight picket style bullets, so a smallbore 40 caliber Purdey express double would have been using anywhere from say 70 grains (2.5 drams) of #6 powder in say 1854 to 110 grains (4 drams) in 1864 to push a 1/2 ounce winged two groove bullet, likely with a small hollow point in later guns..  My pitiful math skills tell me that is somewhere around 220 grains, so that would be a little over 2 times round ball weight for the caliber and a lot less bearing surface than one of those big honkin target slugs!!!  I read that another makers 50 caliber express rifle from the period was regulated with a load of 5 drams or 137.5 grains.  I figure that the bullet would have weigh somewhere north of 375 grains.  That is actually kind of similar to what you would see in a "slower" twist modern evil inline today.
« Last Edit: August 18, 2009, 09:40:58 PM by jmforge »