Let’s talk about the F’s

[Grenadier1758]

1Fg= Muskets
2Fg= Rifle
3Fg= Pistol
4Fg= Prime

It's a nice simple theory of the real black powders to be used in specific muzzle loading firearms. However, as we have learned on this Forum and from our own personal experiences, the choice of black powder is far more diverse. Reasonable starting point, but by the time load development is done, you may well be using 3fg in your rifles and for prime. Then the energy of the specific brand of powder may very well influence your choice.

In other words, it's just not that simple.

 

[Smokybob]

As far as specific brand of powder goes, I wish I had that luxury. Right now I have Graf & Sons label powder. Does anyone know where I can get some Swiss??

 

[hanshi]

If you all will indulge me an ignorant question...

I am experienced handloader of metallic cartridges with smokeless powder. My question pertaining to this subject is: when going to the finer powder, I see it consistently stated that you lower your charge weight. Is the relationship between different F rating powders similar or the same as that of smokeless powders with different burn rates? What im getting at is, with smokeless when one uses a faster burning powder than what is considered "ideal" you have a faster pressure spike and therefore while it makes for economical "plinking" ammo, you do lose some velocity potential compared to the more ideal powder. Does this principle carry over to black powder? Not that velocity is my tunnel vision goal here, just looking to learn more about this subject. I've always run FF because that is what was recommended in my owners manual and all I had to go by for many years. I'm considering getting some FFF to try and not sure if I should expect the same velocity I can get with FF or if that would be an indicator of over loading. Just looking for some guidelines from more experienced hands on the subject.

Yes, to an extent, sorta. Smokeless is a progressive-burn powder; black powder is not. Smokeless burns faster and with higher pressures than BP ever could. As the pressure inside a smokeless rifle starts to increase at the instant of ignition, it quickly burns hotter, faster and continues adding more pressure until the bullet exits the bore. Black powder burns the same every time, all the time. BP pressures are very low compared with smokeless and has a steady burn.

I use 3F almost exclusively in .32 up to .62. Some guns like one, 3F, or the other, 2F. The choice of which one to use is determined by what shoots better in a particular gun.

 

[dave951]

As far as specific brand of powder goes, I wish I had that luxury. Right now I have Graf & Sons label powder. Does anyone know where I can get some Swiss??

Back Creek.

 

[Christophero]

I found 3 decades ago that 65 grains of FFFg achieved what 80 grains of FFg did velocity wise, but with less fouling.

 

[RIDE-RED350R]

Yes, to an extent, sorta. Smokeless is a progressive-burn powder; black powder is not. Smokeless burns faster and with higher pressures than BP ever could. As the pressure inside a smokeless rifle starts to increase at the instant of ignition, it quickly burns hotter, faster and continues adding more pressure until the bullet exits the bore. Black powder burns the same every time, all the time. BP pressures are very low compared with smokeless and has a steady burn.

I use 3F almost exclusively in .32 up to .62. Some guns like one, 3F, or the other, 2F. The choice of which one to use is determined by what shoots better in a particular gun.

Thank you Sir.

So by loading the same charge level of FFF as I have with FF, I would think that would increase peak pressure and possibly be unsafe? If a lower charge of FFF achieved the same velocity as a higher charge of FF, kinda tells me that there is more pressure by volume generated by FFF. Thank you for helping me better understand this. And just for the record, I'm not looking to break any chrony records with my ML. Just want to make sure I fully understand the nuts and bolts of it before experimenting with different powder.

 

[dave951]

Thank you Sir.

So by loading the same charge level of FFF as I have with FF, I would think that would increase peak pressure and possibly be unsafe? If a lower charge of FFF achieved the same velocity as a higher charge of FF, kinda tells me that there is more pressure by volume generated by FFF. Thank you for helping me better understand this. And just for the record, I'm not looking to break any chrony records with my ML. Just want to make sure I fully understand the nuts and bolts of it before experimenting with different powder.

Yes, 3f can generate higher pressure than 2f in equivalent weight charges. That’s why you cut by 10% and work from there. For any given production lot, 2f, 4f, 1f, it’s all the same powder. What changes is the size of the individual powder granule. Smaller granules have more surface area meaning more powder is ignited.

 

[DuncNZ]

Thank you Sir.

So by loading the same charge level of FFF as I have with FF, I would think that would increase peak pressure and possibly be unsafe? If a lower charge of FFF achieved the same velocity as a higher charge of FF, kinda tells me that there is more pressure by volume generated by FFF. Thank you for helping me better understand this. And just for the record, I'm not looking to break any chrony records with my ML. Just want to make sure I fully understand the nuts and bolts of it before experimenting with different powder.

It is most unlikely you would blow up a well made ML by changing F size The pressure will increase but as long as you use a sensible load all you will get is increased velocity and a little more recoil .
Different makes of powder make a great difference to velocity etc . I started off using Curtis and Harvey powder then switched to Goex and found there was a great difference in velocity , accuracy and fouling for the same F granulation , same with Swiss , and now Schutzen .
I only use FFg in smooth bore large caliber guns for either round ball or shot shooting , I use FFFg in all other calibers with no ill effects to the firearm or accuracy . Since I can use a smaller charge of FFFg to that of FFg the price of the shot also comes down .

 

[Smokybob]

Back Creek.

Can I order over the phone and have them ship to me? Their website says you can buy in person.

 

[RIDE-RED350R]

Thank you gents for taking the time to explain that. Now you've got me wanting to get some FFF to try in my 50cals.

 

[deerstalkert]

Thank you gents for taking the time to explain that. Now you've got me wanting to get some FFF to try in my 50cals.

you will never go back!

 

[RIDE-RED350R]

It is most unlikely you would blow up a well made ML by changing F size The pressure will increase but as long as you use a sensible load all you will get is increased velocity and a little more recoil .
Different makes of powder make a great difference to velocity etc . I started off using Curtis and Harvey powder then switched to Goex and found there was a great difference in velocity , accuracy and fouling for the same F granulation , same with Swiss , and now Schutzen .
I only use FFg in smooth bore large caliber guns for either round ball or shot shooting , I use FFFg in all other calibers with no ill effects to the firearm or accuracy . Since I can use a smaller charge of FFFg to that of FFg the price of the shot also comes down .

Yessir. As I said before, I'm not looking to be setting any velocity records. I'm sure a 385gr maxi running 1300fps or so is plenty capable. I will definitely heed the advice given and start well below the known FFG loads and see how things go. Funny thing is, I have never run my muzzleloader through the chrony. I'll have to send a few with FFG to get a baseline so I know when to say when. I like the idea that you can do the same with less powder per shot, especially these days with powder availability being so hit and miss.

Think I'm going to order a couple pounds of FFF real soon.

 

[dave951]

Can I order over the phone and have them ship to me? Their website says you can buy in person.

Unless Jackie has changed his policy, you can order over the phone.

 

[ibud38]

I may not be in the proper thread but here is what I have anyway... I just recently aquired a PH Whitworth Birmingham no less, s/n 322. The tumbler is equipped with a fly, did all Whitworth come with one? My 'Volunteer' and 'Muskatoon' did not. Also have a Dyson mould, any tips on how to cast with it before I screw something up. 70 gr of 2f ok?
Can't wait to get to the range with this beautiful piece.

 

[sportster73hp]

Yessir. As I said before, I'm not looking to be setting any velocity records. I'm sure a 385gr maxi running 1300fps or so is plenty capable. I will definitely heed the advice given and start well below the known FFG loads and see how things go. Funny thing is, I have never run my muzzleloader through the chrony. I'll have to send a few with FFG to get a baseline so I know when to say when. I like the idea that you can do the same with less powder per shot, especially these days with powder availability being so hit and miss.

Think I'm going to order a couple pounds of FFF real soon.

I found in my encore that a larger/heavier charge pushed my point of impact to the right. Higher velocity isn’t always better. Maybe from recoil??

 

[Bad Karma]

It is most unlikely you would blow up a well made ML by changing F size The pressure will increase but as long as you use a sensible load all you will get is increased velocity and a little more recoil .
Different makes of powder make a great difference to velocity etc . I started off using Curtis and Harvey powder then switched to Goex and found there was a great difference in velocity , accuracy and fouling for the same F granulation , same with Swiss , and now Schutzen .
I only use FFg in smooth bore large caliber guns for either round ball or shot shooting , I use FFFg in all other calibers with no ill effects to the firearm or accuracy . Since I can use a smaller charge of FFFg to that of FFg the price of the shot also comes down .

It’s not likely that you could damage a well built rifle by filling the barrel completely full of 3f and capping it with a bullet… matter of fact, it’s been done. To a CVA mountain rifle. No harm was done to the rifle except the stock was cracked.

 

[hanshi]

I've never seen a need (within reason) to worry about reducing a 3F charge. Pressures in muzzleloaders with black powder pale in comparison with even modern .38 spl cartridges. Pressures from 6,000 psi to 12,000 psi cover the spread of the vast majority of loads used for target up to hunting. Charges that are out of reason on the high side are not normally accurate, nor faster than a more moderate load. 70 grains of 3F in a .45 is about as high as I usually go simply because it gives such fine accuracy. Even 80 grns of 3F is a good load. This is the same 70 grn load I use in a .50 though I've done lots of shooting/hunting using 100 grns. Most guns I have burn 60 to 70 grns of 3F and I see no need to go higher.

 

[Ian Straus]

If you all will indulge me an ignorant question...

.....Is the relationship between different F rating powders similar or the same as that of smokeless powders with different burn rates? What im getting at is, with smokeless when one uses a faster burning powder than what is considered "ideal" you have a faster pressure spike and...

Smaller grains burn faster and so have a higher pressure spike. This is true for black powder and also for nitrocellulose powder. I first heard it at the Field Artillery school decades ago. So the nitrocelluose grains in 8-inch howitzer bags are as big as my thumb, to burn in a really long (but not infinitely thick) barrel and push a really big projectile. The grains in 105mm bags (yes there are bags inside those big metal cartridge cases, that's how you can cut charges) are about the size of a little finger joint as I recall, fit for the shorter barrel. 155mm is intermediate.

Naturally nitrocellulose as a class produces more energy faster than black powder does as a class. The grain size principle applies within chemical formulations.

I would be surprised if that rule didn't hold for any gunpowder no matter how it is formulated.
I am not sure how the one-piece cylinders of black powder substitute sold for in-line muzzle loaders are formulated
(they must be for folks who consider it burdensome to measure charges) but I suspect that compared to Pyrodex the formula is adjusted to speed up the burning rate to compensate for the large single 'grain".

Yes, us rifled musket shooters often use an un-historical load of 3F. That pressure spike will spread the skirt of the Minie better than with 2F or 1.5F, which compensates for loose fits between true barrel caliber and actual Minie diameter, also compensates for thick Minie skirts.

 

[Doc]

My wife and I are very serious shotgun shooters. A few years ago we switched from 2f to 3f, not only cleaner burning but we are getting higher velocity which means a smaller lead and a higher hit rate. It’s a win win.
Doc,

 

[Smokybob]

Well quick range report, I tried two loads of FF first I tried 5 rounds with 60 grains behind a Pritchett bullet. See pic below for results. Not terrible but definitely room for improvement. Second charge was 55 grains and the results were so bad I didn’t even shoot the last two cartridges. I think I may need to bump up a little from 60 grains to improve accuracy. What say you? This was using my 1862 Richmond Carbine that is currently for sale in the marketplace