Black powder felt recoil?

[Hogpost]

I love the boom and flash and heavy recoil of black powder, but the reason always given for the heavier felt recoil seems incomplete. Absolutely, that 50% of the powder charge that remains unburned and is ejected with the bullet has some effect, but it cannot be all of it. In my 44-40 revolver, for instance, Swiss FFFG feels a whole lot stiffer than Unique, even when the muzzle velocity with the same bullet is similar. But 50% of 35 grns BP is only 17.5 grns, much of which remains in the barrel as fouling. Adding 10-15 grains to the bullet (5-8% of a 200 grn bullet) would not make that much difference in felt recoil.

In my opinion, the other reason is the extremely fast burning rate of BP, resulting in an almost instantaneous "hammer blow", rather than the slightly longer "push" of progressive-burning smokeless. While the total recoil energy (mass x velocity) may be the same, it feels stiffer with BP because it is felt less (in microseconds) gradually.

However, that's just my engineer's guess. Anybody out there have some real information?

[Springfield]

Actually I have always felt the opposite, BP has a softer "push" while smokeless has a sharper Bang to it. BP is usually still burning while the bullet goes out the end of the barrel while smokeless is usually done by then.

[Hogpost]

It's difficult to compare BP & smokeless rounds when the performance of the two loads is different: most smokeless loads provide higher velocity and/or use different bullets. Try 44-40 in a 7 1/2" Colt, the Lyman 427098 bullet: 35 grns FFFG Swiss versus 9 grns Unique. The Unique provides 986 FPS, while the BP gives only 909 FPS, but virtually anyone holding the gun will tell you the felt recoil is noticeably greater with the BP. Try a direct comparison like this, and I think you will see what I mean.

And that orange flame you see exiting the barrel rarely includes any un-detonated powder, unless in the case of an overloaded muzzle loader. It consists mostly of glowing bits of fouling, the hot residue of the burned BP. One of the reasons most indoor ranges will not permit BP shooters is that their floor is littered with unburned "progressive" smokeless, and the falling hot embers of BP may ignite it.

But Springfield, I appreciate your input, and it's not different from many folks I've talked to. I could easily be 'way off base.

[Springfield]

I bet if you downloaded the Unique to equal the BP velocity you would see a difference. I shoot BP in my 45 auto in Wild Bunch matches. I fill the case all the way with fffg and use a 260 grain bullet and the recoil is still much more manageable than any kind of full power smokeless. Maybe all the smoke and noise is making it seem like it has more recoil.

[RMulhern]

I've shot thousands upon thousands of rounds through .45 Colt SAA revolvers with SP and the felt recoil of 37 grs. of FFF BP is more potent on recoil! As for rifles in the 12# class or slightly heavier.....even with the 50 2 1/2 case....the felt recoil...IMO....is nothing compared to the same weight rifle in say a....300 Win Mag with a good 1000 yd. target load!

[NickSS]

I have been shooting black powder in rifles for over 45 years and the last 22 years I have been shooting BPCR matches. That said I will say that the felt recoil is greater using black powder compared to smokeless powder for a given bullet and a given velocity. When shooting my 45-70 with 535 gr postels over 65 gr of FFG after firing 50 rounds prone in a day my shoulder is tender. Shooting the same bullets pushed by AA 5744 at the same velocity firing 50 rounds prone in a day and my shoulder does not feel any affect at all. As a result I never fire heavy bullets in my 45-70 without a recoil shield on my shoulder. Other wise I start flinching on the second day of a two day match. Why this is I do not know but I suspect it is becasue of the greater volume and weight of the gas blowing out of the muzzle gives a greater recoil due to the jet effect of the gas. With smokeless there is less gas so less push.

[Stampede]

I have mixed “feelings” about the BP or Smokeless kick backs.

The kickback with my .45-120SS is very hefty but not unbearably (I love it). But the kick back from my .300WM is way more and my .338LM is in between!!!! Go figure.

There is all so a weight issue with the gun it self. I have three .50-70 (12.7x44R) rifles. My Remington RB is a light weight compared to my RB Husqvarna infantry rifle and kicks therefore even more with the same BP load.

I my experience the BP loads “Push” and the Smokeless “Kicks” more, but hey that’s my opinion.

Peter (Stampede)

[Hogpost]

NickSS & RMulhern, thanks, that's exactly what I'm talking about: with the SAME bullet & velocity (or same total muzzle energy) & SAME gun weight, the BP load always feels seriously heavier.

And I agree with virtually everyone else that the larger mass of ejected BP fouling essentially adds to the bullet weight, which is part of the cause of heavier felt recoil. (Approx 50% of BP charge weight remains as solid material) But I also think the almost instantaneous "hammer blow" of BP combustion, compared to "progressive" SP is an additional factor in the feel.

I'm hoping someone out there has some real data on that because I think many of us would like to know. I sure would!

[TXGunNut]

I've always felt the "push" and "boom" of a BPCR fired w/ BP was more pleasant than an equivalent SP load but NickSS has proved that theory wrong. I don't shoot SP in my BP guns and vice versa so I doubt I'll do any testing on my own in rifles. Thanks guys, interesting thread.

[Chicken Thief]

100degF at 10% hum compared to 100degF at 90% hum. Which is warmer?

See the problem?

You cant compare BP recoil and SP recoil.

BP flamefront moves way way below half the speed of SP. The top speed of bp is somewhere aroung 2000fps and the max speed with SP is over 5000fps.

[Hogpost]

Aw, Cheese, Chicken Thief, let's stay on point here, and stick with real info:

1. FACT: (repeated God knows how many times from hundreds of shooters) using the SAME bullet launched at the SAME velocity from the SAME gun, the recoil from the BP load FEELS heavier.

2. FACT: under the conditions indicated above, one reason is that BP ejects a large mass of solid (fouling) material, roughly equivalent to 50% of the charge weight. This mass is additional to the bullet weight, resulting in an ACTUAL increase of total energy including recoil. (Energy = Mass x Velocity squared). This is one reason for fact #1.

3. Black powder combustion is very very much quicker than smokeless, which is why smokelesss is also called "progressive" burning. SP initially accelerates the projectile at a slower rate than BP, but continues to do so much further down the barrel than BP. Your "flame front" velocities are irrelevant, as SP combustion velocity increases with chamber pressure, unlike BP. Thus, by comparison, BP deals a sort of "hammer blow" to the projectile, while smokeless delivers a more gradual acceleration.

Since #1 and #2 and #3 are FACTS, I wanted to know if there was FACTUAL support for the concept that #3 is an additional contributing factor to #1; and I would dearly like to see some real DATA.

[mustanggt]

The question is "Felt recoil" right? It feels like more force is slamming into my shoulder when I fire a black powder load and I love it.

[Cap'n Morgan]

I love the boom and flash and heavy recoil of black powder, but the reason always given for the heavier felt recoil seems incomplete. Absolutely, that 50% of the powder charge that remains unburned and is ejected with the bullet has some effect, but it cannot be all of it. In my 44-40 revolver, for instance, Swiss FFFG feels a whole lot stiffer than Unique, even when the muzzle velocity with the same bullet is similar. But 50% of 35 grns BP is only 17.5 grns, much of which remains in the barrel as fouling. Adding 10-15 grains to the bullet (5-8% of a 200 grn bullet) would not make that much difference in felt recoil.

In my opinion, the other reason is the extremely fast burning rate of BP, resulting in an almost instantaneous "hammer blow", rather than the slightly longer "push" of progressive-burning smokeless. While the total recoil energy (mass x velocity) may be the same, it feels stiffer with BP because it is felt less (in microseconds) gradually.

However, that's just my engineer's guess. Anybody out there have some real information?

I simply believe the difference is due to accelerating a larger mass (boolit+powder) over a shorter time. Even with everything else equal, the extra 28 grains when comparing 35 grains BP to 7 grains Unique will increase recoil 20%. I don't think the "rocket effect" at the muzzle has any significant effect on recoil in a low pressure round like the 44-40.

[montana_charlie]

It might be a 'fact' that hundreds say BP recoils harder, but I doubt that those 'hundreds' obtained their findings by shooting identical rifles, to test their similar loads.

Because 'felt' recoil is the critera, all kinds of extraneous factors enter into this pointless discussion. Rifle weight, balance, buttpad, even the shape of the buttstock is material to how the recoil 'feels'.

If there is a machine that can produce the 'hard facts' that you are asking for, it's output would not take 'feelings' into account.
Therefore, while you might have a scientifically provable 'number' for your records, you would still get argument from human shooters.

CM

[plourbag]

Stampede, I notice your comparing calibres. I've only started using BP loads in my 45/90 and haven't cronographed them to compare them to smokeless but I find smokeless much more comfortable with the same projectiles and as much FFg as I can compress in the case without distorting it. However, I have shot a lot of large calibre smokeless "African" calibres in my mispent youth and found that gun weight and stock configuration have a heck of a lot of effect on perceived recoil. I have had rifles in the same calibre, shooting the same ammo; one was extremely comfortable and the other crossed my eyes(I had a .505 Gibbs that I could only sell to someone I disliked). I'm not recoil sensitive (my mates reckon I'm a masochist). I notice others on this post use the same rifle for BP and smokeless so my comment only refers to your post. Anyway, shoot whatever you're comfortable with as long as it hits where you're pointing. After all it's the most fun you can have with your pants on.

[redneckdan]

One of the reasons most indoor ranges will not permit BP shooters is that their floor is littered with unburned "progressive" smokeless, and the falling hot embers of BP may ignite it.

I have seen this happen first hand, it is a pretty interesting occurrence.

I bet if you downloaded the Unique to equal the BP velocity you would see a difference. I shoot BP in my 45 auto in Wild Bunch matches. I fill the case all the way with fffg and use a 260 grain bullet and the recoil is still much more manageable than any kind of full power smokeless. Maybe all the smoke and noise is making it seem like it has more recoil.

Interesting. Is holy black required for the wild bunch match? Does it cycle your 1911 okay with a stock recoil spring?

[Hogpost]

By the way, the specific data I would like to see is related to my original question about the combustion rate of BP being faster than smokeless: surely someone out there has come across some charts or graphs of pressure over time while the bullet is in the barrel, comparing BP versus smokeless.

[LazyJW]

By the way, the specific data I would like to see is related to my original question about the combustion rate of BP being faster than smokeless: surely someone out there has come across some charts or graphs of pressure over time while the bullet is in the barrel, comparing BP versus smokeless.

Way back in the foggy reaches of my caffeine crazed memory banks, I recall an article in Guns & Ammo(?) by Ross Seyfried (I think). Very foggy, so I'm not going to be too adamant.

Short story: said article showed pressure traces of Black Powder versus Smokeless. BP had a significantly SLOWER pressure curve rate, contrary to popular belief. The pressure rose much slower, peaked lower, and ended later.

This was some years back, and I doubt that I saved the article, just working on memory here.
Joe

[Springfield]

BP has a lower and slower pressure curve. Just read any article about shooting Smokeless in an old Damascus barrelled shotgun the the charts come out of the woodwork. They all say the opposite of you, the smokeless peaks way sooner than BP, thus the danger of shooting a smokeless shotgun round in a BP designed barrel and blowing it up. And no, BP is not required, nor even recommended for Wild Bunch matches. My stock 1916 Colt 1911 works fine as long as I use a heavier than normal bullet, as the BP doesn't provide a sudden enough push to work the slide otherwise.

[Ed in North Texas]

Aw, Cheese, Chicken Thief, let's stay on point here, and stick with real info:

1. FACT: (repeated God knows how many times from hundreds of shooters) using the SAME bullet launched at the SAME velocity from the SAME gun, the recoil from the BP load FEELS heavier.


Since #1 and #2 and #3 are FACTS, I wanted to know if there was FACTUAL support for the concept that #3 is an additional contributing factor to #1; and I would dearly like to see some real DATA.

There is the problem. "...the BP load FEELS heavier." You are trying to get an answer which quantifies a subjective determination.