doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com I read it in a magazine...

Bill,
I think there are some extreme examples of pressure differences with same weight. The whole damascus reloading premise is based on low pressures and the flagship argument is that you can't pick a modern over the counter load that is acceptable based on velocity. So, some guys are claiming reloading can give them sub 6ksi pressures with velocities/payloads equivalent to modern loads constantly spouted/touted as max SAAMI pressures. If true, that's pretty real life.

Frankly, I don't believe for a minute that every factory load is max SAAMI, some not even close. I've measured a few and those were down a couple thousand psi. But that's still a substantial pressure difference for same/similar velocities/payloads.

You can "perceive" anything you want. The only test I remember reading was 20-30 years ago, in Guns and Ammo(I think). The results in a blind test, using fast burning powder vs slow burning powder to produce the same velocity with the same payload and shot by "experienced" shooters. They could not distinguish which shell was which. Gough Thomas has written a crapload of crap, in his lifetime, as well.

A very good friend of mine once let me read his copy of Gough Thomas. When you get back to your copy & do thorough checking you will find First; Thomas did not run the test, but reported on one done by a "Powder Manufacture" (un-named) who obviously had A DOG IN THE FIGHT ie powder to sell. ABSOLUTELY no details of the test as to how it was done, what types of powders were used etc were given. Reasons given were pure "Speculation" on Thomas' part. What was meant by "Blind Test"??? If it was absolutely "Blind" how did a group of shooters tell which loads recoiled the most??? Would they not have had to have known there was some difference as they fired them or they could not have stated which group recoiled the most. There are simply far too many unanswered questions in the Thomas report & the reasoning so absolutely ridiculus for this to even be considered as any kind of data at all. The fast powders recoiled so quickly the shooters didn't have time to feel it as much!!! If you believe that my friend please send me your mailing address, I've got a few items I'd like to ship to you COD PRONTO.
8-Bore has very aptly stated the facts concerning modern powders, the available ranges of either charge wt or burn rate for a suitable load are narrow at best. Many years ago as the change was made from black to bulk smopkeless the charge wt for equivelent loads was reduced by about half. When the change was further made from bulk to dense the charge wt was again dropped close to half again. Thus a 3 dram load of black weighed 82 grains, a 3 dram equivelent of many bulk powders as Shultz, DuPont etc weighed 42 grains while a 3 dram equivelent of many dense powders weighed around 22-24 grains. These were significant changes in actual charge wts & each change of powder type did result in lowereed recoil when given similar ballistics. There is little doubt in my mind the loadss the powder/ammo maker Co had tested which Thomas "Reported on" were loads containg a bulk powder versus a dense one & they in fact did recoil less. As Thomas gave us absolutely no details on that test though, actually I don't think he had any, my guess is worth exactly what his was, a Big Fat "0", but I am at least honest enough to state mine is nothing but a guess. My reasoning though is much more belivable than his if a little common sense is applied.

"Blind", in the test I mentioned, means the shooters were handed the shells with no idea which ones contained the fast burning powder and which ones contained the slow burning powder. They were unable to tell which was which, by the recoil they "perceived". It's also very popular to state that shells loaded with black powder give you a "push" rather than the "punch" deliver by smokeless powder, same velocity and payload. These folks obviously have never fired BP cartridges. They are just parroting the myth written by other parrots. If you don't believe me, shoot a round of skeet or trap with BP shells and follow that with a round of smokeless shells. The difference is significant. The BP shells recoil considerably more, because of the extra weight of the powder(70 to 80 grains). I have done this many, many times and am speaking from personal experience.

When a debate gets to the point that a reader can't tell what side a poster is on, it is time to give up and go back to the reloader. My questions are; "Why is powder considered an ejecta?" and "Why are we comparing black with smokeless, when powder weights of smokeless differ by only a very few grains?"

I read the G&A test. It involved about 5 shooters and, IIRC, only about 10 shots per shooter. Ie., it had zero statistical significance. The more subtle an anticipated difference, the greater is the required sample size. I like to read G&A sometimes, but........

The problem is even worse than that because experiments involving human subjects have hurdles not encountered in physics lab. One simple illustration: how would we rule out the possiblity of a bimodal distribution, ie., that some human subjects genuinely discriminate faster burn rate as "greater recoil", while other subjects genuinely draw the exact opposite conclusion.

On to formulas. The formula for recoil energy does not include terms for pressure. So, obviously, powder burn rate doesn't affect calculated recoil energy, except inasmuch as slower powders increase ejecta mass. The problem is the presumption that the perception of recoil by humans is best modeled as an energy. Does the area under the force/time curve come closest to telling 100% of the story, insofar as recoil perception is concerned? Oddly, nothing I have ever read has so much as addressed - let alone established - this. Invariably, this is just assumed.

We do not grant the energy equation exclusive validity when discussing terminal ballistics (the other "end" of recoil). We all remember reading about "killing power" as a moment (mv, Keith), as a velocity (Roy W), as a force, and even as power (KW - don't laugh, I've seen it). Maybe we've gotten smarter. Nowadays noone treats calculated energy as more than just a rough guesstimate in the realm of terminal ballistics. Maybe we should acknowledge the recoil equation as just one piece of the perceived recoil puzzle.

Sam

Everything that moves out of the shell is part of the ejecta. Powder, wad and shot. I didn't make up the formula. I brought up the black powder aspect because the amount(grains) of black needed to produce a given velocity is so much more than any typical smokeless load. 4 to 5 times as much. AND the noticeable extra recoil produced by the BP shells is undeniable, to anyone who has actually tried it. This proves to me that the amount of powder darn sure affects the amount of recoil, true recoil.

I'll definitely recheck the Thomas reference, which I think I'm remembering correctly--because I've cited it here before, and I've received the same replies. And I think I've made the same comments, which I'll repeat once again:

If a powder company is selling a variety of powders--which they all do--what "axe" are they grinding by promoting one as recoiling less than another? Like, Alliant is going to make more money getting folks to switch from GD to RD--or vice versa? Sorry, but that one does not pass the logic test.

In addition, there are some folks here who are nonbelievers in the existence of such a thing as "felt recoil", as distinguished from "measurable recoil"--even if a bunch of experienced shooters say "Hey, that load kicks more than this load", when doing the math would indicate that there should not be any difference. Felt recoil is a bit like the existence of God: it's something you have to accept on faith and the personal testimony of "believers", because it can't be proved scientifically.

As for defending Gough Thomas, I don't intend to go there. However, I will point out that he pretty much invented the MOI concept of gun handling dynamics, in which a lot of folks place great store. Jim and Miller, while I respect you both for your contributions here, can you claim any such ORIGINAL concepts you've come up with???

Well Larry perhaps I canot lay claim to any "Original Concepts". I have however been reading & studying any & all things concerning ballistics etc for the past approximately 55 years. Over those decades I have definitely learned a lot about seperating the "Wheat from the Chaff". I will have to say in all honesty that one particular article on recoil by Gough Thomas was the biggest load of "Chaff" I have encountered in all those years. I am not currently at home but if you would like I can post a section from an Alliant loading guide from a few years back where they spent an entire page of it showing "Less Felt Recoil" from a "New Powder" they had introduced which fell in burning rate "Between" Red Dot & Green Dot. You know Larry, there's just not much of a gap there to fill is there.


Quite obviously Larry you didn't research your answer any better than Thomas did his article for Alliant indeed did just exactly what you stated they would have "No Axe to Grind" by doing. They in fact promoted a new powder of theirs as producing less "Felt Recoil" than their very own old standby which had been a #1 seller for decades.

Incidently Larry if you believe Alliants "Proof" they prove Thomas Wrong, but if you beleive Thomas' "Proof" he proved Alliant wrong for their "Proofs" are diametrically opposed.

Jim;
I understood how the blind test you referred to was conducted, however I have no idea at all how the one referenced by Thomas was done as he gave no details at all on it other than the "Supposed" results, for which I have only his & Larry's word, neither to my knowledge has ever stated who actually made them, except Larry thinks Thomas did them himself, which I am certain is incorrect. I was offered the opportunity to buy his book but after reading it I just saved my money for something else.

I once believed that all there was to recoil was the physics absolutes of kinetic energy, i.e., the ejecta expelled from the barrel at a given velocity imparted a rearward velocity to a gun of a given weight. One half mass times velocity squared and you had the recoil energy. I still mostly believe that, but I really think there's got to be more to it.

I encourage all here to read the article "Something For Nothing" in the Jan. 2010 American Rifleman. It tells of a new powder used in Hornady Superformance ammo that give measurably greater velocity with less recoil. After you read the article it sounds plausible though I have not tried it, and anyway, I only have my unscientific shoulder to evaluate it.

I have burned a LOT of black powder, but very little in shotguns. For the most part, I would characterize the recoil as more of a shove than a sharp jab. A .69 cal Zoave replica I had, with 160 grs. of FFG and a 440 gr. ball would rear up and push me back a couple steps. But it never hurt a bit. I'm going to relate a story that I have been reluctant to tell when we've discussed this recoil thing in the past... partially because it is a bit long and mostly because I have no explanation for it. I'll try to keep it short.

About 5 yrs. ago, I decided to try a new bullet in my .50 cal Hawken flintlock. This was the T/C Maxi Hunter 325 gr., a pure lead hollow point. I had been using the 370 gr. Maxi Ball, and thought this new bullet might shoot a bit flatter being 45 grs. lighter, and hopefully it would expand better being a hollow point. I bought 2 boxes of 20 and hoped they would shoot near the same point of impact as the heavier Maxi Ball with the same charge of 90 gr. of GOEX FFG.

The first shot hit center and about an inch higher than the Maxi Balls. Second shot almost touched. "Cool," I thought, "one more like that and it's time to go hunting." I fired and that curved brass buttplate and thin comb smacked me like a sledgehammer. I thought maybe I screwed up and double charged or rammed down two bullets. A count of bullets and pre-measured powder vials proved I had not made a mistake, and no, I had not shot my ramrod. The shot went several inches high and wide.

I loaded another and put the bullet right in with the first two. With still no idea what happened on the hard recoiling shot, I decided to try one more. Again, it kicked like a mule and the shot went high and wide. Now, I'd been playing this flintlock game for over 25 years and never ever had anything like this happen.

I kept shooting and would get a normal recoiling shot or two that went where I expected it to go, then I'd get one that literally belted me and sent the bullet high and wide by 7 to 10 inches. The difference in recoil was huge. Instead of the normal hard shove that never bothered me, this was like shooting a 12 ga. magnum slug gun with a curved brass buttplate. It HURT, and I've never been particularly recoil sensitive. Then I noticed that the hard kickers were harder to ram down the barrel, so it became predictable that I was about to get walloped. Even so, I tried my best to avoid flinching, and with the set trigger and sandbag rests, I think I did. Still, those hard kickers flew wild on the target. I was losing daylight and decided to quit for the day, clean the gun, and try again the next day at a makeshift range near the hunting camp.

The next morning, I hunted grouse until noon and went back to the truck for lunch and to resume sighting in the flintlock for deer season which opened in 4 days. Well, it was the same as the previous day with those Maxi Hunter bullets. Roughly 1/2 of them kicked and shot normally while the other 1/2 felt like Mike Tyson was using brass knuckles on my poor shoulder. Part way into the second box of 325 gr. Maxi Hunters, I decided this was no fun any more. I shot several of the old 370 Maxi Balls I normally used to confirm that they and the gun were OK. No problem, except that my shoulder and cheek bone were already beaten to a pulp, so it was hard not to flinch.

I put the flintlock back in the truck and went back out grouse hunting for the rest of the day. I secretly hoped I would not flush any birds because I did not wish to fire my light 16 ga. DS Lefever double. (now we're on topic)

Now I'll concede that firing a 370 gr. conical with 90 gr. of FFG may give more than a little shove, but it isn't at all bad. So explain to me how the same 90 gr. charge with a 45 gr. lighter bullet, both pure lead, could kick dramatically more. But only sometimes.

Recalling that the hard kicking shots seemed harder to ram down the bore, I miked the remaining 10 or 12 Maxi Hunters. As I recall, some were around .495" like the Maxi Balls, and some ran as much as .003"-.004" larger. But still, were talking pure lead projectiles here so I would not think that could account for the vast difference in recoil. Same lube. Same loading technique that never gave me a problem over decades and thousands of shots. Same powder charge from the same can of FFG Goex. So how in hell do I account for the huge difference in recoil? If I had to quantify it, I would have to say the heavy kicks were at least twice as hard as the normal kicks. It was enough that I was concerned I might split the stock. Those of you who are rolling your eyes are justified. I have no explanation.