Front driving band size.

[Lost Dog]

Gotcha fiver. My background was army (2 1/2 years S.E.Asia with lots of "contact") and near 3 decades of police work (3 shootings, w/a 5&0 win/loss) Guess I sought function, and though long now retired, I still train for it as I've got critters here that grow big and hostile. It's ok.

Rick, what can I say? Never made rounds like that. In fact, don't know nuthin' about 200yd shooting session on iron targets with pistols! If I showed up at one of your shoots it would be as a spectator.
Reckon I'll stick to my skinny front driving bands and police style shooting. I still got "Varmint Cong" out in my woods (hogs, coyote, cottonmouth and copperhead snakes and such) to deal with. And armordillo are ALWAYS prime targets!

 

[Ian]

Re: Fiver post 20: There Ain't No Such Thing As A Free Lunch.

Bob Crane had the same conundrums with camshaft grinds.

 

[Rick]

Dog, Sounds like you think I was trying to convince you to follow my lead. Nothing could be further from the truth, my only intent was to describe how I make long range revolver match ammo. As I said in an earlier post it all depends on what your intended use and goals are. Anyone doing things their own way and happy with the results is definitely doing it the right way for them. Others may be interested in how others shoot and load for that shooting.

.

 

[Lost Dog]

As shucks Rick. But yeah, if I showed up at one of your shoots to compete, why the whole line would laugh at my attempts!But that's what diversity is all about.
I cheated once at the small town range/gun club I was a member at long ago. Used to compete in BP cartridge and ML shooting and especially in the standing position. Our club was doing a 100yd standing shoot at a paper Turkey target. Top score was next year's dues free. Bunch of deer hunter types with scoped 270's and such. I stepped up with an original 1884 Springfield trapdoor rifle. Five shots each to score. Bunch of shooting. And the young lad with the ancient rifle with iron sights got his dues paid that next year... But if I was untrained it would have never happened. That's why you won't see me do much different than now. In close quarter combat shooting, well let's just say there I'm trained. In your field? I'm laughable!

 

[KHornet]

Fiver, I agree with your para on changing something to gain something, and loosing something else as a result. Always looking for a better mousetrap I guess.

 

[Paden]

I'm quite sure I have far less experience than most here, but curiously I have not yet encountered a cast bullet intended for revolver with a smaller diameter forward driving band (?). In fact, the idea never even occurred to me before reading this thread. All I have ever played with for my .45C or .500L have been full diameter. I have seen many with a smaller width forward band... All the bands on my pet bullet are the same width (0.090), if for no other reason than because I like symmetry, but I believe a meaty forward driving band facilitates positive land engagement with reduced propensity for skidding. My .45 Colt bullet dimensions and brass treatment generally conform to what Rick has described (tho the leading edge of my forward band rests at the top of the ramp and just kisses the rear of the throats, falling just short of actually engaging the throat when chambered). During launch the forward band is firmly in contact with the forcing cone and beginning to engrave into the lands while most all of the bullet aft of the crimp groove is still firmly within the cylinder throat. By the time the GC clears the throat the forward two driving bands are fully engraved and the third is beginning to make contact. This seems to work well for me/my gun; I get excellent accuracy and zero leading. Tho, I am still working on 100 meter proficiency and will likely never claim any level of 200 meter proficiency in my remaining lifetime.

Or . . . What I do for 200 meter revolver accuracy is use a heavy for caliber bullet sized to a mild snug fit in the throats. Brass sized only to the depth the bullets seats. When a cartridge is chambered the front driving band is inside the throats, bullet isn't sized down or shaved from the edge of the throat and it's centerline is aligned with the centerline of the bore. By the time the leading edge of the front band reaches the forcing cone the center and rear driving bands are still in the throat keeping the bullet aligned with the centerline of the bore. When the rear of the bullet is clearing the throat the front band is engraved in the rifling. Bullet stays as straight as possible and pressure is fairly well contained behind the bullet until the entire bullet is in the barrel.

I did crimp testing a few years back and with these loads the type of crimp made little difference. The main concern is just enough crimp to keep the bullets from pulling under recoil. Any more crimp than that serves only to be tough on the brass.

 

[Rick]

Na not laughable. Every shooter new to silhouette had pretty much that same idea though. Every shooter new to the sport needs to be told that every one of these shooters, regardless of how much experience they have or how good they may be were themselves brand new to the sport at one time.

But I don't shoot silhouette anymore, age, cataracts and diabetes has seen to that. For 30 years it was a big part of my life, finally had to admit to myself that sight alignment via braille just wasn't working.

.

 

[9.3X62AL]

I have SWC revolver moulds of both types mentioned in the above texts--some with front drive bands smaller than throat diameter (Lyman's #358477) and Keith-type with full-caliber front drive bands (Lyman #358429), and a bunch more in other calibers from 30 through 45. I cannot discern an advantage of one over the other, but I've only been at this since 1981.

There is one tendency I've noted that DEFINITELY can cause shorter bullets in revolver to slice off into poetic travels from a wheelgun......if a bullet is so short that its front end has yet to fully engrave into the rifling leade before the bullet base clears the cylinder face, your chances of wider distribution downrange goes up MARKEDLY. E.g., the loads we once carried in our 38 Specials--W-W 110 grain JHP--were across-the-board-less accurate than heavier/longer bullets, jacketed or cast/swaged. I am seeing similar outcomes in my own 357 Magnum carry guns with the adoption of the Federal 125 grain JHP/Federal 357B load as recommended by FBI. They have more report, a bit less recoil, and a lot less accuracy than the old load (W-W 158 JHP).

 

[Lost Dog]

Well all of my moulds cast slightly smaller front driving bands. Old Ideal and older Lyman both. 357466, 358429, 358429HP, 429360, 429421, and 454424. Only an old Ideal 358495 full wadcutter casts a caliber size up front. Never even paid attention to it until I read the article by that guy cussing one mould in particular that he claimed was rotten due to the front driving bands being undersized. Course I didn't have an issue with mine. Go figure huh?

I can see where short bullets could get cockeyed at the forcing cone. For a test, I bought some pointed 105gr bullets from Badman Bullets to piddle with in a .38Spl. They have a short bearing surface but do ok out of my old S&W and fair from my Cimarron model P in .357mag. These are pointed like 9mm bullets but sized .358" with a crimping groove. But I sorta thought that the faster twist in the Cimarron and nearly as fast in the Smith had more bearing on the matter with conventional bullets being much longer and shooting better than shorter ones.

 

[JSH]

Rick, what/who's design did you settle on for your FA?
I have an LBT LFN 220 for my 357. Shot a 35 Sunday, not a personal best but I was very happy for that after being absent from my IHMSA shooting for a year.
296/H110 healthy dose, starlike brass and small rifle primers.

I have had some success with the RCBS 180 Sil.in the 357 max Ruger. I still think it could be be better.
Jeff

 

[Rick]

RCBS 35 200 and RCBS 180 Silhouette, used the 200 to win the state with a 60x60. Only went to the 180 for the better BC but I can't say it shoots any better than the 200. The RCBS 35 200 is an outstanding bullet. Never used much 296, a top load with H-110 cause it doesn't work well reduced. Cut my 200 meter groups, ES, SD in half when I switched from Fed 205 to CCI 550.

..

 

[9.3X62AL]

Lost Dog--

That whole "shorter bullet going cockeyed in forcing cone transition" is purely theoretical, but has its basis in real-world experience on paper and in the field. My old shop stuck with that W-W 110 JHP +P 38 Special from my hire date (11/77) until Winchester discontinued it about the time of my retirement (6/2005). Somebody was very enamored of the Super Vel/1970s/8-track tape deck mindset, for darn sure. SITS--Stuck In The Seventies. Given that cop shootings happen at close ranges, a given load's intrinsic accuracy wasn't and isn't of paramount importance. (Other issues/concerns about service shooting "accuracy" or absence thereof will remain silent here) My own thoughts are that the "FBI Load"--158 grain lead SWC/HP +P is probably single-best in the caliber as felon disincentivizer/autopsy precursor, but I wasn't often consulted and far more frequently got advised or ordered. Such is the reality--that those with the most at stake for an outcome will have the least input in its processing.

Where I REALLY noticed the accuracy fall-off with the squatty JHPs was while varmint hunting. Speer, Sierra, Hornady et al all advertise bullets of this type as being ideal for small quarry, and I have done my darnedest lo these many years to cause havoc and prompt consternation for rats, jacks, badgers, and coyotes whenever possible. Well, those short little speedster bullets hive rats and jacks like nobody's business when they do connect, but I noted that MAKING those connections had a much better hit rate with the heavier/longer 140-160 grain-class 38/357 bullets, regardless of range. I preferred using service-load duplicators (or actual service loads carried more than 6 months) for varminting, but they flew too poetically for my tastes.
'

 

[Rick]

The idea isn't that the bullet goes cockeyed at the forcing cone, if the front band isn't in the throat when chambered to align it straight with the bore it is lying on an angle in the chamber. That angle is how it will go through the throat and how it will go into the forcing cone and through the barrel. Once slammed into the throat in a manor that it isn't concentric there isn't any magic to straighten it back out, it goes down range the same way. How much any of this matters depends on what your loading for and what your shooting. What could group into a decent cluster at short range would be measured in feet downrange.

.

 

[RBHarter]

I get all the weird crap.

Al
I had a Taurus 66 once that would shoot 38s and plus Ps into neat little clusters but the instant it crossed the line into 357 territory it was over . SWC, JHP, plated TC....it didn't matter 125-158 gr ,in my days of store bought jacketed bullets. Red Dot, Blue Dot, Unique none of it changed the out comes .
Fooling around with a box of free stuff that just happened to be 75 and 85 gr Gold Dots for 380 stoked up about 2 gr over the 357 125 gr maximum loads . Those shot amazing tiny little groups...... in hindsight I suspect that the pistol had been tooled 9mm rather than 38/357 which would have been a perfect world for the .355 bullets. This theory backed by having to forcibly remove cases loaded with the Speer Blue Dot data in Federal Cases under Speer JHP 158 gr start loads for 357.

I know apples and oranges .

As to short bullets doing strange things I had some commercial 230 RN that were most likely doing the described tip in the forcing cone bit in a RBH Colts . With start loads of Unique all was good but above 75% (of the load window) the ability to hit a 5 gallon bucket at 100 ft went away and recoil doubled . My only explanation is that the too hard ,marginally sized bullet was tipping .

But again early on in my cast learning curve ,good lord was I dumb then ....... at least I'm older now .

 

[9.3X62AL]

Rick, I suspect you are correct. As said, my belief--and that's all it is--is pure theory. Class it with Flat Earth and Global Warming. The tendency held for a whole lot of 38 and 357 wheelguns for long enough duration that I stopped using the short bullets sometime late in the Reagan Administration. Now that our 357s are required to use the Federal 357B ammo, I have reluctantly returned to doing 357 refills with 125 grain JHPs (Remington, currently).

 

[Lost Dog]

It's an interesting theory just the same. Then I thought of round ball. In my BP revolvers that round ball is crushed into the chamber. Blasted out by a charge of fast burning bp. Then out of a chamber with a slightly flair tapered mouth. Then past a fairly large gap (needed for the excessive fouling ). Then into an abrupt forcing cone and then into the barrel. Quite a journey for a mashed up hunk of lead with a minute bearing surface. Yet this poorly fitted bit of ballistic stuff will often shoot remarkably good groups rivaling that of a good fixed sighted revolver with new smokeless powder and sized cast bullets of substantial length. Amazing. And in practice blows the short bullet theory a bit.

But.... at the same time, cast conical bullets, as a whole, do NOT shoot well from a BP revolver. The bearing surface is far more adequate. The bullet being in both chamber, barrel gap, and forcing cone at the same time thing is there. Just like with a cartridge revolver and longer bullets. But on average conical bullets stink from a BP revolver. A well proven and documented fact. BP revolvers have much slower twist in their bores. And cartridge revolvers have faster. Well that makes sense. At least to me. One of our projects required to graduate from gunsmithing school was to build a Single Action Army in the caliber of our choice from a big box of parts and missing pieces to be built. I located a .44Spl barrel and cylinder. When done it had a bore of .427" and turned out to have a 1:16 ratio. A might fast for this caliber, but worked out really well with those long Keith SWC's and 6gr of Unique. And it wasn't a Colt barrel either being designed I think ,for a .44-40. Either way it shot well. But not so well with 180gr JHP. And no, I don't have it as it was sold in my shop long ago.

 

[Brad]

But a cap and ball revolver always has the ball centered in the cylinder throat, the entire chamber is the throat.
Rick is speaking of a cylinder with a step at the rear end of the throat. A bullet that has a portion of the bullet sitting square in the throat I more likely to enter the throat straight than one the doesn't enter the throat and may be lying on the bottom of the cylinder. Good chance of that bullet hitting the edge of that step and being cut.
Apple and oranges

 

[Lost Dog]

Imagine this spoken like Peter Sellers as Jaque Cluseau. (I don't spell well).....

I knew that! Of course the chief inspector is right. I was merely pointing out the pitiful plight of the poor round ball. All alone in ze world being pummeled and pushed around by ancient powder. The poor round ball. ...

Then as I'm looking at something else, I pull the trigger of my Colt Dragoon. The ball bounces off a brick. Careening off a passing truck's hood and into the Eiffel Tower, which then collapses into a pile of junk as dust plumes into the air. ....

 

[quicksylver]

Are we saying that a full WC in theory should not be as accurate as a SWC with a smaller front band?

Just asking...

 

[RBHarter]

As a quip, who can tell if RB tumbles ?

Does it matter if an RB turns in the forcing cone ? Would a 456 RB through a 454 throat into a 452 groove be as or more consistent than a 454 WC with 2 bands in the throat and an only neck sized case ? How do we ensure that every chamber is perfectly aligned with the bore/groove both centered and parallel ? If it is off by even seconds tip ,shaving and oval can be introduced in the forcing cone. Maybe the front band being 452 for a 454 throat and a 452 groove would off set better the stacking tolerances .

In my mechanical dissection which I can see but am completely illequipted to relate either in words or pictures it makes me wonder how those Smith or Wesson rim fire revolvers managed to hit the barn from inside with all the doors windows and lofts closed. With the highest precision tools of the 1840s keeping 11 holes , 8 which were tubes ,1 threaded and 1 threaded to mate it's a wonder a bullet would hit a target across a table much less a room or at 20 paces . 73s from pre-1900 couldn't have been much better . To be completely honest I'm in absolute awe of the fitment of a particular N frame made in 1918 ,the tooling used bought with war contract money was no doubt the best that could be had but is probably of remedial entry level today of a hopelessly over built sort.