Boolit nose shape in relation to the forcing cone

[44man]

Has anyone ever experimented with the nose shape and what effect it has in a revolver when it meets the forcing cone? I have two boolits of the same weight, same grease grooves, gas check, etc. The only difference is one has a different shaped ogive then the other. One shoots super groups and the other can not be made to group near as good.

[Bass Ackward]

Has anyone ever experimented with the nose shape and what effect it has in a revolver when it meets the forcing cone? I have two boolits of the same weight, same grease grooves, gas check, etc. The only difference is one has a different shaped ogive then the other. One shoots super groups and the other can not be made to group near as good.


44man,

Sure. There have been a lot of people do this. And when people play around with sizing can affect the cone fit too. They might not know why or care and just say that one bullet shoots better than something else. What is possible is that at some point in the life cycle of your handgun, the other bullet may have performed better. Or another way to look at it is that as your gun continues to change that performance of the one design may continue to get worse in the accuracy department.

The more a revolver is shot, the more gentle the taper becomes in a forcing cone. Eventually what you do is to shoot in what some people have cut in early called a Taylor throat. Matching this angle should provide the most bearing area for the strongest bullet design possible in that gun to fight any possible cylinder misalignment. So it is possible (I would think) to have this perform just like a rifle as the leade angle changes. I have chased rifle throats, but not handgun forcing cones. Rifles are easy to do because you simply seat out a little farther until you reach rifling. Imagine how involved it would be to do this in a handgun?

But since you consistently push the accuracy envelope, most guys never get the chance to see what you are seeing. I fall into this crowd now too because I no longer have the guns rigged to test it to that level. Now ignition is everything to getting what you would refer to as mediocre performance.

[felix]

Yep, in a 6 shot revolter, you ideally have 7 forcing cones! Ideally, because the boolits should be large enough for a tight fit through their respective boolit exit holes in the cylinder. Only one forcing cone for small boolits. Lots of interesting things go on in designing a great load for a revolter! ... felix

[Char-Gar]

This is not science..just observation and educated (or not) guess work. Many of us sixgun shooters have noticed that RN bullet deliver the best accuracy. The folks wisdom is the RN tends to center itself in the forcing cone of the barrel.

This might not stand up to hard science, but it is an observable fact and a reasonable explaination.

[44man]

Charger, the boolit that shoots my tightest groups are from my home made mould and is a copy of the LBT but the ogive is straight. I got carried away when filing the nose on the cherry so I just left it straight instead of the gentle curve I wanted. The other boolit has a rounded ogive.
Seems as if the screw up was to my advantage.

[Bret4207]

I believe this was why Elmer wanted such a strong front soulder on his designs. The idea was the forcing cone would "knock" the bullet into alignment and a strong front shoulder was needed with a SWC to do that. It would seem a RN or TC type design would be more "self centering" than say a SWC or WFN.

Just one more variable to keep the game interesting!

[Beau Cassidy]

.44
You need to post a picture of that bullet.

Beau

[Char-Gar]

Tpr. Bret... It has been some years since I read St. Elmer's stuff, but my failing memory tells me he wanted the deep front driving band so the bullet would center itself in the cylinder throats. The sharp corner on this band was to cut clean holes in flesh.

We have since learned it is not the shoulder, but the meplat. Elmer figured flesh would react the same as a paper target. He was most often , but not always correct.

[9.3X62AL]

I think that "self-centering" idea--either via RN or strong-shouldered & closely dimensioned SWC--is an individual thing from revolver to revolver. I've gotten good accuracy with all shapes of boolit, but it varies from platform to platform. I can't make a hard and fast rule to cover all bets, other than to say that in a few guns I've made improvements where the square-shouldered boolits didn't work well by trying shouderless designs. The Lee 100 grain RN in 32-20 comes to mind here--the old Colt Bisley I have is NOT fond of SWC boolits--at all.

[44man]

Here is the boolit. It will shoot 1" or less at 50 yd's and has put 4 out of five in 1-1/4" at 100 yd's.
.44 mag, 21.5 gr's of 296 and Fed 150 primer. RSBH.

[44man]

I cut my forcing cone to 11 degrees years ago and this boolit is also 11 degrees.
Do you think, just maybe, that the boolit is not deformed in any way when it enters the forcing cone? Unlike a Keith that can go any which way if the chambers are out of line a little. Seems as if a round nose can go off too.
Maybe we should get a boolit nose that exactly matches the forcing cone angle for which ever gun we have.

[Bass Ackward]

I cut my forcing cone to 11 degrees years ago and this boolit is also 11 degrees.
Do you think, just maybe, that the boolit is not deformed in any way when it enters the forcing cone? Unlike a Keith that can go any which way if the chambers are out of line a little. Seems as if a round nose can go off too.
Maybe we should get a boolit nose that exactly matches the forcing cone angle for which ever gun we have.


44,

We go through hoops to match rifle lead angles in rifles. And a far jump for a rifle might be 1/8". During that 1/8" the bullet might be up to 200 - 400 fps.

Now a handgun on the other hand can have up to 1/2" to traverse before the bullet slams (between 600 and 900 fps based on my loads using Quickload) into the forcing cone. Some like to cut down the jump seating farther out. Some like to burn slower powder powder. Some like to size smaller. Still a wheeler bullet undergoes much more distortion than a rifle bullet. Would strength of design help here?

I think that until some others get into the super accurate pistol game we might never know. One gun is an example. Several become a trend if there is one.

[StarMetal]

I think a forcing was thought of basically to start the bullet into the barrel without shaving it. Kind of like the old Lyman bullet sizers. They didn't have that taper like the new ones and often bullets got sized off center or even worse shaved on one side. Thing about it. If that barrel was finished just square with no cone it sure would tear up the bullet bad. 44man I think you're barking up the wrong tree on this one . Look at 38 special full wadcutter. Those things shoot remarkably accurate out of wheelguns and they are flat on the nose! To me making a bullet with the same taper degree of the forcing cone would make for more friction as more of the bullet would be mating up with the cones ramp. Nope, bad idea. Then take old Joe's Model 25 Smith....bullets undersized in comparison to the cylinder throats and the baby still shoots really really good. By the way not only the RCBS 255 SWC shoots like that, but all the SWC's meant for 45acps that I've shot out of my 1911's, other 45 Long Colt bullets, and all sorts of jacketed. That's an awful lot of different nose configurations and that Smith shoots them all really good. Must be luck huh?

Joe

[44man]

Joe. I am not saying other boolits don't shoot good. I have shot thousands of wadcutters too and every type boolit ever thought of out of every caliber from .38 up. But a most of them were low velocity loads. The slam them down the bore, knock the cape buff off his feet type loads are different, My other boolits shoot good and most would say very good, but this boolit has shown the most cosistancy and best accuracy of all the rest. Could there be something to it? Could it make the difference between a 2" 25 yd group and a 1" 50 yd group? Could it be that the boolit nose, being the same shape as the forcing cone, will center better then a boolit with a small portion of the ogive slamming into the cone?
Since most .38's were cut with a 5 degree forcing cone, don't you think the wadcutter or Keith would shoot better? Or a round nose? How about an 18 degree forcing cone? Has anyone cut a boolit to match it to see what would happen?
I have not made a blanket statement that it's the way to go, I only asked if anyone has experimented with it. But then, being Joe, you had to jump on me again.
I just don't know why I never get an intelligent answer!

[StarMetal]

44man

I didn't jump you and I gave an intelligent answer. I said being the nose is the same angle as the forcing cone I believe it creates more friction since more area mates up on impact. You idea my shoot better but I don't think it's because the bullet nose and forcing cone angle are the same. There, hows that? better?

Joe

[44man]

OK, I accept that. But what harm would a little friction cause?

[StarMetal]

Well, probably none. Does raise pressure some, but your loads aren't dangerously over pressured. I'm just wondering if it distorts the bullet more. I'd like to see what a really long very gentle tapered forcing cone would do on a revolver. One that gently squeezes that bullet down to bore and groove size.

Joe

[44man]

Called Taylor throat

[StarMetal]

I'm talking even more exaggerated then the Taylor throat.

Hey you know a Dan Wesson would be good to experiment with those quick change barrels. Would make a very good test vehicle.

Joe

[lovedogs]

Interesting topic, guys. Several years ago I was well acquainted with Dave Michno, who was a Dan Wesson rep at the time. He used to send me different barrels, grips, sights, etc. to try on my DW44. I'd shoot and evaluate and tell him what I thought. At one time they were playing with different forcing cone angles. I tried four different bbl's they sent and couldn't really tell enough difference to matter. We finally came to the conclusion that if all else is right, charge holes aligned with bore, tight cylinder gap, etc. that if we used any well-made bullet it seemed to work. The folks back there had lots more money and equipment to do the research with than I did and they decided to leave things as they were. Our experiments had proved nothing either way. So many variables. Dave and I finally agreed that there are other things that affect accuracy more than forcing cone angles. If things are lined up right and attention is paid to keeping everything in specs it'll usually shoot any well-made bullet well.

[44man]

Lovedogs, now that was a very good answer and what I was asking about. I just never gave it any thought before and with this boolit, I got curious. It might just shoot better because of better boolit balance and not that it fits the forcing cone. I guess it is one of those mysteries that will never be nailed down so it can be applied to other boolits.
Thank you.