Cast bullets:bevel VS flat base

[Qc Pistolero]

I shoot mostly revolvers.I too thought that a flat base bullet is more efficient than a bevel base(efficient=accurate).Life brought me on a path where I became owner of a few bullet moulds of bevel base design.Well,what a shock:some of them proved to be more accurate than my prefered flat based bullets.Most of the others were as accurate as the flat based.
Anybody else has found that?The only explanation I find to date is that the phenomenon might be similar to that of a boat tail bullet in a rifle.What's your theory?

 

[rockquarry]

I'm speaking in very general terms as there are exceptions, but with handgun bullets, cast flat base versus bevel base accuracy is hard to predict. If bullet fit, alloy, pressure, etc. is right, there should be very little, if any, difference in accuracy between the two designs.

Someone else here may remember more about this than I, but there was mention of the flat vs. bevel topic, I think, in the NRAs book CAST BULLETS, primarily a compilation of cast bullet articles and experiments by AMERICAN RIFLEMAN technical staff member Col. E.H. Harrison. That was when AR had a technical staff and published technical gun and handloading articles. Articles and information are mostly from the '60s, but the material remains useful today. I think Harrison found the H&G #50 flat base wadcutter was slightly less accurate than the #50 bevel base version. Again, I'm not positive on this; been a long time since I read it.

Completely different story with boattail rifle bullets. I'm not sure they can really be compared with bevel base cast handgun bullets. Usually, a flat base rifle bullet is at least slightly more accurate than a boattail counterpart. When working up a handload and I have a choice, I'll go with the flat base design first as it will probably shoot better.

If one chooses a boattail design these days, however, it will likely still shoot very well. With the current long range fad, boattail bullet designs are far more popular. While they have a higher ballistic coefficient than a flat base design, this only becomes an advantage when ranges exceed 300-400 yards and beyond. At shorter distances, flat base designs will often shoot more accurately. With today's superior bullets and very accurate rifles, the differences may be very small.

 

[Rocket3]

Head over to Cast Boolits

Great folks and more good info on cast bullets than one can imagine

 

[johngalt]

The flat based .452 185 gr LSWC I got from a caster in Cincinnati was considered to be more accurate than bevel based, according to the local bullseye shooters. Those guys usually know what they are talking about.

 

[4barrel]

Flat base for me and I am not going to change. They lube better also. You cant put a gas check on a bevel base. If you look at the base on a bevel bullet most are not round. When you size and lube a flat base they are round. I shot this with the middle top bullet.

 

[rockquarry]

I also prefer flat base because of the lube mess with the bevel base design.

 

[fredj338]

It will depend on the bullet design, but I have always felt a good flat nase more accurate thana bevel, but not by much. Any anomoly in the edge of the flat base, the be el base will be more accurate.

 

[Qc Pistolero]

I think Harrison found the H&G #50 flat base wadcutter was slightly less accurate than the #50 bevel base version. Again, I'm not positive on this; been a long time since I read it.


The H&G 50 is one of them I've seen a difference in favor of the bevel base.Talk about luck!
Thanks for the info.

 

[Fishinfool]

Like others, I have found both can be accurate, but I lean towards flat base overall. Another benefit of a flat base cast bullet is less gas cutting around the base, and subsequently, less leading. In a bevel bases defense, they can be easier to seat with minimal case flare, with less risk of base deformation, especially with progressive reloading presses.

Larry

 

[gwpercle]

Have heard all my 50 years of reloading flat base is best, from Elmer Keith onwards. But why do boat tail rifle bullets work so well...they have a big beveled base ?
After actually shooting a bunch of Valiant bevel based cast bullets in 45 acp and 38 special I can see no difference.
In magnum loads this may not be true but in standard pressure 45 acp (200 grain SWC over 5.5 grains Unique) and 38 special (158 grain SWC over 5.0 grains Unique) no loss of accuracy has been seen. With those loads flat or bevel bases worked equally well.
If I'm buying a mould and casting them myself I generally go flat base, but I have a few with small bevel bases and rather like them, easy to lube/size and to load.
Gary

 

[Engineer1911]

I had two 200 gr SWC molds that were H&G #68 clones, 200 gr SWC with the longer nose. I had a friend mill off the top of the Lyman mold (4 cavity) to remove the bevel base. It is now 185 gr SWC and a JOY to size and lube.

I carefully trimmed out the bevel base on the 6 cavity Lee mold. Bullet weight went from 200 to 215 grains. It is as easy to size and lube.

With my mid-range AA #2 powder target loads, both bullets shoot to the same point of impact without sight changes and no noticeable difference in recoil. Flat bullet base eliminated all the lube mess I dealt with in the seater die.

 

[cowboy4evr]

I don't have a ransom rest so I have never really noticed much difference . Some days I shoot better than others , bullet design doesn't seem to make a lot of difference . Regards , Paul

 

[Rpg]

I cast H&G #68 in bevel based configuration.

Plenty accurate and easier to reload since cases need not be belled as much. Less likely to shave lead when seating, reduces case mouth cracks from multiple loadings.

 

[Pisgah]

I have only had one instance where a flat-based bullet gave me significantly better accuracy in a particular handgun than a bevel-based. The gun was a 5.5" Super Blackhawk, the bullet a 260 gr. "real" Keith SWC from the long-ago Dry Creek Bullets. The Keith gave fantastic accuracy in that gun as compared to several different bevel-based SWC bullets, but I honestly cannot say that the flat base alone was the important factor. It could have been just the overall very high quality of the bullets or an individual preference of that gun.

 

[Vulcan Bob]

The part of using a flat base bullet with a square profile lube groove is that it will obdurate "jug up" better to fit a oversize cylinder throat. This mostly in .45 Colt revolvers that have cylinder throat sizes all over the place.

 

[dogdoc]

More leading near forcing cone with bevel base bullets. I have obtained best accuracy with flat based bullets but for plinking or uspsa, it does not make much difference. Many other factors also affect accuracy ,not just the bevel base. Some bevel based bullets loads can be accurate

 

[rufgr]

I just pulled out my copy of Cast Bullets by Col. Harrison and in the article titled .45 ACP Handload Accuracy the bullet producing the smallest groups was the Lyman 45266 bevel base.

I have a four cavity mold for this bullet and it casts very easily and I have no problems sizing and lubing in my Star sizer.

 

[rockquarry]

I just pulled out my copy of Cast Bullets by Col. Harrison and in the article titled .45 ACP Handload Accuracy the bullet producing the smallest groups was the Lyman 45266 bevel base.

I have a four cavity mold for this bullet and it casts very easily and I have no problems sizing and lubing in my Star sizer.

Thank you for looking that up. I was completely wrong on the bullet. I'm not familiar with the #45266 but it appears to have been discontinued decades ago. I don't have many of the old Lyman books, but #43 from 1964 doesn't have data for it.

 

[GBertolet]

The main plus of using the cast bevel base in handguns, is in bullet seating, especially in progressive loaders, that's why they are made. Whether they shoot more accurate or not depends on the gun and load. In rifles the main advantage of boat tails is superior ballistics at long range. They are not inherently more accurate than plain base.

 

[Milton]

GBertolet came very close to describing why some folks have accuracy problems with flat based bullets.Many things considered equal(which ain't easy to do) a flat based bullet will give an increase in accuracy over bevel based ones ,most of the time.But,when flat based bullets are hand loaded you must be very careful seating the bullet as many folks damage the thin basal edge of the bullet.This produces a bullet that is not balanced in a most critical area for accuracy;the base.The base is the "steering" end of the bullet.In order to keep this from happening you may have to slightly increase the case flare and load carefully.
Bevel base bullets fit much easier in loading and if any damage occurs in loading the steeper entrance angle of the bullet base allows for less damage.