bevel bases: impair accuracy?

[catboat]

I'm still swirling around trying to decide what mold I want for my 45 acp Sig 220. A question for you master casters. Has anyone CONCLUSIVELY determined that a handgun mold (particularly in 45 acp) is has any difference in accuracy that incorporates a bevel base design?

I'm hoping for someone who has shot two similar molds side by side in the same gun, one with and one without a bevel base, from a supported rest, at a reasonable distance (~ 15-25+ yards) to provide "hard data."

My short list for molds now includes: SAECO #69 (200 gr SWC, no bevel base), SAECO #68 (200 gr SWC with bevel base), RCBS 45-201 (200 gr SWC no bevel base), Lyman 452460 (even though I'm getting some feedback that they cast at .451" with wheel weights, and I'm looking for .452 (min) and would prefer something in the .453" range-as cast). The Lee 6 cavity 230 grain truncated mold still intriques me.

Can anyone pass along "as cast" boolit diameters of these molds (with wheel weights, or if you have a special alloy mix, please include)? Anymore feed back on these SAECO moulds (SAECO #69 appears to be a good copy of the H&G #68-I'm waiting for info from SAECO on that mold).

Lumpy, if you read this, have you had a chance to find that mold you mentioned during our phone call ( for 45 acp)? I got your brass-thanks.

Thanks in advance.

[beagle]

Not speaking of the .45 here but I have shot thousands of #398 Saecos in a .357 Marlin carbine and the bevel base is not near as accurate at bullets with a plain/unbeveled base.

The same with Lyman's 429667 in the .44 Magnum. I've recently had the BB removed from this one and will test it in the M94 .44 Mag and see what kind of accuracy that I obtain.

In my opinion, the BB produces a little less accuracy. Not much but enough to make a difference./beagle

[Larry Gibson]

Catboat

Year ago there was a commercial cast outfit (Greer) in the town I lived in. They had been makind some very nice FB'd bullets and i used several of theirs in .38.357, .44 and .45. They then began to use the same bullet designs only with BBs. Their stated reason was the bullets fell from the moulds more readily and didn't stop production because of a stuck bullet in a cavity.

I shot those two different bullets side by side out of accurate revolvers mounted in a Ransom Rest. Loads were worked up "accuracy' loads" with the only thing different being FB and BB'd bullets. Test targets were at 50 yards and with the revolvers all groups were of 12 shots. In the .38, the .357, the 44 Magnum and .45 ACP (M1925 S&W) the FB'd bullets produced groups half the size of the BB'd bullets. Groups ran 2 - 3" with FB'd bullets and 4-5" with BB'd bullets. I also conducted the test with a very accurate M1911 with the H&G #68 FB and BB'd bullets loaded over 7.5 gr of Unique (1025 fps out of the 5" barrel). Accuracy for 8 shots was 3.25" for the FB and 5.7" for the BB'd bullets.

That was convincing enough for me. I still shoot some BB'd bullets now and again but all of my serious cast bullets have GCs or are FB'd. Subsequent test always proove the FB is more accurate.

Larry Gibson

[catboat]

Larry and Beagle,

Thank you for your excellent feedback regarding your experiences with bevel base bullets. Just what I was hoping for.

Looks like I'm narrowing my selection to non-bevel base bullets.

Additional results welcome from other casters on this issue.

[felix]

If Larry or Beagle said it, take it to the bank and forget any further ramifications. ... felix

[44man]

I removed the BB from a Lee .357 mold and cut groups in half. Nuff said?

[dwtim]

Does it make a big difference at 50 feet or under? Why aren't heel-crimped bullets similarly effected?

[AZ-Stew]

The replies mirror my observations, but I have no written records to prove it.

In my case, I was shooting commercial cast SWCs (hard) and using midrange loads (.357, .41 and .44 cal at about 900 fps), so it may have been that the bullets weren't slugging up due to the hard alloy and low chamber pressure.

Regards,

Stew

[runfiverun]

i have a few molds that i am definately going to take the bevel off of.
my h&g #68 isn't one of them though.

[Buckshot]

..............There was an article in "Handloader" I think it was about this. The authors name was Stan (I'll probably massacre his last name) Trzoniac. Basicly he used several handguns of known high accuracy levels. He had H&G produce a mould of thiers either with, or without a BB to match their already available design. He had one of each now. One with the BB and one without.

The test covered over 5,000 rounds fired from a Ransome rest. After it was all said and done there was NO statistical difference in accuracy. He then loaded up another thousand of each and other then batch numbers, were not identified which was which. They were sent off to the Speer ballistics lab and shot through an anchored universal reciever in their underground tunnel. Again, there was no statistical difference in accuracy between the 2.

Just more input to cogitat on

Well dang! I just looked through a couple of my copied artical notebooks and couldn't find it. However now I don't know if it was Stan T......... or Robert Zemanck that did the BB/FB test.

....................Buckshot

[Bass Ackward]

I was shooting a customer's 280 Remington Saturday with 130 grain Speers. One flat base, one bevel base that they call a boat tail. I used the same load developed for my cousins outfit using the flat base design. The customer watching the event concluded that the flat base was clearly more accurate than the boat tail. Then I adjusted the charge up for the BT a little bit and it came in. If the harmonics of the barrel would have had the flat base working at maximum pressure, I could not have done that. The point?

Removing weight from the back of a bullet (creating a bevel base) changes the center of balance of the exact same design and makes it harder to stabilize. Increasing the weight on the back (making a flat base) achieves the same thing as removing it from the nose. (hollow pointing) It makes the bullet stabilize .... "easier " at a lower velocity level.

Not all bullet designs are equal. So the bevel works differently on different designs just as shooting a check design without a check will be. Since the problem with handgun accuracy is launching correctly not to disturb what stabilization that you create, a comparison of a flat base and a bevel would show the accuracy edge to the flat base. Every time? There are no absolutes, just trends.

No matter how close they look, the bevel is for all intents and purposes another bullet design that must be treated and developed as such. Because of the limitation of strength with lead, it may never be as accurate. What ever the accuracy point of your PB was, the likelihood is that the bevel would have to be harder, to be driven a little faster to achieve the same level of stabilization. As with the 130 grain Speer example above, if you can go higher, it will happen. If you are at the top defined by leading already, your screwed.

So is a flat base more flexible in it's design for cast? Yes Same with hollow points, smaller meplats, or anything that shifts the weight toward the back of the design and makes a design easier to stabilize and travel unaffected through air or flesh.

[Lloyd Smale]

ill go a little differnt route. Ive shot pails full of both. For the most part ive had better luck with flat based bullets but not allways. Handguns can be funny. Ive seen handguns that wouldnt shoot them worth crap and ive seen handguns that i was about to peddle becuase they wouldnt shoot come alive with a bevel based bullet. to me its kind of like 22 rimfires. Every gun has a majic load it likes. For the most part i can stock about 3 diffent 22 loads and usually out of that 3 one will shoot in a new gun but not allways. So i usually have at least a box of about every brand i can find. Ill will occasionaly run into a 22 that likes some odd ball ammo and shoots well enough with it that it justifys stocking it. Look at the h&g mold for the 45acp. Very few guns wont drive nails with that bullet. Bevel based bullets are not majicaly inaccurate. There just subject to the same gremilins every bullet design is subject too. How many of us have boughten one of the lee group buy molds thinking it was going to be the alitmate bullet and found it to be a dud? If i go back to the boatail rifle arugment i have to agree that in most cases a flat based bullet will group better then a boatail but that isnt wrote in stone. Ive had many guns that favorite load was with a boatail and to me there still worth having on hand and trying when im working up loads for a new gun. So yes, ive had better luck with flat based bullets but bevel based bullets arent the evil some make them out to be.

[Bob Krack]

d I'm looking for .452 (min) and would prefer something in the .453" range-as cast). The Lee 6 cavity 230 grain truncated mold still intriques me.

Can anyone pass along "as cast" boolit diameters of these molds (with wheel weights, or if you have a special alloy mix, please include)?

cb,
I have the 2 cavity Lee TL452-230-TC mould and it casts right at .4535 with straight wheel weight alloy and the boolits weigh right at 245-246 grains with that alloy.

I cast 600 yesterday and less than 20 were outright rejects. I weighed all of them for bullseye shooting and about 65% were 245.5 grains plus or minus 1/2 grain and the other 35% were 246.5 grains plus or minus 1/2 grain. There were less than 80 total that were under 245gr or over 247gr and that includes the rejects. I was very happy.

These are a true joy to cast with the two cavity and I have heard that Lee 6 cavity moulds are better than their 2 cavity moulds!

Vic

[Boerrancher]

Now this is not really a valid test but.... It worked for me. I have the lee TL 358-158-SWC, which is a bevel base mould. I solved my problem by having a friend build a tool that makes gas checks to fit on plain based boolits. By adding the homemade 5 thousandths thick check to the base of the boolit and swedging it on like a partial jacket, it leaves the base with a nice sharp corner at the base. It worked so well that I had him make me one for my 44 boolits.


Best wishes from the Boer Ranch,

Joe

[GabbyM]

I've got the Saeco #068 in a two cavity.
They are cut to drop a bullet cast from 2/6 alloy. So when you use 50/50 ( WW / pb ). you get a smaller bullet. Mine will size to .452 as long as I keep the heat up. laped that mold the other day and havn't tried it again. I would expect a more concentric bullet and about a .0005” diameter gain. Usually whatever the high spot on your bullet is will be your finished diameter after a good lapping with two or three lap slugs. You may get lucky and get one that drops nice round bullets of desired size with your alloy. My Saeco #428 and #377 were that way. It's a crap shoot.

VillageIdjit: Sounds like you could mill the BB off that mold and have a good 230gr boolit.

[beagle]

Kind of amazing that us casters have worked over the years to get bullets with absolutely flat bases as we know these shoot more accurately. Then, we even add gas checks to further enhance this phenomonen and improve accuracy.

Then. along comes some company and add's the bevel base which negates all we've worked for over the years and we wonder why the BBs don't shoot as well.

Kind of makes me think we're reinventing the wheel./beagle

[jahela]

One argument I missed in this discussion :
The bevel is famous to avoid damaged edges of the FBs. So they are naturally the better choice for "factory-casters". For a "home caster" it would be more reliable to handle FBs - no packing, no shipping etc.

I prefer BBs for another reason (another point that is not mentioned) :
I think it's easier to cast a exactly perpendicular to the axis - base ring with a BB mould than with a FB - here is the perpendicularity given by the position of the sprue plate.
Important for accuracy is that the whole circumference comes out of the barrel at the same time, irrespective if it's a BB or a FB.

It's difficult for me to describe. I hope I can make understanable what I mean.

Dirk

[HeavyMetal]

Buckshot:
That was Robert Z did the test you quoted. It's reprinted in one of the cast boolit manuals, I think.

[KCSO]

IF you can sort a bevel base and get a PERFECT bevel it MIGHT shoot as well as a flat base. My eyes arn't good enough and I'll be darned if I sort under a magnifying glass.

[Bob Krack]

VillageIdjit: Sounds like you could mill the BB off that mold and have a good 230gr boolit.

Gabby,
That might be a viable option in the future. Unclebill bought the mould and even though it belongs to me now, I will continue to cast some for him until he comes to the same conclusion(?).

Thanks for your input.

Vic