Boolit Design and Accuracy

[ColColt]

What makes one boolit design in the same caliber more accurate than another? Case in point, I have three Lyman molds dating back some 35 years, 429421, 429360 and the 429352. The 429421 outshines the others in the accuracy department in general. There's not much difference other than the band sizes and a minute difference in OAL as all three are SWC's.

[cbrick]

Could be any number of things, I do however know . . .

What Elmer would say! :mrgreen:

And Glen Fryxell would say . . . Elmer!

429421 is Elmer's pride and joy design and it has been working extremely well for many decades now.

Rick

[RobS]

Balance, aerodynamics, meplat, firearm shot from, barrel twist rate, velocities shot at, among many other things. Of the many 45 revolver boolits I have shot there are those that shoot well with the right load and others that will shoot well with just about anything you put to them. Case in point, in the past I shot the RCBS 45-270-SAA and had 2 very good loads worked up for my revolver and then there is the LFN style boolits that seem to shoot very well with multiple loads.

[ColColt]

Yep, Elmer was da man...honored to have met him in the flesh. The #429421 has a somewhat longer nose than the other two. From the crimp groove to the top of the nose about .435". That's longer than the boolit is in diameter. I'm glad I got Erik to open the bands on this one as it's a favorite. No more beagling! This one seems to shoot with nearly anything I put in the case from Universal to 2400. It was born to be wild.

[MtGun44]

Hard to tell, I have had good results with a few LBT designs in .45 LC and .357 Mag, but not
so much with .44 mag so far. A bunch of factory LBT hard commercial (Cast performance) made
8-20" patterns at 25 yds in every kind of load I tried. Not saying that LBT is no good, and I
don't think that is true. But the facts are that when I tried commercial versions in many different
weights, with GCs in most cases, they shot extremely poorly for me in S&W 629, Colt
Anaconda and Ruger SBH. YMMV.

Hard to know, and there are certainly many that have had different results. These are
significantly different than 429421/H&G 503 Keith designs, but some others are not very
different at all, yet seem to work less well - based on reports. I have not tried them,
personally, so don't know.

Bill

[ColColt]

When it's all said and done, it's hard to beat the 358429 and 429421 molds.

[W.R.Buchanan]

Every .44 mould I have is a SWC style mould. My S&W M29 would easily shoot 5 Lee 240 gr SWC's into 1.5" at 25 yds and had done it many times.

I have shot a variety of commercially available cast bullets including WFN's LFN's and round noses thru my Marlin Rifles , and have yet to break 3" at 50yds with any of them. That's 6MOA+ which is not stellar accuracy even for a slingshot!

However .429244 shoots well inside of 2" at 50yds with no real attempt made to shoot as accurately as possible. IE just plinking.

Here's my theory as to why this occurs. The Marlin .44 cal Rifles all have 1:38" twist barrels all pistols seem to have 1:20" twist barrels. Pistols need the faster twist due to the slower speeds generated .

The rifles will stabilize bullets up to 265-280 gr nicely(still in the 3" range) but anything longer doesn't seem to fly right at all. I think this is due to the "bearing surfaces length" of the bullet which is longer on NON SWC designs, and NOT the overall length. Thus the longer bullet doesn't not stabilize as well in the slow twist of a rifle or low speed of a pistol.

This issue of longer bullets needing faster twist to stabilize is common knowledge. But is it the longer bearing surface or the OAL of the bullet that matters???

Me thinks it is the bearing surface. this would also explain why Lyman 311299 does so well in .30 cal rifles at moderate speeds even though it is significantly longer than most jacketed bullets. It is a bore rider design and only has about 1/3 of the bullet actually engaging the rifling.

In contrast the SWC design has a relatively short Bearing Surface Length (slightly more than half the OAL of the bullet) which makes the bullet think it is shorter and so it stabilizes like a shorter bullet would. IE requiring less rpms to stabilize and fly strait.

In my theory the nose section doesn't influence how the bullet stabilizes, only the length of the bullet in contact with the rifling influences the flight characteristics.

If either one of my Marlins give any kind of accuracy with 310 gr SWC's but not LFN's, it would seem to validate my theory? I already know 300gr LFNs fly sideways, sooo?

If someone could send me about 20ea, 300+gr SWC's, preferably with Gas Checks, I could test this theory quickly.

Randy

[cbrick]

I'll check and see if I have any RCBS 44 300 Gr. cast up, its my pig bullet and it likes pork almost as much as I do.

This is the photo on the cover of Glen's book.

Rick

[white eagle]

very sexy boolit there
what with the daisies n all

[ColColt]

very sexy boolit there
what with the daisies n all

All that's missing is a bottle of Harvey's Bristol Cream.:wink:

[cbrick]

Hhmmm . . . The flower. In the spring time those shrubs you can see behind where I took the picture shed those flowers like its snowing. 3 or 4 times trying to take the picture I blew them away and just as I clicked the shutter there was another one. Just look at it as my feminine side I guess.

Rick

[cbrick]

Actually Randy, the RCBS 300 isn't all that typical of SWC's. It has more bearing surface and less nose length than the typical SWC. It shoots very well out of my OMSBH 7 1/2 inch.

Rick

[RobS]

Every .44 mould I have is a SWC style mould. My S&W M29 would easily shoot 5 Lee 240 gr SWC's into 1.5" at 25 yds and had done it many times.

I have shot a variety of commercially available cast bullets including WFN's LFN's and round noses thru my Marlin Rifles , and have yet to break 3" at 50yds with any of them. That's 6MOA+ which is not stellar accuracy even for a slingshot!

However .429244 shoots well inside of 2" at 50yds with no real attempt made to shoot as accurately as possible. IE just plinking.

Here's my theory as to why this occurs. The Marlin .44 cal Rifles all have 1:38" twist barrels all pistols seem to have 1:20" twist barrels. Pistols need the faster twist due to the slower speeds generated .

The rifles will stabilize bullets up to 265-280 gr nicely(still in the 3" range) but anything longer doesn't seem to fly right at all. I think this is due to the "bearing surfaces length" of the bullet which is longer on NON SWC designs, and NOT the overall length. Thus the longer bullet doesn't not stabilize as well in the slow twist of a rifle or low speed of a pistol.

This issue of longer bullets needing faster twist to stabilize is common knowledge. But is it the longer bearing surface or the OAL of the bullet that matters???

Me thinks it is the bearing surface. this would also explain why Lyman 311299 does so well in .30 cal rifles at moderate speeds even though it is significantly longer than most jacketed bullets. It is a bore rider design and only has about 1/3 of the bullet actually engaging the rifling.

In contrast the SWC design has a relatively short Bearing Surface Length (slightly more than half the OAL of the bullet) which makes the bullet think it is shorter and so it stabilizes like a shorter bullet would. IE requiring less rpms to stabilize and fly strait.

In my theory the nose section doesn't influence how the bullet stabilizes, only the length of the bullet in contact with the rifling influences the flight characteristics.

If either one of my Marlins give any kind of accuracy with 310 gr SWC's but not LFN's, it would seem to validate my theory? I already know 300gr LFNs fly sideways, sooo?

If someone could send me about 20ea, 300+gr SWC's, preferably with Gas Checks, I could test this theory quickly.

Randy

WFN style designs, there could very well be more bearing surface for an equal weight bullet however not necessarily with a LFN.

Pictured left to right (all 45 cal boolits):
True Veral LBT LFN style designed 280 grain bullet with a .320 meplat, next is a Keith 280 grain also has a meplat of .320 and then finally my modified 300 grain LFN style design with a .340 meplat.

http://i612.photobucket.com/albums/tt206/RobS01/LFN280Keith280LFNstyle300.jpg

The Keith is obvious on bearing surface and a person can see the LFN's as they set right next to the Keith. Both the 280 grain Veral LFN and my 300 grain LFN style design have shorter bearing surfaces.

[W.R.Buchanan]

Maybe we should ask Elmer Keith? he designed the damned things. He had it figured out long before I was born.

Randy

[Lloyd Smale]

if i knew id be the only caster in history that did know.

[357shooter]

When it's all said and done, it's hard to beat the 358429 and 429421 molds.
For 357 magnums, generally a SWC is more accurate than any other design. It may be by as little as .2 inches, but still more accurate. The other designs just aren't as consistent. At least in my guns.

The 358429 and Lee TL358-158-SWC (barely a SWC) seem to be the most accurate when compared head-to-head with everything else (SWC & non-SWC). The NOE 358429 also outshoots the Lyman 358429 most of the time.

I will say the BRP Hornady clone (a SWC with a long nose) looks like it's going to as accurate, maybe even more. It's too early to say yet, however it's already outstanding.

The most accurate bullets in a 6inch barrel, 16.5 inch twist revolver also are the most accurate in the 20 inch barrel, 30 inch twist, lever action too. Interestingly, the most accurate loads for each gun are the same too. However I have some more testing to do with H110 and max loads.

I do know for sure, the most accurate loads with a fast powder in the revolver are also the most accurate in the rifle, with a fast powder.

[singleshot]

So far, my most accurate boolit is my 44 mag Lee 310 grain. I have shot it in both my 7.5" RSBH and my Ruger 77/44 rifle, and can't match the accuracy with anything else I own....yet. Both the RSBH and 77/44 have 1:20 twist barrels, one reason I like my 77/44 so much vs a Marlin.

[white eagle]

while I don't make any claims to know anything about boolit
design ...I have found in my guns that the designs like CBrick and Robs
have posted are more accurate in my guns vs say a more Keithie type boolit
I do however have Keith designs that I refuse to sell
this design is from Tom @ Accurate Molds and is one of the finest shooters I
have in the stable @ the moment
http://img.photobucket.com/albums/v730/kempobb/boolits1.jpg

[white eagle]

those boolits have that appearance because
they are made into soft tips
pb/hardball
they will be my hunting boolit this coming fall season
bear or deer

[ColColt]

I would imagine a boolit design with more bearing surface, such as cbrick's avatar, would definitely aid it stability and hence a bit more accuracy. I'm wondering about the length of the nose as well and wonder if the Keith style with a longer nose usually doesn't aid in that as well...I'm sure it does for long range shooting.


Every .44 mould I have is a SWC style mould. My S&W M29 would easily shoot 5 Lee 240 gr SWC's into 1.5" at 25 yds and had done it many times.

I've read quite a few times on the forum of folks getting groups like this at 25 and 50 yards. I'd have to put mine(Ruger GP101 or M29) in a machine rest to get that kind of grouping at those distances. Even sitting at the bench I can't get those kind of groups consistently at 15 yards, much less 25 or 50. Either it's me or it's the boolit and I don't think it's the latter. However, I don't see how you can foul up too bad from a bench. It's definitely better than standing when you're trying to work up loads for accuracy.

[white eagle]

I am beginning to think (re-think)
what makes a boolit accurate
I do believe bearing surface has more to do with
accuracy than I used to
that is why I get better groups with the boolit like I posted,
the nose while long,longer has a great deal of bearing surface
than say a Keith with the long fully un-supported nose
my last design was more bore riding design than I normally get
and while primary the results are looking good......
I know its hard to see and I apologize for that
but this is what I am referring to
http://img.photobucket.com/albums/v730/kempobb/a.jpg,
http://img.photobucket.com/albums/v730/kempobb/a1.jpg

[Changeling]

Every .44 mould I have is a SWC style mould. My S&W M29 would easily shoot 5 Lee 240 gr SWC's into 1.5" at 25 yds and had done it many times.

I have shot a variety of commercially available cast bullets including WFN's LFN's and round noses thru my Marlin Rifles , and have yet to break 3" at 50yds with any of them. That's 6MOA+ which is not stellar accuracy even for a slingshot!

However .429244 shoots well inside of 2" at 50yds with no real attempt made to shoot as accurately as possible. IE just plinking.

Here's my theory as to why this occurs. The Marlin .44 cal Rifles all have 1:38" twist barrels all pistols seem to have 1:20" twist barrels. Pistols need the faster twist due to the slower speeds generated .

The rifles will stabilize bullets up to 265-280 gr nicely(still in the 3" range) but anything longer doesn't seem to fly right at all. I think this is due to the "bearing surfaces length" of the bullet which is longer on NON SWC designs, and NOT the overall length. Thus the longer bullet doesn't not stabilize as well in the slow twist of a rifle or low speed of a pistol.

This issue of longer bullets needing faster twist to stabilize is common knowledge. But is it the longer bearing surface or the OAL of the bullet that matters???

Me thinks it is the bearing surface. this would also explain why Lyman 311299 does so well in .30 cal rifles at moderate speeds even though it is significantly longer than most jacketed bullets. It is a bore rider design and only has about 1/3 of the bullet actually engaging the rifling.

In contrast the SWC design has a relatively short Bearing Surface Length (slightly more than half the OAL of the bullet) which makes the bullet think it is shorter and so it stabilizes like a shorter bullet would. IE requiring less rpms to stabilize and fly strait.

In my theory the nose section doesn't influence how the bullet stabilizes, only the length of the bullet in contact with the rifling influences the flight characteristics.

If either one of my Marlins give any kind of accuracy with 310 gr SWC's but not LFN's, it would seem to validate my theory? I already know 300gr LFNs fly sideways, sooo?

If someone could send me about 20ea, 300+gr SWC's, preferably with Gas Checks, I could test this theory quickly.

Randy

Overall length determines the Rotation/Twist necessary for any bullet stability. There are slight departures relative to velocity/bullet style/ accuracy at a given range, but the latter is the bottom line of truth!

[W.R.Buchanan]

Col Colt: I was 28 years old when I shot those groups and was shooting 100-200 rounds a week.

I refused to believe at the time that groups better than 1.5" at 25 yds were even possible.

My gun would shoot 1.5" groups often if I didn't pull a shot or do somethig stupid.

I have a friend whose name is Paul Hantke. Known him since grade school. He writes freelance articles for gun mags, and is considered knowledgable by some. We shot alot together at that time.

We were at the Ventura Police Pistol Range one day in 1978 and we were shooting our .44's at 25 yd targets. He had an old 3 screw SBH and I had my M29 with 8 3/8 barrel. At the time the S&W was consideered to be far superior to the Ruger with respect to accuracy.

He bet me he could shoot a better group than my tyypical 1.5" cluster. I bet him $10. I lost! He shot a 5 shot group that was just below 1". Mine was 1.5" as usual. To add insult to injury he used my reloads! They were Lee 429-240SWC CG with 23 gr of H110.

All of these groups were shot off a sand bag rest while sitting down at the firing line bench.

28 year old eyes help a bunch. I haven't been able to duplicate that level of shooting for quite a few years, and I definately wish I had never sold that pistol. He still has his.

All I can tell you about this is that "the sun don't shine up the same dog's ass everyday" Sometimes the planets align sometimes they don't. I couldn't do it on a bet now. Wouldn't even try.

Randy

[ColColt]

Young eyes does help, that's for sure. I'd give a month's pay to be able to see the target(and my sights) like I did at that age...even when I was 40! Use to I could knock the knee caps off a woodpecker at 100 yards with a rifle of any kind. Now I'm fortunate to see the woodpecker at all. I reckon I ought to just count my blessings I can still see.