350 Legend and Cast Boolits

[Oldfeller]

I have 2 cavity lee molds that get hot too quick. I can't make myself use the wet rag trick so I just take a break and let the mold cool off. Nice work by the way, I wish I had that talent.

BB

Bikerbeans,

Think of it in your imagination that you are "boolit casting in a Steam Punk world" with big puffs of live steam coming from your steam heated mold ......

[cwlongshot]

How are these bullets shooting? I received mine from BB yesterday. (THANK YOU!) Ill powder coat then size later today.

Merry Christmas guys!

CW

[kenton]

I would suspect that your pointed form drill didn't cut well because the web has no chisel edge so it is not cutting but just smashing material out of the way. You might be able to try to split point the drill or it might be easier to make just the web into a D bit cutter with the edge aligned with one of the flutes.

Twist_Drill_-_Point_Geometry elements of twist drill.pngPoint-Split-Point.pngTAPEREDDBIT_zps7d1753f4.jpg

[Oldfeller]

Kenton,

In as much as you say, you are correct. D forms are single edge "scrapers" which are the least effective form of the cutting edges. Sharp edges at proper the proper angle for the material being cut with the proper cutting relief cut better because they can form chips, but such things are hard to come by in "impromptu tooling".

I will give you an example, a ball end cutter (round end end mill) never cuts well in plunge cuts because it cannot form chips, just fine scrapings.

I will remove the bulk of cavity material with drill bits (making chips) and only use scraper types to impart the final form to the bullet end.

[cwlongshot]

F8596D9D-DCFD-48DC-9044-D7203E358618.jpg


This is the shorter 180g.

Good looking bullet guys!!

Merry Christmas

CW

[P Flados]

CW, Glad to see them purty rounds. Hopefully they will work for you. I am eager to see some results.

Old Feller, Some of my D Reamers have not cut as good as I liked. These were mostly reamers for making sizer dies etc. On the other hand, the D Reamers I made for the 357AR and other similar shaped bullets have actually cut pretty good. As I recall, I drill at 3/16" or so pilot hole and ran the reamer in pretty fast with frequent pull backs to clear chips and re-lubricate. And yes they were decent thickness "chips" instead of real thin shavings.

I did find the D Reamer I used to make the 357AR loaner mold. See post 214 for the original profile. I later made the meplat flatter and wider, 0.180", see below:

IMG_20191225_220635138.jpg IMG_20191225_220532611.jpg

[Oldfeller]

Question for the day ......

How big do you cut the cavities (in diameter) to hit close to 355"-.356" once your WW castings cool?


Like most things here, conflicting info is available.

To make it "doable" I figured I would have to cut to the low side and if cutter run out didn't run me OS then I could lap up to a desired finished "as cast" size as I have that pretty much got mold lapping down to a science.

But ...... the "design to cast size" question still exists -- mostly unanswered.

Tom Meyers answered it with a whole bunch of complex calculations, which just leads me to believe doing it empirically off my lead and my pot might be the best method for me to pursue.

P Flados did it while shooting for .358" off the cutter he shows above and he got a tapered range of +2 to +4 on the mold I borrowed.

REALLY, boys and girls ----- it ain't that easy to make molds ......


PF, what does that cutter mic out at, BTW .....

[P Flados]

The reamer is just a smidgen under 0.355". I think it is good for cutting holes no more than 0.0005" over the reamer size.

I did lap the shanks of both cavities on the loner mold to open things up and get boolits suitable for the 0.358" barrels used on the 357ARs.

For the 350L, the target OD just prior to sizing should probably be 0.3565" to 0.3570". So dropping around 0.3555" to 0.3560" should be good. However, starting small allows lapping, starting big is hard to "fix". I would target a mold ID of 0.3550" - 0.3560" to start with. I would not worry about the difference between mold ID and boolit OD.

Again the plan should be cut, cast, coat, measure and lap as needed.

[Oldfeller]

Good info, delivered quickly -- that is the very best kind !!!!

[Oldfeller]

My new order of diamond coated abrasives came in and they do cut the hard cobalt HSS like it is mild steel and they are easy to use -- achieving that impossible "good chip cutting relief" is now DONE.

My meplat now measures .195" and that is about right to me. I also narrowed and lengthened the nose a bit too, to take magazine binding out of the picture.

IMG_20191229_111552093.jpg

Issue is now the form is too long now for a shorter bullet -- only 200 grains and up need apply. Ditto for the HPC bullet form -- something around 250 grains minimum would be about right for that bullet form.

Both of these have about 50% unsupported bullet nose lengths, and as such won't shoot well in a PC coated, cast soft WW bullet.





Oh well, I learned how to do it and I can make me a bullet form cutter now going from elongated flat tip to HBC forms ---- but I can see that good accuracy lives with the short truncated cones and the round/flat tipped bullets which act to minimize those unsupported out of harmonic balance bullet noses.

There is a reason that the traditional round nose is a popular 35 Whelen cast rifle bullet form. It maximizes both accuracy and bullet weight in the shorter bullet forms. There is also a reason that 35 caliber jacketed and plated pistol bullets are generally all round/flat styles -- they have to be short enough to go inside revolver cylinders and still be heavy enough to work well while swinging a meplat.

[cwlongshot]

I shot a handful of the “community” bullet in 180g but only using my accuracy load of 20.3g 4198.

Kinda suked.

A73AC7D9-F306-4D07-A938-D3A8508ED551.jpeg

But same load with a Saeco 396 does this:

5638AC6B-2B95-4616-AA77-5092F9A89D15.jpg

These are 100y Groups.

Need to do some more testing!! Fun begins!

CW

[bikerbeans]

I shot a handful of the “community” bullet in 180g but only using my accuracy load of 20.3g 4198.

Kinda suked.

A73AC7D9-F306-4D07-A938-D3A8508ED551.jpeg

But same load with a Saeco 396 does this:

5638AC6B-2B95-4616-AA77-5092F9A89D15.jpg

These are 100y Groups.

Need to do some more testing!! Fun begins!

CW

You can always blame the poor group on the fellow that cast those boolits.

BB

[P Flados]

Or the dummy that came up with mold in the first place.

On the other hand this is hopefully just a "non-optimum" combination in some form. With my 357AR I had some really bad groups, but eventually found loads that were pretty consistently less than 2 MOA.

My biggest frustration early on was when I would get a group with 3 touching at 50 yards, one an inch away and one several inches away. Some of this was probably gun related, some may have been brass problems (formed from range pickup 223), some may have been loading problems (cobbled together dies and tooling), and finally there is the other ever present variable (me, the shooter).

It would be easy for me to look at the CW group and note that two hit very close together at close to the same POI as his accuracy load. So with two "good" shots and two "bad" shots, what caused the problems with the bad ones.

FYI, have you determined the COL that puts the boolit in contact with the rifling? How does this compare to the max that will run through your magazine.

[cwlongshot]

I have discovered shooting my cast nearly exclusively now for a couple years that they do nit at all respond like jacketed... MUCH more Black/White. Take that load above. 19 & 21g shot three inch groups @50. My “target is 1” or less @ 50 and 3” or less at 100 BUT ROUND groups. I dont wanna see flyers to make a large group. (Who does right) Flyers are usually ME, either poor shooting or a bad miss culled bullet.

This IS NOT AT ALL DISCOURAGING!! Just what I had happen on the very first loading. No blame cast anywhere!

CW

CW

[tomme boy]

The problem is the bullet is entering into the throat crooked.

[Oldfeller]

IMG_20191231_045840705.jpg

This is a truncated cone form that is all "as ground" clean angles. It CUTS cleanly.

Meplat flat nose is .250" diameter. Height of cone is .250" Raw cut diameter of the body portion right now is .354"

I suspect it will fly pretty well in a balanced mode. Weight will depend on cut depth --- at .850" max depth over the pins in the LEE blocks I have now we are talking somewhere around slightly over 210 grains ????? meatball estimate ?????



IMG_20191231_065750921.jpg

Enough with dubious meatball weight estimates, time to drill a series of depths and pour some molten WW lead into them ......

[Oldfeller]

IMG_20191231_073501333.jpg

OK, it is a bit crude but better than a raw guess, in any case.

1/4" deep = 120 grains

1/2" deep = 140 grains

3/4" deep = 180 grains

1" deep = 210 grains

Took the 1" slug and cut it down to .850" long (max cavity depth in current LEE blocks) and it weighed 203 grains.

[Texas by God]

277 posts for 3 pics of groups on paper! That has to be a record. Thank you P Flados and CW for keeping it real.

[Oldfeller]

277 posts for 3 pics of groups on paper! That has to be a record.

IMG_20191231_084936901.jpg



That's right, Texas --- none of it is real but just the 3 groups shot on paper.

Boy, I really missed my audience, didn't I?





The pic is a maximum LEE four up block filling 175 grain bullet weight that is approaching the profile of the P Flados Little 'un. This bullet would only get good rifling support for slightly more than half the length of the bullet and as such it would not be supremely accurate due to getting easily cocked in the throat, etc.

However, it packs a .190" meplat and looks like it would have a very good BC for the 175 grain weight that it packs. Being a slim nose design, it could live mostly outside the case, which is not true for the truncated cone version shown right before this one.

But over in Texas, it would be considered "unreal" and not worth considering.

[Phlier]

Boy, I really missed my audience, didn't I?

Well, since one side of the audience showed up, the other side might as well, too.

I've read every post. Loved every minute of it. Just don't have anything useful to add to the conversation, so haven't said a word.

But I've learned more in this particular CB thread than I've learned in quite a while. And it's much appreciated by us guys that just hang in the background, reading everything, but without having anything meaningful to contribute.

My wife will have you to blame for yet another gun purchase... can't wait to put together an AR Legend.

Very much appreciated, OldFeller.