Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

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GunFunZS
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Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by GunFunZS »

I've done a few searches with no results, both here and at castboolits. I know this has been done for other molds, but can't find anything for this.

Basically the idea is to take the standard Lee 160 grain tumble lube mold and mill off the portion of the mold which makes the gas check shank and the first tumble lube rib. This would result in a bullet that is ~0.140" shorter. The new bullet would be " ~0.784" long, with the bottom of the remaining TL groove making a very slight bevel base. It might be more accurate to call it a plain base. Anyway, when I cut off a Lino cast bullet that was 148 grains after PC, and weighed it, the resulting bullet was about 116 grains which sounds like a sweet weight for SS loads.

I've found that depending on alloy the full mold makes bullets from 148 to 155 grains.

The trial loads I made and tested on Sunday based on 150 grain data were flops.
Basically this is what happened. I made the usual dummy cartridges with very fat unsized uncoated rounds to check manual chambering. Projectile measured 0.314". The portion of the bore riding section just behind the ogive measures .307". These chambered fine at an OAL of 2.020".

So I make up a couple ladders of basic loads using 150 grain data and CFE BLK and the same thing in H110. These were sized to .309" dead, after powder coat. The forward portion was .308"

the nominal max load of H110 wouldn't fit uncompressed, so I went a couple tenths under 100% load density as my max. These ran OK until one had severe pressure signs. Then one of the CFE blk loads stuck in the chamber. Upon inspection, the PC made the portion behind the ogive just big enough to engage the rifling for about 0.124" intermittently. So I need to either seat this bullet deeper or find another mold.

I am willing to find another mold, but what I really want is a 110 - 125 grain mold with a reasonably good BC which groups well. I see no reason not to face my mold down 0.140" and give it a try, unless someone else here can point me to someone else failing at the same experiment.

I've already PMed Dolomite about my plans for a custom mold in this category, but it would be a great time saver if I could make a workable hold over out of the mold I have in hand.

I welcome your input.
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GunFunZS
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by GunFunZS »

For reference, I am talking about THIS bullet
Image

http://leeprecision.com/mold-dc-tl312-160-2r.html
Boolit_Head
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by Boolit_Head »

Before you reinvent the wheel why not peruse the selection over at Noe's website?

http://noebulletmolds.com/NV/index.php?cPath=30_360
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GunFunZS
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by GunFunZS »

Boolit_Head wrote:Before you reinvent the wheel why not peruse the selection over at Noe's website?

http://noebulletmolds.com/NV/index.php?cPath=30_360
Thanks for the response.

"Why reinvent the wheel?" Answer #1-- I have looked through NOE, as well as the other manufacturers. It seems no one is making a bullet that does what I want. You linked me 150 grainers, but I am looking more in the 110- 125 grain range for super sonic bullets.

The NOE Crayola of Death as it is known here would be close, if it got good results, but it seems that most people are not getting good results from it. Generally the very pointy spire points don't shoot well with high pressures because they distort under force. That design slightly blunted might do, but most of the other features are detrimental too.

Pretty much all of them have lube grooves or features for useless gas checks which allow for more fillout errors and interfere with the coating. More importantly, 300 BO puts a lot of leverage on the small neck area, and the grease grooves here give less surface to support that weak connection.

This NOE bullet is pretty close, http://noebulletmolds.com/NV/product_in ... cts_id=123 , but it still has conventional lube grooves, right where the crimp needs to be.

"Why reinvent the wheel?" 2) The mold I have, but cut shorter is pretty close to what I would draw up on paper. The ogive is a little blunter, and I would make the nose a little pointier if I could, but not as pointy as the "crayola". I can face the whole mold shorter for free in my garage with the CNC mill. That's about the limit of my CNC skill. I'm willing to do a custom mold from scratch eventually, but this would hold me over. It sounds like Dolomite may have something in testing which would be worth trying out too.


However, the thread was mostly asking if anyone had tried doing this exact modification, and if so what results they got. I can't find any threads about that.
xdmalder
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by xdmalder »

GunFunZS wrote:
Boolit_Head wrote:Before you reinvent the wheel why not peruse the selection over at Noe's website?

http://noebulletmolds.com/NV/index.php?cPath=30_360
Thanks for the response.

"Why reinvent the wheel?" Answer #1-- I have looked through NOE, as well as the other manufacturers. It seems no one is making a bullet that does what I want. You linked me 150 grainers, but I am looking more in the 110- 125 grain range for super sonic bullets.

The NOE Crayola of Death as it is known here would be close, if it got good results, but it seems that most people are not getting good results from it. Generally the very pointy spire points don't shoot well with high pressures because they distort under force. That design slightly blunted might do, but most of the other features are detrimental too.

Pretty much all of them have lube grooves or features for useless gas checks which allow for more fillout errors and interfere with the coating. More importantly, 300 BO puts a lot of leverage on the small neck area, and the grease grooves here give less surface to support that weak connection.

This NOE bullet is pretty close, http://noebulletmolds.com/NV/product_in ... cts_id=123 , but it still has conventional lube grooves, right where the crimp needs to be.

"Why reinvent the wheel?" 2) The mold I have, but cut shorter is pretty close to what I would draw up on paper. The ogive is a little blunter, and I would make the nose a little pointier if I could, but not as pointy as the "crayola". I can face the whole mold shorter for free in my garage with the CNC mill. That's about the limit of my CNC skill. I'm willing to do a custom mold from scratch eventually, but this would hold me over. It sounds like Dolomite may have something in testing which would be worth trying out too.


However, the thread was mostly asking if anyone had tried doing this exact modification, and if so what results they got. I can't find any threads about that.
How fast were you wanting to push it?
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GunFunZS
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by GunFunZS »

xdmalder wrote:
GunFunZS wrote:
How fast were you wanting to push it?
Equal to jacketed data for a bullet of comparable weight. I want that flat trajectory, and will alloy+ heat treat a bullet strong enough to handle the pressure.
Last edited by GunFunZS on Tue Apr 04, 2017 1:45 pm, edited 1 time in total.
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GunFunZS
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by GunFunZS »

here's a picture showing the bullet I cut down next to an uncoated original:
Image

Notice how it provides a lot of contact with the case neck, and a flat base with very slight chamfer. The nose profile is a little blunter than ideal, but at least it is one known to survive reduced 30-06 pressures with suitable alloy. I've had the full sized bullet shooting reasonably accurately at estimated 2600 FPS out of 30-06 and 308 win with 22-24 BHN.
xdmalder
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by xdmalder »

GunFunZS wrote:here's a picture showing the bullet I cut down next to an uncoated original:
Image

Notice how it provides a lot of contact with the case neck, and a flat base with very slight chamfer. The nose profile is a little blunter than ideal, but at least it is one known to survive reduced 30-06 pressures with suitable alloy. I've had the full sized bullet shooting reasonably accurately at estimated 2600 FPS out of 30-06 and 308 win with 22-24 BHN.
What kind of twist rate is your 300 blackout. I'm guessing your 30-06 and 308 have a 10 or 12 twist. When you go with fast twist barrels, cast becomes harder to shoot fast. Go over to castboolits.gunloads.com and check out RPM threshold. I'm not saying you can't but will be much more difficult. I could go out and see what 145 grain hollowpoint pushed hard will do in mine if you like.
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GunFunZS
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by GunFunZS »

I'm loading for a 1-7 and a 1-8.

I'm aware of the RPM calculator. It would seem that the slower twist 1-8 has a better chance of being accurate with light and fast.
xdmalder
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Re: Cut down a CTL 312-160-2r Mold to make a ~116 grain SS bullet?

Post by xdmalder »

GunFunZS wrote:I'm loading for a 1-7 and a 1-8.

I'm aware of the RPM calculator. It would seem that the slower twist 1-8 has a better chance of being accurate with light and fast.
Yeah I was estimating about 1700 max with that RPM philosophy. I have the NOE make of that LEE 160 in a hollowpoint version. I haven't done any testing with it so maybe I'll go out and do that quick like.
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