Beautiful bullet doesn't want to shoot. Help!

[CJR]

Neverhome,

Some preliminary questions for you:

1. What is the sprue hole diameter in your mould?
2. Describe how you cast; i.e. normal temperatures or slightly superheated(degrees above melting), air-cooled or water quenched, etc.
3. What type of casting flux; i.e. Marvellux, sawdust, etc?
4. If this is a NOE mould, what is the location of the CP(Center of Pressure) and the location of the CG(Center of Gravity) ? NOE typically provides this info on their bullet drawings.

After getting these questions answered, if you like, we can discuss bullet stability as researched/patented by the US Air Force and Arrow Tech,VT.

Best regards,

CJR

[outdoorfan]

For kicks and giggles, I would shoot that bullet real slow (subsonic or maybe even well subsonic) with a fast/faster burning powder to see if it looks somewhat stable at the lower end of the velocity scale. I've gotten a 190 grain wfn in my Rossi 92 357 magnum to shoot 3-4 MOA most of the time with a mere 600 fps. And that is to 100 yards

But, like R5R said, life is too short to continue to mess with it if you've done everything you can to make it work.

[bosterr]

All of my MGM barrels have the rate of twist etched underneath.

[Neverhome]

I've tried it numerous times subsonic but I don't know HOW subsonic. Used various amounts of Clays and Trailboss for these plus a safe but lighter load of H110 .I do own a chrono but don't currently have a set up for portable lighting or anything of appropriate height to sit it on at the range. I mean I could put the chrono downrange but that is asking for a shot chrono with this bullet.
Anyway, all attempted velocities failed to reliably hit an 18 inch target at 50 yards.

For kicks and giggles, I would shoot that bullet real slow (subsonic or maybe even well subsonic) with a fast/faster burning powder to see if it looks somewhat stable at the lower end of the velocity scale. I've gotten a 190 grain wfn in my Rossi 92 357 magnum to shoot 3-4 MOA most of the time with a mere 600 fps. And that is to 100 yards

But, like R5R said, life is too short to continue to mess with it if you've done everything you can to make it work.

[Neverhome]

I'd have to get home to measure the sprue hole. I'll check it later.

I don't check temp of the melt yet but I typically run the pot just at the point where it starts to oxidize as I ladle. Mold is hot enough to fill out. Latest batch was filled out but not frosty. When I run the 158s I have to make them frosty to get fillout but the 225 does ok without.

Flux is usually a good stirring with a paint stir stick. It burns as I go.

yes Noe mold. I'll check the drawings for CP and CG.

Neverhome,

Some preliminary questions for you:

1. What is the sprue hole diameter in your mould?
2. Describe how you cast; i.e. normal temperatures or slightly superheated(degrees above melting), air-cooled or water quenched, etc.
3. What type of casting flux; i.e. Marvellux, sawdust, etc?
4. If this is a NOE mould, what is the location of the CP(Center of Pressure) and the location of the CG(Center of Gravity) ? NOE typically provides this info on their bullet drawings.

After getting these questions answered, if you like, we can discuss bullet stability as researched/patented by the US Air Force and Arrow Tech,VT.

Best regards,

CJR

[Neverhome]

CG= 46.21% from base

CP= 47.99% from base

Neverhome,

Some preliminary questions for you:

1. What is the sprue hole diameter in your mould?
2. Describe how you cast; i.e. normal temperatures or slightly superheated(degrees above melting), air-cooled or water quenched, etc.
3. What type of casting flux; i.e. Marvellux, sawdust, etc?
4. If this is a NOE mould, what is the location of the CP(Center of Pressure) and the location of the CG(Center of Gravity) ? NOE typically provides this info on their bullet drawings.

After getting these questions answered, if you like, we can discuss bullet stability as researched/patented by the US Air Force and Arrow Tech,VT.

Best regards,

CJR

[Neverhome]

Mine says 16 twist but I felt like I should check it just in case

All of my MGM barrels have the rate of twist etched underneath.

[popper]

Marginal stability- go faster, barely stable above 1K fps. Also sounds like they need to be sized smaller - tails on the recovered, concave base. Might try a slower powder.

[Neverhome]

Well that is interesting input! I had no idea what that might indicate nor that it was out of the ordinary. Thank you

Marginal stability- go faster, barely stable above 1K fps. Also sounds like they need to be sized smaller - tails on the recovered, concave base. Might try a slower powder.

[popper]

My 40s are 16:1 works well with short but your heavy is much longer. Longer is higher BC but needs faster twist (or fps).

[Larry Gibson]

Have to disagree with popper. Your .95" long bullet in a 16" twist has an Sg (stability factor) of 2.16 at 1000 fps, an Sg of 1.44 at 300 fps. That is using the Miller formula which gives bullets full stability at an Sg of 1.4. I have shot the RCBS 35-200 which is longer than your bullet down to 500 fps out of 16" twist 35 Rems and 35 Whelens with excellent accuracy. Something else is happening. Can you post a picture of you cast, sized and lubed bullets?

[Neverhome]

Everything I read and checked said I should be golden stability-wise as you said. It's been my feeling as well that something else is at work here but I couldn't pinpoint it.
I don't have any cast at the moment. Haven't been making any for obvious reasons. I'll cook
Up a handful later.

I had a chance to shoot today briefly in the literally 35 mph winds here on the East Coast. Winds were at 6 o'clock thankfully and I was only shooting at 50. Gun grouped well with 4 different bullets. Lee 125, 158, and 200, and Hornady 158 xtp.
Ive demonstrated plenty often that I can put all the pieces together but I feel like I'm missing something with the 360-225. None of the above bullets are SWC. Is there anything loading-wise that is pecular to SWCs?

[Neverhome]

As cast



Sized

[303Guy]

I would suspect internal voids in the casting.

I've discovered voids that were invisible on the casting but once fired, the void collapses under pressure, becoming visible.

Try cutting underweight castings just to see.

https://www.artfulbullet.com/index.p...-gas-cut.1244/

[Neverhome]

I'll weigh this batch and see how consistent they are!

I would suspect voids in the casting, likely near the base.

I've discovered voids that were invisible on the casting but once fired, the void collapses under pressure, becoming visible.

Try cutting underweight castings just to see.

[runfiverun]

I would show all that info to your rifle.

[Neverhome]

You're right. Trial and error is a much better idea than a little FREE research.

Maybe I'll try one of those 300 grain Thumpers NOE makes and just let the rifle tell me if it'll work instead of doing a little research first. No?

I would show all that info to your rifle.

[runfiverun]

you can research read and calculate all you want.

the only one that has the answer to all your questions is the target.
that's just how it is.

[Neverhome]

Ever read a reloading manual? 2? 3?

They obviously won't show you how your rounds will print on paper as you say but I hate to break it to you but that's research preliminary to the actual shot.

Ever pose a question on here? Research yet again.

I guarantee you that the AMU researches continuously and then as you say tests on paper. They are constantly looking for an edge and I guarantee they don't just throw random components together.
But I do agree on one thing, your rounds need to group on target or why bother.

you can research read and calculate all you want.

the only one that has the answer to all your questions is the target.
that's just how it is.

[Neverhome]

Thought about this some more. So I loaded up a couple different velocities with the 225 and fired into duct seal. That's how I recover mine.
12 grains of H110 and 10 grains of IMR 4198.
Nothing special about these loads except one would be high pressure/velocity and the other lower pressure/velocity.
The point was just to recover the bullets and inspect the bases.

Both showed similar slight concaveness and finning where the trailing edges were pulled back by the rifling.
Then I shot a load with a Lee 125 and 5 grains of Clays. This shot fantastically today at the range.
Same exact look to the base when recovered.

The bullet bases LOOKING the same is not very scientific I guess but lets say they are the same.
Could the finning cause a uneven release from the crown? And if so would the short 125 in the 16 twist be affected in the same way as the long 225?

Marginal stability- go faster, barely stable above 1K fps. Also sounds like they need to be sized smaller - tails on the recovered, concave base. Might try a slower powder.