SLOW Twists and FAST Casts Using CUSTOM Barrels...Results, Please?

[44man]

I see 45 2.1 is showing banned now. Thats great another wealth of information and excellent bullet designer who did an outstanding job with group buys is now banned. This banning seems to be pretty common anymore.

Several people from this forum who helped me very much starting out are now banned. Guess its time to find a new forum this is getting ridiculous.

I have to ask WHY myself. I truly do not know how I have hung on myself. yes, we lost some good guys and maybe it was from personal attacks. I will attack a process but a few will get nasty and needs a response. But they are not bad fellas. We need to be together even with differences.
Nobody should be banned, Just have a discussion. We all have opinions.
I have gone round and round with 45 2.1 myself but he will be a loss.
I have been a mod and am now a global mod on a site. You have to pee in my boots to get banned by me. Don't PM me and say a guy should be tossed. Personal stuff can be worked out.
I might be the nastiest, most opinionated bastard you ever seen but I respect all of you, personally, I have no better friends then all of you. You can cuss me!
Please bring back 45 2.1.

[Larry Gibson]

Took Dawn (BRNA VZ24 M98 barreled with a 31" Broughton barrel with 16" twist) out yesterday as I had recently made up 100 new 30x60 XCB cases and loaded them with some LBT 150 gr SPs cast of #2 WQ'd alloy. I consider these as "culls" because the original sprue plate was not cutting clean, pretty jagged actually. Thus I just kept them for such a purpose. Goodsteel subsequently made a new sprue plate that works excellently BTW. I did not weight sort the LBTs but only did a cursory visual inspection . The last of my Blammer GCs were used and they were sized at .311 and lube with 2500+. I loaded them in 10 shot strings over 4895. Ten shot test strings were used going from 37 gr to 46 gr. Winchester 30-06 cases were used to form the 30x60s and other than initial forming and turning the necks no other match prep was done. I also only used the M35P Oehler chronograph for this test as fire forming the cases was the primary goal with a base line of velocity potential being the secondary goal. The start screen was 15" from the muzzle and 18 - 20 fps can be added to the instrumental velocity to get close to the muzzle velocity.

Attachment 130761

The 1st cold clean bore shot with the 37 gr load went low and away as expected. The 2nd shot also was slightly low out of the group but I counted it anyway. Group size was 2" at 2578 fps.

The 38 gr load went into 1.48" at 2645 fps.

I called the 1st shot low left on the 39 gr load and it was so I discounted it from the group. The remaining 9 shots went into 1.44" at a recorded 2689 fps.

With 40 gr the velocity was 2747 fps with a 1.55" group.

At 41 gr the group was 1.6" at 2802 fps.

The above groups had a Dacron filler. The following did not as load density with the thrown powder chargers was at 85%+.

Attachment 130759

Then things went south...........fast!

The 42 gr load opened up to 2.7" at 2775 fps.

The 43 gr load opened to 6.6" with one really bad flyer. Velocity was 2822 fps.

At 44 gr the velocity was 2881 fps and the groups size was 2.65". Now some might yell and shout about that but in reality, given the previous group and the 2 groups following it just happened to be a smaller group.

The 45 gr load clocked 2948 fps with a group size of 5.8"

And lastly the 46 gr loaded pulled in at 2991 fps (3000+ fps if corrected to the muzzle) with a scattered 7" group.

Attachment 130762

As I stated originally in the original 30 XCB thread one my objectives with the 16" twist barrel would be to see how far we could push #2 alloy before it's structural strength was severely compromised. Now with 2 bullets (the 30 XCB and the LBT 150) cast of #2 alloy pushed to 3000+ fps I've found that objective. It appears #2 alloy holds up quite well to an acceleration rate of 2700 - 2900 fps depending on the bullet design, the twist and the powder burn rate used. Some where in there the alloy begins to plasticize under the 48 - 50,000+ psi required to reach those velocities. I'll move on to another alloy (linotype) and push it as far as I can in the 30x60 XCB with the 30 XCB bullet and the LBT bullet. I have already pushed the 30 XCB bullet to 3100+ fps at 56-57,000 psi.

Another objective of the 30x60 XCB with the 16" twist was to achieve 2 moa or less accuracy at 2800 - 2900 fps while maintaining linear dispersion at extended ranges. That objective was met within the first 150 rounds fired out of Dawn with 2 different cast bullets of #2 alloy. More testing to follow.

Larry Gibson

[Larry Gibson]

Mike

Yes, I mix it using the Lyman formula using linotype, lead and tin.

Larry Gibson

[44man]

Am I still here, seems I can't post.

[Bjornb]

Yeah you definitely reached the limit for the alloy. I couldn't make it happen in my rifle with fixed ammo, ran out of powder space. But with the breech seater we moved into linotype territory quickly.

[Bjornb]

Am I still here, seems I can't post.

You're here 44man, you haven't been banned........yet

[btroj]

I think I can help you with that Brad. If you can't reproduce your alloy, you're dead in the water. I say this especially if that group you posted in the HV thread was shot with this unknown alloy. You need to be able to get back there if it was a combination that sorta worked.
I can beg a favor from my buddy with the XRF machine.
Funny story there. He came to me a few weeks ago in a panic and told me that he had lost his titanium wedding band and his wife was about to kill him. He showed me pictures of the original, and I cut him a new one out of titanium. A couple hours under a microscope with a graver rendered a very fine band that looked better than the original. Yeah, he owes me big time. LOL!

I made 110 pounds of that stuff last fall. That would make over 3000 bulelts. That is a heap of shooting. If it works I can whip up another 200 pounds pretty easily.

I may send you a sample of the monotype. I had it tested years ago but don't trust the results at all.

[cbrick]

Jim, you were probably trying to post in a thread that went poof. Like the revolver accuracy thread.

Your post here most definitely looks like a post to me.

Rick

[btroj]

I didn't get a PM?

I haven't shot the 190X in a while, I am currently using the MP 30 Sil.

The 190X has similarities to the 30 XCB bullet by NOE, the 30 Sil is very different. The 30 Sil is designed to let the pressure alter the bullet in a specific manner. This in general requires a lower Sb alloy. That bullet also prefers to be seated off the lands. The 190X is a strong, morse taper type fit in the throat. Like the NOE bullet it will prefer to be on the lands, I suspect.

I find it hard enough to find time in this weather to test one bullet, trying 2 or 3 would border on impossible.

[Rattlesnake Charlie]

I've enjoyed this website ever since I first found it.

I've learned much, and hope to continue to do so.

I enjoy reading about each different approach.

I do wish we could enjoy all ideas and opinions here without flaming.

Our goal should be to expand the knowledge and boundaries of shooting cast boolits.

Let us not destroy a good thing.

[44man]

Jim, you were probably trying to post in a thread that went poof. Like the revolver accuracy thread.

Your post here most definitely looks like a post to me.

Rick

Might be. Got a thing from the administrator but the posts might have been kaput.

[MBTcustom]

I didn't care for the MP 30 SIL personally. Beautiful mold, and it cast very consistent bullets, but there was an awful lot of unsupported nose on that one. Then again, that was back when I had the janky 10 twist barrel.....
Hmmmm
I agree with Brad here. One bullet design with several choices of lube, alloy, and seating depth, could keep a guy busy for several months of hard testing before he might tentatively venture an opinion on it's merit or lack thereof in one rifle.
That said, there have been plenty of designs that just suck rocks and it only took one range session and a bit of reading to come to that conclusion.
I designed the XCB bullet to be absolutely the best mid to high speed bullet right off the bat, and so far, it's been a rave success. (it surpassed my wildest expectations.) I'll be ragging it out for a while.

[btroj]

But that unsupported nose is designed that way. It doesn't stay unsupported for long if the alloy is right.
I wish my berms allowed for better recovery of spent rifle bullets. The clay is pretty hard on them unless a bit damp and then they just burrow forever. Seeing how much of the nose engraves would tell a bunch about how the specific alloy responded to the pressure.

[MBTcustom]

Trust me, that's something I have wanted for a long time. But the lead is so soft (even made of HT alloy) that just shooting through a light fluffy material at HV will damage the bullet terribly.
I had in mind to buy a long cardboard pillar form, blow insulation into it, set it out at 500 yards, and try to lob a boolit in there to catch it. Let the air take care of slowing it down, and let the insulation take it from there.
Unfortunately, that requires me to be able to hit a 12" circle at 500 yards with a cast bullet, and that is nigh impossible with a fast twist barrel. Or at least it was for me.
Matter of fact, that's a really good idea! Recon you could lob one in there Brad? I would like to see if a bullet could be caught in that fluffy stuff.

[btroj]

I wish it was that easy! I will be able to find some come summer when it dries out but they generally have the nose eroded away from impact. I may need to try some at longer range and see how they look. Will need to find a day when I have the range to myself, maybe a late evening.

[Yodogsandman]

Can't you load it to lower velocities for that? Then shoot into your medium close in.

[btroj]

Won't work, not the same pressure lefel or pressure curve. Pressure is what makes the metal flow so unless we have the same pressure it tells us little. What bullet recovery would let us see is how each bullet was changed by the firing process.

A high speed camera setup would be helpful too but they aren't cheap, least not a good one.

[MBTcustom]

$50,000 IIRC. That'll hair lip a country boy.
I did some testing with cat sneeze loaded when I was designing the XCB bullet, shooting all my 30 caliber designs into a sand box and recovering the bullets. I learned a thing or two about engraving and how the bullet reacts, but Brad is correct, the only way to know what happens to a bullet when fired with a specific full house charge of powder is to recover a bullet that had suffered that trauma. Unfortunately, the very thing that's affecting the alloy and making it work the way we think it might, is the very thing that makes it so hard to recover.
Its like trying to measure a smoke ring with a pair of calipers.

[runfiverun]

I can get one in a less than a 4" circle with no problem at 300 yds.
Unfortunately it only has a 2400 fps muzzle velocity.
Dr. Mann used oiled sawdust back in the day I prefer snow except for the finding them part.

[btroj]

We don't have that kind of snow. I'm OK with that.
A light, finely divided powder mght work but it would need to be pretty deep. Maybe flour?
The realities of the process make it largely impractical. Even oiled sawdust would require large box, lots of oiled sawdust, and a means to get it properly located for shooting into. Longer ranges would be best as the air is the single best non-destructive "slower downer" of bullets in existence.

Like so much of this reality tends to bite one in the keister. I hate that.