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Post by cowhunter on Sept 8, 2014 23:16:22 GMT -5
As promised, Dan at Cutting Edge sent me 20 of the 323 grain .458 boat tail billets we have been discussing. Wow, in the flesh they are a beautiful bullet I want to use on a critter, but we promised to test them. I'm not sure what the BC is on these, but I'd say similar to the MH. I have some .416 CE bullets that Hillbill described as having a BC of .780. Even shooting my favorite mellow speed of 2760fps, at 600 yards I still have over 3300 foot-pounds of energy, and the energy and speed just keep going. So you imaginative guys need to think of a way to build a .600 BC bullet--and CE would probably build it. I say one of the positive characteristics with the .45 is that we can stuff any length bullet down our muzzle. My favorite CE billet is hollowed out on the inside rear to enable more length. But Dam said we might not have enough twist for long bullets. So maybe we can talk Dan into making the bullet -- and the barrels will come. I would substitute one of my 1/22 Pacnors for a 1/14 twist Pacnor if I can get another 2-300 .BC. I can sell one of my good-shootin 1/22 barrel since ithey are proven shooters. Mmm. Maybe I should check to see what twists Pacnor makes. I knew I kept that clunky barrel wrench for something.
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Post by 7mmfreak on Sept 9, 2014 3:01:14 GMT -5
.458 barrels can be had from a 1-10 (Lilja) to 1-14 or 1-15 (Lilja and Krieger for sure and probably others) to any of the twists commonly found here on Doug's. I don't think you are going to hit a .600 G1 without breaking 400gn (and a long 400gn at that) but I could be wrong. I've done a lot of scaling in preparation for this bullet making project I am about to undertake. What I can tell you is a cup and core bullets gets LONG and HEAVY really quickly when achieving a BC over .550 G1 and if I am having those issues a mono will only be longer and/or heavier.
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Post by Deleted on Sept 9, 2014 3:59:49 GMT -5
yes monos get very long but in most cases long is a good thing for BC. yes it will be hard to up the BC much without getting shoulder killing heavy but I would be up for trying a 375 grn bullet if it had a high enough bc. can never tell what will happen around here....
I have used 14,18,20, and 22 twist barrels in these .45s and Im sure the 14 or 18 twist would handle some really
heavy stuff fine..
Keith
I am looking forward to seeing what your bullet looks and shoots like, we need all the bullet choices we can muster as the bullets I shoot now are very hard on the backside...LOL
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Post by edge on Sept 9, 2014 5:06:17 GMT -5
I may be wrong, but a hollow base is only an advantage for keeping the cartridge AOL the same.
A hollow base, in effect lowers the density of the bullet and that is bad for stability and for BC.
Generally the BC of two bullets with the exact same shape in the same caliber is proportional to their mass.
Does an open base create less drag than a closed base, that may be a question since a hollow point on a target bullet is almost always better than a solid point.
Why, perhaps because a solid point adds mass forward, or perhaps a hollow point is more consistent...perhaps Rossman can add something here???
IMO, long is a twist's enemy but it boosts BC by mass proportionately, and much more if by shape.
edge.
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Post by 7mmfreak on Sept 9, 2014 16:23:27 GMT -5
Bill,
I hear you on the bullets. My biggest drive behind these is to cut my cost of shooting the SML (especially if I take the plunge on a .416 SML and/or CF) and eventually start making my own .308 match bullets as well but we'll see where it goes. I'm hoping to make and test the first batch by Xmas. The dies should be here October or November but based on the timeline from time of order to when the swaging press arrived I think December is a safe bet. Hopefully, my Xmas present to the board will be some targets that show clean round holes and tidy groups.
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Post by fishhawk on Sept 9, 2014 16:48:21 GMT -5
I may be wrong, but a hollow base is only an advantage for keeping the cartridge AOL the same. A hollow base, in effect lowers the density of the bullet and that is bad for stability and for BC. Generally the BC of two bullets with the exact same shape in the same caliber is proportional to their mass. Does an open base create less drag than a closed base, that may be a question since a hollow point on a target bullet is almost always better than a solid point. Why, perhaps because a solid point adds mass forward, or perhaps a hollow point is more consistent...perhaps Rossman can add something here??? IMO, long is a twist's enemy but it boosts BC by mass proportionately, and much more if by shape. edge. With my .416 the hollow base does bring the bc down some. The CEB bullet is 340gr and it's external dimension twin is 375gr. I chose to start with the 340gr because it had a higher listed bc than their 350gr which is shorter in length. I also thought that especially with annealing that the hollow base might help with obturation. I have some of the 375's but the velocity loss of the heavier bullet somewhat cancels out the higher bc, they also recoil more. |
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Post by hankinsrfls on Sept 9, 2014 18:58:19 GMT -5
I got my new 323 grain CEB bullets yesterday and they do look sweet... I don't know when I will get to shoot them but I will. I have been busy testing the 416 and so far have found the 350 grain CEB to be the most accurate. Shot a five shot group last night under 3/4 moa at 100 yards... Shot the same load with the 340's and my group was about 2.0 moa... My velocity is 3050 and I am looking for a bit more... Jeff.
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Post by edge on Sept 9, 2014 19:01:28 GMT -5
With my .416 the hollow base does bring the bc down some. The CEB bullet is 340gr and it's external dimension twin is 375gr. I chose to start with the 340gr because it had a higher listed bc than their 350gr which is shorter in length. SNIP. Not to be a jerk here but there is no free lunch  Longer is a better BC because of mass and rarely anything else. IMO, they use bullet SHAPE to compute BC which is one of the least reliable methods. If I did that then I could use just the jacket with no lead and claim a high BC. When it comes to BC lead is your friend because of the mass, about 11 times that of water and copper is about 9. Twist is based on length and mass. BC is basically form x SD for a G1. The main Drag components for computing BC are Nose, Skin, and Tail. Skin drag is normally about 5% but the longer you make the bullet the more skin drag you get. Once again I reiterate that there MIGHT be an advantage to a hollow based bullet but I don't know of this being used in the 1K tournaments! edge. |
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Post by Deleted on Sept 9, 2014 20:27:42 GMT -5
I would like to see a picture posted of the 323 gr .458 boat tail. Kyle
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Post by cowhunter on Sept 9, 2014 23:40:33 GMT -5
Jeff, I'm glad you are shooting the 350 grain .416 bullet so well. I must admit I bought a box long ago but never tested them head to head with the 340 grain. I was just so happy to get the 340 grain shooting well (for me) that I bought more boxes of that and quit testing. I'll be happy to get more accuracy if it works out. I agree these new .45 CEs are pertty. I'm interested in your testing of the accuracy. If I am able to anneal some I'll send some to you to size and shoot.
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Post by cuda on Sept 10, 2014 6:53:44 GMT -5
Could a double core bullet work? Maybe a center core of aluminum surrounded by lead with a copper coating or plating them? Or a copper bullet with a aluminum core or any lighter core with a better BC. I am no bullet designer just trying to figure out a longer lighter bullet that might be a better BC and not weigh a ton. I would love a better BC bullet in the .458 300gr range for the 45. If it was a .458 it would shoot great in the 50s too.
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Post by hankinsrfls on Sept 10, 2014 7:08:25 GMT -5
Weight= BC.. You could make an aluminum bullet 3 inches long and lets say it weighs. 300 grains.. Even though it looks like a rocket the BC would be very low...(crapy) mass weight in small packages make for the best BC..combinations. If we had a material heavier than lead and made a bullet from it it would have a better BC than the exact bullet shape in lead form, copper bullets, the BC goes down, brass bullets, the BC goes down even more. Steel bullets down more and aluminum bullets practically no BC. Jeff.
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Post by Deleted on Sept 10, 2014 7:32:36 GMT -5
A lot of guys have had great luck with the hollow based .416 340 CEB vs the 375 CEB, right? Well looks can be deceiving...all 3 bullets look like the same right....?  But they're not... 300 grain, 340 grain 375 grain CEB CEB bullets made the 300 grain bullets also.  I had this done for the same reason you guys are talking about now. The lighter bullets don't shoot as good as the heavier bullets. |
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Post by jims on Sept 10, 2014 18:53:51 GMT -5
If Rossman could get ahold of depleted uranimum then you might get what you are after.
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Post by edge on Sept 10, 2014 19:01:25 GMT -5
If Rossman could get ahold of depleted uranimum then you might get what you are after. Or better yet, take those tungsten bushings and slip them inside the bullets, they should be about 19 times the mass of water...gold is about the same but that might get expensive to shoot unless you are Zuckerberg! edge. |
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Post by hankinsrfls on Sept 10, 2014 20:17:46 GMT -5
At $50.00 a bushing.. The cost of a tungsten bullet would be astronomical. Jeff
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Post by jims on Sept 10, 2014 21:11:14 GMT -5
In a perfect world or if we had the Midas touch.
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Post by cowhunter on Sept 12, 2014 0:15:21 GMT -5
EArnhardt: did you make that 300 grain CE yourself or did you talk CE into customizing them for you? Give us a little more detail on how they shoot!
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Post by 7mmfreak on Sept 13, 2014 10:35:25 GMT -5
The lighter bullets don't shoot as good as the heavier bullets. My guess would be that is due to the nature of spin stabilized objects. When you keep the same weight but increase length (say 180gr conventional to 180gr mono) you lose gyroscopic stability at given twist rate since monos are less dense and therefore longer. Take that same mono, keep the length (which you did), but reduce the weight, and you have the same issue: decreased stability. |
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