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Rule of thumb for loading cup and core vs. solids??

2K views 26 replies 12 participants last post by  unclenick 
#1 ·
Is there a rule of thumb on start loads for interchanging a cup and core bullet in place of a solid copper?

For example, I have data on a couple of powders for the Barnes TSX 110 gr. in 270 Win., but not for the Hornady 110 HPBT which I am wanting to load. I am wanting to try a couple of new powders.

Thanks.
 
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#3 ·
The Hornady bullet will take up less space in the case, and engrave into the rifling easier. So, it isn't going to hurt to start with the Barnes TSX data, but likely it won't reach full speed. I'd contact Hornady and ask them for suggestions.

Could also look around for another cup'n'core bullet of the same weight to compare data to (Sierra?).
 
#5 ·
My Alliant manuals only show the TSX in the 110 gr. weight. I was looking at Pro Varmint and one of the RL powders.
 
#10 ·
Yes it is.

I don't remember a "Rule of Thumb" for substituting cup and core for monolithic (solid copper ) bullets . I honestly believe you would be best served with Data from a Hornady manual and the Hornady 110 gr. HPBT in the powder(s) of your choice .
I've found the Hornady reloading manuals an excellent source of data since buying my first in 1967 ...Edition #1 ... the 8th Edition has the data you seek with that 110 gr. HPBT bullet with ten different powders . Having the manual in front of you would be helpful if you wanted to test some new powders ...seeing them in a loading chart helps you get a handle on which end of the burn rate spectrum all the powders fall .
Varget is never a bad choice ... if you have or can get some !
Gary
I am only about 5 editions behind on the Hornady Manual. I also have a number of Speer, Sierra and Nosler books...but none newish. My Lyman is the 48th. I was going by my newest Alliant manual (2020 Edition) and the TSX is the only bullet offering in that weight. I have an excellent H4831 load with the Hornady bullet, but was interested in trying a couple of new Alliant powders I had on hand. I have used Varget (and have a couple of pounds) and the 4895's, but nothing has outdone the 4831 load. I've not tried any 4350 and may give it a try. Hodgdon has data for their powders.

I'll talk with Hornady when I get a chance. Thanks for the input

Thanks for the input.
 
#7 ·
My personal rule of thumb...

Any bullet moving over 2800 fps and there's a chance a shot could come at under 75 yards; that's when it's time to go with the more advanced bullets. (for most cartridge's). Such a shot is bound to rip a cup & core up.

The other time I reach for the monolithic or bonded bullets is when I need a cartridge to punch above its weight a bit. Like hunting moose with a .257.
 
#8 ·
Is there a rule of thumb on start loads for interchanging a cup and core bullet in place of a solid copper?
The only thing that can reasonably help you, is "Like for like", is never a bad idea; but not universal.
So anything solid soft copper that's been heat treated, I would personally use Barnes data. Anything that's a "hybrid" or case-esque type alloy (Hornady) I would use regular data.

For an example of an exception(maybe) is the FlatLine series of solids. The story Warner told me, was that it is a soft copper alloy that is sticky to other coppers, so no mixing fouling or "weird things can happen". I dunno what construction type that makes them. But they aren't "sticky" to other coppers, nothing weird happens when you mix them, and according to the pressure trace, they act like a cup& core or Hornady monolithic.

Cheers
 
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#9 ·
I don't remember a "Rule of Thumb" for substituting cup and core for monolithic (solid copper ) bullets . I honestly believe you would be best served with Data from a Hornady manual and the Hornady 110 gr. HPBT in the powder(s) of your choice .
I've found the Hornady reloading manuals an excellent source of data since buying my first in 1967 ...Edition #1 ... the 8th Edition has the data you seek with that 110 gr. HPBT bullet with ten different powders . Having the manual in front of you would be helpful if you wanted to test some new powders ...seeing them in a loading chart helps you get a handle on which end of the burn rate spectrum all the powders fall .
Varget is never a bad choice ... if you have or can get some !
Gary
 
#11 ·
Okay. I waited on hold with Hornady forever yesterday and gave up (Holiday hours).

Anyone have a newer Hornady manual and see if they give a load for 270 Winchester with the 110 gr. BTHP Match bullet with Alliant Pro-Varmint Powder. Reducing the Max load by 10% shown in their book for the TSX, it is ~ 44 gr. which only fills the case to about 65%. Not sure if I like that. Depending if the Hornady Manual shows anything, I will probably just stick with my 4831 and 4350 loads.

Thanks in advance.
 
#12 ·
Okay. I waited on hold with Hornady forever yesterday and gave up (Holiday hours).

Anyone have a newer Hornady manual and see if they give a load for 270 Winchester with the 110 gr. BTHP Match bullet with Alliant Pro-Varmint Powder. Reducing the Max load by 10% shown in their book for the TSX, it is ~ 44 gr. which only fills the case to about 65%.
🤔🤔
If you want data for a Barnes bullet, why don't you simply ask Barnes? Barnes and Hornady's monolithic aren't the same.
No, there is no Varmint data in #9(10 current I believe).

Looking at Alliant's data, they don't suggest it.

Cheers
 
#14 ·
Gotcha, I got confused along the way somewhere.
Best of luck. 👍
 
#17 ·
The only 'rule of thumb' I've heard about solid copper (monolithic) bullets is that they need more jump due to higher engraving forces.
Some may have higher engraving forces, others don't. Again it goes back to construction, and why there isn't a simple "Rule" he can follow.

Cheers
 
#18 ·
CAUTION: This post discusses experimental load suggestions that either are not published anywhere or have not been properly tested for safety and may exceed published pressure maximums for the cartridge(s) mentioned. Neither the writer, The Shooter's Forum, nor the staff of The Shooter's Forum assumes any liability for damage or injury resulting from using this information. DO NOT ATTEMPT TO DUPLICATE THE DESCRIBED LOADS without first working them up while watching for pressure signs. If you don't know how to do that, don't try.

Darkker put his finger on it. The old solid designs, like Barnes, were solid bronze of copper with smooth sides and present about twice the resistance to engraving a cup and core bullet does. This shows in QuickLOAD and GRT as start pressure. But more recent (last couple of decades) designs are banded solids and their little driving bands with spaces between them reduce that start pressure closer to that of a cup and core bullet; just not always all the way. So you would need a different rule of thumb for solid solids than for banded solids, and it still wouldn't apply perfectly to all of them. I can tell you that in GRT, using Barne's 3.240" COL, the Hornady bullet needs about 3.9% more RL15 to reach the same peak pressure. Pro Varmint isn't in their database.

Incidentally, while I don't trust their absolute numbers a lot, the QuickLOAD and GRT interior ballistics software are usually pretty good about ratios, including loading ratios to match pressure and other factors. GRT is free to download, though there is a learning curve.
 
#19 ·
7MMRLC shared some newer Hornady and Lyman data with me (no Pro-Varmint though) and comparing it against my Alliant data, a start load of 10% below Alliant MAX should be okay with a cup and core bullet. I charged 10 270 cases with 44 gr. of PV (the MAX was listed as 48.7 gr.). It only gave me about 65% case fill which I don't like. I think I'll save the PV for just my 204 and maybe some 22-250.

I have a Lyman 50th on its way which should be delivered Monday.
 
#20 · (Edited)
I have 14 pages of test rounds for my 35-300 in my 20in. barrel marlin336 .. I've tested many powders and bullets barnes , speer , Hornady and sierra. . I've found that different brass manufacturers and neck tension makes a greater difference in velocity and pressure then bullet designs. . That is jacketed or solid of the same weight. . I've noticed no crimp verses crimped only helps with velocity stability with no other notable difference. . Just my conclusion
 
#21 ·
Lyman #50 shows a flat base Sierra soft point as their 110-grain bullet. For Reloader 15, they have 45 to 52.7 grains in a Winchester case. GRT shows the max at just under 80% loading density. I suspect the low fill you found for PV is the reason it's not in the books. With light bullets in a large capacity case, you always have to look hard for something that will burn fast enough to keep up with the rapid expansion in the barrel due to a light bullet's speed, and yet still fill the case well without developing too high a peak pressure.
 
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#22 ·
Thanks nick. The Alliant Manual shows the MAX for RL15 as 49.7 gr. for a velocity of 3301 fps with the Barnes TSX bullet. The Lyman 48th gives the same recipe as your 50th.

Thanks again.
 
#23 ·
My 50th came in yesterday. Yay!! It is nice having a lot of my older manuals, but having a newest isn't a bad thing either. I have the newest Nosler and Alliant's, but lack in the others. I'll rely on on-line data and y'alls help for other things.

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#24 ·
I emailed Barnes regarding their 130 grn 308 tsx, at that time I couldn't get the powder suggested (ram tac) as the most accurate and wanted to use CFE 223. After a couple of days they suggested reducing the start at loads by a couple of per cent and work up from there in small increments, this I did.
Bearing in mind my rifle has a 26" barrel chambered 308 win I attach an image of 100 metre target that has all the detail on. Please note that my rifle is a ruger #1 and these loads were developed for it, they may not work in your guns. So the rule of thumb is reduce the start at loads by 5% and come up slowly. The groups were fired with a magnetospeed sport hanging off the end of the barrel. Black Wood Line Font Circle
 
#25 ·
That may work for the tsx, but I would not count on it being identical for other brands or forms of solid.
 
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#26 ·
Uncle Nick, you're 100% correct, I did include a caveat about what appeared to be safe in my rifle but like a lot of (99.9%) internet information/advice caution is the better part of valor.
I'm going to the range today to test fire some 308 win with a new powder, Lovex D073.6 which is an A2520 substitute and, tbh, I'm starting at the conservative end of the range to get some idea of the performance against the magnetospeed chrono I have.
I've loaded up some 147 grn FMJs so if the powder does as the makers claim, I'll load it behind my 130 grn tsx bullets.
It has one major advantage, it's about 25% cheaper than cfe 223.
The down side is there are only a limited amount of bullets in the maker's manual so there's still a question mark over the loads for barnes products.
 
#27 ·
That powder is also in the GRT and QuickLOAD powder databases, if you want a computer load opinion.
 
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