Alloy Content as a Variable for Accuracy

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  • Last Post 22 July 2025
Wm Cook posted this 21 July 2025

As I’ve slowly progressed in my hunt for cast accuracy I’m starting to consider that alloy content may be as important as weight deviation and possibly even appearance. This summer is my third anniversary since I took up cast accuracy. And 100% of what I’ve shot since then is Linotype. And the wear in the leade of my bore shows it.

When you look at the last three years of results from the Benchrest Nationals, Linotype is used by most everyone shooting Unlimited (R & P) and Heavy. Most all are running velocities greater than me, but then again some of those folks are in the same 1700fps vicinity I’m in.

Same, same with Production class. Most all are running less than 1750fps, but still using Linotype.

The obvious exception is PB and the sub 1500fps velocity they shoot.

My “to do” list includes a comparison of softer alloys and Linotype but I have to finish a few other projects. If they go well I’d like to play with something besides the #2 Alloy I have on hand. I’m trying to develop a chart that’ll tell me how much lead to add to 90-5-5 to bring it to something softer.

But when it comes to tweaking alloys I’m at the kinder garden level. I was just curious if Antony had an opinion on this. Bill C

Ps; Assume bullet to bore fit & bench practices are at match level. Thanks again.

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Glenn R. Latham posted this 21 July 2025

Wm, I did all my match shooting in 30-06 for decades with air cooled wheel weights and velocities from 1520 to 1620. When I got a new Hoch mould, I wasn't getting the accuracy I thought I should so I tried linotype to get a fatter bullet. That made the difference and I shot that lino bullet, and increased the velocity because it could handle it. The lino bullet shot well at my old pedestrian velocity too.

When I tried my old 270 with CBs, the dimensions out of WWs looked good, but accuracy was not, so once again I tried lino and the fit was better, as well as accuracy. I have not tried any alloys between WWs and linotype.

BTW, the first bullet I used with the 30-06 back in the 80s did not shoot as well with lino as with WWs. You just have to experiment, but that's half the fun.

Glenn

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Wm Cook posted this 21 July 2025

The thing that got me thinking was a K Hornet I was working with. It shot the Sierra 40 grain real well but was struggling with cast. The 225438 shot about best and with #2 I thought I was closing in on a load around 1800fps. So I cast some Linotype thinking it would only get better and I got the opposite.

Where the #2 looked like they were starting to knot up, the Linotype groups opened back up. Then life happened and I didn’t have time to prove that one or the other wasn’t a fluke.

When time permits I want to give softer alloys a try with my 308. Like you said, that’s what makes it so much fun. Bill C.

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99 Strajght posted this 21 July 2025

I always start with Lyman # 2 and if it will not group I go softer and that seems to work for me. Point of impact will also move with different alloy mix.

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Wm Cook posted this 21 July 2025

So how do you create the formula to turn #2 alloy (90-5-5) into “something softer”. Is it all seat of the pants or do you start with the dry weight of the casting pot and calculate the amount of lead needed to bring it to what you want.

I know this sounds as crazy as a chicken wearing bib overalls but working with custom alloy blends makes bullet to bore fit look like a proven science. Bad example, the latter may be close to a fact, but you get my meaning.

But working with alloy it’s something I want to learn. Just one more step towards casting knowledge. Thanks again, Bill.

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Lucky1 posted this 21 July 2025

Hi Bill, I've been using bulletmatch.com to customize my alloys. Saves a lot of mental gymnastics on my part.

Scott Ingle

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Wm Cook posted this 21 July 2025

Thanks for that! Good place to crunch numbers.

Now can anyone shed some light on ratios of antimony to tin ratios or is that all subjective. I.E., everyone has their own opinion and the decision for ratios is subjective? Trial & error? I’m 75 now so I am carrying an expiration date on my butt.

Believe me when I say I’ve been spoiled even more than the Brittany’s I used to hunt behind by casting with Linotype. It’s hard to argue with alloy that cast bullets that look & weigh like Linotype does.

But something happens when bullet obturation occurs. This is compounded when you study terminal performance on game.

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Tom Acheson posted this 21 July 2025

Not sure if it was here in the forum or in The Fouling Shot but my memory says John Alexander was gravitating to a softer alloy.

For years I shot nothing but gas checked CB’s in my revolvers, completely oblivious to what the Plain Based Bullet rifle guys did by avoiding muzzle velocities above 1400. A few of my loads approached 1200 but most were between 900 and 1100 fps. Today I only use softer, non gas checked bullets in my wheel guns.

So for me I too have been drifting towards the softer side of the street. In recent years the two rifles I spend the most time with are a Model 74 Sharps and a CPA, both older design single shots. The softer the alloy, the better the accuracy. The softest so far has been 30:1. But the breach seating of the CPA really wants a soft alloy.

FWIW

Tom

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Wm Cook posted this 21 July 2025

You are right.  John shot 25-1 in the 21, 22 and 23 Nationals and in those three years his 100yd average agg'd .998 while lolly gagging along at a blistering 1450fps.  Mr Alexander cuts his own path.   

Other than Dale Flinchum in 2024, all the other .223 shooters in the past four years were in the 1700 to 1850fps ballpark.  And half of them were using Linotype.  The rest were using either #2 or a blend just softer than that.  The majority were shooting NOE 79gr. 

I bet you a dollar to a doughnut hole that if you asked the folks here on the forum what was expected in BR competition with the NOE 227-79 out of a .223 most would think Linotype and + 1850fps.  At least I would have thought that.  But I'm not that smart.  It won't transfer to 30 cal's in Heavy and Unlimited because the tiny groups shot out of the 30BR's at +2000fps wouldn't be possible. But in the Production class....????

I'm shuffling casting furnaces at the moment and converting my ladle casting from the little Lyman's to the 20# Lee's.  I don't know if I'll be around long enough to give it a go but from what I think I see with my K Hornet, I think I have to give soft ally a go with both my .222 and the K Hornet.  Thanks for letting me think this through.  Bill C.      

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Glenn R. Latham posted this 21 July 2025

Bill, I've found the "little bores" (22 and 6mm) to shoot much higher velocities with soft bullets than the 30s.  I can shoot air cooled wheel weights to 2300-2400 fps in the 22 Hornet (16 twist) and 223 (14 twist) with good accuracy.  In the 6mm (10 twist) I heat treated WWs and then drew them back to 15 BHN and shot them at 2050 fps with good accuracy.

Glenn

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Wm Cook posted this 21 July 2025

What bullet and alloy were you using in your Hornet Glenn?

This is off topic but can anyone explain why the power’s to be made 14 - 16 twist standard on the Hornet. Even NOE’s 60gr FP keyholes.

After more than a couple thousand rounds through the K Hornet I‘m getting leading with #2 with velocities over 1800. Or at least I think that’s the reason. I’m using LBT blue and having a heck of a time getting the lead out.

Does anyone know Randy at Connecticut Precision Chambering? I was thinking about a new barrel. I called but his old number’s not valid any more.

Apologize for the diversion. Bill

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Glenn R. Latham posted this 21 July 2025

Bill, I've shot the Lyman 225438 and the RCBS 22-055-FN.  Best load with the Lyman is 9.0 of RL-7 for 2015 fps.  With the RCBS bullet best load was 11.0 of Thunderbird 680 for 2417 fps.  Don't know how it compares to AA1680.  Most of these loads were shot at 50 yards and accuracy was just sub-1" in the Lyman Mini-Sharps.

Glenn

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RicinYakima posted this 21 July 2025

The original Hornets were made on Springfield Armory Model 1922 training rifles in 22 LR. The twist was 1 - 16 as that was best for the 40 grain LR bullet. 

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shootcast posted this 22 July 2025

You can find on the web a reprint of E.H . Harrison. I had heard of his writing but never found the article. I was amazed when reading this. Everything he stated that I have done is right on. I wish I had read it twenty five years ago. His work was with the 30-06 military. Very good reading. Google it. 

I have never been one of our top shooters. I have a pretty good stash of w/ Wts. And so use them. I do blend them with Lino and possibly tin. I have fooled around with air cooled and quenched and oven heated and quenched. Have tried to match alloy BHN to pressure. Using my blends I have never reached more than 1950 FPS with any kind of accuracy. I have thought on many occasions that I found the alloy. Worked good until match day. Finding consistency that repeats time and time again is the key. It usually comes much quicker with Lino. Simply the best alloy for casting. Better bullets normally mean better accuracy. Softer alloys can shoot well but not at the top velocity. What I have found you have to give up velocity by several hundred feet. Lately because of high prices and not being able to get what you want, I have switched back to old school.shotgun powders at lower velocity and even plain base bullets. You don’t give up much at 100 yards. It does show at 200. 

 

 

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