SO WHAT?

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Last Post 23 July 2018

CBA Member

joeb33050 posted this 21 July 2018

The event-a cartridge is fired-is fairly simple, easily explained and relationships represented with a set of numbers.

To estimate velocities of a given cartridge case/rifle/bullet over a set of charges, we could measure MV for each of the charges, OR, measure MV at the lowest and highest charges, calculate the slope, and interpolate the MV for each/any charge between.

The latter procedure requires less measuring of velocity.

For example, MV at powder charges of 5.5 to 8.5 grains with a given powder, bullet and cartridge case are of interest. I measure MV 13 times as my minimum sample size. The 13 measures X 7 charges = 92 measurements.

Or, measuring MV 20 times at 5.5 and 8.5 grains = 40 measures, plus 20 measures at 7 grains to check linearity = 60 measures that give a much more precise estimate of MV across the set of charges.

We can estimate MV for other bullets, cartridge cases, and barrel lengths.

With some chrono estimates of MV; we can estimate MV for any cartridge case, charge, and barrel length.

With enough data, we can find the relationships between accuracy and the variables; find out why cast bullets are not as accurate as jacketed and fix the cast bullets.

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joeb33050 posted this 21 July 2018

CBA NM records show that group sizes have remained sorta constant over the last 20 years. We don't seem to have made any leaps in the accuracy department. Some shooters come, some shooters go; mostly the same folks do the same thing over and over and luck plays a big part in outcomes.

In the Cast Bullet Association National Matches, from 1998 to 2017, 20 years, the 100-yard 5- shot 4-group aggregate has been below .5” only 36 times.

At the International Bench rest Shooters 2017 National Match, all 75 shooters in the 5-shot 100- yard 5-group Sporter match shot aggregates below .5”. Every single one.

Jacketed bullets can be shot more accurately, easier, than cast bullets.

Why?

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pat i. posted this 21 July 2018

Opinion? Bullet balance, bullet balance, bullet balance, wind. A round ball ML will never shoot as well as a cast bullet BR rifle at 200 yds although they're both shooting. I think trying to equal jacketed bullet BR results with cast bullets is an excersize in frustration. We're playing 2 different games so will have 2 different results no matter what anyone tells you that if you do everything exactly right, but don't tell you what that is or put themselves in a situation to prove it, you'll be shooting in the zeros. If no one has come along with any earth shattering improvements in 20 years using the exact same equipment as the jacketed guys maybe we're here to stay. No one really dominates any of the classes and everyone has the opportunity to win or place well so maybe we should just accept the fact that it is what it is and enjoy the game as it stands.

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Scearcy posted this 21 July 2018

Amen

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45 2.1 posted this 21 July 2018

Jacketed bullets can be shot more accurately, easier, than cast bullets.

Why?

Jacketed bullets have a hard jacket and a soft 2% antimony lead alloy. Here, you fellows like to use linotype (because it casts well). Hard bullets are a mismatch for the low velocity/pressure loads you're trying. Those same hard bullets are probably undersize for the rifles throat also, but that's what you want to shoot and that's ok............ just don't complain that it's not doing as well as you thought it would.

If no one has come along with any earth shattering improvements in 20 years using the exact same equipment as the jacketed guys maybe we're here to stay.

It's not that anyone hasn't improved the sport, because they have. They just don't play this particular game. It seems you guys have reached the limit with the loads, alloy, loading method and mold designs you've chosen. There are a lot of options among those things you haven't tried. Remember Edison tried 10,000 different filaments in electric light bulbs before he found what worked. All it means is you aren't there yet..... keep trying.

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pat i. posted this 21 July 2018

I don't think 28 or 29 grs of Varget or VV 135 in a 30 BR case would be considered low pressure with lead bullets. Please read the sentence I wrote immediately preceding the one you quoted. I feel this is a prime example. I also don't think questioning something is the same as complaining about it.

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45 2.1 posted this 22 July 2018

I don't think 28 or 29 grs of Varget or VV 135 in a 30 BR case would be considered low pressure with lead bullets. Please read the sentence I wrote immediately preceding the one you quoted. I feel this is a prime example. I also don't think questioning something is the same as complaining about it.

If you'll notice, I mentioned the low pressure reference was in reply to joeb33050's post. I never mentioned load intensity in reply to your post, but you probably should reread the reply to confirm that.

Edit: In addition to the above reply, I noted your preceding sentence.... and have little disagreement with it, but only responded to what I posted. In addition, Joe has been at this situation for quite a while. By inference, it seems he is somewhat frustrated with the developments he has tried.... without a decisive answer... thus the complaint (maybe too strong, maybe not... hard to decide without hearing the spoken word).

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pat i. posted this 22 July 2018

It's debatable what you were replying to since the quote you took out of Joe's post was related to BR shooting. Anyway so instead of the usual snipe and run tactic why don't you explain exactly what has to be done to break that 1/2 inch barrier. Or better yet why don't you sit yourself down at a BR match and do it? This ain't brain surgery we're talking about and the listening audience seems intelligent enough to get it without private lessons or PMs. Personally I'm all ears and can't wait to start pounding out those 1/4 inch groups.

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Standard Member

Geargnasher posted this 22 July 2018

Pat, he just told you one of the things you need to know to do better, right here in this thread. But you were devoting your attention to...something else instead of taking note and asking questions that might lead to something good.

The technology involving bullets cast from linotype alloy, bump-sized to fit the rifle's custom throat, launched with shotgun powder at 1600fps, was mature a very long time ago as Joe has pointed out, so why keep doing the same thing looking for improvement? This isn't NASCAR where the rules prevent any alternative technology to the status-quo...or did I miss it in the CBA rules that linotype alloy is required?

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45 2.1 posted this 22 July 2018

It's debatable what you were replying to since the quote you took out of Joe's post was related to BR shooting. I'm not interested in any debate with you. Joe can speak for himself without your help as he seems quite able to do that. Anyway so instead of the usual snipe and run tactic why don't you explain exactly what has to be done to break that 1/2 inch barrier. Really, that information has been in print for the last 100 or more years. It's fairly simple if you understand what they said. The proof in that is being able to do it. Or better yet why don't you sit yourself down at a BR match and do it? Give it a rest. I'm not interested in the matches CBA shoots. I have shot in quite a few matches, shot off a benchrest though and have demonstrated what I've talked about. Those aren't run by the CBA either. This ain't brain surgery we're talking about and the listening audience seems intelligent enough to get it without private lessons or PMs.Well, it doesn't show, they either can do it and are not talking about it or they can't and still aren't saying much. You might be interested to know some people here are doing that exact thing (undertaking private lessons) because they are stuck and can't advance......... Several people here have acknowledged that fact about the CBA (joeb did it in his second post on this thread as well as John's posts in another thread recently ) not showing any advancement in the last 20 years. It would seem that if you don't advance, you need to try something different. Personally I'm all ears and can't wait to start pounding out those 1/4 inch groups. I said 1/2 " groups aren't all that hard to get....... not 1/4".

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CBA Member

pat i. posted this 22 July 2018

As usual no concrete answers. I hope you take as much offense to what I'm about to write as intended. If BS was dynamite you'd be an atomic bomb.

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Geargnasher posted this 22 July 2018

Well.....continue to enjoy being stuck where you are then.

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45 2.1 posted this 22 July 2018

The point "pat i" is that this information is already out there, in print and on the internet. To use it, so you can do the same thing, requires some discernment on the individuals part as to what you see and believe. There isn't much light in some of it and little more in other areas. Use of linotype has reached a dead end as well as switching common bullet designs to try. You need a bullet that actually fits the rifles throat and has the correct temper to shoot more accurately than is currently reported in the CBA records. Until shooters see that they won't go to far.........................

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pat i. posted this 22 July 2018

Good God they're multiplying!!

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pat i. posted this 22 July 2018

The point "45 2.1" is its just the same old regurgitated vomit you've been spewing all over the internet for years with nothing to back it up except a worn out keyboard.