.30-78

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  • Last Post 17 February 2012
Uncle Russ posted this 01 November 2011

:):thinking:OK Lads, enlighten me. Read the article in the Book of Wildcats. Seems like another version of the .30 Johnson. Why don't I see more of either of these when the pictures of the groups shot are almost unbelieveable. Is it because it is a wild-cat? Seems to me its only draw back is resale but I hardly ever sell anything unless someone begs me for it. A chamber reamer is a chamber reamer, the guy making it just follows a different drawing. So it can not be reamer cost. And a custom built rifle is a custom built rifle regardless of chambering. So what's the deal?

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CB posted this 02 November 2011

Wildcats are generally made from a base cartridge already in use in a particular rifle, not necessarily because of any inherit accuracy of that particular design. All accurate cartridges have two or three dimensions in common and that is 90% + powder capacity for a particular bullet weight, powder and velocity. An accurate cartridge will have nominal dimension in the neck area where the bullet is supported at ignition and also a correct throat for a particular make or designed bullet.

It appears to me that the 30-78 was intended for single shot rifles with blocks and extractor already cut for the 30-30 base size, thus a shorter version and more efficient and accurate cartridge. The modern competition of CBA matches are mostly using a bolt action rifle with a rimless cartridge size and extractor for the 308 Win base. The 30-78 cartridge would fall into the ASSRA form of rifles and competition, but the 30 Miller and 30 Miller Short have now shown their dominant accuracy potential in the ASSRA matches”¦”¦”¦.Dan

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joeb33050 posted this 02 November 2011

It is not clear that cartridge size/volume has much to do with accuracy. Looking at CBA match results 2005-2009, PRO class 308 Win, HVY and UNR classes 30BR/308 X 1 1/2, we see, for 5 and 10 shots, 100 and 200 yards, all summed: 308 Win. 1.452 moa HVY 1.040 UNR 1.035 (See the book for the article.)

So 30BR shoots groups ~ .71 X 308 Win groups in rifles that have substantially more bells and/or whistles. The only reports I have found about accuracy vs. case volume are the original John Ardito reports where he used one barrel.

It may just be that smaller case volumes make shooters FEEL more accurate, but don't make them SHOOT more accurately. joe b.

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joeb33050 posted this 02 November 2011

It is not clear that cartridge size/volume has much to do with accuracy. Looking at CBA match results 2005-2009, PRO class 308 Win, HVY and UNR classes 30BR/308 X 1 1/2, we see, for 5 and 10 shots, 100 and 200 yards, all summed: 308 Win. 1.452 moa HVY 1.040 UNR 1.035 (See the book for the article.)

So 30BR shoots groups ~ .71 X 308 Win groups in rifles that have substantially more bells and/or whistles. The only reports I have found about accuracy vs. case volume are the original John Ardito reports where he used one barrel.

It may just be that smaller case volumes make shooters FEEL more accurate, but don't make them SHOOT more accurately. joe b.

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32ideal posted this 02 November 2011

Joe for once I agree with you on something, It is not clear that cartridge size/volume has much to do with accuracy.but maybe not completely for the reason you used.

THE CAST BULLET you produce and its fit to your rifles/pistol's bore and chamber are far and away more important than case capacity, maybe the alloy you use should be included as one of those factors also. 

The reason I enjoy the CBA competition/match's is because the playing field is leveled, YOU have to cast/make/lube/size the projectile, all the $$$ you can throw at the rifle, barrel, stock whatever will not help a poorly cast bullet shoot accurately, last but not least, everyone I have met in the CBA will share their winning list of items they use with everyone else.

I am not saying you can shoot a Junker and win CBA match's, but take a look at the scores and groups being shot with pre WWI, WWI & WWII military rifles (I am not calling Military Rifles Junkers by the way my 03 shoots as well as my eyes can see those tiny sights), the case capacities on most of those are rather large with generous chambers and throats, but with the correctly made and Fitted CAST bullet those rifles shoot amazing scores and groups.

Me I'm a poor judge of wind, so I will never be as good as most of CBA competitors, I like casting my bullets and playing with different moulds, making the BEST lube in the world in my kitchen and a fine/accurate rifle/handgun as it seems CBA competitors members do.

This is just my opinion with a few proven facts, so Uncle Russ, if a 30 Johnson or 30-78 would make you or someone else more confident in the rifle, I'd say everything else being equal and correct it would more than likely shoot better for you!

32ideal

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Uncle Russ posted this 02 November 2011

Thank you Gentlemen: Your comments are greatly appreciated and soaked up like a sponge. Many good thoughts to ponder. With all that in mind, my next choice would be the >308x11/2. I live in the world with RicfromYakima. He is one great coach so I keep trying! :thumbsup:

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RicinYakima posted this 03 November 2011

Hey Uncle Russ, nice to see you on the BB!

Like the others, I don't think it is the volume, but a carefully made reamer used correctly to make a chamber that is in line with the bore.

My theory is that a bullet that is centered in the bore when the cartridge is ignited is more accurate than one: a case laying on the bottom of the chamber, the chamber is off axis with the bore, the centerline of the bore is not the center line of the bullet.

I also theorize that a bullet that is off axis (tilted) when the primer is ignited will never straighten out and will remain off axis forever.

So, I also think cases with long necks and smaller capacity will be easier to make shoot case bullet than otherwise.

Ric

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Brodie posted this 03 November 2011

Ric; I agree with you wholeheartedly, wouldn't this also indicate that a bullet with a bore riding front section-that fits the bore closely-tend to be more accurate than a non-bore riding bullet in the same chamber. Brodie

B.E.Brickey

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RicinYakima posted this 03 November 2011

I think the word is “tend” because it is hard to find a straight nose on the bullets. My moulds don't make bullets that are really round or straight, but we work with what we have. My best accuracy comes from bullets with about 40% to 50% bore ride and the rest bands, and fast taper nose (311284,311299,311679). With a custom throat or tapering you may get something different. Also I shoot mostly Springfields, so I can't do better than Armory chambers and barrels.

Best wishes, Ric

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Uncle Russ posted this 03 November 2011

Ric is on me like a chicken on a June Bug! Ideas on where to find articles and info on .30 Miller and .30 Miller Short. Also more on the .308x11/2. Now I'm kinda leaning that way for several reasons. Still think rounds made up on .30-30 brass are nifty. Just hard to find a platform to try them on.
You guys ever watch a guy put 10 rounds in one hole with a Springfield 03 @ 100yds? I watched Ric put in five and ponder. I told him “You'll never know unless you try". So he dumped in 5 more. Good day shootin'. I was impressed.

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RicinYakima posted this 03 November 2011

Uncle Russ,

The American Single Shot Rifle Association has a web site with a lot of Schutzen stuff, so I'd start there.

Ric

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32ideal posted this 03 November 2011

Uncle Russ,

My CBA target shooting with cast bullets has been about 90% breech seated plain base bullets over the last 5-7yrs so I do not think in terms of neck to throat concentricity as I once did, I spend time on the ASSRA site also and have many shooting friends that also breech seat and some that shoot the 30BR (308x1 1/2) and some production class rifle shooters.

Most of my buddies shooting PB CPA rifles are using the 32-20CPA round, it is the 32-20wcf case using bullets .321-.322” diameter & bullets around 200-225gr weight and are doing very well in the PB class in CBA match's, some are also using the 32 Miller short, most I have spoke with like the 32-20wcf case for ease of case production, just neck it up and trim. Powder of choice for the 32-20CPA right now seems to be AA 4100.

I shoot the 32 Ideal case in a CPA, but my main heavy match PB rifle is in 32-40 Winchester caliber and it seems to hang with the smaller cases when I do my part.

The best part of picking a new caliber is the re-done or new rifle/barrel that goes with it along with dies/tools and the learning we all gain by trying something new and different.

Good luck with whatever you choose Uncle Russ,

32ideal - Mike

 

Uncle Russ wrote: Ric is on me like a chicken on a June Bug! Ideas on where to find articles and info on .30 Miller and .30 Miller Short. Also more on the .308x11/2. Now I'm kinda leaning that way for several reasons. Still think rounds made up on .30-30 brass are nifty. Just hard to find a platform to try them on. You guys ever watch a guy put 10 rounds in one hole with a Springfield 03 @ 100yds? I watched Ric put in five and ponder. I told him “You'll never know unless you try". So he dumped in 5 more. Good day shootin'. I was impressed.

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EdS posted this 03 November 2011

For many years I shot in J-boolit benchrest matches with a .308 chambered 0.020” short, resulting in a case length of 1.805". The nice thing was that I could make my dies by cutting 0.020” off the bottom of a good set of competition dies (Redding). I'm not sure how much you could cut off of dies before the body taper started working against you, but at 1.805", I got a nice “fitted” case in my chamber. I hope this helps. Ed

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EdS posted this 03 November 2011

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frnkeore posted this 17 February 2012

Let me add this regarding case capacity that equates to loading density.

First, that 71% will win a match hands down. when we shoot in matches, sometimes they're won by just a few thousands.

I've shot in ASSRA matches since '85 and shot in CBA matches from about '88 untill at least '95.

I study match results at every opportunity and this is what I see.........

308's shoot at 1400 - 1800 fps, a lot of winners are near the 1600 fps mark.

30 BR's and wild cats shoot at 1800 - 2100 fps and have a substantial wind drift advantage. I can't prove this but, I believe they have a more even pressure rise and more stabile barrel vibrations (my theory only).

A off shot is much more common with a 308 Win as opposed to the 30 BR.

Loading density is much less a problem with breech seating. You can still get those winning scores and groups with the full size 32/40 case but over a years time, more short cases win than larger ones. that could be in part to their being more short cases shooting matches now but, a couple of weeks ago, a 32/20 CPA case shot a .562 ten shoot group @ 200 yds in Modesto, CA.

Frank

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