Boolit Length

[mag_01]

I have always thought that the longest boolit (longer bearing surface) would give the best results in some cartridges like 308---7.62x54---K-31---303-- or dose it really come down to twist rate as well as other factors ?

[piwo]

I have always thought that the longest boolit (longer bearing surface) would give the best results in some cartridges like 308---7.62x54---K-31---303-- or dose it really come down to twist rate as well as other factors ?

There are so many factors that determine what is most accurate in any given rifle, that there just isn't enough room to discuss them thoroughly. The Benchrest crowd is the leading edge of accuracy, probably in the world. Controlling harmonics is paramount: almost everything benchrest shooters do to their rifles and their ammunition is done to provide consistency that dampens harmonics. In some rifles, the long bearing surface will provide superior results: in others, it will not. In some rifles, it will provide superior accuracy at short or intermediate distances, but completely fall apart at longer ranges. Shooter, rifle and ammunition must all be fine tuned to provided "extreme rifle accuracy", and barrel twist, length, projectile configuration are just a few. If one wants to read an older book on what determines accuracy, read “The Accurate Varmint Rifle" by Boyd Mace. You will learn more about what makes rifles accurate by this book then any other single source I can think of.

I am fortunate to be a member of the Benchrest Rifle Club of St. Louis. Our club has several members who own world records. Ron Hohn has won the civilian US championship several times and is readily accessible at our club. The late Art Freund, one of the founding fathers of Benchrest was also a founding member of our club, and died with several records still to his name. He is mentioned in Sierra's reloading manual on the history of benchrest, and was also a legendary benchrest gunsmith. I am blessed to own a "hunting" rifle assembled by him just before he quite building rifles. This rifle, built on a simple Remington 700 action, has recorded a 3 hot group of .395 inch group... AT 300 yds!!! Not bad for a hack like me...

If you want to know what makes rifles accurate, I strongly recommend you read the book. It's well worth the time, even though it's over a decade old. Not bad reading in the cold, winter months…..

[PAT303]

I have a mk III enfield that will shoot 100 grn 32/20 bullets that are 1/2 inch long into 1 1/2 at 100 meters,and then will shoot 225 grn that are 1 5/16'' into the same group. An old feller at the club said it was impossible until I did it. pat

[Maven]

It is a combination of many things, but twist rate & bullet length can't be ignored. I.e., twist rate sets a limit on how long/heavy a bullet can be in order to be stable/fly accurately. On the other hand, I don't think such formulae (Greenhill, e.g.) tell us how SHORT/light a bullet needs to be in order to be stable/accurate. In short (no pun intended), the Lee 113gr. soupcan, sized properly of course, is accurate in rifles with twist rates that will also stabilize ~200gr. bullets: It is supremely accurate in my K-31's, but so is the 195gr. Ly. #311644.

[JeffinNZ]

PAT: I think you mean "an expert" at your club said it was impossible.....
1 in 10 twist in .303 British will stablise a bullet up to 1.35 inches in length. That's a LONNNNNNGGGG bullet and about 250gr in lead.

[PAT303]

Jeff I don't know what it's like in NZ,but we have plenty of ''experts'' over here that disagree with every thing.

[Bass Ackward]

There are two ways to utilize or maximize or minimize twist rate how ever you want to look at it. One is bullet length. The other is meplat size. Larger meplats require more twist to stabilize. The problem is where to draw the lines between meplat and weight as a compromise.

But since pressure on the base of a bullet is cumulative and negatively affected by bullet weight and faster twist rates anyway, I prefer a shorter / lighter bullet and a descent (60%) meplat. This will allow higher velocity. But again, where is the compromise. Slow it down too much and you lose stabilization again.

[mag_01]

Meplat------ ?----- not in dictionary-----Boolits composition ?

[Ricochet]

The flat place on the nose of the boolit.

[Finn45]

The landing area for the game on sight...

The flat place on the nose of the boolit.

[mag_01]

Thanks guys

[Edward429451]

Maybe that's been the Mini-14's problem all along. Wrong twist? All our Mini's are 1-7" and never been fed anything longer than a 55 gr bullet.

Another Bill Ruger joke to go along with his no one needs more than 5 rounds philosophy?

[piwo]

Maybe that's been the Mini-14's problem all along. Wrong twist? All our Mini's are 1-7" and never been fed anything longer than a 55 gr bullet.

Another Bill Ruger joke to go along with his no one needs more than 5 rounds philosophy?

It is the Mini -14's problem exactly! It was assembled with the wrong twist to stabalize the light bullit the military uses, and is most commonly used. It requires a heavier bullet. WORD......... Chief AJ used to do accuracy work in this area for M1A's and mini-14's ( he was a long time Marine armorer in another life). With use of the heavy .223 bullets, they actually did shoot much better!

[Edward429451]

Would I be wasting my time to try premium longer bullets in my Mini? Are the 77's even mag length compatible?

[Larry Gibson]

Would I be wasting my time to try premium longer bullets in my Mini? Are the 77's even mag length compatible?

The original Mini14s with 1-10" twists were actually quite accurate with bedding and a trigger job. They shot very well with 50 to 64 gr bullets. Made the mistake of trading mine and then went through several disappointing "new" Mini's with the 1-7" twist.

Larry Gibson

[piwo]

Would I be wasting my time to try premium longer bullets in my Mini? Are the 77's even mag length compatible?

OAL for the case will determine, and I think you'll be OK. Don't load it longer then OAL recommended, and with a shiny pair of jap calipers, determine how far seated the bullet is in the case with it. If it's into the shoulder of the case, probably not good. But I doubt it will be, so what you will be doing is just seating more bullet in the neck and that's not a problem.

I really think you'll be fine since that's what Chief AJ did, was shoot the 77's.