I am confused

Lyn P

Lyn P

New member
I am very confused, does anyone check .224 bullet lengths, velocity and barrel twists. Starting with 50 gr and 55 gr on plastic tip bullets for following; Hornet, 221 Fireball, .222 and .223. Any of the other .224 I did not check, but if they are above 3400 fps should not be issue. I have found number of different twist calculators by the following William F. Davis, Bowman-Howell, Bob McCoy, Greenhill, and the newest one by Don Miller. Of the course everyone states they have the best. Some are very old and served us very well over the years. For years I have used 55 gr Blitz Kings shot out of 1:12 Ruger KM 77VT MKII. The 55 gr I have chronograph between 3150 to 3250 fps depending on powder, temperature, ect, ect. I have never seen any problem with 55 gr. Blitz Kings and my .223 @ 3250 fps. Most talk about a “Stability Factor” should be above 1.2 up to 1.5. I have look for bullet lengths on the internet and found some to be incorrect. The best way is to measure at least 10 from you stock. I measured 55 gr Blitz Kings at .826. They will vary from lot to lot, but a couple of thousands will not matter. If I use William F. Davis with calculator on my Ruger using stability factor of 1.2 it requires 11.29 twist. If I use the Miller calculator it states the stability factory is .999. Miller uses color code, red at below 1.0, yellow is above 1 up to 1.3 and green is above 1.3. If you use V-Max they maybe a little shorter, but would make very little difference. If you are using a Hornet most I have 1:14 twist. Using a 50 gr .784 length Blitz King at 2500 fps Miller shows .709 stability factor. With 221 Fireball that may have 1:12 or 1:14 with same 50 gr Blitz Kings at a velocity of 2900 fps Miller shows a 1:12 @ 1.01 stability factor and with 1:14 @ .745. So at that do not even think about using 55 gr in the Hornet or Fireball. It is very good that my Ruger cannot read twist rate calculators. Now I have a Fireball I did find that Sierra 50 gr Blitz # 1330 is .673 long, and will work with Fireball. A friend of mine said some time ago he recalls a calculator that required the length if plastic tip. It reduced the overall length by some amount. This may make sense because tip does not weight as much as the rest of the bullet. Has anyone seen such a calculator? I have never heard of any stability issue with any 55 grain Plastic tip bullet from 1:12 above 2900 fps.
 
I found a paper that deals with Miller and adjusting it. You probably have read it.

PART #1 http://arxiv.org/abs/1410.5340

PART #2 http://arxiv.org/ftp/arxiv/papers/1410/1410.5737.pdf

Without a doubt the tip makes difference. Shooting 17 caliber Hornady 25's tipped and non-tipped gave me battleships or tiny groups. Same load,same gun.

Might I suggest you try and clarify your postings with some paragraph formation?

Greg

PS: Theory is great but it doesn't pull triggers. Barrels vary from one to the other. Rifling has an effect. With my BHW barrels tat Ritch uses I get faster velocities for same same loads and have found, anecdotally, I can USUALLY shoot one heavier weight for caliber than the formulas say.
 
Originally Posted By: GLShooterI found a paper that deals with Miller and adjusting it. You probably have read it.

PART #1 http://arxiv.org/abs/1410.5340

PART #2 http://arxiv.org/ftp/arxiv/papers/1410/1410.5737.pdf

Without a doubt the tip makes difference. Shooting 17 caliber Hornady 25's tipped and non-tipped gave me battleships or tiny groups. Same load,same gun.

Might I suggest you try and clarify your postings with some paragraph formation?

Greg

PS: Theory is great but it doesn't pull triggers. Barrels vary from one to the other. Rifling has an effect. With my BHW barrels tat Ritch uses I get faster velocities for same same loads and have found, anecdotally, I can USUALLY shoot one heavier weight for caliber than the formulas say.

Yes I did find that Miller has two different Calculator today. One is for non tip bullets like on Burger site http://www.bergerbullets.com/twist-rate-calculator/ if you it with tip bullets you are not close. That is what I was doing. The second one is by JBM it has a place to insert the tip length. If you measure the overall length and the tip length, it is as close as you can get today. http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

The JBM site will work for both tip and non tip bullets. JBM also uses pressure in place of altitude.
 
Originally Posted By: Lyn PI am very confused. Does anyone check .224 bullet lengths, velocity and barrel twists?

Starting with 50 gr and 55 gr on plastic tip bullets for following; Hornet, 221 Fireball, .222 and .223. Any of the other .224 I did not check, but if they are above 3400 fps should not be an issue.

I have found number of different twist calculators by the following William F. Davis, Bowman-Howell, Bob McCoy, Greenhill, and the newest one by Don Miller. Of the course everyone states they have the best. Some are very old and served us very well over the years.

For years I have used 55 gr Blitz Kings shot out of 1:12 Ruger KM 77VT MKII. The 55 gr I have chronograph between 3150 to 3250 fps depending on powder, temperature, ect, ect. I have never seen any problem with 55 gr. Blitz Kings and my .223 @ 3250 fps.

Most talk about a “Stability Factor” should be above 1.2 up to 1.5. I have look for bullet lengths on the internet and found some to be incorrect. The best way is to measure at least 10 from you stock. I measured 55 gr Blitz Kings at .826. They will vary from lot to lot, but a couple of thousands will not matter.

If I use William F. Davis with calculator on my Ruger using stability factor of 1.2 it requires 11.29 twist. If I use the Miller calculator it states the stability factory is .999. Miller uses color code, red at below 1.0, yellow is above 1 up to 1.3 and green is above 1.3. If you use V-Max they maybe a little shorter, but would make very little difference.

If you are using a Hornet most I have 1:14 twist. Using a 50 gr .784 length Blitz King at 2500 fps Miller shows .709 stability factor. With 221 Fireball that may have 1:12 or 1:14 with same 50 gr Blitz Kings at a velocity of 2900 fps Miller shows a 1:12 @ 1.01 stability factor and with 1:14 @ .745. So at that do not even think about using 55 gr in the Hornet or Fireball. It is very good that my Ruger cannot read twist rate calculators.

Now I have a Fireball I did find that Sierra 50 gr Blitz # 1330 is .673 long, and will work with Fireball. A friend of mine said some time ago he recalls a calculator that required the length if plastic tip. It reduced the overall length by some amount. This may make sense because tip does not weight as much as the rest of the bullet.

Has anyone seen such a calculator? I have never heard of any stability issue with any 55 grain Plastic tip bullet from 1:12 above 2900 fps.

Ok, broke that up a bit for readability but TBH most of what you have posted just seems like random info and as far as I can tell it boils down to:

"A friend of mine said some time ago he recalls a calculator that required the length if plastic tip. Has anyone seen such a calculator?"

If I'm missing the point, apologies.
 
Originally Posted By: Bob_AtlThe JBM www site also has a pretty good list of booolet length and tip length.
(for the lazy ones like me)
bored.gif

Yes I do use it - but be careful some length are wrong.
 


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