The FR Range: Weekly Thread for March 5th, 2004

FR | 3/5/2004 | Longcut and risk

[risk]

I don't know about all of you, but two issues have continued to stay on my mind over the last week. There has been violent abuse to the English language, and to our laws. This has come with the left's anarchistic redefinition of the word "marriage." But it should come as no surprise! Given the carelessness that our politicians treat the language in our second amendment, their wanton disregard for the phrase, "shall not be infringed" is where it began. I think it started in 1934 with the machine gun ban, and continued through the 1968 gun control act, and carried on with the 1986 firearms protection act and the Clinton "Assault Weapons" Gun Ban. Joe Brower and others have continued to post articles and information about the situation with Senate Bill 1805. The keyword AWB has served as an excellent cookie for finding these posts. Please keep them coming.

People, when they come for our battle rifles, it's too late. We have to fight for our Republic with every political tool we have left. That's why I'm trying to follow in big footsteps here on FR by starting this weekly thread. If Rosie O'Donnel can abuse us with her cries for "rights," then we can surely fight a crusade for the upholding of a sacred, existing constitutional amendment.

I'm posting in news/activism this time, and

not as a vanity. I hope this is acceptable. Counsel otherwise is welcome.

[risk]

ping

[Woahhs]

Well it's about damn time!

I was ready to start the milk and cookies instead of waiting for the friday night gun porn thread.

[Eastbound]

Hi, risk! Well, I'm still waiting for an answer about my twist question. Let me repeat it. Maybe somebody will answer.

M1's for example, have barrels that have 1 twist in 10 inches; 1 twist in 11 inches, and 1 twist in 12 inches.

Just trying to find out why? Thanks.

[risk]

I took the bait and followed http://www.google.com/search?q=barrel+twists to see where it might lead (again). I came across this interesting link: What is the Meaning of This Thing Called "Barrel Twist"? by Dick Culver.

Here's what I can come up with after a few minutes of reading. I see several factors involved:

1. Projectile weight, material, and density.
2. Propellant compound and amount.
3. Breach construction.
4. Barrel metalurgy.

Putting these factors together we set three often conflicting goals:

1. Bullet stability (spin, trajectory, and lack of tumble).
2. Bullet speed.
3. Barrel life.

Compressed twist ratios lead to slower but more stable trajectories; they also lead to barrel wear! So you want to find a sweet spot for projectile weight, propellant, and barrel material. Of course your goals of accuracy and range are significant.

I would say you'd want to talk to your gun smith to find out for a given M1 (for example) what would serve your needs best. For me it would probably be longevity of my equipment.

[Eastbound]

Great, risk. Thanks a lot! I'll read up on it.

[Shooter 2.5]

There are three fights going on for the CCW laws. Kansas and Nebraska are trying to turn their state into a "Shall Issue" State from a "Rights Denied State" New Hampshire has introduced legislation that would allow any law abiding citizen of the state the ability to carry a CCW without the licensing procedure.

From some stupid reason that defies all logic,[which is so typical] the anti's seem to blame Texas for the CCW laws. They don't understand the history of the recent laws which states the Florida resurrected the trend.

Since they blame Texas, they use inflated statistics to show that Texas has a higher conviction rate among license holders. It's so false that the Texas Department of Public Safety which overseers the licensing requirements had to publish the true rates.

They are here:


http://www.txdps.state.tx.us/administration/crime_records/chl/convrates.htm

[Who is John Galt?]

I see several factors involved...

I believe air temperature may be a factor as well. IIRC, the military went to a fast twist in the M-16 barrel in part because they wanted decent accuracy in arctic conditions. But if you're not going to be feeding your AR-15 tracer ammunition at 30 degrees below zero, you might get by with a slower twist...

[Atlas Sneezed]

When you post

to the bang list

don't forget

your ass-to-risk!

(Burma Shave)

[SAMWolf]

[ExSoldier]

Bump for later

[absalom01]

  Here's a bit more along these lines (the math is kind of interesting):

The needed rate of twist is effected by the diameter of the bullet and the bullet's overall length. Longer bullets need a faster twist to stabilize. As an example, a 1:12 twist in .30 caliber will adequately stabilized most commercial bullets of up to about 200 grains. To use a heavier (longer) bullet or to obtain optimum stability and accuracy with long pointed or boat tailed bullets of that weight requires a 1:10 twist. For best accuracy the slowest twist that will stabilize the bullet should be used.
...

There is an old formula called the Greenhill Formula that, while it was designed for estimating twists for boat tailed lead core bullets of moderate velocity, does a pretty good job of estimating twist required for flat based bullets under "normal" conditions.

T = Twist in inches
K = Greenhill's constant = 150 (This has to do with the specific gravity of a jacketed lead bullet)
D = Bullet diameter in inches
L = Bullet length in inches

T = (K * D²) / L

Using a 1.35 inch long .308 bullet (200 gr) and crunching the numbers we get about 10.5 (One turn in 10.5", which is pretty close to the 1:10 twist normally used in .30-06 rifles. The twist for the .308 is nominally 1:12 because it was based on the shorter bullet of  the150 gr military ammunition from which the .308 commercial round was developed. Most match rifles in .308 have a 1:10 twist to stabilize the 180 and 190 boat tailed match bullets better. The results from the Greenhill formula are on the conservative side--indicating a faster twist than probably needed. That doesn't cause any problems because a little too much stabilization is better than too little.

...

More at the source.

[Eastbound]

Thanks for the great link. Somehow I get the feeling that the more I get into this, the harder it is going to be to get back out. Y'all have answered my question in fine style and saved me from maxing out my credit card unnecessarily.

[risk]

LOL, Burma Shave messages were at least fit for a family forum!

Leaving the * off of *bang_list was a cut and paste error, which reminds me: we lack a ping list maintenance feature on Free Republic. A list could be owned by one or more people, and anyone could opt in or out of it; to be complete, the list owner would have to approve adds. To be really complete, only the list owner and his designated appointees could either ping that list or see its contents.

[risk]

Kansas and Nebraska are trying to turn their state into a "Shall Issue" State from a "Rights Denied State" ... New Hampshire ...

It makes me wonder why don't we challenge the lack of shall-issue here in California using the second amendment? Or the Kali AWB?

[risk]

Excellent point in that cartoon, SAMWolf. We have chaos throughout our society (as Rosie O'Donnel demonstrated on the steps of our courthouse), and plenty of serious problems legislators could be solving. Instead they are trampling on our constitutional rights -- all the while terrorizing naive votors into believing their labor of tyranny is essential to the public good.

P.S. Running a weekly gun thread with you guys is too easy. I just sit back and wait for the good posts!

[SAMWolf]

[hardhead]

Okay, here goes. I publish gleaned news links (Monday through Friday) in a newsletter called Liberty Watch. It is primarily concerned with loss of Constitutional rights, but also covers judicial-government-political-societal corruption, globalization, preparedness, greens and the environment, our borders-language-culture, science and technology, and health and medicine. It contains no commentary or feedback, just the news. Its a quick compendium of the really important items, out in the mail by about 0800 MST, give or take an hour. You can subscribe by sending a blank e-mail to millennium@mail2webmaster.com with 'Liberty Watch' in the subject line.

[absalom01]

...saved me from maxing out my credit card ...

A temporary condition, most likely. Long range shooting is a whole lot of fun, but man, it can really break the bank. Optics, re-loading equipment, rangefinders, "accessories", ammo, add it all up and the rifle is practically a footnote to the financial equation. If you choose well, it'll last a lifetime (no, I don't buy into the notion that you should re-barrel every x thousand rounds as long as everything is working), but the expendables are a constant drain on the old wallet.

[absalom01]

From some stupid reason that defies all logic,[which is so typical] the anti's seem to blame Texas for the CCW law.

Uh, illogical and dishonest, yes. Stupid, no. It's a Bush-bash -- plain and simple. Remember, Josh Sugarman started out his advocacy career with his "right wing watch" organization before he lit on the notion of creating the VPC. He's a partisan puke from the git-go, and remains so today.