Intermarkets' Privacy Policy Support
Donate to Ace of Spades HQ! Recent Entries
Sunday Morning Book Thread - 10-06-2024 ["Perfessor" Squirrel]
Daily Tech News 6 October 2024 Saturday Overnight Open Thread (10/5/24) Music Thread: The Unbearable Lightness Of Messenger Bags Hobby Thread - October 5, 2024 [TRex] Ace of Spades Pet Thread, October 5 Gardening, Puttering and Adventure Thread, Oct. 5 What would Eric Hoffer, The Longshoreman Philosopher, be thinking about now? The Classical Saturday Morning Coffee Break & Prayer Revival Daily Tech News 5 October 2024 Absent Friends
Bandersnatch 2024
GnuBreed 2024 Captain Hate 2023 moon_over_vermont 2023 westminsterdogshow 2023 Ann Wilson(Empire1) 2022 Dave In Texas 2022 Jesse in D.C. 2022 OregonMuse 2022 redc1c4 2021 Tami 2021 Chavez the Hugo 2020 Ibguy 2020 Rickl 2019 Joffen 2014 AoSHQ Writers Group
A site for members of the Horde to post their stories seeking beta readers, editing help, brainstorming, and story ideas. Also to share links to potential publishing outlets, writing help sites, and videos posting tips to get published.
Contact OrangeEnt for info:
maildrop62 at proton dot me Cutting The Cord And Email Security
Moron Meet-Ups
|
« Food Thread: What Makes Everything Better? [fill in the blank] |
Main
| Sunday Overnight Open Thread (1/31/21) »
January 31, 2021
Gun Thread: Rifling Re-Run Edition! [Weasel]Howdy, y'all! It's Sunday, and we all know what that means, don't we? Why yes, yes we do! Sunday evening means it's time to climb up on your 'ol pal Weasel's knee and talk about guns, gun stuff and shooting. In the process, perhaps we can also forget about the retarded world we live in for a bit. Win-Win! For some reason, I have been getting a lot of email questions on rifling and barrel twist rates lately. Is something going on I don't know about? Seriously, in the last couple of weeks I've answered at least a half-dozen questions on this very topic, so perhaps it makes sense to cover the matter in a little detail tonight. It also occurs to me that we've had this discussion before, so I went back into the GT Archives, dusted off some previous material from June 2019, and added some new information. In other words, a Gun Thread re-run, with just enough new stuff to provide a veneer of legitimacy. Let's take a peek at that below, shall we? Cutaway 105mm Tank Gun Barrel Rifling There are four general machining techniques used to achieve the pattern of lands (high part) and grooves (low part); cut, button, broach and hammer-forged rifling. In "cut" rifling, an adjustable cutter is pulled through a cold barrel multiple times to make a single groove. The process is repeated until the desired number of grooves and depth are achieved. Cut rifling is an older and slower process, but results in very accurate barrels in the hands of a skilled machinist. The second is "button" rifling, where a very hard bullet shaped button is pushed or pulled through a cold barrel displacing metal to impart the desired pattern in a single pass. This is a more modern process which lends itself to mass production. Button rifled barrels can also be accurate. 'Broach" rifling is sort of a hybrid of cut and button processes. A broach is a metal bar with multiple cutters of increasing depth which cut the pattern in a single pass. Lastly, hammer-forged rifling is accomplished with a mandrel and rotary hammer forge. There are pros and cons for each method depending on the application and your budget, discussed in detail here and here. Q: Gee, Weasel, that's fascinating! What do you use in your match guns? Q: Excellent choice for accuracy! How about all of your other guns? Here's a look inside a couple of rifle barrels using a borescope. Regardless of the rifling process used, a key element is the twist rate, or the distance along the length of the barrel it takes the rifling to make one complete revolution. This twist rate should be stamped on the barrel, but can also be measured at home with a cleaning rod. Without delving into a whole lot of math and aerodynamic theory, the twist rate is important because different combinations of bullet design factors require different amounts of gyroscopic spin created by the rifling to properly stabilize them in flight. It is not, as stabilization charts would imply, solely the weight of the bullet that makes a difference, but also length and several other factors including muzzle velocity and the bullets ballistic coefficient. The general rule is longer and heavier bullets require more spin or "faster" rifling to stabilize them. Ammunition manufacturers list the bullet weight on the packaging and that's what is used to generally group bullets in stabilization charts. For the aspiring Rocket Surgeons out there, a number of online stabilization calculators are available which are useful for determining if a rifle will stabilize a particular bullet. Here's one from Berger and another from JBM Ballistics if you're curious and have some basic information on a particular bullet. Both of these use the Miller Twist Rule and the required inputs can usually be found buried somewhere in the bullet manufacturer's website. The Berger calculator helpfully contains a library of their bullet specifications, but if you don't know what bullet you're using and the necessary data, just stick with a chart. Why look! We have one right here! Sample 5.56mm Stabilization Chart So why am I telling you all this? Very simply put, if you are wondering why some ammo shoots well in your rife while other ammo doesn't, it may be that you have not correctly matched a particular bullet and load to your rifle barrel twist. If you under stabilize a bullet or spin it too slowly it will not fly true and may begin to tumble (not good), and if you over-stabilize or spin a bullet too bigly, the jacket can separate and the bullet will disintegrate in flight (very not good). Scroll down in the following articles here and here for recommended bullet weights by caliber and twist rate. A good article on the topic of barrels from Bear Creek Arsenal was sent to us by our pal redc1c4. Since a video is worth a thousand words, here's an explanation of the hammer-forge process by a guy with an accent. Well this is pretty wacky, here's accent guy again! Who needs grooves and lands? Forget all that crap I said up there and just get one of these. First up, our pal and delightful 'ette Ladyl recently took the plunge and became a crazed gun nut. I think hearing other people's stories helps those considering gun ownership, and Ladyl was kind enough to summarize her experience for us. I recently bought my first firearm, a Glock 43X. It was a purchase I wasn't enthusiastic about at first, having lived my many years without being around guns. After my husband died, my younger brother had encouraged me to arm myself and even gave me a generous gift certificate to a local range. That certificate expired, unused, many years ago. I know for a fact Ladyl can shoot - I've seen her with a rifle making a steel plate at 500 yards look really stupid! Thank you Ladyl! So! You left your favorite pistol out in the rain for a few years, and have a little rust problem. I have to say I'm a little surprised the thing came out looking as good as it did. You will notice, however, there wasn't a demonstration of the pistol firing afterward and I would be very leery of what that barrel looks like in the inside. Clearly this is an extreme example, and it emphasizes the wisdom of not storing your firearms outdoors and generally preventing corrosion in the first place. Do any of you have experience restoring firearms? Our pal OldBlue was recently looking for a shooting diagnostic chart to correct a low right/left pattern in shot groups which had developed. While I was fooling around trying to find one I had shown here before, OldBlue looked online and found a good one! Thanks OldBlue! Link-O-Rama I'm really very seriously not kidding around anymore. Buy Ammo This is awesome on just so many levels [h/t JT] Please note the new and improved protonmail account gunthread at protonmail dot com. An informal Gun Thread archive can be found HERE. Future expansion plans are in the works for the site Weasel Gun Thread. If you have a question you would like to ask Gun Thread Staff offline, just send us a note and we'll do our best to answer. If you care to share the story of your favorite firearm, send a picture with your nic and tell us what you sadly lost in the tragic canoe accident. If you would like to remain completely anonymous, just say so. Lurkers are always welcome! That's it for this week - have you been to the range? | Recent Comments
Dr Pork Chops & Bacons:
"Even taking government "efficiency" out of the equ ..."
Wolfus Aurelius, Dreaming of Elsewhere [/i] [/b]: "Regarding the wipers, it's not the hook on the Bui ..." Florida Peasant : "Every time I see one of those things I think of th ..." Divide by Zero [/i]: " I think it was the Presbyterians who ended every ..." screaming in digital: "My Mom went through some sort of spiritual journey ..." Wolfus Aurelius, Dreaming of Elsewhere [/i] [/b]: "[i]Wifey has a dead headlight in the Miata and the ..." Skip : "German vehicles of every kind got a Sdkfz number d ..." Unknown Drip Under Pressure: "[i]Every time I see one of those things I think of ..." screaming in digital: "If these areas and communities have any resiliency ..." Dr Pork Chops & Bacons: "Here's one of my favorite versions of "Ave Maria". ..." Unknown Drip Under Pressure: "[i]Western policy makers should note that he didn& ..." Divide by Zero [/i]: " [i]I love 'How Great Thou Art'. I want it sung a ..." Recent Entries
Sunday Morning Book Thread - 10-06-2024 ["Perfessor" Squirrel]
Daily Tech News 6 October 2024 Saturday Overnight Open Thread (10/5/24) Music Thread: The Unbearable Lightness Of Messenger Bags Hobby Thread - October 5, 2024 [TRex] Ace of Spades Pet Thread, October 5 Gardening, Puttering and Adventure Thread, Oct. 5 What would Eric Hoffer, The Longshoreman Philosopher, be thinking about now? The Classical Saturday Morning Coffee Break & Prayer Revival Daily Tech News 5 October 2024 Search
Polls! Polls! Polls!
Frequently Asked Questions
The (Almost) Complete Paul Anka Integrity Kick
Primary Document: The Audio
Paul Anka Haiku Contest Announcement Integrity SAT's: Entrance Exam for Paul Anka's Band AllahPundit's Paul Anka 45's Collection AnkaPundit: Paul Anka Takes Over the Site for a Weekend (Continues through to Monday's postings) George Bush Slices Don Rumsfeld Like an F*ckin' Hammer Top Top Tens
Democratic Forays into Erotica New Shows On Gore's DNC/MTV Network Nicknames for Potatoes, By People Who Really Hate Potatoes Star Wars Euphemisms for Self-Abuse Signs You're at an Iraqi "Wedding Party" Signs Your Clown Has Gone Bad Signs That You, Geroge Michael, Should Probably Just Give It Up Signs of Hip-Hop Influence on John Kerry NYT Headlines Spinning Bush's Jobs Boom Things People Are More Likely to Say Than "Did You Hear What Al Franken Said Yesterday?" Signs that Paul Krugman Has Lost His Frickin' Mind All-Time Best NBA Players, According to Senator Robert Byrd Other Bad Things About the Jews, According to the Koran Signs That David Letterman Just Doesn't Care Anymore Examples of Bob Kerrey's Insufferable Racial Jackassery Signs Andy Rooney Is Going Senile Other Judgments Dick Clarke Made About Condi Rice Based on Her Appearance Collective Names for Groups of People John Kerry's Other Vietnam Super-Pets Cool Things About the XM8 Assault Rifle Media-Approved Facts About the Democrat Spy Changes to Make Christianity More "Inclusive" Secret John Kerry Senatorial Accomplishments John Edwards Campaign Excuses John Kerry Pick-Up Lines Changes Liberal Senator George Michell Will Make at Disney Torments in Dog-Hell Greatest Hitjobs
The Ace of Spades HQ Sex-for-Money Skankathon A D&D Guide to the Democratic Candidates Margaret Cho: Just Not Funny More Margaret Cho Abuse Margaret Cho: Still Not Funny Iraqi Prisoner Claims He Was Raped... By Woman Wonkette Announces "Morning Zoo" Format John Kerry's "Plan" Causes Surrender of Moqtada al-Sadr's Militia World Muslim Leaders Apologize for Nick Berg's Beheading Michael Moore Goes on Lunchtime Manhattan Death-Spree Milestone: Oliver Willis Posts 400th "Fake News Article" Referencing Britney Spears Liberal Economists Rue a "New Decade of Greed" Artificial Insouciance: Maureen Dowd's Word Processor Revolts Against Her Numbing Imbecility Intelligence Officials Eye Blogs for Tips They Done Found Us Out, Cletus: Intrepid Internet Detective Figures Out Our Master Plan Shock: Josh Marshall Almost Mentions Sarin Discovery in Iraq Leather-Clad Biker Freaks Terrorize Australian Town When Clinton Was President, Torture Was Cool What Wonkette Means When She Explains What Tina Brown Means Wonkette's Stand-Up Act Wankette HQ Gay-Rumors Du Jour Here's What's Bugging Me: Goose and Slider My Own Micah Wright Style Confession of Dishonesty Outraged "Conservatives" React to the FMA An On-Line Impression of Dennis Miller Having Sex with a Kodiak Bear The Story the Rightwing Media Refuses to Report! Our Lunch with David "Glengarry Glen Ross" Mamet The House of Love: Paul Krugman A Michael Moore Mystery (TM) The Dowd-O-Matic! Liberal Consistency and Other Myths Kepler's Laws of Liberal Media Bias John Kerry-- The Splunge! Candidate "Divisive" Politics & "Attacks on Patriotism" (very long) The Donkey ("The Raven" parody) |