January 13th, 2015

Calculate Barrel Weight with FREE Software from Dan Lilja

Dan Lilja Rifle BarrelsAre you re-barreling a match rifle and need to know if you will still make weight? Or perhaps you want to select the right contour to hit an optimal carry weight for a new varmint rifle? Dan Lilja offers FREE software that will calculate barrel weight for straight contour, straight taper, and radius-tapered barrels. Dan’s software even calculates how fluting alters barrel weight.

For general info on barrel weight calculation for straight and straight tapers, read this article on Lilja’s website. Click HERE for another article explaining weight calculation with barrels that have a radiused (curved) contour section.

Here are the free software programs offered by Dan Lilja. Right click and “Save As”:

Straight Contour (.exe file) | Straight Contour (Excel file) | Contoured Barrels with Radius (Excel file)

Dan Lilja Barrel Contour diagram

Permalink Gunsmithing, Tech Tip 2 Comments »
October 24th, 2013

When Will Your Barrel Die? Spreadsheet Predicts Barrel Life

We can predict, with some certainty, how long a light bulb will last (in use), or a shingle roof, or even a nuclear reactor. But how about barrels? Is there a way to reliably estimate barrel life based on known characteristics? This article explains one effort to quantify barrel life…

Rifle Barrel Life CalculatorHow long will a barrel last before the accuracy “goes south”? There are so many variables involved (powder type, bore diameter, bullet coatings etc.) that it’s hard to predict. You might say “Well, my buddy has a .243 and he got 1500 rounds before the throat was shot out” — those kind of comparisons can be useful, but they’re not very scientific, and they won’t help much if you’ve got a gun in a new chambering (such as the 6.5×47) for which long-term test results are lacking.

Is there a more reliable way to predict barrel life — one that will work for a broad range of calibers? Well, Forum member MikeCr has developed an Excel spreadsheet that accounts for a number of variables, and gives a pretty good estimate of useful barrel life, whether you’re shooting a .223 Rem or a 338 Lapua Magnum. Mike’s program predicts barrel life using five variables: 1) Bullet Diameter; 2) Powder Charge weight; 3) Powder Heat Potential (KJ/kg); 4) Pressure (in psi); and 5) Bullet Coating (yes/no). Mike provides a table with Heat Potential ratings for most popular powder types. The user needs to know the pressure of his load. This can be estimated with QuickLOAD.

You can download the lastest version of Mike’s spreadsheet below. You’ll need Excel or an Excel viewer to open the file.

Click to Download Spreadsheet: Barrel Life Spreadsheet (Latest Version)

Shown below is Mike’s Spreadsheet, with variables for a 6BR shooting 105gr “naked” bullets with 30.3 grains of Hodgdon Varget powder. The formula predicts 2401 rounds of barrel life. That corresponds pretty well to what we’d expect for a 6BR — about 2500 rounds.

Barrel Life ProgramBarrel Life Program

Mike observes: “There has been alot of discussion lately related to cartridge design and resulting barrel life. This is a really important factor to consider amongst a myriad of choices. Barrel life is controversial, and subjective. There are no clear-cut standards for comparison. But a few years ago, I put together a spreadsheet based on Bart Bobbit’s rule of thumb. It worked pretty good, only occasionally failing some tests when validated against posted barrel lives.

According to Ken Howell, I had to account for pressure. And Henry Child’s powder temperature testing provided another piece needed. So, I’ve tweaked it here and there to pass more tests. From 223rem to 300 UltraMagnum. Another element added, but turned off is shot interval. I would need way more tests to lock in on this. But everyone knows, the faster you shoot, the worse the barrel life.

Anyway, another factor hard to define is ‘accurate’ barrel life. This cannot be quantified without standards. Barrels are replaced when expectations are no longer met. I feel that a [barrel] passes peak potential in a finite period due to throat erosion. But that don’t mean it’s toast, if it still shoots well enough. It’s just as likely that many of us never see that peak potential anyway. It’s a slippery thing. Point-blank BR competitors will toss a barrel when it leaves the 1s. I could get another 4000 rounds from it, and be content with its performance, I’m sure.”

NOTE: Mike says: “This spreadsheet may show a lower barrel life than you prefer. But it pretty well spotlights cartridges to stay away from if you plan much time at the range or in dog town.”

Editor’s Comment: We want to stress that Mike’s spreadsheet is a helpful tool, but it is not a definitive “take-it-to-the-bank” indicator of barrel life. Mike cautions that predicting barrel life involves so many different factors (including how hot the barrel is run), that the task is a bit like predicting tread life on car tires. Still, the spreadsheet is very helpful. It can certainly warn us that some chamberings (such as the 6-284) are likely to be barrel burners. That can help you make a smart decision when choosing a chambering for your next rifle.

Permalink Tech Tip 8 Comments »
July 27th, 2012

Handy Excel Formula Predicts Useful Barrel Life

Rifle Barrel Life CalculatorHow long will a barrel last before the accuracy “goes south”? There are so many variables involved (powder type, bore diameter, bullet coatings etc.) that it’s hard to predict. You might say “Well, my buddy has a .243 and he got 1500 rounds before the throat was shot out” — those kind of comparisons can be useful, but they’re not very scientific, and they won’t help much if you’ve got a gun in a new chambering (such as the 6.5×47) for which long-term test results are lacking.

Is there a more reliable way to predict barrel life — one that will work for a broad range of calibers? Well, Forum member MikeCr has developed an Excel spreadsheet that accounts for a number of variables, and gives a pretty good estimate of useful barrel life, whether you’re shooting a .223 Rem or a 338 Lapua Magnum. Mike’s program predicts barrel life using five variables: 1) Bullet Diameter; 2) Powder Charge weight; 3) Powder Heat Potential (KJ/kg); 4) Pressure (in psi); and 5) Bullet Coating (yes/no). Mike provides a table with Heat Potential ratings for most popular powder types. The user needs to know the pressure of his load. This can be estimated with QuickLOAD.

You can download the lastest version of Mike’s spreadsheet below. You’ll need Excel or an Excel viewer to open the file.

Click to Download Spreadsheet: Barrel Life Spreadsheet (Latest Version)

Shown below is Mike’s Spreadsheet, with variables for a 6BR shooting 105gr “naked” bullets with 30.3 grains of Hodgdon Varget powder. The formula predicts 2401 rounds of barrel life. That corresponds pretty well to what we’d expect for a 6BR — about 2500 rounds.

Barrel Life ProgramBarrel Life Program

Mike observes: “There has been alot of discussion lately related to cartridge design and resulting barrel life. This is a really important factor to consider amongst a myriad of choices. Barrel life is controversial, and subjective. There are no clear-cut standards for comparison. But a few years ago, I put together a spreadsheet based on Bart Bobbit’s rule of thumb. It worked pretty good, only occasionally failing some tests when validated against posted barrel lives.

According to Ken Howell, I had to account for pressure. And Henry Child’s powder temperature testing provided another piece needed. So, I’ve tweaked it here and there to pass more tests. From 223rem to 300 UltraMagnum. Another element added, but turned off is shot interval. I would need way more tests to lock in on this. But everyone knows, the faster you shoot, the worse the barrel life.

Anyway, another factor hard to define is ‘accurate’ barrel life. This cannot be quantified without standards. Barrels are replaced when expectations are no longer met. I feel that a [barrel] passes peak potential in a finite period due to throat erosion. But that don’t mean it’s toast, if it still shoots well enough. It’s just as likely that many of us never see that peak potential anyway. It’s a slippery thing. Point-blank BR competitors will toss a barrel when it leaves the 1s. I could get another 4000 rounds from it, and be content with its performance, I’m sure.”

NOTE: Mike says: “This spreadsheet may show a lower barrel life than you prefer. But it pretty well spotlights cartridges to stay away from if you plan much time at the range or in dog town.”

Editor’s Comment: We want to stress that Mike’s spreadsheet is a helpful tool, but it is not a definitive “take-it-to-the-bank” indicator of barrel life. Mike cautions that predicting barrel life involves so many different factors (including how hot the barrel is run), that the task is a bit like predicting tread life on car tires. Still, the spreadsheet is very helpful. It can certainly put shooters on notice that some chamberings (such as the 6-284) are likely to be a barrel burners. That can help you make a smart decision when choosing a chambering for your next rifle.

Permalink Gunsmithing, Tech Tip 18 Comments »
November 14th, 2011

FREE Quickoffice App for Android Devices — Nov. 14th ONLY

For the remainder of today, November 14th, the Android OS Quickoffice Pro App is FREE for the taking. That’s right, this App, normally priced at $14.99, costs zero, zip, nada. This productivity App lets you create, edit, and view Word, Excel, and PowerPoint files. The Quickoffice Pro App also includes a PDF Viewer for Adobe Acrobat files. Remember this FREE OFFER is good for today only on Amazon.com!

Quickoffice Pro Android App

Permalink Hot Deals No Comments »
December 13th, 2009

Job Watch: USPSA Seeks Steel Challenge Coordinator

Looking for a position that lets you work from home and be involved with many of the leading organizations in the gun industry, such as Ruger, Smith & Wesson, and the USAMU? The U.S. Practical Shooting Association (USPSA) is seeking a coordinator for its annual Steel Challenge competition, held each summer in Southern California.

Steel Challenge USPSA

The Steel Challenge Coordinator will assist in producing the Steel Challenge World Speed Shooting Championships. The successful candidate must be good with details, able to meet deadlines, have a good working knowledge of Excel spreadsheets, and have some event experience. The position also requires some Shooting Sports Industry experience and working with sponsors. The Coordinator will work from home but must be able to travel to the SHOT Show and the World Speed Shooting Championships. To apply for the job, send email to Scott Moore, SSC Director, scott@steelchallenge.com, or call (602) 687-9675.

Permalink News No Comments »