Hand Crafted
Match Bullets

Frequently Asked Questions

What makes Bison Ballistics bullets better?

The best bullets have a balance of inherent accuracy, ballistic performance, flexibility in seating depth, and of course, recoil (determined by weight). What we have done is to examine each of these characteristics and quantitatively design a bullet that balances them all for an optimum combination for high accuracy mid-to-long range shooting. Our bullets are not ELR bullets. They are not short range benchrest bullets. They are carefully designed and optimized for one purpose only - 600 to 1000 yard precision shooting out of single shot match rifles. Our bullets are not mass produced in a factory - they're hand-swaged customs. That means that there is immediate feedback if something isn't right - if an bullet feels wrong coming out of the press, we toss it. The end result is consistency far beyond what you will get from the major manufacturers. Quality control is an inherent part of the process.

Do you make hunting bullets?

No. The bullets we make are designed for target shooting, and exactly zero effort has been spent on terminal ballistics design. We cannot in good faith recommend our bullets for hunting applications.

What about tactical bullets?

Nope. Our singular focus is on match grade long range rifle bullets.

Who is behind Bison Ballistics?

Bison Ballistics is a one-man shop started by Damon Cali. Damon is a life-long shooter and High Power Rifle and F Class competitor with over 25 years of reloading experience. Previously, He spent 6 years at NASA as an aerospace engineer working on projects ranging from composite material testing to structural dynamics. He has 10 years of software development experience, and has spent that time developing ballistics design software - at first out of a quest for knowledge, but now applied to the bullets designed by Bison Ballistics.

Where are your bullets made?

All Bison Ballistics bullets are manufactured in Nebraska with materials sourced from American companies.

Does Bison Ballistics sponsor competitive shooters?

No. Virtually everyone who shoots our bullets in competition paid full retail price. I say "virtually", because we do give away small numbers of new products to volunteer testers as a part of our Prototype Program so that we can gather data and information about how well a new offering performs and to work out any production issues. In the worst case, I'll send a design back to the drawing board if I'm not happy with what the volunteers found, or if I discover a problem when ironing out production details. We also occasionally donate or discount bullets to encourage junior shooters to take up the shooting sports.

What happened to the blog?

It's still there. Bison Ballistics started years ago as a blog where I wrote articles on various aspects of precision shooting. I'll keep it up as time permits. All the old articles, downloads, and calculators are still available via the top menu bar on this site.

Are the ballistic coefficients measured or calculated?

We know how annoying it is to find that BCs have been inflated by manufacturers. Although the marketing copy uses an aspirational "we", Bison Ballistics is a one-man shop. I don't have a Doppler radar or a fully-featured ballistics laboratory. I do have access to 1,900 yard range for testing, a Labradar, and some sophisticated engineering software. The BCs are calculated and sanity-checked by range testing and Labradar measurement. Any BC published here is and will always be the best objectively determined estimate available given the means I have at my disposal. If I find any of them to be inaccurate, they will be adjusted.

How are the ballistic coefficients calculated?

We calculate the drag coefficient as a function of Mach number, and then determine a BC that best matches the custom drag curve to a standard drag curve (G1 or G7). We find our bullets are a very close match to the G7 drag function during supersonic flight. There is typically a divergence at transonic and subsonic speeds, where it is advisable to use a custom drag model.

Do you use Army or ICAO atmospheric standards?

Any time a standard atmosphere is needed, we use the ICAO (International Civil Aviation Organization) standard.

What is jump sensitivity?

Jump sensitivity is a number that tells us how sensitive a bullet is to dispersion due to unbalance or tipping. The higher the jump sensitivity, the less accurate a bullet will be, all else equal. Jump sensitivity is dependent on twist - a higher twist will increase jump sensitivity. We provide jump sensitivity factors so that you can make relative comparisons between bullets to get an idea as to the balance between ballistic performance and accuracy potential. A higher jump sensitivity bullet will not always shoot bigger groups in any given rifle, but we find it helpful as a rule of thumb, and it helps to illustrate the accuracy loss due to faster than necessary twists. The jump sensitivity factors we report assume a muzzle velocity of Mach 2.5. For more information on jump sensitivity, take a look at the article, Jump Sensitivity Factor - A New (Old) Way to Evaluate Bullets.

My bullets are slightly lighter or heavier than the package says. Why?

Bison Ballistics bullets are all hand made. Every core is hand-swaged and weight-sorted prior to seating and point up. What this means is that not every lot will be exactly at the target weight. If the bullet's nominal weight is 200 grains, you might find one lot that weighs 200.1 and another lot that weighs 199.9. This lot to lot variation would be cost prohibitive to avoid - it's just the nature of doing everything by hand. Individual lots are of course held to tight weight tolerances.

Which is better - G1 or G7?

Our bullets are a better fit for G7 BCs. We provide G1 BCs only as a convenience so that you can compare our bullets with those from other manufacturers who use G1 BCs. For actual ballistic calculations, use a G7 BC or our custom drag models if your software supports them.

How are the minimum twists determined?

In our detailed, you'll find two minimum twist numbers. The first refers to a gyroscopic stability factor (Sg) of 1.0, which is the absolute theoretical minimum required for stable flight. The second refers to an Sg of 1.5. Based on research done by Applied Ballistics, 1.5 is the stability factor required to minimize yaw and drag. We recommend using a rifling twist that will give you an Sg of 1.5 for long-range shooting. The recommended twists are calculated for standard atmospheric conditions at sea level. In most cases, this is a conservative estimate and you can effectively use a slightly slower twist rate.

What is a .drg file?

The Lapua Edition of QuickTARGET Unlimited specifies a file format for custom drag models, which is what we have chosen to use. Unfortunately, the software is a bit out of date, but you can still use it on older systems. We've published the files anyhow, as our hope is that more ballistics calculators will adopt it or another standard format for custom drag models. If your ballistics calculator is able to use custom drag models, but requires another format, the .drg is pretty easy to convert - it's just a text file with a list of Mach numbers and drag coefficients.

What is a .bul file?

A .bul file is is a bullet data file that can be imported into the QuickLOAD internal ballistics program. It contains bullet geometry, weight, and other information needed by QuickLOAD. See the QuickLOAD user manual for instructions on how to install a .bul file and for details on the format. Our .bul file includes G7 BCs only.

Do you have loading data?

We do not have tested loading data for our bullets. We recommend that you invest in QuickLOAD and download our free .bul files. As always, and especially when using nonstandard overall lengths or wildcat cartridges, start 10% below the maximum charge weight and work up, looking carefully for signs of pressure along the way. QuickLOAD is good, but it's just software. Be safe and follow standard reloading practices. If you are new to reloading get help from an experienced reloader.

Does Bison Ballistics ship internationally?

Currently, we only ship to the US, but I am working on changing that. If you are an international customer, plase contact me at [email protected] and let me know your situation.

What is your return policy?

It's' simple. We want you to be happy with our product and service. If you don't like the bullets, send them back for a refund. See our Shipping & Returns policy for more detail.

Do you accept credit cards?

Yes, we accept Visa, Mastercard, Discover and American Express. Debit cards are also accepted.

I have another question. How do I contact you?

Your best bet is to send me an email at [email protected]. You can also call at (512) 609-0096, but chances are good that you'll get voice mail. Just leave a message and I will get back to you as soon as I can. Unfortunately, demands of the shop prevent me from talking on the phone as much as I would like to.

Do you accept checks?

Yes, if you choose to mail us a personal check, your order will ship as soon as the funds clear.

How long will it take to get my bullets?

Sales are made on a pre-order basis. Once you order, your card will be charged and your bullets will be mailed out when they are ready. If your bullets are in stock, they will ship within 2 business days via USPS. If not, shoot us an email and we'll give you an estimate on how long your order will take to fill. If you decide to cancel an order, you may do do at any time prior to shipment for a full refund.

Can I order bullets from a single lot?

Every effort is made to make sure each order gets bullets from a single lot. You do not need to provide any specific instructions - we do this by default. However, due to the nature of hand made bullets, it is not always possible to guarantee a single lot, especially for larger orders.