About Us

 • 9 minute overview movie

Subsonic & Specialty Ammo   
 • 5.56/.223 Ultra Stealth Match Subsonic
 • 7.62/.308 Thumper Subsonic

 • 7.62/.308 PBS-Precision Bonded Subsonic

 • .300 Winchester Magnum Subsonic
 • .338 Lapua Magnum Subsonic
 • 7.62x39 Jackhammer Subsonic
 • 9mm Tactical Subsonic
 • .40 S&W Subsonic
 • .44 Magnum Subsonic
 • 7.62x39 Tracer

 • 12-ga KlinkMeister

Frangible Ammo
 • 12 ga. Frangible ENTRY Slug

 • 9mm Tactical Frangible
 • .40 S&W Frangible

 • .45 ACP Frangible Reduced Hazard
 • .223/5.56 Frangible

 • .308/7.62 Frangible
 • .300 Winchester Magnum Frangible

Government & Military
 • 40mm CQB
 • 7.62/.308 Limited Penetration
 • 7.62 x 39 Facility Protection Frangible

 • 5.56/.223 Subsonic

 • .50 cal Anti Ricochet
 • 6.5 EBR

Weapons and Related

 • For Sale

"The Straight Dope" Information and Tools
 • READ ME Proper Use of Subsonic Ammunition
 • Why use Phosphate Removal for Subsonic Ammunition?
 • Instructions on how to use EBR Phosphate Removal

 • Ballistics Calculator
 • Greenhill Formula For Rifling Twists
 • Twist Rate, continued

 • First-Round Pop
 • Subsonics Do Not Like Long Barrels!
 • The Use of Mil-Dots & Subsonic Ammunition
 • 7.62 Thumper vs. 7.62 PBS?
 • Speed of Sound Chart
Use of Subsonic Ammunition
 • Verifying Stability
 • FAQ - Frequently Asked Questions

 • Testimonials
 • Image and Video Gallery
 • Our Distributors
 • Industry Links

Flash movies

Wounded Warrior Project Donation

Twist Rate (#1)

6/11/2004 - For dual use in .30 calibre (i.e. both supersonic and subsonic ammunition), the very best compromise is a 1:10" twist rate. Our extensive testing has proven that there is NO accuracy degradation with supersonic high-velocity ammunition, and that with the correct subsonic ammunition, this twist rate will give more than acceptable, sub-minute accuracy.

For use with subsonic ammunition ONLY, a 1:8" twist rate is best. This gives added stability and permits the use of less than optimal projectiles. The use of the 1:8" twist will mean that this gun is dedicated solely to the use of subsonic ammunition.

Twist Rate (#2)

6/11/2004 - We are often asked what is the best twist rate for use with different calibers of subsonic ammunition. Here are some basic guidelines that will help you to achieve the best results:

For subsonic pistol calibers, the factory barrel/twist is usually just fine, as most pistol ammunition is just marginally supersonic anyway, with a very few exceptions.

Rifles: First of all, if you are going to go to the expense and trouble of creating a platform for use with a suppressor, it only makes sense to pitch the factory barrel and have it replaced with at least a decent mid-grade tube.

Companies such as Schneider, Shilen, Douglass and several others can provide you with an air-gauged and properly finished barrel, installed and threaded by them for in the $300 range. This is just $100 more than the cost of the tax stamp for your suppressor, and will ensure that you do not experience accuracy and safety problems due to a poorly finished or inspected barrel, and is therefore worth the investment!

Accuracy is almost always enhanced by this move, and for some unknown reason, many U.S. factories still make .308 barrels with the obsolete 1:12" twist rate, and 5.56/.223 rifles using the 1:12" twist rate.

For .308, 1:10" is best for dual purpose use and for 5.56/.223, 1:7" or 1:8" is best if the operator wishes to use both supersonic and subsonic ammunition.

While you *might* get lucky with the factory tube, often it is the source of many headaches when trying to utilize subsonic and even supersonic ammunition. This is true regardless of the original maker.

Engel Ballistic Research, Inc.
Phone (512) 360-5327 | Fax (512) 360-2652
Click Here to Contact Us
All prices FOB Smithville, Texas, U.S.A. & Subject to Change W/O Notice

Copyright © EBR, Inc, 2008, All Rights Reserved