To answer a few questions which I know will raise some also but here it goes.
No one built our rifling machines. We did, along with the bore reamer machine. The machines have far exceeded our expectations. What we can do with the rifling machines has been extraordinary. We also have patents pending on them also.
As far as the gain twist type barrels. We are calling them "T" style rifling (transitional). Why? Simply because we can cut any twist we/the customer wants. Straight conventional style twist, a very uniform slow gain type twist or a radical gain type twist.
We can enter anything the customer wants. The tooling still plays a part and can effect the cost of the barrel on a gain type twist.
Who wants or uses gain twist type barrels? Gain twist type barrels have been around forever. It was used a lot back in Popes day with the false muzzle loaders shooting lead type bullets. A lot of lead bullet shooters and rimfire shooters have asked us to do barrels for them. Also shooters shooting the new solid machined type bullets with driving bands on them want a gain twist type barrel. Supposedly it's easier on the driving bands as the bullet enters the rifling. Also in bigger calibers like 20mm etc...the gain twist is used. Mostly because you are starting a very heavy bullet into the barrel. Most 20mm cannon rounds have a bullets that weigh around .75 pounds. Not like shooting your standard .308 150gr. bullet hey!
Is it for everyone? At this point in time I would say no still. Also remember gain twist type barrels back when had a radical type gain. The one that Tony and couple of other guys have are not a drastic type gain. The couple that Tony has only goes from a 1-15 at the breech to 1-14.25 at the muzzle. It didn't seem to hurt him at all at the Nationals. He picked the twist and we made it for him.
I would agree with the general statement that most gain twist type barrels don't shoot conventional jacket/lead core bullets well or should I say extremely temperamental. Now a slight gain seems to be o.k. after what Tony's did.
Yes there was a company several years ago that was called The Gain Twist Barrel Co. If I'm correct it was owned or co-owned by Steve Garbe. If any of you know Steve he was also one the guys who was helping run Ballard Rifle and Cartridge up until a few years ago. Steve had told me that even just a 1/2 a gain twist from breech to muzzle the barrels shot better (with lead bullets, I don't know about jacketed bullets). For us we need more testing to be done. Both on our end and out in the real world. What is the magic receipe for a certain shooter or caliber etc...we don't have the magic book for that. Maybe with the new technology that is available to us it can lead us into different areas.
Anyways we can do things like this custom twist in our barrels for customers who want them.
Later, Frank @ Bartlein Barrels