No short explaination. Here it is:
The SPS Tactical in .223 is suppose to be 1/9. However, they do not advertise that as a spec in a clear manner. But it is and will continue to be a 1/9.
Here's the part that adds confusion. When released, the first batch of SPS Tacticals in .223 were actually 1/12. This was an error. The first 125 rifles they claim, but more like 1,500 I've heard.
There are two ways to tell what you have.
1. Is to do the cleaning rod test. Put a piece of tape on the rod, mark a spot on it. Push it through until the dot rotates 360 degrees, measure the distance the rod traveled in inches and that's your twist rate.
2. Call Remington and give them the serial number of the rifle - they will be able to confirm what it is over the phone.
How do I know this? I wanted a 1/9, got a 1/12 ...went to run a patch through it to take it out for the first time and noticed that the rod was not spinning as fast as it should (used to cleaning 1/7 barrels and they are like a cork-screw). Did a measurement - was 12". Called Remington, they confirmed. Remington offered to make it right by paying shipping and having a 1/9 put on. However, I contacted Sportsman's Safari (100% top notch customer service, wow is all I can say) and they made it right. They didn't know of this either - they gave me the serial number of the replacement and confirmed it with Remington. I have a 1/9 now.
A bit of a hassle. All new ones should be 1/9 without question. But, you never know if any unsold first batch 1/12's are out there floating around.
PS, this rifle is a tack driver. I get consistent .4-.6" 5-shot 100 yard groups. Not 3 shot. Not "group of the day" ...consistent! with 69smk, LC brass, Rem 7.5 and Varget - and of course - nice clean trigger control.
I don't know if anyone has a documented range of serial numbers, but my first one that was 1/12 started G665*** ...the replacement with the 1/9 started G666***
