I'm having a Rem. 700 rebarreled in 7mm STW and going to a 4 land Lilja barrel. How much velocity increase should I expect in going from 6 lands to 4 lands?

Welcome aboard 7mmfan, I would check with the people at Lilja, they should know something folks here don't.

I wouldn't expect any velocity increase. Am I missing something?

Pumpkinslinger wrote:

I wouldn't expect any velocity increase. Am I missing something?

We all know barrel length makes diff but I didn't know amount of groves made a diff. Maybe Lilja is up to something we haven't heard about.

Maybe I am thinking about this all wrong but, it would seem to me that if you are digging 1/3 less grooves into the bullet then for a given barrel length, powder charge and bullet weight the resulting reduction in friction/restriction would have to result in increased velocity .

Fewer lands but I bet they are wider. Either way I wouldn't expect any appreciable increase. If you find out different let us know!

I don't think the original 2 land 30-06 barrels had any advantage in velocity over the later barrels.

The barrel lands are propotional in general, and after the initial shock of forming at the throat of the chamber it really doesn't effect anything all that much I dont think. And as Mike mentioned the "cheaper" 2 land barrels produced by various militaries for different firearms in times of war shot the same as the non-wartime production 4 grove barrels, but required less cutting passes to cut hence the money and time savings.

Dimitri

I took 1895SS's advice and emailed Dan Lilja. Pumpkinslinger was correct in that when they reduced the number of lands they kept the nominal about of bearing surface the same so there will be essentially no net gain in velocity. However, there is a slightly longer service life due to the lands being wider and that is important with an overbore like the 7mm STW that I am going to.