This is an interesting one.

I was talking to a chap called Steve East a few weeks back, who is a well respected TR shot ( team, coach etc) and he was involved with testing some loads they were going to have proofed for use as a club load.

They get a very good deal on TR140 in bulk, and were formerly using N140.

I use N140 on my 7.62x51, my .308 F/TR rifle, and my No4, so it seemed to make sense to use the cheaper powder in my less critical rifles.

The stink of it seems to be that they are different, if anything the TR being a tad slower.

That said, 3 people on one range all had different opinions, I base my comments on advice from folk like Steve (who have chronoed several hundred rounds accross a competitive load development program for sale as a loaded round) and Mik Mak, who does a lot of LD fof F class and other folk, and also sells TR140...and is an acredited balistic testing type chappie...so they might know what they are on about.

The both say it has proven to be slower.

A mate who used to use N140 in a .303 says he is now half a grain up, so I am going to load my old N140 load (that was low enough anyway) and 42gr of TR also and see how it goes.

The rifle has proven OK with 43gr of DO73.6 which si a double base, faster powder in any event.

Lauri holland was saying they are almost interchangeable, but like most things, you have to be sensible.

As an aside, if you have purchase the 180gr .303 S&B bullets lately, take a close look at them, the have changed.

I thought there had been some mistake.

The Base and the Ogive has changed, and the bullet is a slightly different length. The boat tail seems steeper when compared with the original, and they look a better quality bullet.

My point is that there was a 20thou difference when loaded with my standard .303 die setting for the older S&B .303 bullet (180gr), and this was the same when I bunged both in a comparator.

Diameter is the same.

I will be interested to see how they go.