Author: britrifles
Subject: 303 British Brass Options?
Posted: December 21 2023 at 4:07pm
What surprised me was the sudden loss in accuracy at 600 yds when the throat erodes. I never trash a barrel based on a throat measurement or a borescope inspection. Accuracy on the target is the sole discriminator. After about 1400 rounds, I noticed 600 yard groups had doubled in size. Then 300 yard groups increased, then 200 yds. Ugly 4 MOA groups. I puzzled with this, talked to many very experienced service rifle shooters and decided to change the barrel. Well, my groups were cut in half and life was good again.
Subject: 303 British Brass Options?
Posted: December 21 2023 at 4:07pm
What surprised me was the sudden loss in accuracy at 600 yds when the throat erodes. I never trash a barrel based on a throat measurement or a borescope inspection. Accuracy on the target is the sole discriminator. After about 1400 rounds, I noticed 600 yard groups had doubled in size. Then 300 yard groups increased, then 200 yds. Ugly 4 MOA groups. I puzzled with this, talked to many very experienced service rifle shooters and decided to change the barrel. Well, my groups were cut in half and life was good again.
Then, 1400 to 1500 rounds later on the second barrel it happened again! That’s when I did extensive research on double based powders. I then switched to H4895 for my service rifle. Barrel #3 is going strong, at 3600 rounds now, and still shoots MOA at 600x.
I’m not making this up guys. I learned my lesson. If you don’t believe me that double based propellants burn hot, put a few thousand rounds of Mk 7 ammo thru your LE then see how it shoots (don’t do it).
I used to use Re 15 with my No. 4. I shot quite a bit of it, perhaps 1500 rounds. I wished I had not, I suspect most of the throat erosion was done with that powder. This is the rifle that now has a whopping 1/2 inch jump to the lands and no longer shoots well, need a new barrel. The first three inches of the bore looks like an alligator.
Well, I’ve said enough, I just wanted to spare anyone here of learning the hard way, especially with a LE were NOS barrels are no longer found.
And of course, if you’re shooting a few rounds a year, don’t worry about it. But if you’re shooting hundreds a year, worry about it.