I just acquired a New Haven Model 70 in 416. It shoots a nice tight group at 100 from a clean barrel. Hornady 400 DGXs. The groups go steadily down hill after that and by a dozen shots the groups are 3" and getting worse. The barrel is allowed to cool between shots. Would lapping the barrel help, maybe start over with a break in procedure, what? Any suggestions? I posted this in BIG BORES also.

FLINCHING????? I know my group would go to hell quickly with that caliber!

Hornady bullets foul like crazy in my .416. Accuracy wasn't affected as badly as you describe but cleanup is a multi day event. I've just gone to shooting TSXs in mine.

Shoot clean, shoot clean, shoot clean. Smooth out the barrel over time.

I used to own one of those. It is now a .458 Lott. However I remember when it was a .414 Rem it would do the same thing. I took it to a smith and we both took a look through a borescope. Boy, those were the most ragged lands I had ever seen. I don't know if the factory reamer was dull or there was tool chatter during the reaming, or what. Who knows, maybe your barrel was the next one in line. At any rate, it might not be a bad idea to have a look at the bore through a scope.

Geronimo

Try fire-lapping, it usually helps that situation.......Tom

Thanks guys.

Rifle is at the gunsmith for a through cleaning, then a light barrel lap, then re-shot
with original ammo and then shot with Barnes ammo. That should tell me more.

quote:

Originally posted by Rick R:
Hornady bullets foul like crazy in my .416. Accuracy wasn't affected as badly as you describe but cleanup is a multi day event. I've just gone to shooting TSXs in mine.

This is copper fouling correct Rick?

The reason I ask is that I wanted to shoot the Hornady 400 round nose 416 as a "practice" bullet instead of my 400 Nosler Partitions. I have the Hornadys on the way and then I found this.

Do you clean it with Sweets or Montana Extreme or something of that kind?

I might be sending the Hornadys back and just use the Nosler.

Would you share what you found, and how did yours come out Butch?

Thanks.

Begno,
I had one of the Win's in .416 Rem for awhile. I had the same problem with it and a .375 as well. I sent the .416 off and had the barrel lapped, even shot bore lapping bullets through it trying to get it to smooth out. Nothing I did worked. Shoot it 20 rounds and clean it for 4 days. It was cheaper for me to sell the gun and buy a different brand.