Bullet engraving

[Big G]

Dont laugh guys, I dont know if I'm stating this right. But why will one gunsmith chamber a rimfire to where the nose of the bullet just touches the riflings and another will chamber it to engrave deep in the riflings? Is there any difference? I see where one of the top rimfire barrel makers definately suggests deep engraving. But from what I have read, Bill Myers likes to chamber his rifles to just touch the riflings.

 

[varminthunter1]

Most rimfire smiths will use a match reamer that will result in a the bullet engraving deep into lands.
There are several reamer designs to choose from, including Calfee, Myers, Lilja, Winchester 52. ect
All very in chamber depth, width, leade angle, ect.
It seems desirable for getting better accuracy. Have a chat with your smith or Dave Kiff from Pacific Tool on reamer design. He will enlighten you.

Jeff Lewis

 

[Kent Owens]

I build my own rimfire BR rifles, and you will get many different opinions on chambers and reamers from different folks. As you've seen from the lack of response to your question people are pretty slow to disclose what works or does not work. Most guys ahve their favorite reamer, and set it up to engrave just so much. I have my own opinions, but so do a lot of other folks too, and they may all be right . So it's hard to get a definitive answer.

I'll say this, a rifle that engraves bullets too much doesn't always work best.
In rimfire BR, we may fire 100 rounds during the course of shooting a 25 bull target. The rifle's accuracy needs to hold up throughout the target. A poorly done chamber can foul and cause the rifle to throw a shot and ruin the target. I shoot IR50/50 and if you drop a point, you're probably going to lose that target.

 

[crb]

There are almost as many engraving theories as there are successful gunsmiths. They all can be made to shoot competitively. IMO, as long as the bullet doesn't get badly deformed by it's trip from case to bore then it's the crown that really determines how the bbl shoots [ this is assuming no significant flaws in the bore ]. A bit simplied needless to say.