I was thumbing through a sinclair cataloge the other night and they showed the holland low angle inside mouth deburrer. At the bottom of the description it said--"not recomended for flat bottom spitzers". JUst a couple days prior I had chamfered some .308 brass with a lyman low angle deburrer. I DID NOTICE that when I seated boattails I got good concentricity BUT the 5 spitzer speers I loaded were all crooked. For the life of me I can't figure out why?? (although it did take a little more pressure to get those started just like most spitzers). Can anyone answer this for me--just curious about the phenominon.

I had never heard such... I have never used a low angle chamfer tool.

I can only surmise that the sharper case mouth created by the lower angle chamfer may be more prone to battering by flat based bullets as they are "finding their way" into the case. Could be that the sharp case mouth is more prone to cut into the flat bases...

I'm not sure that this explains the concentricity problem with the Speers, though. That might simply be another issue...

Can't really say!

Dan Newberry
green 788

KRAKY,
The reason for deburring tools of different angles is to prevent the case mouth from mutilating the sides of the bullets as they are seated. The low angle toll is intended for the flat base bullets. The low angle brings the slope nearer to the outside of the neck, creating a wider taper for the base of the bullet to enter the case mouth. It also creates a edge at the bottom of the taper that is further from the outside of the case than the slope created by the steeper angled tool. This lower edge will scrape metal from the outside of the boattail bullet.

The steeper deburring tool gives a long slope for the boattail bullet. At the same time, the mouth of the case is narrow to the point the it will scrape metal from the outside of a flat base bullet, while letting the boattail bullet be seated without scraping metal from the bullet jacket. Metal scraped from the bullet will effect the accuracy of the bullet. Hence two different tools. Good luck.

[ 10-24-2002, 12:26: Message edited by: BigBob ]

As a plumber, I have to comment; a 22 degree cut is a relatively flat angle. A standard 45 is comparetively sharper. Not the other way around. No wonder confusion's running rampent. I also have experience in this matter, and mostly what has been said holds true [if you flip-flop the terminology!] However, you can use a low-angle cutter with flat-based bullets depending upon neck-tension. Typically, if you use a lot of tension prior to seating, your luck will not be grand, ALTHOUGH if the case necks have been expanded with something reasonably concentric, you may be ok. I've used the 22 degree jobs on Berger's 88gr. low-drags [a flat base], and runout was equal to the usual 95 VLD -- which is less than 1/10000. Of course, I've never had any trouble with a 45 cutter and a flat-based bullet--a 45 was chosen specifically for a 90, i.e. a flat base. If in doubt, buy a 45 and 22--there are valid reasons for the exsistance of both!