Hornady Comparator vs OGIVE

[bsumoba]

It seems that the tangent ogive, hybrid ogive and Lapua Scenar style bullets do not require "chasing" the lands to group well, so the system's grouping ability is maintained as the throat erodes.

bsumoba, do you notice a drop in muzzle velocity as the throat erodes though? Do you increase the powder charge to compensate?

To your point, people shooting secant ogive bullets typically have to jam the rounds to see the best accuracy. What I have seen people do to maintain the same jam over the life of a barrel is to simply soft seat (for those that do not know what this means, it is using just enough neck tension to hold the bullet) a bullet long into the case and let the chamber seat the round from there. It will theoretically maintain the same jam length at that point. The bullet only exits one way. If you try to do this, then unload the round, be prepared to clean up a lot of powder and using a cleaning rod to pop the bullet out of the lands.

I have seen velocities drop slightly once you get to the higher round counts. I had one barrel start at 2890 and when I retired it (1400 rounds), it was around 2870ish. Another barrel was at 2830 and it finished off around 2800 fps if I remember correctly and that barrel had around 1,100 rounds. Barrels seem to be at its best around 100-700 rounds in my experience. That is shooting them in the format I shoot them, which is F-Class. For the everyday shooter, the barrel could probably last up to 1,500-2,000 rounds if the barrel heat is managed and throat erosion minimized.

I have not increased the powder charge to compensate that I can remember. That being said, in my match guns, I don't usually use a barrel with more than 800-1,000 rounds down it in big matches for the reasons that there are just too many variables and risk for the barrel to go south at that point. I probably dont need to do any compensation because the barrel comes off before then.

[dreyna14]

Where the contact of the comparator is isn't relevant to offsetting the bullet from the lands. As long as your measurement instrument is the same, it doesn't matter. You are marking a reference point of where the bullet is when it makes contact with the lands, then backing it off a given distance from there. You can do this from the ogive, from the tip, or even from the bullet base, it doesn't really matter in theory.

[NiMiK]

Where the contact of the comparator is isn't relevant to offsetting the bullet from the lands. As long as your measurement instrument is the same, it doesn't matter. You are marking a reference point of where the bullet is when it makes contact with the lands, then backing it off a given distance from there. You can do this from the ogive, from the tip, or even from the bullet base, it doesn't really matter in theory.

+1 on this. It gives me a reference to work off from. I use the Hornady overall length gauge on a modified case that I tap. I'll normally measure 3 times to confirm there are no inconsistencies with a comparator tool and then play with the seating depth.