COL vs chamber length?

[Jpsmith1]

6mm Remington loading a Hornady 100gr Interlock BTSP

Listed COL is 2.810"

I played around, carefully nudging the bullet deeper until the bolt closed and didn't smear a sharpie on the ogive because I don't have the fancy tester tools.

Seated 2.882"

Powder is IMR4064 and I ran a ladder 37.0-39.0 by 0.5grains.

I'm safe, right? Just dipping my toes into going "off book" so to speak and not following book loads exactly.

 

[streamerfish]

What's the book max charge?

I see 38gr at 2.775" in the Hodgdon data. Based on that, if your not seeing any big pressure signs. Your probably ok at 39gr and 2.882" At the least not way over pressure.

 

[Jpsmith1]

What's the book max charge?

I see 38gr at 2.775" in the Hodgdon data. Based on that, if your not seeing any big pressure signs. Your probably ok at 39gr and 2.882" At the least not way over pressure.

Data from the Hornady App

32.9 to 39.0gr is the min/max range. Listed COAL is 2.810

I just loaded these last night, so no pressure signs as they're all still loaded ammo. I will be watching and logging data more carefully than I have before.

 

[jkoehle1]

Matters a lot how far the jump is to the rifling. I wouldnt push it without knowing.

Perciseload.com is basically web based quickload

 

[Axlrod]

6mm Remington loading a Hornady 100gr Interlock BTSP

Listed COL is 2.810"

I played around, carefully nudging the bullet deeper until the bolt closed and didn't smear a sharpie on the ogive because I don't have the fancy tester tools.

Seated 2.882"

Powder is IMR4064 and I ran a ladder 37.0-39.0 by 0.5grains.

I'm safe, right? Just dipping my toes into going "off book" so to speak and not following book loads exactly.

The best tool to do this, you already have- your chamber. You only need to remove your firing pin & spring, and your ejector (if it's a plunger w/spring). Load long, and keep adjusting seat depth deeper as you try to chamber the round. When your bolt falls shut under it's own weight, your bullet is right at touching the lands. This is also an excellent way to set your sizing die. There are videos out there that are way easier to follow than my explanation.

 

[Jpsmith1]

The best tool to do this, you already have- your chamber. You only need to remove your firing pin & spring, and your ejector (if it's a plunger w/spring). Load long, and keep adjusting seat depth deeper as you try to chamber the round. When your bolt falls shut under it's own weight, your bullet is right at touching the lands. This is also an excellent way to set your sizing die. There are videos out there that are way easier to follow than my explanation.

This is basically what I did.

I confirmed no contact with the throat using a sharpie as well.

I'm going to dummy a round up tonight and see about figuring bullet jump.

 

[Jpsmith1]

View attachment 1048979
Matters a lot how far the jump is to the rifling. I wouldnt push it without knowing.

Perciseload.com is basically web based quickload

This is a very interesting tool so thank you.

Your load is a bit stout as I only loaded up to 39.0 not 39.5 the bullet jump seems to be the issue, and I plan to do a little more figuring and certainly not jump immediately to full house loads jammed into the rifling

 

[streamerfish]

Data from the Hornady App

32.9 to 39.0gr is the min/max range. Listed COAL is 2.810

I just loaded these last night, so no pressure signs as they're all still loaded ammo. I will be watching and logging data more carefully than I have before.

What brass are you running? Your most likely fine. Your running a longer COAL with the same powder, never know 100% until you shoot a couple to make sure. But you probably fine.

As long as you aren't in or right on the lands. 20 thou off or more and your good to go most likely.