308 c.o.a.l. 168g bthp

[Edik310]

I have a question for you guys. I have a tikka t3 Tactical in 308. I used hornady chamber guage to check ogive length (hornady 168g bthp bullet). I'm getting a reading of 2.180. That's touching the lands. The total length of the cartridge is "roughly" 2.791. I normally load ELD bullets longer than 2.800.

My question to you guys is it still safe to load 10, 20, 30 thousandths off the lands even though I'll be way under the 2.8 coal?

Thank you for any help

168 bthp
Lapua case
Acc 2460
Fed 210 LR

 

[waveslayer]

Yes you should be fine, the issue on rifle cartridges is bullets jammed in the lands will create pressure.

 

[Edik310]

Yes you should be fine, the issue on rifle cartridges is bullets jammed in the lands will create pressure.

I thought it also builds when you go down into the case as well.

 

[nn8734]

I thought it also builds when you go down into the case as well.

That’s correct, deeper bullet means less capacity which translates to higher pressures. Bullets jammed also increases pressure all other things equal.

 

[Edik310]

That’s correct, deeper bullet means less capacity which translates to higher pressures. Bullets jammed also increases pressure all other things equal.

Thanks for that input. Do you think it's still ok to come 20 thou off the lands even the the coal will be shorter than 2.800? It is a 168g bthp bullet. I've never loaded shorter, it's always been longer than 2.8 but with a different bullet. Thanks

 

[BCP]

I have a question for you guys. I have a tikka t3 Tactical in 308. I used hornady chamber guage to check ogive length (hornady 168g bthp bullet). I'm getting a reading of 2.180. That's touching the lands. The total length of the cartridge is "roughly" 2.791. I normally load ELD bullets longer than 2.800.

My question to you guys is it still safe to load 10, 20, 30 thousandths off the lands even though I'll be way under the 2.8 coal?

Thank you for any help

168 bthp
Lapua case
Acc 2460
Fed 210 LR

If you make a dummy handload at 2.8" COAL does the bullet touch the rifling?

 

[nn8734]

Thanks for that input. Do you think it's still ok to come 20 thou off the lands even the the coal will be shorter than 2.800? It is a 168g bthp bullet. I've never loaded shorter, it's always been longer than 2.8 but with a different bullet. Thanks

You’re welcome. To detect overpressure, measure your unfired rounds at the base of the csse just above the extractor groove then measure after firing - use a 1” micrometer or good pair of dial calipers. Compare the two measurements; anything showing over .0005” expansion means overpressure.

so seat them at .020, measure, fire, measure.

 

[Edik310]

If you make a dummy handload at 2.8" COAL does the bullet touch the rifling?

I have the hornady guage and I used the 168g bthp. It touches at 2.180 on the ogive and measures "roughly" 2.791 coal. Naturally the tip will different

 

[spife7980]

I thought it also builds when you go down into the case as well.

It does but it’s a negligible amount of change in a rifle sized case. Jamming is what you need to concern yourself with for rifles.