Pressure signs not showing at Max load

[MOOSE39465]

Is this a new barrel?

It's a factory Remington SPS with about 75 rounds down.

 

[MOOSE39465]

If you think that's max, you haven't been to max

Anyways its possible you could find another good node at 42.5 or so but I wouln't mess with it. I have a long throated Tikka and load to 2.925 and 43.2. That same load is unsafe in a normal; chamber.

After thinking about it I will probably stay at max and change primers. If I see improvements then I will start moving the bullet. This rifle is intended to hunt out of a box stand up to 400 yards. The Energy that is created should be enough for a 180 pound deer.

 

[chickm1]

I see primer cratering and flattening of the primer. Those are indications that you have exceeded you rmax load, for that rifle.

 

[Randy Tidwell]

I agree Cody, I was just getting ready to post that I see pressure signs. You beat me to it.

Not bad pressure signs, but they are there. Another half grain you would prob see primers start flattening.

I commend the OP for asking advice before guessing that it would be safe to push the load much farther.

 

[robpiat]

After thinking about it I will probably stay at max and change primers. If I see improvements then I will start moving the bullet. This rifle is intended to hunt out of a box stand up to 400 yards. The Energy that is created should be enough for a 180 pound deer.

Where are you on OAL and distance to the lands?

 

[MOOSE39465]

I see primer cratering and flattening of the primer. Those are indications that you have exceeded you rmax load, for that rifle.

It seems I'm right at the very edge of being over pressure.

 

[jasonco]

You aren't at max charge with 40.5gn of H4350, 140-143 bullet and Hornady 6.5 brass. For whatever reason, the loads were "dumbed down" and 42gn of H4350 is nominal. 43gn is achievable, in my three 6.5 Creedmoor's. Work up in .3 increments.

Cratered primer is not an indication of over pressure.

 

[chickm1]

If you want better groups, experiment with OAL, or a different bullet. If it is not pillar bedded, do that and a trigger job, and make sure there is no barrel impingement with the stock. But. don't load anymore powder. I would back off .5 grain.

 

[MOOSE39465]

Where are you on OAL and distance to the lands?

I'm at 2.808 right now. The throat is so long I run out of case before touching the lands.

 

[MOOSE39465]

If you want better groups, experiment with OAL, or a different bullet. If it is not pillar bedded, do that and a trigger job, and make sure there is no barrel impingement with the stock. But. don't load anymore powder. I would back off .5 grain.

Thanks for the advise.

 

[MOOSE39465]

You aren't at max charge with 40.5gn of H4350, 140-143 bullet and Hornady 6.5 brass. For whatever reason, the loads were "dumbed down" and 42gn of H4350 is nominal. 43gn is achievable, in my three 6.5 Creedmoor's. Work up in .3 increments.

Cratered primer is not an indication of over pressure.

Not a very good picture but the case on the left is minimum and the case on the right is maximum. Only difference I see is a little Cratering. Definitely not flattened primer.

 

[chickm1]

[QUOTE="Cratered primer is not an indication of over pressure.[/QUOTE]

A cratered primer is caused by material from the primer cup, being forced back into the firing pin hole, upon ignition. This occurs from too high a pressure in the case. Flattened primer, is from the same thing. Although the flattening on this primer is minimal, it is there. He has just barely exceeded max pressure. You can shoot, but over time, he will have increased head space and will shorten the life of his barrel throat.

 

[MOOSE39465]

I agree Cody, I was just getting ready to post that I see pressure signs. You beat me to it.

Not bad pressure signs, but they are there. Another half grain you would prob see primers start flattening.

I commend the OP for asking advice before guessing that it would be safe to push the load much farther.

Thanks for the advice Randy.

 

[jasonco]

With the 24" barrel, velocity should be in the 2700-2800 with 140 class bullets.