Lilja has confirmed that they are using the SAAMI chamber.
I measured our just-received Grendel reamers back from PTG after re-sharpening and measured the throat diameter. It isn’t easy to measure exactly without optical equipment because of flute stagger built into the reamer. But I get .2643” on the major diameter.
Reamers are ground with a stagger meaning that a 6-flute reamer does not have each cutting face exactly 60º from the next face. There is a table in the Machinery Handbook that calls out stagger. This is to help eliminate reamer chatter while the tool is cutting. So, this also means that when measuring dimensions on a reamer, like the throat diameter, the two flutes are not opposite each other and are probably slightly larger in diameter than the measuring tool indicates.
I had a discussion with Dave of PTG on this very subject at the Shot Show last month. He’s also very aware of the variations in throats and the history of the Grendel cartridge. He and his company are very capable of grinding reamers to the necessary specifications and to closer tolerances than called out on a reamer print.
The Grendel cartridge has an interesting and intriguing history. I remember some years ago talking to Alexander and Lou Palmisano at the Shot Show about the round. They were very excited about it then and the round has since taken on a life perhaps larger than they imagined back then. I hope this helps explain what I know and our involvement with the AR barrels we’re making for it.
And Mark Hostetter at Precision Firearms confirms that they are also.
We are using the 6.5 Grendel SAAMI spec reamers.
I know ours are the same as AA as we sent Dave the license from AA back when we needed it and he sent me the same reamer they send to AA. We reorder the same dimension reamer each time. I do have a 264 LBC reamer too but the throat is shorter and is .295
instead of 300. The liberty barrel I have here is definitely shorter than either. I will try to take some pictures.
Obviously ours is correct as our barrels are definitely not short throated.
I can easily see the taper on the throat portion of the reamer.
Really this is the responsibly of the reamer manufacturer to make sure they
are making the reamer to SAAMI specs unless the customer sends in a drawing
requesting differently.
I measured our just-received Grendel reamers back from PTG after re-sharpening and measured the throat diameter. It isn’t easy to measure exactly without optical equipment because of flute stagger built into the reamer. But I get .2643” on the major diameter.
Reamers are ground with a stagger meaning that a 6-flute reamer does not have each cutting face exactly 60º from the next face. There is a table in the Machinery Handbook that calls out stagger. This is to help eliminate reamer chatter while the tool is cutting. So, this also means that when measuring dimensions on a reamer, like the throat diameter, the two flutes are not opposite each other and are probably slightly larger in diameter than the measuring tool indicates.
I had a discussion with Dave of PTG on this very subject at the Shot Show last month. He’s also very aware of the variations in throats and the history of the Grendel cartridge. He and his company are very capable of grinding reamers to the necessary specifications and to closer tolerances than called out on a reamer print.
The Grendel cartridge has an interesting and intriguing history. I remember some years ago talking to Alexander and Lou Palmisano at the Shot Show about the round. They were very excited about it then and the round has since taken on a life perhaps larger than they imagined back then. I hope this helps explain what I know and our involvement with the AR barrels we’re making for it.
And Mark Hostetter at Precision Firearms confirms that they are also.
We are using the 6.5 Grendel SAAMI spec reamers.
I know ours are the same as AA as we sent Dave the license from AA back when we needed it and he sent me the same reamer they send to AA. We reorder the same dimension reamer each time. I do have a 264 LBC reamer too but the throat is shorter and is .295
instead of 300. The liberty barrel I have here is definitely shorter than either. I will try to take some pictures.
Obviously ours is correct as our barrels are definitely not short throated.
I can easily see the taper on the throat portion of the reamer.
Really this is the responsibly of the reamer manufacturer to make sure they
are making the reamer to SAAMI specs unless the customer sends in a drawing
requesting differently.
You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live. - John Galt