280 AI Saami Chamber with 180-190s

[264MHC]

Wondering if someone here with a saami spec off the shelf 280 AI chamber could tell me if some of the heavier bullets seated at the lands place the boattail above the Neck/Shoulder junction? I am looking at ordering a 280 AI prefit barrel and it would be much easier/cheaper if I could just use the standard reamer. Specifically looking at the 184 Hybrids, 190 LRHTs, and 190 A-Tips. Not sure about the A-Tips but the 184s and 190s both have a significantly longer bearing surface than the 180 Hybrids and 175 Elites according to Berger's specs. Also interested in velocities attainable with these bullets in 24-26" barrels with RL23/RL26 or VV N565.

Thanks,
Cole

 

[Plinker147]

I can't say for sure but I just had one built and I had it custom throated for the 175. I made a dummy round where I wanted it to be just off the land. The boat tail Was slightly below the neck/shoulder junction and it was about 3.575 COAL if I remember correctly. In order to seat the 184 or 190 in a sammi spec chamber I think the bullet would be well below the neck/ shoulder junction.

Out of one 280AI we get 2830-50 out of 180 ELDM in 24 inch barrel w R26. I haven't got to shoot
My new one yet but I think it will be around 2900 24in barrel with 175

 

[LongWalker]

SAMMI spec chamber I'm at 2.729 ogive to the lands with the 175 EH and an OAL of 3.445. The 177 Hammer Hunter is 2.765 ogive to lands with an OAL of 3.430. Bearing surface will obviously be different but it's longer than the 175 EH at 1.665.

 

[Bob Wright]

So here is my dummy round with a 145 Barnes LRX. Next to it is a 180 Berger VLD.
Both visually seated at neck /shoulder.
My SAAMI chamber would need to be lengthened .150 just to seat the 145 Barnes as shown. My CBTO measures 2.721 seated at the lands, so it's close.
Hope this is a good visual. Lance T Kenyon does shoot the 175 EH I believe.

 

[LongWalker]

Lance does and was a wealth of information and help to me.

 

[264MHC]

Thanks for the help guys. Looks like the Saami throat is a little short for what I want to do. The magazine on the rifle this would be going in is 3.7" inside dimension so even with these long bullets in a long throat I should be able to still fit the Magazine. I guess I need to decide if I want to buy a 280ai reamer or do something like a 7mm-6.5 RPM since the cost wouldn't be much different at that point.

 

[CEB]

What is freebore length on SAAMI reamer?