crazyhorse
Well-Known Member
Back in the spring I decided to design my own reamer for a 7mm Rem Mag. I've never done anything like this before and was slightly intimidated, but I was inspired by all of the success with folks making their own reamer for the 300WM and 215 Berger. Figured I'd spent 250ish dollars on dumber things in my life so what the heck...
Using the same logic I took a sized piece of ADG brass (all I use) from my die and seated a Berger 175 Elite Hunter where the base of the bullet was even with the base of the shoulder. Bonus was the Nosler 160 Accubond seated almost exactly the same due to the ogive difference from the Berger. After finishing my dummy round, I sent it off to JGS for a set of prints. The folks at JGS were awesome and took the time to help a hobbyist get exactly what I wanted.
I was due a new barrel and ordered a Bartlien varmint contour 1-9t while I waited on the reamer to be finished. Reamer took about 3 months and eventually all my new parts were sent to the smith who had it together in short order.
Now for the good part!
The Berger 175 EH is averaging 3057fps using 70.5 of retumbo @ 3.845" OAL base to ogive and groups are averaging in the .4's
The 160 Accubonds have been nothing short of amazing!
I'm getting an average of 3160fps using 74.5gr of IMR8133 @ OAL of 3.900" with an SD of 4 and ES of 11!!
I only shot 10 rounds today and all were with the magnetospeed attached but groups were under an inch and I'm betting will be better with the MS off the barrel.
Bringing an already long story to a conclusion, designing my own reamer was (for me) a huge success!
I'm able to get a good bit more velocity from seating the bullet farther out without increasing pressure. Both of the loads mentioned above show zero signs of pressure and I'm running slightly above for the Berger and and just under book max for the Accubond. An added bonus is factory ammo will chamber and shoot just fine in a pinch.
Using the same logic I took a sized piece of ADG brass (all I use) from my die and seated a Berger 175 Elite Hunter where the base of the bullet was even with the base of the shoulder. Bonus was the Nosler 160 Accubond seated almost exactly the same due to the ogive difference from the Berger. After finishing my dummy round, I sent it off to JGS for a set of prints. The folks at JGS were awesome and took the time to help a hobbyist get exactly what I wanted.
I was due a new barrel and ordered a Bartlien varmint contour 1-9t while I waited on the reamer to be finished. Reamer took about 3 months and eventually all my new parts were sent to the smith who had it together in short order.
Now for the good part!
The Berger 175 EH is averaging 3057fps using 70.5 of retumbo @ 3.845" OAL base to ogive and groups are averaging in the .4's
The 160 Accubonds have been nothing short of amazing!
I'm getting an average of 3160fps using 74.5gr of IMR8133 @ OAL of 3.900" with an SD of 4 and ES of 11!!
I only shot 10 rounds today and all were with the magnetospeed attached but groups were under an inch and I'm betting will be better with the MS off the barrel.
Bringing an already long story to a conclusion, designing my own reamer was (for me) a huge success!
I'm able to get a good bit more velocity from seating the bullet farther out without increasing pressure. Both of the loads mentioned above show zero signs of pressure and I'm running slightly above for the Berger and and just under book max for the Accubond. An added bonus is factory ammo will chamber and shoot just fine in a pinch.
