ascast wrote on Apr 25^th, 2026 at 1:38pm:


I have a similar firearm, I have never fired it. I ask myself why did I want it, I don’t shoot a shotgun, but I did buy 40 rounds of S&B ammo. I read the same information as you. Basically 280 Remington reduced do to the weaker break open action. It has a single set rifle trigger.
Mike

As I understand it, the 7x65R loads are already reduced from the 7x64 loads because the rimmed cartridges were expected to be used in all kinds of break open rifles (singles, doubles, combos, drillings) of many vintages. Mine happens to be a strong falling block single (Heeren) but I felt no need to even think about exceeding the data published for the 7x65R. It is a potent cartridge as is. That said here are some velocity figures I recorded for loads with the Speer 160 grain Grand Slam bullets at an OAL of 3.41 inches: 4350 47 to 50 grains 2280 to 2611 fps; 4831 49 to 51 grains 2205 to 2358 fps. Some of the loads I tried with the Lyman 287308 at an OAL of 3.457 used the following powders and amounts just for fun: Unique 11 and 12 grains; 2400 16 and 17 grains; 4759 22 and 24 grains; Red Dot 11 grains. I didn't record the results on target with any of these since before I got serious with anything my friend talked me into trying his 6.5x57R barrel on the rifle. From memory though, the Speer loads shot very well. (The 6.5x57R factory loads are real whip crackers, too.)

In my old Speer manual it says to use 280 Rem. and 7 X 64 data interchangeably.  I used to have a 7 X 64 Brenneke and just to feel comfortable used starting data, and never needed more.  I would think a slightly reduced 7 X 64 starting load would suffice.

Found some more data. Note - while the 280 Rem and 7x64 Brenn can use the same data their max pressure is 60,000 psi (C.I.P. 415 mpa) but the max pressure for the 7x65R is limited to 55,000 psi (C.I.P. 380 mpa). Here's some German published data in charts in this thread in post #7 (note the loads are Max) (You need to Login or Register to view media files and links)'s%203800%20bar%20limit.
Also note for what it was worth back before 2020, a guy way down on page 3 didn't like S&B brass saying it was prone to head separations but there were no other comments on this. I seem to remember to having had a choice between Norma and Lapua brass.

Thanks all - I think I can reduce 280 or 7x64 loads by 10% on powder and be safe and work up from there.  I am looking for a deer killing load for 300yd; standing broadside shots only.
On DIES - Can 7x64 be used if I am 1) mindful of longer length - or 2) trim back about 30 thousands ( 1 mm plus). I don't see throat/chamber erosion as an issue.  I can get a Lee set for about $40, the other guys are way out there.  Currently have 7mm Lyman 310 stuff that will get me going.  I have correct shell holder.
On Bullets - what jacketed to use for whitetail 300 yd kill ? too expensive for trial and error

thanks all