I have a couple boxes each, the Speer Mag Tip and the Hornady Spire point in 175 grain. Just wanting to know what powder to start with to get the highest velocities and what to expect from a new 24 inch barrel.

Try Rel 25, or IMR 7828.
Usually 66 gr will get you 2800 + but you may be able to go higher, just tread slowly. Watch the magtips, as they have more bearing surface area than the Hornadys do.

Altho I'm a believer in heavy for calibre bullets, I am unsure as to why one would willingly give up 300FPS and the long range capability this splendid round offers, unless loads are being specifically tailored for short range and brush.
I firmly believe that the 160 grain 7m/m is the best bullet for the Rem mag, however, I like and use 175s, I just save them for the 7X57.

Well I never went over 160s in my 7mag but my thoughts. Stay with a real slow powder like RL25. While 7828 works for the 140 lower will work better with 175.

Hornady shows 65.8 @ 58100 for 2873 with a 175 partition. Loadtech shows this load 58650 and 2885fps. When I run it for the 175 mag tip is give me a max of 70.7 @60,000 for 3045.

I have no clue.

IMR7828 is a slow powder & a good choice for the 7remmag. Others to try are RL25 & H870 or AA8700. I would think 2800-2850fps from your 24"bbl.

I'm loading with Retumbo 68.5 gr gives me 2923 fps from a 175 Partition in a 25" barrel. The same load w/ RL 25 is supposed to be a good load. Always start 5% below any load given as each rifle and bullet combo is different and may not be safe in your rifle

In my old Sako, 66 grains of RL22 in Winchester cases goes 2950 fps with a 175 partition. I have considered loading RL25,as I think it should be possible to get 3000 fps, but this load shoots so well I can't see the point for 50 fps. I've shot this load for years, but there is a lot of variation in the amount of powder used with the 7Mag. I'd just up the charge till it was around 2900 and stop. You will use a lot less powder to get to max. with the Speer bullet than you will with the Hornady, so don't try to use the same load.

I am going to try RL 25 first and if necessary Retumbo. Thanks.

quote:

Originally posted by rickt300:
I have a couple boxes each, the Speer Mag Tip and the Hornady Spire point in 175 grain. Just wanting to know what powder to start with to get the highest velocities and what to expect from a new 24 inch barrel.

I used to use Norma N205 then Norma MRP with 175 grain bullets in my No.1B, 26" barrel. I could get over 3050 FPS with 1" groups at 200 yards. Then, when Norma powders became unavailable. I tried RE22, and the best I could do was 2900 FPS. So I tried IMR 7828, and got back up over 3000 with it. It is also accurate at these velocities in my gun.....

I have a half pound of 7828. Enough anyway to run some tests. In searching for loading data H870 seems to commonly provide top velocities in several manuals, has anyone tried it?

I tried it and got the higher velocities, but just didn't get the fine accuracy that I was used to. It also is a pain as you will have to use drop tubes to get 80 grains or so in the case. I don't mind using the drop tubes if I'm getting great accuracy, but to pick up 50 fps it just didn't work in my rifle.

Well Iworked up to 64.0 grains of Reloder 22 which is 3 grains above max in the Reloder manual. Primers are flattened some but nothing extraordinary and cases easily extracted. Off to the range next week. Cases are Remington, primers are CCI 250 and the bullet is Hornady's 175 grain Spire point. If it shoots well enough it will certainly work on feral hogs and deer.

I loaded both 160 grain Speer Hot cors and the Hornady 175 grain Spire points on top of the same charge in an attempt at getting a similar point of impact and I achieved that and 3/4 moa on top of it. Very pleased with RL22.

H870 will bust 3000 fps with the 7Mag in some rifles. You'll load possibly as much as 80 grains and will need to use a drop tube and Win. cases. You will definitely not want to use the same charge with Speer and Hornady bullets. the Hornady will need the most of any you will try, the Speer the least. My old Sako wasn't compatible with H870, I shoot a lot of 175 NP with RL22 and it goes 2950 fps and always under an inch.

I load 66 grains of RL22 and have for years, but this load is not safe in most rifles. Mine is quite old and probably has some throat wear or wouldn't take that much powder.

RL-25 From 53.2 grains to 68.5 grains
CCI-200 Primer