143 gr Hammer Hunters in 7mm rem mag

[Jbumblebee]

7 mm rem mag
Remington 700 ADL 24" barrel
1:9.25 twist
Gun Werks once fired brass. Neck sized, trimmed, primer pocket deburred and cleaned
Federal Large Rifle Magnum primers
143 gr Hammer Hunter
c.o.a.l. 3.684" to fit magazine
7828 SSC
64gr 2976 2994
65gr 3019 3014
66gr 3026 3116
67gr 3089 3093
68gr 3163 3119

I only shot two strings because my primer supply is slowly dwindling. The best group ( 1/2" ) was with the 65gr rounds. I used my Pact1 chronograph 8' from the barrel of the rifle. The wind was intermittent and maybe 2-3 mph coming from my back. I plan on doing more 65gr loads to see if they expande on contract.

 

[RockyMtnMT]

Looks like you have a ways to go to get to pressure. I would expect to see about 3350 fps on the top end. Gunwerks brass is tough stuff and should have no trouble handling the pressure. I would continue working up like you are but only 1 shot per charge. This will save on components. Shoot at the same target with every shot. This will give you a good idea if the rifle is liking the load. Once you find some pressure then back off a bit depending on how hard you hit pressure. Then start loading multiples and see if there is any need to tinker the load. Usually there isn't a need to tinker.

 

[codyadams]

Using H4831sc I am running them at 3250, I hit 3300 or a shade over at pressure signs. 24" barrel. I would bet there is another node up higher in your work up. A 143 grain bullet at 3019 isn't very far out of reach of a 6.5 creed.

 

[Jbumblebee]

i should have added the targets with the original post. I was happy they were on the paper, to begin with.

 

[RockyMtnMT]

With most rifles we see things tighten up as the pressure comes up. Some rifles just shoot everything.

 

[Philward]

Interesting, I loaded some 145lrx from Barnes in my 7rm that was an adl from the 60s, used 65g 7828ssc for some tight groups. Chrono was broken so not sure of velocity. It not a hot load but right below Barnes book max.

 

[Shane Lindsey]

Using H4831sc I am running them at 3250, I hit 3300 or a shade over at pressure signs. 24" barrel. I would bet there is another node up higher in your work up. A 143 grain bullet at 3019 isn't very far out of reach of a 6.5 creed.

Yeh, you have plenty more steam. Keep working it up.

I am at 2948 FPS with the 177 and no pressure signs. I could continue up, but why???

 

[billyjo]

I'm watching this with interest, please keep us posted.
My 7 RM only has a 9.5TW so I'm thinking about trying the 131's.

 

[Jbumblebee]

I've loaded up one each of 69, 70, and 71 gr of 7828 SSC to chrony. I also loaded a few with 4831 SC to see what they look like speedwise. I'm also going to chrony my hunting load Barnes 160 TSX FB with 61.5 grains of RL22. The main reason I'm trying these new loads is due to the scarcity of RL22.

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[Flackin Hoover]

How close would the 7 WSM be with this powder bullet combo? not neccesarily the charge wieght , but the 7828, and the 143 HH?

 

[RockyMtnMT]

How close would the 7 WSM be with this powder bullet combo? not neccesarily the charge wieght , but the 7828, and the 143 HH?

The wsm might need faster powder in order to get enough in the case if you have to seat for a short action.

 

[Jbumblebee]

I went up three more grains. I'm going to overlay the targets and see how they look.

69​	3.663​	3049​
70​	3.681​	3091​
71​	3.683​	3093​

 

[Mark37082]

I must be missing something. At 68 gn you were over 3100 and added 3 gn and dropped to 3093. Something changed. Same powder and bullet?

 

[Jbumblebee]

I must be missing something. At 68 gn you were over 3100 and added 3 gn and dropped to 3093. Something changed. Same powder and bullet?

I'm wondering about that also. It's what the Chronograph read. the only difference could be the seating depth which was minor or the barrel temp. Maybe even the battery dying in the Chrony. They were shot on different days which still doesn't make sense.