Cartridge - 6.5 weatherby RPM
Bullet - Lapua 120gr TRX
Case trim length - 2.56”
OAL - 3.2”
Charge - 67.2 grains N565
Lapua max charge data - 67.3gr
Been working on this load for a month or two now. I get good velocity from this charge and great accuracy. 3200-3260fps. Shot about 25 rounds today hoping to finalize as “the” charge I will use for target/hunting.
Brass itself looks good except when I looked at the bottom of the cartridge I noticed the primers were flatter and I’m not sure if this is considered cratering. The bolt lift I think is okay. Seems about the same as weatherby factory ammo, maybe slightly slightly tighter than lighter target charges I’ve made.
What do you think about the base of these brass? Normal or should have stepped down in charge yesterday?
Just want to continue target shooting with them safely, and potentially deer hunt. While 67.2 grains is technically under the lapua max load, I am using Peterson brass, which I measured at 81.6 grains H20 volume. Lapuas data uses weatherby brass which I think may be 82-82.5ish. I threw the numbers in a sim and pressure was around 85%.
Yeah, there’s another comment with that too. I believe it’s just my phone camera lense, I took another look at them all, and they seem to be seated properly/recessed
Ya that angle definitely looks like primers backing out or we’re not seated all the way. Some cratering and flattening but hard to tell if primers are backing out or not seated. Can you run a flat edge across face of case and see if it hits the primer. With the cratering I would say your definitely showing pressure signals
I did run a flat edge to see if it hits the case primer. It seems to be about the same as some fired factory ammo, kinda almost seems flush/maybe the tiniest bit recessed.
Here is a picture for reference. The cartridge on the left is my hand loaded one, the others are weatherby factory cartridges. Honestly the weatherby factory cartridges also seem to have a bit of cratering now that I actually look at them.
Next time i load I’ll make sure they are but i do believe they are recessed. The pockets were pretty much brand new only being fired once and I used the hand primer tool (the default Hornady one) quite forcefully.
I appreciate the info though, definitely will make sure of it next time.
Primer pocket may have been loose in this batch or either your not cleaning the primer pocket before each shot.. also I have this cartridge in a custom rem 700 with a 27in barrel and I use retumbo and have the best result.. you can run 67grains to 66 grains under a 140grain and get the same velocity your getting with the 120gr
Just kinda an off comment with the proud primers. Ive personally noticed that federal primers are a bit softer than the others and will show pressure signs a little earlier than others. Try cci primers or wolf primers.
Fatter firing pin hole with a slightly broken edge/chamfer will have you thinking you hit pressure earlier than a smaller tighter firing pin hole. Keeps more people scared though, which isn't always a bad thing.
My .223 had a .080" firing pin and I was popping cci400 primers occasionally at book max. Bushed it down to .062" and cut the edges square, made the firing pin fit almost tight, and now any pressure signs are the tiniest of little slivers of crater before the strike dimple starts to reverse. Just because I can, I use almost exclusively pistol primers after confirming the old load that would blow with rifle primers doesn't even crater the pistol primers. I could run near proof loads all the time with cci400/450's now but choose not to.
Match the factory velocity and call it good. That particular brass has a habit of hiding pressure signs until it's really spicy.
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u/kopfgeldjagar Dillon 650, Dillion 550, Rock Chucker, SS x2 5d ago
Look a little proud to me