.300WM Christensen Arms Load Development

[300RUM]

A range in a trench??? That has to be a real treat after a heavy rain.

[lancetkenyon]

After the ladder test, and shooting 3 of the factory HSM loads that were very inconsistent, inaccurate, and too hot, I pulled , he remaining 17 apart. I was kind of shocked at the results. Charge weights were off across the 17 rounds by over .5 grains.

 

 

 

 

 

[Big Browns]

Typical factory ammunition! That's really too bad considering how expensive that ammo is.

[HuntHarder]

Did you contact HSM and ask them if this is their norm? I would be interested to know if that is acceptable to them. Have you done a burn test to try and determine what powder you think they are using?

[duckhunter175]

VERY DISAPPOINTING!!

 

I've used their ammo in 25/06, 7rm, 7RUM, 30/06 and always had sub-moa results...

 

If you contact them I'm interested to hear what they say.

[lancetkenyon]

So too make a long story fairly short, I also shot my own charge weight testing loads. If you remember, the factory Winchester stuff shot about 2.5", and the factory HSM stuff shot over 4" groups at 100 yards.

 

I can say my loads shot significantly better after finding a good node in my ladder test.

 

Here were my charge weights I was testing.

 

 

I also seated them with a .0100" jump this time.

 

 

 

 

 

 

 

 

 

 

First group was just over 1", and it went down from there. 1", .8", .6", etc.

 

Here were the last two groups before it started to open back up.

 

This one is right at .6" for 3 shots

 

 

And this one is about .3" for 3 shots

 

 

So next is seating depth testing. I hope to at least remain as tight as this, and if it goes down, that will make me ecstatic. An 8.7# .300WM that shoots in the .3s? Yeah, that would do just fine.

[Big Browns]

This is a great thread. Great job Lance!!!!

[dse]

What did you think of the Swaro X5?

[lancetkenyon]

Funny you should bring this back up. The Swarovski X5 3.5-18x50 is a very clear scope. Good glass, good color, hardly any CA. Turrets are OK, not great, but not bad either. It seems to track well also. I have taken it from 100 to 952 yards, and while I have not confirmed it returned to zero from the longer ranges this weekend, it seemed to track where I needed it to go between 100, 200, 100, 600 (dead on), 802 (just a touch low impact center of group), and 952 (just a touch high impact center of group). It is not an illuminated reticle, which I prefer for a hunting scope. But it has a decent reticle in the BRM variety. It is still a BDC type, and not a true MOA type reticle, but if you know your drops, and verify, it should work fine. It is also a SFP scope, so the reticle stays consistent at various magnifications.

 

Over the last 2 weeks, I have also finished my testing.

 

I do not have a ton of photos of the seating depth testing, but I did see a difference in the group sizes. This rifle seems to like a lot of shooter input as well. I think being so light, you need to really get behind it and pre-load the bi-pod consistently to manage recoil. I tested at 200 yards, and the best seating depth was 2.783" CBTO. It shot just about .75 MOA. I could not recreate the .3MOA that I got at 100 yards during charge weight testing with any seating depth at 200.

 

 

 

 

 

 

 

I also got out this weekend to verify at some longer ranges.

 

 

I was quite pissed off at myself for the first 4 rounds. I thought I had a good shooting lane picked out at 600, and dialed for elevation, held for a 2.2mph L-R wind and allowed for a bit of spin drift. First shot was about 2' high and 2' right......WTF? Second shot was low and left....WTF????? Third shot was low and 3' right.....WTFFF??????

 

I decided to break out one of my proven rifles and let a few fly.....my 7RM pushing my known 180 Hybrid load was about 2' right and a foot high........AARGH! Tried 2 more shots, with crazy results. High left, high right. I was fuming at this point. I had my son-in-law take a shot while I watched through the spotter this time...... right by about 2'. But, I found the issue. When he shot, I was watching the vapor trail and saw a piece of desert shrubbery fall about 150 yards out. I had been hitting a bush I thought we would clear and deflecting bullets all over the place. About a 4-5' difference in POI just because of a few tiny branches and leaves.

 

I walked out and trimmed them off, and shot for confirmation with the .300WM. Boom...clang! Better, much better. The wind was picking up, so I had some horizontal dispersion, but not terrible for 600 yards. Thank goodness we had a truck to run back and mark the groups.

 

 

 

Moved back to 802 and the winds lessened for a while, allowing me to shoot this group.

 

 

 

 

Moved back to 952 and the winds picked up again, and the shooting conditions were not the greatest. Holding for windage, I had a few just off the right side, but I did not want to change wind holds to see how the rifle was doing. Since I can't plot the misses for POI, I am going to hope it was about MOA? Probably slightly more.

 

 

 

After I finished confirmation, the winds really picked up and it actually started spitting rain, so we packed it up and headed home. I was hoping to shoot a ladder test on a new 168 SMK load I have been toying with, but did not get the chance. Look for that thread to follow soon.

 

All in all, I am fairly happy with the rifle and load. Final load will be a 190 Berger HVLD @ 3070fps under MOA in an 8#+ rifle. I think it is a great mid range light carry mountain elk rifle option.

[dse]

For just best glass would you give the edge to the X5 Swaro, or the K624 Kahles?

[lancetkenyon]

1. Kahles K624i Gen 3

2. Swarovski X5 3.5-18

3. Kahles K624i Gen 2

 

But everything else on the Kahles K624i Gen 2 kills the Swaro X5. Glass is very close on the Kahles Gen 2 & Swaro X5. The Kahles Gen 3 beats the Swaro X5 in every field except CA.

[300RUM]

I had been keeping a list for you of GPS coordinates of prefect trees to wrap a rifle around. Should I just delete it?

 

There is a point in life where a nice lightweight rifle becomes a necessity, not just a desire. I passed that point a few years back. With an accurate load that sounds like a sweet light weight rig.

[Redman]

Thank you for taking the time and detailing your actions with this thread, I really enjoyed it (sounds like you didn't while in the middle of it) but I commend you and your skills for loading. Wish I could load like you.

[Big Browns]

I thought I was the only one who said WTFFF while at a range:)

[dse]

Thanks been going back and forth between the two for months. Just ordered the K624 CCW MOAK.