Absolute Hammer's 7mm mag......Strange result

[Longtine88]

Ok, new rifle and first time trying the absolute hammer for 7mm Mag and 154 Grainers. Used Reloader 23. I had 50 prepped and primed cases ready from last night. Got home late and only 40 mins of shooting light and I couldn't resist trying a few so put on the Magneto Speedo. I loaded the first 7 just to find the velocity of the combo and was nervous about it so I loaded 7 rounds at 1 grain increments. Started at 60 grains then went 1 grain each load to 66 grains, seating depth 0.020" from touching the lands.

60 2849 FPS
61 2890 FPS
62 did not record
63 2960 FPS
64 3005 FPS
65 3060 FPS
66 3072 FPS

So at this point still no pressure signs so walked back in and loaded a few more

66.5 3204 FPS Primers started to flatten
67.0 3204 FPS Primers flattened and small shiny mark on head stamp
67.5 3225 FPS All the above with sticky bolt. Stopped here.

So you know that data doesn't look all that crazy little flat spot found even with the large gap in the grains of powder. The crazy thing was this, 60 grains started 4" high straight up no horizontal deviation. 61 was .25" below the 1st shot and 0.10 right horizonal shift. 62 about the same about .25" lower than previous spot and 0.1" right of it also. This kept the pattern to 66 grains on the 7th shot low and right each time of the previous spot. Then on the next batch 66.5 went 1" right of the 66.0 previous shot. 67.0 went .25" right 66.5. 67.5 went 1.5" straight up above the previous two. So It seems like I will be exploring the 66.4 to 67.0 range on the next day I get to shoot.

I just found it interesting that the groups were headed down instead of up. It's almost like the string of 10 shots where making a sine wave on paper headed down and right the up and right.

So, I was curious about the 66.5 shot and I went back in and loaded 2 more rounds up at 66.5 and those two velocities went 3,194 fps and 3,195 fps along with he previous one shot at 3204 fps so that's like a SD of 8 or so.

So what's my plan of attack next time? Play with the node I found or play around with the seating depth. I was thinking of moving the bullet down to 0.070" and play with the powder nodes again. Someone with more Hammer experience give me a little thoughts and opinions.

 

[Bucklowery]

You have good es so stick with that and now seating depth to get groups


Thanks

Buck

 

[Hard rock]

Ok, new rifle and first time trying the absolute hammer for 7mm Mag and 154 Grainers. Used Reloader 23. I had 50 prepped and primed cases ready from last night. Got home late and only 40 mins of shooting light and I couldn't resist trying a few so put on the Magneto Speedo. I loaded the first 7 just to find the velocity of the combo and was nervous about it so I loaded 7 rounds at 1 grain increments. Started at 60 grains then went 1 grain each load to 66 grains, seating depth 0.020" from touching the lands.

60 2849 FPS
61 2890 FPS
62 did not record
63 2960 FPS
64 3005 FPS
65 3060 FPS
66 3072 FPS

So at this point still no pressure signs so walked back in and loaded a few more

66.5 3204 FPS Primers started to flatten
67.0 3204 FPS Primers flattened and small shiny mark on head stamp
67.5 3225 FPS All the above with sticky bolt. Stopped here.

So you know that data doesn't look all that crazy little flat spot found even with the large gap in the grains of powder. The crazy thing was this, 60 grains started 4" high straight up no horizontal deviation. 61 was .25" below the 1st shot and 0.10 right horizonal shift. 62 about the same about .25" lower than previous spot and 0.1" right of it also. This kept the pattern to 66 grains on the 7th shot low and right each time of the previous spot. Then on the next batch 66.5 went 1" right of the 66.0 previous shot. 67.0 went .25" right 66.5. 67.5 went 1.5" straight up above the previous two. So It seems like I will be exploring the 66.4 to 67.0 range on the next day I get to shoot.

I just found it interesting that the groups were headed down instead of up. It's almost like the string of 10 shots where making a sine wave on paper headed down and right the up and right.

So, I was curious about the 66.5 shot and I went back in and loaded 2 more rounds up at 66.5 and those two velocities went 3,194 fps and 3,195 fps along with he previous one shot at 3204 fps so that's like a SD of 8 or so.

So what's my plan of attack next time? Play with the node I found or play around with the seating depth. I was thinking of moving the bullet down to 0.070" and play with the powder nodes again. Someone with more Hammer experience give me a little thoughts and opinions.

Thats sounds like what I would do 66.7 might be your load

 

[Longtine88]

Thats sounds like what I would do 66.7 might be your load

Thought the same as you

 

[GLTaylor]

First curiosity is how you know distance off lands. Absolutes have a reduced ogive that does not touch the lands prior to the driving bands. Are you describing distance from driving bands to rifling?
Second is, bullet impact changes are just a function of barrel harmonics. What you saw is pretty normal.
Third, stick with low es load. Hammers don't generally exhibit sensitivity to seating depth.
If you have some, try R26. You may find better top velocity based upon work of others.
I'll post this. Thanks. Keep us informed of further work.

 

[Sockeye66]

I do find it interesting that the 66 to 66.5gr loads jumped 132fps, considerable when compared to the other loads, but I have used rl23 quite a bit and have seen some pretty good jumps in speed just not that much.

 

[Longtine88]

First curiosity is how you know distance off lands. Absolutes have a reduced ogive that does not touch the lands prior to the driving bands. Are you describing distance from driving bands to rifling?
Second is, bullet impact changes are just a function of barrel harmonics. What you saw is pretty normal.
Third, stick with low es load. Hammers don't generally exhibit sensitivity to seating depth.
If you have some, try R26. You may find better top velocity based upon work of others.
I'll post this. Thanks. Keep us informed of further work.

Well on the off the lands I used a Hornady comparator and ran the bullet out until it stopped. If the bullet didn't touch the lands what stopped it?

I under stand that bullet impacts are different but going down with increase in velocity seemed odd to me as constant as it was.

So you think if I play with the depths it's not going to change much.

I do have lots of powder and yes several pounds of RL 26. Steve told me to try 23 and said the RL 23 had worked good for them. I'll try 26 next time and post the result's back here.

What kind of velocities are they getting with RL 26? I use it in my 180 VLD loads in this gun.

 

[Longtine88]

I do find it interesting that the 66 to 66.5gr loads jumped 132fps, considerable when compared to the other loads, but I have used rl23 quite a bit and have seen some pretty good jumps in speed just not that much.

agree. I was like did I shoot the wrong bullet. Made me double check to see if I skipped a load.

 

[Troutslayer2]

Well on the off the lands I used a Hornady comparator and ran the bullet out until it stopped. If the bullet didn't touch the lands what stopped it?

Hah

 

[Bob Wright]

That .5 gr sure jumped the speed, where Re23 is very predictable in 10 shot ladders.
From about ~37 fps in 1 gr increments to ~130 fps in .5 grain. Some of the original testing showed that pressure can go way up in a hurry. So, I'd say you're bumping into the limits at 66.5 and depending on brass, can it take it?

 

[Longtine88]

Not sure. It was virgin nosler brass. Only thing I could find recently. Waiting on some ADG brass. Was going to run a few ladders on it when I get it. The jump was crazy. I'd never seen a jump like that either before this. Maybe it's the hammer bullets I don't know.

 

[Sockeye66]

rl23 IMO is a great powder, I like 26 also, but in a big case, 23 is ideal. I think Steve gave solid advice. If their is one reloading tool that I have used that has given me the most grief, it's the hornady (stoney point) OAL gauge, I quit using it. I do think it's possible that the OAL could have been an issue with the jump in velocity.

 

[GLTaylor]

If you pushed the bullet forward until it stopped, you were likely hitting the driving bands on the body of the bullet. One of the secrets of the Absolutes and their speed is the modified ogive design of the bullet. On most bullets, the ogive gets to caliber diameter much further down the bullet toward the nose. The earlier engraving contributes to variations in BC from barrel to barrel and rifle to rifle. The design of the Absolute was an attempt to reduce this BC variation from rifle to rifle. The amount of increase in speed obtainable was somewhat of a surprise and very pleasant to Steve and Brian. With less bullet engraving the lands plus the parabolic drag reduction bands, Absolutes frequently achieve 200+ fps increase over standard construction bullets of like weight.

It would be good to read all of the post on "Introducing the Absolute Hammer." A full description of this bullet design and explanation of reloading quirks can be found there. It's a long post, but should be required reading for anyone attempting to load either regular Hammers or certainly the Absolute Hammers. These bullets do not behave like traditional bullets and require different loading techniques.

Regarding seating depth, many/most people seat the bullets so the base of the bullet (intersection of the body and boat tail) is at the bottom of the case neck. Once seated there, the only variable is powder charge. Hammers don't exhibit much preference to seating depth like cup and core bullets can.

We don't have data for a 7 mag and Deadblow Hammers. The SAUM is closest in capacity. R26 gave slightly more velocity in that cartridge with your bullet weight. We do have a data sheet on the 2nd post in the thread Absolute Hammer Load Data- I assume you are familiar with it?

 

[Bob Wright]

Not sure. It was virgin nosler brass. Only thing I could find recently. Waiting on some ADG brass. Was going to run a few ladders on it when I get it. The jump was crazy. I'd never seen a jump like that either before this. Maybe it's the hammer bullets I don't know.

Yes, the Absolutes have different reloading characteristics that you must find where in your rifle becomes a redline.
My opinion is 66.5 redline based on a massive speed jump from 66. I've never seen that with Re23 and using Fed GM215M. Just steady ~30 FPS ladders and low ES once I find a node.
Nosler brass won't last long with flattened primers in my experience.