Not the first time... 7mm Rem Mag - issues with ELD-X 175gr.

[coyotezapper]

I do understand, but look at it from my point of view. Am looking for a swift load for a Magnum cartridge with high BC heavy-for-caliber bullet. If I would start somewehere around 64.0gr MRP-2, it will produce velocity approx. 2650 fps. To achieve at least 2800 fps I've to load at least 68 gr. It will make no sense if I would hit some node around 66-67 gr., it will be still slow. Thatswhy I started with 68.0 gr and worked up in 1/2 grain increments up to 70.0gr. My QL velocity calculation correlate pretty well with LabRadar measurements.
I still have some bullets so tomorrow will the story continue on the range.
Thanks for your post.

I've run the numbers in Berger's twist rate stability calculator, please, see yourself.
Click on preview for bigger pics.

After you chrono are you adjusting your QL variables to match your actual velocities? You stating you are close to QL predictions tells me no. Go back into QL and change those variables to make QL match your results 100% and then your graph will tell you where your best charge will be or close to it.

There will be several powder nodes that can be seen and correct QL inputs can help you identify these but certain inputs have to be correct. Case capacity, burn rate and temperature have to be inputted correctly for QL to work.

Even your seating depth testing has no methodology to it. The Berger website has a good article on seating depth adjustment.

Why are you testing groups at 300 yards. Again too many variables that can affect your results. If it shoots at 100 yards it will shoot at 1000 if the powder node is good.

 

[lovec_1]

Will you list your charges and velocities for the MRP2 loads so we can see what you have going on?

MRP-2 with 0.02" jump:
68.0gr : 2877, 2885, 2882 fps
68.5gr : 2939, 2944, 2946 fps
69.0gr : 2952, 2960, 2961 fps
69.5gr : 2969, 2975, 2977 fps
70.0gr : 2979, 2987, 2983 fps

MRP-2, 66.5gr.
0.04" jump : 2795, 2792, 2782 fps
0.06" jump : 2783, 2797, 2786 fps
0.079" jump : 2782, 2785, 2785 fps
0.098" jump : 2778, 2788, 2779 fps
0.118" jump : 2789, 2779, 2784 fps

MRP-2, 66.0gr.
0.004" jump : 2765, 2752, 2759 fps
0.01" jump: 2755, 2765, 2765 fps
0.138" jump : 2763, 2775, 2778 fps
0.157" jump : 2723, 2736, 2742 fps

 

[lovec_1]

After you chrono are you adjusting your QL variables to match your actual velocities? You stating you are close to QL predictions tells me no. Go back into QL and change those variables to make QL match your results 100% and then your graph will tell you where your best charge will be or close to it.

There will be several powder nodes that can be seen and correct QL inputs can help you identify these but certain inputs have to be correct. Case capacity, burn rate and temperature have to be inputted correctly for QL to work.

Somehow the "node predictions" didn't corresponded with real world results...

Even your seating depth testing has no methodology to it. The Berger website has a good article on seating depth adjustment.

As you can see in previous post, I did more detailed seating depth test than Berger recommends...

Why are you testing groups at 300 yards. Again too many variables that can affect your results. If it shoots at 100 yards it will shoot at 1000 if the powder node is good.

Because I am competitive shooter and long-range hunter, this is part of my training. On the 300 meters range where I usually test my loads, there are practically none other variables as on the short 100 meters range. The range is relatively narrow and both sides are protected with walls.
If it shoots at 100 meters, it may shoot well at 300 meters. But I found in some cases that the load which was great at 100, later came apart at 300. Testing first at 300 spares me the potentially useless testing at 100.

 

[lovec_1]

Today I have tested more loads with Hodgdon 4831SC, charges between 63.0 up to 66.0 gr. Velocities from 2850 fps to 2960 fps. No success, bullet holes all over the target. Not the smallest indication of some grouping.

I love my old Sako and don't wanna burn great barrel because of non-working bullet. I will give the rest of the bullest to some friend with 7mm caliber.
As next I will try the 175gr Accubond LR. Maybe it will give me the desired result.

 

[SergeantD]

Hi guys, hereby I'm asking for any help.
Here is the story: I shoot older Sako rifle, it has 24.5" long factory varmint barrel with 8.66" twist. Last two seasons I've shot Berger Hybrid 180gr. very successfully. But I love to try always something new and different. So I bought two boxes of Hornady ELD-X 175gr. Also have brand new Sako cases with measured capacity 87.7gr of water - little bit bigger then usual.

First attempt: bullet seated 0,02" off the lands, five loads with Norma MRP-2 from 68.0 up to 70.0gr., velocities between 2877-2985 fps. Accuracy - terrible. At 300 meters I got wild groups around 5 to 8 inches. Useless.

Second attempt: I was told to try bigger jump. So I prepared five loads with 0.39"-0.59"-0.79"-0.98"-0.118" jump. Loaded with reduced amount 66.5gr. of Norma MRP-2. Best 5-shot group at 300 meters measured roughly 4.5"-5". Again nothing world-shattering.

Third attempt: Tried more jump. Also a less jump, closer to the lands. So this time jumped 0.004"-0.008"-0.118"-0.138"-0.157". Loaded with 65.0 gr. of H1000 and with 66.0 gr. of Norma MRP-2. No luck again except one load.
Three shots at 300 meters, load of 65.0gr H1000 jumped 0.157" gave me unbelievable group of 0.90". Very happy with it but it's terribly slow, only around 2690 fps.

After this I tried faster loads with 0.157" jump. I've loaded again H1000, Retumbo and Reload Swiss RS62 (similar to Reloader 16). I got higher velocities but again nothing worked. Holes spreaded all over the target, no grouping.

So the question is - I never give up - where would you start again after all this? Any advice, criticism or idea is highly appreciated.

Thx.

 

[SergeantD]

Finding the right bullet for a particular rifle can be mind boggling. I also shoot a 7RM and found out quickly that it didn't like Nosler Partitions. You would think premium bullets would perform better than others but this is not the case. It seems my Ruger M77 only likes Hornady and Speer bullets. Like others have said, try another brand and go from there. Make sure the twist rate of the bullet you pick matches your barrel twist rate. This will ensure bullet stability in flight.

 

[6.506ai]

Not sure which one! But your mate is running about 11% over any published Max Load that I can see. He's loading hot for sure. Or does he shoot a 28" barrel?

26inch barrel. He's done lots of reloading. They are up there but not pressuring out.

 

[DartonJager]

I'm a HUGE believer in try the cheapest easiest solution first. As you already have bullets that you KNOW work stick with them. Absolutely LOVE Speer Grand Slams but no matter what I did wouldn't shoot worth a pile of pigeon droppings out of my M700 338wm which shot Nosler Partitions lights out good.
Stuck with the NP's till I tried the NAB's and they shot even better. Now I always try a NAB in all my hunting rifles and every one has shot NAB's quite well and that includes a 300wsm, 7mm STW, 308/W, 6.5x55, and a two friends 300wm's I make reloads for.
Rifles are like people, some just defy all logic and don't like what they should love.