Help me rescope and reload for Christensen Arms Summit Ti.

[robby denning]

I wouldn't argue with you Pathfinder, but I'm outta time. Season opens Oct 10 and I have an archery hunt between now and then and too much work in between. I'll likely swing back on this project as Mike suggested above now that I know the potential of some of these loads. I'm running the Vortex LRBC right now and next trip to range I'll be sighting in and checking hash marks. Thank you.

 

[robby denning]

Pathfinder, you reminded me of an article I did on SD a few years back. I think you and I are talking the same language here. It's a different way to arrive at it but the 10 shots you recommend would produce the same data:

Understanding Your Rifle's Performance Through Standard Deviation - Rokslide

 

[PathFinder]

Pathfinder, you reminded me of an article I did on SD a few years back. I think you and I are talking the same language here. It's a different way to arrive at it but the 10 shots you recommend would produce the same data:

Understanding Your Rifle's Performance Through Standard Deviation - Rokslide

Right on the same train of thought for sure. I like having both the velocity SD and the 10 shot group to gather more data. I've screwed myself up by mass producing loads that weren't what I initially thought they were by going off of one three shot group that ended up being a fluke. I like the idea of calculating an SD for physical bullet impact too. I haven't done that before but it's a good idea. I get where you're coming from running out of time, seems like I end up in that boat more often than not! It's hard to accept anything but perfection from a weapon system when we put so much into every other aspect of the hunt. Good luck man, let us know what you decide and how it turns out!

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[robby denning]

I've screwed myself up by mass producing loads that weren't what I initially thought they were by going off of one three shot group that ended up being a fluke.
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me too!!!!! and I'm hoping this ain't one of those times.

 

[danmayland]

(My previous comment regarding temp sensitivity of the reloader powder was directed at RL22 (I thought that's what I'd read for the loads). RL26 is a different animal and should be very STABLE for temp swings!
If you had more time, I'd run that lowest ES RL26 all day long. You can tune the seating depth to get it to shoot better I guarantee.

But if you're out of time, run the 4831 load that shot the best and make sure you have a good zero and verified velocity. Play with RL26 after this season.

Mike


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This would be my suggestion as well. Don't disregard the Quest for low sd and Es. This is where your accuracy will lie. You'll just have to tune the load to get there.


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[robby denning]

OK guys, I just ran the Vortex LRBC. I've had pretty good luck with this ballistic calculator on three other Vortex scopes, including a muzzleloader project and it's been amazingly accurate compared to actual range results.

For those just getting here, part of the reason for the change up was that my previous load--63.5gr R19 w/ 130 gr Berger Classic Hunter-- was only clocking in at 3125 fps, a little slow for this caliber, but like this project, I finally ran out of time so I stopped there and hunted two seasons with that load.

Here is the BDC reticle charts and corresponding drop charts. Depending on your screen res, you might/might not be able to see them, so I'll type them out too.

130 gr Berger Classic Hunter at 3125fps:

So my last hash mark was at 670 yards

Energy at 600 yards was 1342 ft/lbs

140 Berger Classic Hunter at 3127fps

So my last hash mark is at 697 yards, a gain of 27 yards

Energy at 600 yards is 1582 ft/lbs, a gain of 240 or 18%

140 Berger Classic Hunter at 3357fps

So my last hash mark is at 766 yards! A gain of 106 yards

Energy at 600 yards is 1878 ft/lbs, a gain of 536, or 40%!

I'm no guru, but those are some good numbers to me, and completely worth the effort.

The unknowns are that the LRBC doesn't list my Razor 2-10x40 LH so I'm using a Viper 3-9x40. But I've substituted other scopes in the LRBC in my other projects as some of those scopes weren't listed either and it made no difference. My only guess why is that Vortex BDC subtensions are the same in all their scopes?

Also, I haven't verified these numbers at the range, so they could change. And as Pathfinder pointed out, I'm working with a small sample size for groups, so accuracy might end up below what I'd accept (1" at 100)

 

[N2TRKYS]

I'd run that RL26 load and not worry about it.

I hope to test my RL26 load out the first week in October. I'm averaging 2950 fps with 160 grain Accubonds in a factory 22" barrel(Model Seven).

 

[robby denning]

N2Turkeys, i’m at the bench right now trying to decide what to do and I look up and notice this

Certainly a sign from God

I think I’m gonna go with...



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[N2TRKYS]

N2Turkeys, i’m at the bench right now trying to decide what to do and I look up and notice this

Certainly a sign from God

I think I’m gonna go with...



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It's like seeing a bright light and hearing angels singing. Lol

 

[robby denning]

Just reading what everybody said about ES, SD and looking at all the loads I shot yesterday, including those that I didn’t post the ES, SD, the lowest numbers are with the R26. So if I consider velocity, ES, and SD, and not just smallest group, then R26 is the best choice at this point. Mike is right that I can always swing back later, just hopefully doesn’t take two years like it did this time.

I just loaded enough rounds to check all my hashmarks, so that’s where I’m headed in the morning. Thanks for all your help everyone.


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[maninthemaze]

When I said R26 wasn't temperature stable, I was referring to an email I received from Alliant Powders. Maybe they have changed their powders since they sent me the email. They did say that their "powders were stable enough for the temperature ranges normal humans would be shooting in". Either way, it was something I wanted to put out there. Like I said, you might not shoot far enough for it to really matter. I used R26 in my 7wsm with fantastic results. Shooting the Berger Classic and it's BC of .528, having a 50fps swing in velocity, only changes the POI 3" at 700 yards, and 7" at 1000. You might not shoot that far, yet. LOL.

I got to were I prefer the temperature stable powders because I routinely have to do load development in the summer here in KY, and then hunt in the west. So I do load development at 500 feet and 90 degrees and 85% humidity. Then last year, I hunted in Wyoming at 7,000 feet and 40 degrees. So having a temperature stable powder took one less thing out of the equation.

Either way, great shooting. And this has been another great thread that I have picked up a few tips from. Danmayland and HellsCanyon really helped me with my 28 Nosler frustrations. They are very very knowledgeable and a tremendous asset to Rokslide.

Just my 2 cents and worth the price charged.

 

[maninthemaze]

Here's the email I received from Alliant....

Eric,
Alliant has three temp stable propellants by their chemistry. These are AR-Comp, Reloder-16 and Reloder-23.* Reloder-26 by its chemistry is not temp stable, but in most applications it behaves much like a temp stable propellant.* The Reloder-33 is not at temp stable propellant. That being said, all of our propellants need to pass, by lot, testing procedures in a wide range of temperatures, wider than any self-respecting human would be hunting or shooting under.
As for load data for the 28 Nosler, Alliant has no tested load data for this cartridge at this time.
I will submit your request to the engineering lab for possible future development. But, there is no timetable as to when this may be looked at for development.
Thanks,
Duane V.
Technical Services Rep
Alliant/Blazer/CCI/Speer

Just my 2 cents and worth the price charged.

 

[robby denning]

Hey Eric, thanks for sharing that and several of us had heard that same thing. Weren’t taking a jab at your earlier comment at all. And as you point out, these are small differences unless a guy’s getting way out there in yardage which isn’t me. Thanks for your insight too.


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[maninthemaze]

Certainly didn't take it as a jab. I've got thicker skin than that. LOL

And I'm certainly not an excellent shooter or reloader for that matter. My farthest shot on an animal to date was 482 yards, laying prone. I practice at much farther distances. But if I can't make a cold bore shot at a milk jug with positive results, I'm certainly not gonna shoot at an animal. Reading the wind is my downfall. Not enough practice.

I'm hoping to read some hunting threads from you in the very near future.

Just my 2 cents and worth the price charged.

 

[robby denning]

Went to the hills Monday morning to check hash marks. I don’t belong to a range cause I can’t stand waiting for everyone plus all the BS sessions that take take up all your shooting time. This place lets you shoot to about 700 within 10 degrees up/down slope

Used Vortex’s LRBC to predict hash marks

-100 yds called for 0.7” high, so I sighted to that

-200 yards is center cross and dead on, skipped it

-309 was predicted for 2nd hash Mark, shot 3.5” group and 2.5” low. I gave the scope 1 click (1/4 MOA) up and 1 click left.

-480 yards was predicted for 3rd hash mark, shot 12” group, 7” low. Pretty sure the bad group was me looking at the MOA groups at 100, 309, 620

-622 yards was predicted for 4th hash mark, shot 5.75“ group, and again 7” low

Last hash (top of bottom post) was predicted over 750 and I won’t shoot that far so I didn’t check it, but for you longer range guys, you can see the potential of this gun/caliber/scope if you want an ultralight gun that will get you to 700-ish

This is the first of four Vortex scopes that didn’t track exactly with the LRBC.

Called Vortex CS, and Paul helped me verify my true hash marks using their LRBC verification process. It adjusted my 309 to 280, 480 to 420, and my 620 to 550. I don’t have my journal with me, but 5th hash was about 700.

He couldn’t explain exactly why this scope didn’t track with LRBC but suspects it needs updated for this particular Light Hunter scope.

Theoretically I could just print my dope card and hunt, but I’m going to check it again. I’ll let you know





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[danmayland]

Yikes that's no Bueno! I'd keep working the loads. She should be shooting better. 12" group at 480 yards is like 3moa!

I really don't like the idea of you having to memorize those awkward hash mark yardages. You should really consider going to a turret dialed system. So much easier and quicker to use!

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[danmayland]

Here's a video on measuring and understanding bullet runnout.

Measuring and understanding bullet runnout - YouTube

In the video I mention that nine times out of ten fliers are attributed to runnout and or inconsistent neck tension. This is of course all things considering is that you executed the shot properly and in the exact same fashion as the previous shots.

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[robby denning]

Here's a video on measuring and understanding bullet runnout.

Measuring and understanding bullet runnout - YouTube

In the video I mention that nine times out of ten fliers are attributed to runnout and or inconsistent neck tension. This is of course all things considering is that you executed the shot properly and in the exact same fashion as the previous shots.

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Thanks danmayland, I'll check that out!

But like I said, the 480 group was probably me. Look at my 100, 309, and 620 groups, they're close to MOA and even below. This is a sub 7.5 gun and very hard to steady--you can see the shake in the crosshairs.

As an outfitter and a hunter, I found that it's faster to memorize hash marks than to dial in the field. Seems like a lot of numbers to work with at this point, but once my hash marks are set, I just count down from the main crosshair each yardage. It will be taped on my scope too. I watched a good buck walk from an experienced long range shooter two years ago as he was trying to dial for elevation and wind (buck was at 700 yards). If you're interested in my reasoning, it's here:

Hash Marks or Turrets? A Mule Deer Hunter's Perspective - Rokslide

I just verified my 3rd hash mark at 420 yards and it was sub-MOA (2 shot group, getting low on ammo). I'll post it in a minute. It's on my phone.

 

[robby denning]

Here is my 2 shot group from yesterday at 420 yards.
Ignore the hole marked “65h”. That was my barrel fouler. Interesting that it grouped with the others though

I had a crosswind but I think I judged it pretty good so I’m confident in that group and am pleased it’s exactly what Vortex said it would be after we verified my trajectory.

That’s the 4th out of 5 groups from 100 to 620yds that we’re MOA or less, so it’ll have to be good enough until I get more time.


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[robby denning]

Good video danmayland! super easy to understand what runnout is and it looks easy to fix, too. That will likely be my next gauge on my bench. Wish I had more time!!!! Thanks for sharing. Everyone on here should watch that video if you don't already understand the concept.