Sierra 64 grain Game Changer load development

[Joe Texas]

I finally got my hands on a box of Sierra’s new Game Changer hunting bullets for use in .223 caliber. Lacking data, I called Sierra. They told me to use 65 grain Game King data. I have used the 65 grain GK in the past and found it to be fairly accurate with H-4895. 24.7 grains produced .8” 100 yd groups at 3150 fps with a SD of 13. Still, that is nowhere near as accurate in my gun as the 69 grain SMK or TMK.

Using Hornady’s COAL tool, I consistently got a measurement of 2.240 in my 26” Sheilen Wylde chambered barrel (Savage 12 action). This is a much shorter COAL than with 69 grain SMK bullets because the ogive on the Game Changer is located much closer to the tip of the bullet. I attached a pic for comparison. Before anyone asks, no - I don’t have a base to ogive measuring tool.

Based on past tests with other bullets, I decided on a COAL of 2.238 for the initial charge weight test.

I don’t have any H-4895 so I am testing 23.4-24.2 grains of VV N135 in .2 grain increments. 23.8 is my best 69 SMK load at 2.325 oal. I loaded 7 rounds of each charge in Starline brass trimmed to 1.743. (I hope that shortish trim length doesn’t affect me too much.) I’ll see if any of them group at 100 yards today. If not, I’ll start over with Lapua brass trimmed to 1.75 and maybe try the Varget I have stashed away for .308.

When/if I find a load that groups I’ll chronograph it for SD, test @ 200 yards and report back. Out of my rifle, these charges will all produce around 3k+ fps so velocity is more for information about drop/windage than a desired outcome. Acceptable accuracy is the goal.

 

[kmw1954]

Joe, good luck with that new bullet, will be looking for a report on performance.

I just started with the 223 last fall and am still deep in the learning curve. So far I've had use of 5 different bullets and two different powders. So far in my guns with a 1:9 twist I found the 62 to 69 gr bullets are liked the best and the results with the TAC and Varget powders have been very similar.
Sometimes confused by what I am seeing but still enjoying this!

 

[Joe Texas]

Joe, good luck with that new bullet, will be looking for a report on performance.

I just started with the 223 last fall and am still deep in the learning curve. So far I've had use of 5 different bullets and two different powders. So far in my guns with a 1:9 twist I found the 62 to 69 gr bullets are liked the best and the results with the TAC and Varget powders have been very similar.
Sometimes confused by what I am seeing but still enjoying this!

I’m learning as well. My first two .223s were 1:9 twists. I found 52 grain SMKs and 52,53,60 grain V-Max bullets to work well in both. 60 grain SP weren’t bad either.

In this gun I’m loading for now (1:8 Savage bolt w/match grade barrel) I’ve not found anything better than 69 grain SMKs. I’ve tried H335, Benchmark, TAC, RE-15, Varget, N140, N135, H4895, and IMR 4064. It’s hard to beat N135 and Varget in my gun. H-4895 and Tac are close seconds.

I know this:
• Consistency is crucial.
• The goal is finding the biggest pressure window (node?) that produces the most similar POI.
• Some powders/bullets have larger pressure ranges that produce similar POI in a given firearm.
• What works for one gun may not work as well for another. That’s why we hand load in the first place.
• The hand loader can control the factors that influence pressure - prep/uniformity, charge weight, neck tension, seating depth/jump, ect.
• All I know to do is try my best to be as consistent as I know how with the tools I have.
• Reloading is fun, addicting, rewarding, challenging, and frustrating.

Though I’m developing this load as a “hunting” round, I’ll likely only hunt paper with it. Someone else will have to report on effectiveness on game. I’ll be able to report on how well it groups out of my gun though. 69 grain MKs consistently produce 1” 5 shot groups at 200 yards from this rig. I’d be happy to get anywhere close to those results with these.

 

[kmw1954]

Understand that! I have been loading Hornady 62gr FMJBT with Ramshot TAC and found with this combination in my 2 Savages I can load from 23.5to 23.8gr with a large variance in length with little to no change in POI or group size. This bullet is inexpensive at around 14c a pc. so it has become my standard for general shooting and practice. Now just this month I have started with the RMR 69gr HPBT and so far am also highly impressed.

I too am a paper hunter!

 

[Ru4real]

@Joe Texas thanks for the bullet comparison photo. Looks like the game changer has about 1/8” more bearing surface? Interested in accuracy and velocity comparison.

Interested in how your development goes. What is your barrel twist? I’m a big fan of the 55 and 65 Gamekings, thinking about switching to Gamechangers once I find some.

10 rounds, bipod, 100 yards, Colt Match

View attachment 996070

 

[Joe Texas]

Range report:
.223 Remington
64 grain Sierra Game Changer
VV N135 powder 23.4 - 24.2 in .2 increments
Starline brass trimmed to 1.743
Federal Match SRP
COAL 2.238 (.002 off lands)
Savage 12 FV w/Sheilen 26” barrel
100 yards bipod/rear bag
7 shot groups

23.4 - 1.125”
23.6 - .9375”
23.8 - .875
24.0 - .8125
24.2 - .9375

See pic of groups on target.

No flattening of primers at all.

I regret not bringing my chronograph. These groups are so similar that the difference may be more me than the load. I like that @ 23.8 and 24 grains 5 of the 7 touched on a similar vertical plane and measured .5”. I’m tempted to split the difference and say 23.9 is the charge to use for further testing. I’m certain that I wasn’t shooting very well today. I will chrono and test 23.9 grains at 200 soon and report back.

Preliminary conclusion: These seemed to group a little tighter across a broader charge range and fly a little flatter than 65 grain SGKs. Consistent point of impact between charge weights. A better shooter or me on a better day could make ‘em group much better. Imma say they are a winner in the accuracy potential department - especially for a hunting bullet. Plus, they will actually fit in my magazine. So, there’s that.

FWIW - 24.0 grains VVN135 also grouped the best with the 65 grain GK’s also a while back. I have a note that says 1.125”. I’m guessing that was for 5 rounds since I didn’t include that info in my notes.

 

[Ru4real]

Preliminary conclusion: These seemed to group a little tighter across a broader charge range and fly a little flatter than 65 grain SGKs.

Nice. What is your barrel twist?

 

[Joe Texas]

Here’s a pic of my rigs. They are both Savage 12 FV’s (Cabela’s “exclusives”). I replaced the tupperware stocks with Boyd’s thumbhole varmit laminate stocks. The .223 has the stainless aftermarket barrel. The other is a .308 with the stock barrel. The stock barrels are capable of excellent accuracy.

 

[Joe Texas]

Nice. What is your barrel twist?

1:8. It is a Sheilen Select match with a Wylde chamber.

 

[Ru4real]

1:8. It is a Sheilen Select match with a Wylde chamber.

Thanks Joe. The picture I posted was shot thru a 24” Krieger 1:9 with a Wylde chamber, which is why I asked.

 

[FROGO207]

I have been doing well with 62 grain bullets and Tac in my 1:8.5 barreled AR. I will keep checking back. This looks like something I should try.

 

[kmw1954]

Joe I think I would repeat with the 23.6, 23.7 and 23.8... just to see if they repeat on another day and then maybe load a few more a few thou. longer and shorter and see if they tighten up even more.

But that spread of 23.6 to 24.2 looks very promising.

 

[Joe Texas]

Joe I think I would repeat with the 23.6, 23.7 and 23.8... just to see if they repeat on another day and then maybe load a few more a few thou. longer and shorter and see if they tighten up even more.

But that spread of 23.6 to 24.2 looks very promising.

Thanks. I can’t load much longer w/o jamming into the lands. I guess I could load ‘em shorter but that sounds a little counterintuitive based on previous work ups with several other projectiles. I will for sure load some more and try ‘em on a different day over my chronograph and at 200 yards.

 

[kmw1954]

My mentor and enabler just sent me photos of his new 6mm gun he just shot for the second time with loads actually made for it that are actually sickening they are so close. Makes me envious!!!

He is one that started with a "Soft Jam" and then start backing off to find the perfect node after he has a good powder node. Honestly I am not good enough to find that level yet. Like you I wonder how much of the inaccuracy is ME.

 

[Joe Texas]

My mentor and enabler just sent me photos of his new 6mm gun he just shot for the second time with loads actually made for it that are actually sickening they are so close. Makes me envious!!!

He is one that started with a "Soft Jam" and then start backing off to find the perfect node after he has a good powder node. Honestly I am not good enough to find that level yet. Like you I wonder how much of the inaccuracy is ME.

I’m certain that I was inconsistent with how much I “loaded” the bi-pod today, causing some of my problems. I think that either of at least two of the best charges were more accurate than I am as is w/o fooling with OAL at all. I need to shoot rifle more. Those 6mm benchrest guys and guns are amazing, right?!

I use that Hornady tool as well as seating a bullet with the bolt. With this bullet, the difference was .073. I think that means I technically could jam 73 thousands and still close the bolt. I have always been leery of loading longer than the Hornady tool average measurement. Also, every length test I’ve ever done has ended up with .002 less than the Hornady tool being the best. After like the fourth one I just started loading new projectiles .002 from that tool’s measurement.

Relying on OAL also means allowing for inconsistencies like those a polymer tip gives. After getting about five measurements with the Hornady tool, I’ll take a locked down average one and use ten bullets to check for inconsistencies that way. These were dead nut to the .001 on every one. Maybe it’s time I learn to measure base to ogive? It’s what serious guys do. All I’m doing like this is QC on Sierra’s product while still allowing a margin for safety.

I’m already exceeding VV’s data and at the top end of Sierra’s. I’m afraid jamming might increase the pressure and make me have to lower the charge, essentially starting over. Who knows though? Maybe a soft jam, as you put it, is a way to improve my loads. I guess I’ve been too cautious to try it.

 

[Nature Boy]

Joe,

Take this as just another data point. I found N135 to be closer to Benchmark than it was to H4895, however, they are all close. It’s a good powder for .223 loads in the bullet weight you’re working with so good luck and bring a chrono next time

 

[Joe Texas]

Joe,

Take this as just another data point. I found N135 to be closer to Benchmark than it was to H4895, however, they are all close. It’s a good powder for .223 loads in the bullet weight you’re working with so good luck and bring a chrono next time

Thanks, NB. BTW, I saw your workup of 165 grainers in .308. Very helpful.

I started using N135 because I found it for $22 per lb a while back. It then gave me my first ever sub .5 MOA groups with 69 SMKs. Of course you know where it falls on the burn charts. Benchmark seems like it belongs where it is, closer to H335. I’ve used N140 also. It was about as accurate as Varget or RE-15 in .223 and .308 with less velocity. It looks like the burn rate chart is correct on that one also. Obviously you know how clean the VV stuff burns.

All I know is that N135 is currently my favorite .223 powder for middle-weight bullets for accuracy and velocity. With the 65 grain GK’s 24.0 grains N135 gave a few more fps than 26 grains of Varget from my gun. That was a pleasant surprise on top of the superior accuracy (w/69 MK’s) and clean burn. It’s why I never bought any more H-4895 even though it did really well in my tests.

Anyway, I loaded more 64 grain GC’s - 14 each @ 23.9, 24.0, and 24.1 (all through the charge range with the tightest groups and least vertical). I’ll chrono and test @ 200 yards next weekend.

 

[kmw1954]

Joe I have been instructed that a"Soft Jam" is the ability to seat a bullet using the bolt w/o actually jamming the bullet to were it sticks in the barrel upon extraction. With that method I've been told to shorten OAL by .020" and start from there moving back shorter.

I just did that last week with a Honady ELD Match 75gr. After setting I measured 2.420" and the Honady book length was stated to be 2.390" so I started at the Hornady measurement. My 1:9 barrel Savage wouldn't shoot them. Maybe I was too slow I don't know but I am not going to try them again.

 

[Joe Texas]

Chrono results:
Savage 12 .223 26” barrel 1:8 twist
64 grain Sierra Game Changer
VV N135
Starline brass 1.743
Federal primer
.02 off lands @ 2.238 COAL

23.9 grains - 3144 fps SD 11 ES 40 (14 rounds)
24.0 grains - 3158 fps SD 10 ES 34 (13 rounds)
24.1 grains - 3166 fps SD 12 ES 38 (14 rounds)

Wind gusts 18-35 mph so I just shot at 50 yards. All 3 charge weights made one ragged hole a little less than an inch wide.

I think 23.8-24.1 might be a winner. If they ever come back in stock I’ll load a few @ 24.0 and play with the jump a bit. As is, I think they should exceed 65 grain game king accuracy and be close to 69 grain match kings out to a couple hundred yards at least.