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New Savage 110 Switchback should be home Friday night. I have a box of Hornady Black to run thru it for a baseline and to be able to get some measurements on the fired brass.
BUT! I had some old 80 gr Sierra SP left over from a 243 so I cleaned and sized up some Hornady brass and loaded up some with Benchmark and did 5 ea. of 25.5, 26.0, 26.5 and 27.0 just to see what it does and to help zero in the new rifle and scope. No ideas as to what I should expect.
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As a rough estimate, you can use hornady's data for their 75 gr Vmax, the switchback is 22" bolt action and the bolt action data is 24", plus an 80 gr bullet should be about 50 fps slower than 75 gr data, grain for grain of powder. The Vmax has benchmark listed. So I would say maybe 100 fps slower than 24", 75-gr bullet data. give or take.
Let us know how it turns out!
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Hornady also lists a 80gr. GMX with a load range of 24.3gr - 28.7gr so I'm about in the middle of that.
Biggest issue will be if the actually chamber at the length I have them at.
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Im in similar place. Rifle due in soon. (Just got call and can pick up this weekend!)
Id LOVE to get 85/95g bullets to do everything. I have a 243 Savage and a custom barreled target 6mm Rem. So 6mm is well covered here. I have 500+ Speer and Sierra 85g bullets. I find sierras "soft" on deer but the Speers have been awesome! (On Deer)
Im also hoping 2520 shoots well, (I have a 8# bottle and a couple 1#'s too!!!
CW
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(02-29-2024, 02:27 AM)KMW1954 Wrote: Hornady also lists a 80gr. GMX with a load range of 24.3gr - 28.7gr so I'm about in the middle of that.
Biggest issue will be if the actually chamber at the length I have them at.
80gr cup and core should make less pressure than the 80gr GMX.
I was trying to find the rifling in my Faxon barrel yesterday. Its no problem with the Hornady and Speer bullets I have, but the 90gr Sierra Tipped Game King is a whole different story.
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If you get the chance to try that 2520 powder please post up results.
Currently have A2460, TAC and Benchmark to work with.
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300 Blk, that is the difference between the tangent (more stubby) ogives of the Hdy/speer and the secant ogive of the sierra tgk. In a few of my 6 Arc barrels (one of them is a faxon) the 90 tgk seats to lands at 2.338-2.350, yet many "regular" tangent bullets are more like 2.200 give or take. The tgk's seat way beyond the mag length for an AR. So in the AR I typically use them at 2.260-ish.
+1 on the gmx vs a cup/core, that's why I don't typically mention the 80 gr gmx/cx data much, most shooting is done with c/c bullets.
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The Faxon barrel is shooting well enough with Hornady Black that I'm putting it on the back burner for load development. The CMMG mag that I have looks like it might allow almost 2.30". Likewise, the SS Duramags (556 and 350L) that I have look to have the same internal lenght. IF I were to "window" one of these mags, OAL might be closer to 2.35". Oddly, other than caliber marking and follower color, I don't really see any difference in the feed lips or followers in any of these magazines.
The Howa is here, and has a longer mag length. Hornady Black is being used for break-in, and seemed to shoot pretty well from the start, and now at 50 rounds. I have 75gr VMax, 90gr ELDX, and 90gr TGKs, but should get some Speer 85gr BTs for inexpensive shooting out to 300.
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Fyi, in another caliber but still AR frame, I run out of room in the mag well at about 2.350 (this is a rough measure I did last nite about 2 AM, but the length should be somewhere like that), so my practical ultimate limit is probably more like 2.330 for some tolerance. But I won't be doing any 90 gr tgk's at that type of setup.
Roger that on the Howa having more OAL room.
