h4831 and the .243win


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trigger45
September 25, 2006, 09:07 AM
just finished loading 21 rnds of .243 went from 39.0 to 42.0 in half grain charges. hope to try them this week. really like this rifle. want to shoot it more. the bullet was 100 gr. hornady soft points. any body got any pointers?

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Smokey Joe
September 25, 2006, 01:46 PM
Trigger45--What rifle is it we're talking about?? The .243Win is a nice cartridge, but many manufacturers make rifles for that cartridge. Have a .243 myself, Ruger M77 MkII Target, and like it very much.

As to yr loading: The Hodgdon Annual Manual copyright 2002 gives 39.0 grains to 42.0 grains as the range of loads for H4831 with a 100 grain bullet. So you've got that covered. You've loaded in 0.5 grains steps, so you have 7 different loads.

I'd shoot 'em very carefully, noting which group seems to be more accurate if there is a noticeable difference. But since you only have 3 rounds for each load, the differences in performance may not be quite clear. You want to allow the bbl to cool between shots, and keep it relatively clean. I usually use a dry Bore-Snake every few rounds, which gets out some of the crud without actually making a clean bore that needs to be fouled again before taking any more shots "for the record."

(If the bore actually needs to be cleaned, using solvent, then it also needs to be fouled with a couple of shots to bring it back to "normal.")

And shooting "for record," you want the steadiest rest for the rifle that you can arrange. But it needs to be the same rest for all shots. You want to remove yourself from the shot as much as possible--this is about inherent accuracy, not about marksmanship.

You also ought to watch for signs of over-pressure--not all max loads are safe in all rifles--and stop if you see any such.

If you do get a difference--say for the sake of discussion that 40.5 grains of H4831 gives you a smaller group than any of the other loads--it's back to the loading bench. Load up a set of rounds bracketing 40.5 grains, but vary the load by only 0.1 grains this time. Out to the range and shoot those. You may be able to find one load that is optimum with this powder, primer, cases, and bullets, for your particular rifle. WRITE IT DOWN CAREFULLY, along with all the other pertinent data.

Only one other suggestion, and that would be to load more rounds of each load to be tested. 5 at a minimum, I'd say. A 5 shot group tells you more about a load's performance than does a 3 shot group. Me, I use 10 rounds per load when I'm testing--that way I have a couple I can waste on "called flyers," clean my bore and re-foul it if need be, and still have enough rounds to get a nice sample. And that way I have to do that much more shooting--awwww. :D

For load testing you want to change only one thing at a time, so keep the bullet, the primers, and the cases all the same while you are changing amounts of powder. But I imagine you already know that.

Anyhow, good luck and enjoy the search for The Perfect Load. And as always, remember, the journey is part of the destination.

GooseGestapo
September 26, 2006, 08:30 AM
Actually, with H4831, you may be able to go beyond the 42.0gr load.
I've got a number of manuals that show as high as 44.5 with "H" 4831.

In the .243, I REPEAT, ESPECIALLY WITH THE .243; DON'T SUBSTITUTE "IMR" FOR "H" 4831 !!!!!

That said, I prefer (as well as my brother in his .243) the IMR-4831.
42.5gr gives over 3,000fps from a 22" bbl. and often is a match-accurate load.

My .243 prefers RL-22 (very, very, close to IMR-4831) at the Nosler #4 recommended max of 42.5gr. It gives just under 3,000fps with a Hornady 100gr BTSP (2,985fps avg.), and 1/2" 5-shot groups. The 95gr Nosler Balistic Tip will edge this slightly at or under 1/2" and just over 3,000fps.

I also prefer Federal #210 primers. No need for magnum primers with the .243.

About as good as it gets with the .243.

The data varies a bit with H4831 as there have been so many different lot#s, and sources through the years. Still a VERY good powder. But I've come to prefer RL-22 for my applications. (.243, .257Roberts, .30/06)

IMR and H4350 are most excellent powders in the .243 and may be better in some rifles than the #4831's and "clones".

kimbernut
September 27, 2006, 04:58 PM
My Ruger M77RL seems to prefer 40.0 gr H4831 and Speer 105 gr.spitzers with Fed 210 primers @2.625 OAL and the same charge with 100 gr. Hornady BTSP @ 2.620 OAL(to the cannelure). A bit slower than I would prefer but .75 MOA with both.

Art Eatman
September 27, 2006, 05:44 PM
I've only used the 70-grain Hornady and the 85-grain Sierra HPBT in my .243. Both loads use IMR 3031. I've had no pressure signs at 40.0 and 37.5 grains, respectively, but I'd suggest working up from a couple of grains down. In my rifle, both loads shoot right at 5/8 to 1/2 MOA for five-shot groups. (Well, okay, back when I was a lot steadier. :) )

Both bullets are quite effective on varmints. I've taken around 20 deer with the 85-grainer--but I've been really, really picky about shot placement and range.

Art

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