IMR 7383 & the .243 Win.

[Big Boomer]

Wanted to report on a load with a controversial powder in my .243. Yesterday while continuing a workup load with my Browning A-Bolt in .243 Win. (Redfield 3-9 Partner scope, 22" barrel), I hit a group that was unbelievable. While only one 5-round group was fired with this load, it sure was surprising. I usually know luck when I see it and I'm not that good a shot anymore - can't hold still (78 years old). One of the few times I wish I had had a camera or a phone that could take pics. Do not know how to post them anyway. I had worked up to 33.5 grains of 7383 with only unsatisfactory results previously following GIBrass' recommendations to follow IMR4831 data (reduced by 15% if I recall correctly). Had carefully worked up loads in quarter grain increments. Winchester brass throughout testing. Hornady 100 grain 6mm Interlock bullet (#2453) seated out against the rifling, as long as the magazine would allow. CCI Mag. primer. Shooting off sand bags. When I fired this load, 33.75 grains of 7383, all 5 rounds went into a group that could be covered by a dime. My first response was I can't shoot that good! Got more work to do with this load. Had loaded more rounds above this load, but none were the equal of this one. Will report more later if this was just a fluke or proves to be a good load with this powder and bullet. Usual disclaimers apply - my rifle, my loads. If you choose to use this you are on your own. Big Boomer

[Maven]

BB, I've been using IMR 7383 in my .243Win., Ruger #1 for years and have found it to be an excellent performer...with either Hornady or Sierra 87 & 85 gr., respectively, HPBT & SP bullets, again respectively. That powder is a tad slower than IMR 4350 in my experience and worth experimenting with IF you have a chronograph (and use it!) and don't push it too hard. Btw, it is an excellent choice when using jacketed bullets in the .30-06 as well.

[Big Boomer]

Maven: I got my 7383 as I indicated from GIBrass a few years back. Haven't experimented with it very much. I had already concluded according to my limited experience with this powder so far, that using IMR 4350 data might be more appropriate than that indicated by the written instructions from GIBrass that I mentioned above (IMR 4831 data reduced by 15% as a starting load). No, I do not have a chronograph but wish I did. Having this experience yesterday with this powder makes me anxious to see if I can do a repeat. Thanks for the input and I noted many times the warnings associated with using surplus powders. Big Boomer