IMR-4350 in the .300 Win Mag

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Tang419

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Noslers website shows 70gr of IMR-4350 pushing a 180gr bullet at 3130. My Lyman manual (49th edition) shows 72.5gr pushing a 180 at 3048. Hodgdon's info shows 71gr at 2974.

Until I get a chrono, I'd like to have some idea what speed Im shooting. So what do I go by ? Average the 3 at 71.2gr for 3050 ? I'm really just wanting to match Hornady's 180gr Heavy Mags.

I went with the IMR4350 because it seemed to show close to what I wanted, and was told it is a pretty accurate powder for the .300 WM.
 
Tang419
Each manual will list the weapon used, barrel length, case mfg., primer, and so on. Take a closer look at the weapons/brass/primer/ et cetera used in each of the data workups. They are probably very different, and also different from your weapon/brass/primer/ et cetera. A lot of factors go into determining pressure, volume and velocity.

Combinations of factors can cause great variances in velocity/pressure. Here are a few factors:

Primer: strength, presence of powdered metal (Aluminum & others), brisance - a measure of the rapidity with which an explosive develops its maximum pressure
Barrel: length; tightness of bore; height of the lands; distance of bullet to lands; temperature of barrel;
Bullet: bearing surface of bullet, alloy of bullet; shape of bullet;
Brass: new/used elasticity; manufacturer, volume;
Powder: new, aged, old, batch powder was from;
Weather: ambient air temp., barometric pressure, humidity
Elevation: above sea level
Other: I am sure I have not listed all.

Now, mix and match them. Would you care to guestimate the number of possible combinations,

Bottom line - - - use the books as references, not gospels. Examine the data, select a low starting load, and work up loads slowly, watching for pressure signs. Your weapons max will probably vary from all other listed references. That’s the fun/frustration of reloading. Only a chronograph will give you the velocity, unless you're good at Voodoo!:evil::what::D

Good Shooting!!!!!!
 
I started with 66gr and worked up to 70. Even the 70 extracted flawlessly, with no signs of pressure on the cases. I'm pretty sure I could go farther, but I'm going to take some Hornady Heavy Mags to the range and see how close my handloads come to their point of impact. I would buy a chrono, but if I spend anymore on reloading, the fiance` will kill me...lol Maybe next week :D

My loadings are 180gr Nosler Partitions, with CCI LRM primers and 70gr of IMR-4350.
 
I haven't worked up loads for a 300 Win Mag for 180- gr bullets but have worked up loads for a 308 Norma Mag for same, IMHO, any of the 4350s are too fast, look to try something in the realms of IMR4831 or similar, that puts you in the area of Norma MRP, RL22, N160, H4831 etc. I feel your best results will come from these sorts of powders.
Steve.
 
Another vote for RL22. I have tried a wide variety of powders in 300WM in the last 15 yrs. Gotta say RL22 has given the best test results. Try it you may like it.
Additionally, once you get a chronograph, you will wonder how you lived without one.
~z
 
I used IMR-4350 for some reduced 150 grain loads and was very pleased. If your going for full power the RL-22 gets the nod though.
 
My experience for 180 gr loads in .300 Win Mag is IMR 7828 works much better than IMR 4350. However, IMR 4350 is the best powder I've found for 180 gr loads in .30-06
 
IMHO, any of the 4350s are too fast, look to try something in the realms of IMR4831 or similar

I agree with Shinz on that one, the idea of a magnum size case, is you can fit more of a slower powder behind those heavier bullets.

IMR-4350 is more at home in a 30-06 size case.
 
Thanks for the advice guys. Im just a few days into this reloading thing, and I have so much to learn. Anyone have a good recipe to push a 180 at 3100 ?
 
I haven't worked up loads for a 300 Win Mag for 180- gr bullets but have worked up loads for a 308 Norma Mag for same, IMHO, any of the 4350s are too fast, look to try something in the realms of IMR4831 or similar, that puts you in the area of Norma MRP, RL22, N160, H4831 etc. I feel your best results will come from these sorts of powders.
Steve.

Interestingly, I have a load using 58.5 x IMR4895 and 180 gr Sierra GKs. About 2800fps, and no pressure issues. Accurate and predictable load. I wouldn't have thought that 4895 would be a good powder, but many sources list loads, and it works well in my M70.

I also have a load using 71.6 x IMR4831. It gives another 120 to 130 fps, but is not quite as accurate.

I use Winchester LR primers as opposed to any magnum primers.
 
So Many Choices,,, So Little Time,,,

WLECOME TO THE 300 WIN MAG DILEMMA ! ! ! Over the past year I have been chasing down load data from this and several other good reloading sites looking for the best powder and bullet recommendations for my 300 Win. Mag and this is how it went. The top listed powders were RL 22 and IMR 7828 nearly 2 to 1 over other powders such as the IMR 4350, IMR 4831 with a little H4831 and an occasional RL 19, RL 25 and WXR thrown in to boot . Some manuals help in that they show some powders tend to perform best at or near max loads and give you a ball park figure as what can be expected for speed. My Browning A-Bolt did not care much for RL 22 or IMR 7828 but loved the IMR 4350 on the top end using a Barnes 168 gr TSX bullet of appx the same length as most 180 gr premium bullets I sent into a dirt pile never to be seen again. The IMR 4350 gave me the speed ( 3215 fps ) I was looking for as well as accuracy at an avg. of .575" on 3 seperate 5 shot test groups . The reason I shot 5 rounds vs 10 when testing was due to this powder being nothing short of horrendously filthy and would start to effect group size after 5 rounds . This does not bother me at all for a very fast and accurate hunting round cuz if I cant bag the beast in 5 rounds I should go home and never venture out again,,,,, ever . Embrace the challenge and have some fun while doing it . 10 SPOT
 
IMR-4350 is more at home in a 30-06 size case.

Actually, RL22 is one of the very best powders for heavy bullets in the .30-06. I regularly use 60.7gr behind a 190SMK for 2900fps in my '06. I would also use it if I had a .300WM.

Don
 
I picked up some RL22 and some new Win brass on the way home from work last night. Going to Work up to the 77gr max listed on Aliants website. I'm loading three rounds of each 73.5, 75.5, and then 77, to take for testing. I am still using my Nosler partitions to experiment with.
 
Tang, even with a slow powder like RL22, I still wouldn't go in jumps of more than 1 grain at a time. Although you are unlikely to get into pressure spike problems with these jumps, it makes it harder to pin your best load down. I normally load in 1 grain increments & shoot for group as well as velocity, I'd rather give away 50-100 fps & get good grouping than a hell burning shotgun. If you have access to a chronograph, max pressure is often reached when the velocity increases per load jump become smaller, but DO NOT rely on this, observe all other signs, primer flattening, bolt lift, case condition etc & be conservative if you're new to the reloading game. We'd like to have you around for a bit yet.;) Make sure you identify your cases & their loads with a marker. You can learn a lot about a load when resizing & repriming. Loose primer pockets, which are a sure sign of way to much pressure, show up at this stage. Hard resizing can be a sign of an over expanded case. Its all part of the story. BTW, the Nosler manual lists a top load of 75,5 grains RL22 with their 180 gr bullets, so don't feel you have to reach Alliants top load, it may be way too hot in your rifle, or not. :)
Steve
 
hi, everybody has their favorite load, and for a good reason. it is what their gun likes! i would never discount anyones favorite load. personally, i (and my rifle) like 70.0 grains of IMR4831. as to "guestimating" the speed of your bullets with a particular load. that is all you will ever be able to do without a chrono. every one of those data quotes you gave is correct. there are so many variables, it just is not funny. anything from the temperature / humidity to that particular batch of powder to the depth of the rifling on that particular rifle will affect the speed of the bullet. the only way to ever really know what is going on with your rifle, is to get a chrono and measure. sorry for the bad news. but there is no sense in lying to you either.
 
I really appreciate the help guys. Nosler had the 75.5 listed as the most accurate load tested, so I'm hoping it is for me too.
 
Its probably fair to say that for a given load you can work out a ball park figure for "around about" the speed your bullets should be going at. 100fps either way is not altogether too significant in real world terms & if you look at some ballistics tables to work out the drop for the bullet you're using or one of similar ballistic coefficient, you will see that there is not a huge difference out to sensible ranges (300 yards?) & beyond that you're getting into the realms of range finders etc to be able to be accurate anyway & often wind drift becomes a greater influence on accuracy than drop at such ranges. Load it,shoot it, enjoy.:)
Steve
 
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