Home Forums Hunting & Shooting Ask The Gunwriters Question on Powder Charges/Burn Rates

I've been meaning to ask this question.
I have Speer, Lyman, Sierra, 2 Hornady - 3 Nosler loading manuals; and Ackley�s, but I rarely use his and feel certain he did not have an attorney. I think I am mostly talking about medium burn rate powders: RL 15, 4064, 4320, Varget, 4350, but also some slower powders -RL 19 &21, 4831.
There is a significant difference in minimum charge from book to book. Without paging thru each book for each powder, I seem to remember a 10 plus grain difference in the minimum charge for the 300 grain bullet in 375 H & H. I�ve heard/read about slow powders causing a pressure spike when under charged. Any idea at which burn rate of powders that is no longer a concern? I wonder if minimum charges should be approached like maximum? Any thoughts on the matter much appreciated.

You ask: "Any idea at which burn rate of powders that is no longer a concern?" Given that the burn rate of powders is a variable I don't think the question has a non-variable answer in any meaningful sense. In other words it depends. For a given powder one load might be reduced a good deal another not so much. At least in my opinion and experience. I'd worry both about secondary explosion effect and about squibs. Rumor says that secondary explosion effect has been observed with powders as fast as Bullseye - others say the observers really saw barrel obstructions. Either way to be avoided. In general terms the best and most useful answer is the very well known and widely discussed suggestion from Hodgdon.

Emphasis added and IMHO it matters.

It is always a concern.

If you want to reduce loads, go to those powders with published data for reduced loads

Clark,

I had an extensive conversation with the head ballistic guy at Hodgdon on the 4895 subject a couple months ago, because I had been recommending IMR4895 for the same use for many years. In fact it has been a staple for making reduced loads since it was introduced.

He said there's no problem using IMR4895 with the 60% reduction. Instead, the reason they emphasize using H4895 is it often (but not always) produces more consistent results. But there is no danger in using the IMR version, which of course is now also sold by Hodgdon.

The reason I called was I'd just published a reduced .223 Remington load using 60% of a maximum charge of IMR4895--which resulted in the most consistent velocities of ANY reduced .223 load I tried, with any powder.

So no, there is no danger in using IMR4895 for the same purpose, and in fact it can produce great results in reduced loads, just as it has since the 1930's.

John,

Speaking of reduced charge weights, what are you thoughts on H4198?

Getting older and less resistant to recoil but wanting to continue shooting my larger caliber rifles, I worked up a bunch of loads using IMR4895 at various reduced levels. .30-06 150 grainers at 2600-2700 fps, .270 with 130's at 2800 and so forth.

It produces amazingly accurate loads when used thus. One .30-06 that was barely MOA on a good day suddenly shot in the .5's and 6's with 46 grains of IMR4895 and 150 grain bullets. While that was the most dramatic improvement I've found that it creates target grade loads across the .270, 7x57, 8x57, 6.5x55, .250 AI, .243, .243 AI et al - basically anything with a medium to medium-large case. Haven't tried it in the .223 only because full loads of TAC don't kick and produce fine accuracy already.

While I'd not want to be stuck forever with just one powder, if'n I had to I could do quite nicely with IMR4895 for everything I shoot. It wouldn't be optimum for the .270 and .25-06 by a long shot but it can turn them into the equivalent of a target level 7mm-08 and .257 Roberts which ain't shabby. And in cases like the .308 and .30-06 and even .223 it will produce top level loads with excellent accuracy.

Thank you Clark, Gentlemen.

After noticing the 375 H & H has a difference in minimum charge weights for W760 of 12.5 grains; Nosler has 74 gr. minimum vs Hornady at a 61.5 gr. minimum, I thought I should ask. I've noticed more difference in minimum charges than maximum.

You're generally better off with extruded powders if you're using less than full loads. W760 isn't one I'd back off too much.

Since I started loading cast bullets in 30-06, I've done a lot of playing around with the fastest burning rifle powders at very reduced levels. I read Phil Sharpe's book and was surprised at the approach to handloading 80 years ago compared to what is considered gospel today. In Sharpe's book, loads for EVERY rifle powder were listed with each caliber, from Unique to the slowest available, which I don't recall. Now I use Unique, 2400, 4227, 4198, 4895, 4064 in very reduced loads for both cast and jacketed bullets in my '06, for practice, plinking, fun.

Recommendations I've read elsewhere speak to using only the faster powders this way, and refraining from loading down the slower powders. And to keep people off my ass, I'll state that you should always follow the guidelines that the manufacturers describe....

Anyway, I have gotten great results with small charges of Unique, around 15gr, and both cast and plated bullets from 150 to 240gr. 2400 and 4227 have been the most accurate overall. It is way more fun to pop off 50 of these mild and accurate loads than 50 full-power loads during a t-shirt shooting session. I regularly encourage handloaders to do do some research, broaden their horizons.

Well there are no absolutes in hand loading or in shooting for that matter to many variables , the hand loading manuals are very useful since I don't have my own lab and pressure sensing equipment to do what they do on my own, I would not want to in any event, as for reduced loads well with in reason they are fine, I when another way in that regard, shoot a smaller cartridge but not every one can have or wants a rack full of rifles, I never bothered with it much, I did with a 300 Weatherby for a time, but it didn't take long for me to figure out that a 308 would have been a better choice for what I wanted to do. But have fun with it, and keep good records of what you are doing and with what rifle and component lot and you will be just fine, a chronograph will be your best friend and a must have in this hobby!

tagging this thread for good information.