Faster burning powders vs. slower burning powders?

[karlrudin]

I am not new at reloading ammo but bulk of my years I have dealt with J bullets. I recently converted to the good boolits and have been enjoying it for the past couple of years. I do a lot of homework reading different manuals, web articles and lots of information from here. Since this is the leading sight in my book to the knowledge of cast boolits.
Getting to my question. MOST manuals, articles, etc. that I come across have sent me down the road of using faster burning powders. In my invertory, HS-6, AA#7, IMR 4227, 4198 and 3031 being in the fast category. These and a lot of others have seem to become the normal burn range, excluding BP because I have never messed with it.
Is this because of manuals, personal usage, accuracy etc.? And why don't we use slower powders? IE, Bl-C2, Imr 4064, 4320, 4350, 4831 etc. Is because there is no loading data, which is my thought, or is it because of something bad or inaccuracy.
Just a thought that has been running in my mind, because I have these other powders, or most would like yall's input. Thanks.

[runfiverun]

there ain't no data for them.
the powder company's don't care and the bullet makers would be doing themselves a dis-service.

you can make your own up though going to a too slow powder won't do anything but fill the case and lower pressures.
how far too slow is dependent on how fast you want to go.

the fast powders are economical and do the job.

[dragon813gt]

Quickload, problem solved as far as load data. Just remember that it's garbage in, garbage out.

[Yodogsandman]

"Since this is the leading sight in my book to the knowledge of cast boolits."

People that write the books and manuals have a legal responsibility to provide information that doesn't blow folks up. So, they don't print stuff that's untested, unproven or controversial to sell to the public.

[LAGS]

The slower powers for the most part generate pressures that are not conducive for lead bullets.
A lead bullet even with a Gas check can only take so much pressure before it fractures or deforms, or can contribute to leading.
But if you load the slower burning powders where they are in a decent Pressure Range, they generally do not fill the case half way.
That can lead to poor ignition, or flash overs .
Using a filler can help with that condition, but the filler can raise pressures too.
Just look at the pressures generated by a powder with the same weight J bullet at the starting load.
And that load is generally the lowest you should go with that powder to prevent flashovers, but the manuals do have a built in Margin of error, so really you can go a little lower safely. But how much lower is the question.
Some Manuals like the Lee second edition have a pressure chart that tells how much pressure a alloy can take based on the BHN of the mix.
for example, a BHN 15 alloy can only take about 20,000 PSI
So what is the slower powder generating at a Minimum load?

[runfiverun]

you need to go to a too slow powder so the pressure comes back down.
20-k psi,,,, please, 15 bhn will take 40-k easily, it's in a confined space where is it gonna go?

[dragon813gt]

Someone better tell my bullets they can't take the pressures they're subjected to. 11 BHN at 30k PSI works just fine. No leading either ;)

[karlrudin]

Well so far, the slower burning powders are shrinking my groups as I tinker with them. I think its agreeable that this group is FULL of tinkerers and I have tried to fall in line with that, on the safe side of course. If they seem to fall off on accuracy I will go back to using the faster powders and tweek something else in my loading procedure to get the groups to shrink. But so far so good.

[garym1a2]

I think for the most part its because the Cast Bullet shooter are CHEAP. Why use 6 grs of WSF for a pistol round when 3.8 grs of Bullseye will do and cost half as much!. Put 12 Grs of Unique in a case is much cheaper than 25 grs of 3031 or 35 grs of 4064.

Those that go with the slower powders tend to want higher velocity's than you can get with fast powders.


Well so far, the slower burning powders are shrinking my groups as I tinker with them. I think its agreeable that this group is FULL of tinkerers and I have tried to fall in line with that, on the safe side of course. If they seem to fall off on accuracy I will go back to using the faster powders and tweek something else in my loading procedure to get the groups to shrink. But so far so good.

[karlrudin]

I'm not looking for velocity. In fact, the velocity with the IMR 4064 is similar to the IMR4198 load I use. All I'm looking for is trimming my group sizes without all the adverse affects(leading, flyers etc) Yes I use a lot more powder this way, 32.5grs of IMR4064 vs 17.5grs of IMR4198 but it did trim my groups from 1.25" to .685. The only load in the Lyman book that came close was Varget. So I took Vargets load data and transposed. Hardly any kick, no noticeable unburnt powder, no leading. This is intended to be used on targets only. No game, plinking etc. Looking to trim my groups is all. I already got other loads for casual shooting.

[williamwaco]

Garym +1.

[Flexy]

Someone better tell my bullets they can't take the pressures they're subjected to. 11 BHN at 30k PSI works just fine. No leading either ;)

I have used even softer lead alloy, around 8-9BHN and driven them (according to Quickload) at around 38kPSI. So, I would have to agree with you. :)

[OnHoPr]

@LAGS "But if you load the slower burning powders where they are in a decent Pressure Range, they generally do not fill the case half way.
That can lead to poor ignition, or flash overs."


I am not sure about that scenario unless I am having one of my dyslexic moments. Unless you are referring to a certain specific large case or large overbore case. Most of the general CB usage cases don't have enough room to fill will the slower powders like 4831.
Though with some large overbore cases reducing slow powder can cause those symptoms in general CB usage, because general cast boolit usage doesn't go in the 50 & 60 K psis.

[Yodogsandman]

I like to fill my rifle cases with powder and that normally means using a slower powder for cast than what is shown in the books. Filled cases normally result in lower extreme spreads and standard deviations in velocity which should give better groups. Just not always!