When reloading for accuracy, there are many things to consider including case volume. I see the ultimate case volume as a full or lightly compressed powder with no air space.

Question:
What best describes your opinion on this?

Choices:
I agree. The less air space in the case the better.
Any air space is unacceptable.
Air space volume has no bearing on accuracy.
Most powders take up about the same amount of space.
The more air space, the better.

 

I just love this ! Guys with an acute sense of humor !!

Custombolt, you don't have my choice listed... it is this... I have gotten my best results (generally speaking) when the powder charge leaves a small amount of airspace.

Compressed loads have only resulted in burning more powder, with very little value returned.

wetibbe: You are very observant.

mike elmer: Thanks for the input Mike. Seems like the first choice would apply best to your loads although not an exact match. To add to your observation, my groups opened up a half inch when I added a full grain to my lightly compressed 7X57 load. Ah....the details...gotta love 'em.

I just developed some low velocity loads for my brother in a Sako 223 rifle.

Powder used are all shotgun or pistol powder, charges are as low as 4 grains.

Many loads shot under a quarter of inch - which I think might be the intrinsic accuracy level of this rifle.

Lots of air in the case.

Thank you Dr. Frankenstein. Seriously, I expect you didn't arrive at that load overnight. How many cases hit the scrap bucket en route?

I checked the poll results. Pretty good cooperation. The winner was interesting!

Now here's some load data you may want to look at

http://www.accuratereloading.com/223rem.html

Various .223 rifles were used, various bullets and numerous powders including the hot, fast, shotgun/pistol and other normal powders down in the range of lower speeds and bigger volumes. There are also many "reduced loads".

Some powders were Red Dot *( #8 ), Green Dot *( #17 ), HP-38 *( #28 ) and Pistol Powder *( #33 ). Group sizes varied from grain volume to grain volume with no consistent pattern. Although velocities were given there was no pressure data. No primer/case data on effect of pressure.

Ballistic calculations showed that:

.223 Remington, .224 45 gr RWS SG bullet, usable case capacity 28.5. 20 grains Red Dot, 3,876 fps, 158,913 psi.

Using all of the same data as above but switching to 20 grains of H4198; 3,013 fps, 34,560 psi.

So !??? What ?

The original survey question was basic and generic but the answer didn't really show any specificity. It was just an opinion. Maybe the next survey should ask why the preference about space.

*( Incidentally I didn't participate in the survey . But it was none the less sort of amusing ).

Looks like 82% said the LESS air space the better and 18% air space has no bearing on accuracy.

I didn't vote either. For the ancient and hoary old cartridges I prefer to work with my answer would be, "it depends".

Thanks wetibbe: I'll check that thread shortly.

When I wrote the survey, I intended to keep the choices fairly simple with a little humor thrown in. My underlying goal is to spark opinions from those with greater experience than I. In addition to the votes themselves, there is always that "thinking outside the box" response that intrigues me and I expected some in-depth opinions and shared experiences. I do relish the details and am always willing to learn. I hope this survey can benefit others as well. Thank you all for your opinions, views and experiences. Keep 'em coming.

Wetibbe: Thanks for the chart. Point well taken.

Saeed. Just to be clear. The Dr. Frankenstein comment was a compliment. Nothing derogatory was intended. I enjoy your posts of thinking outside the box.

If the blue dot loads are indicative, a little extra oxygen ain't all bad. Similar results have been had with other fast burning powders in reasonably medium to large capacity rifles. roger

This is what the experts at Hodgdons powder company recommend...IMO this is very good advice.

"Choosing a Powder for a New Cartridge: You just purchased your new hunting rifle in a cartridge where you have no loading experience. What powder do you choose? When you look at reload data, the list of powders is usually long, and any one of them might work great. But here is the trick to hone in quickly on the ones that may work best.

First, choose the bullet for your intended use. Review the reload data to find the velocity level you wish to achieve. As you look at the powder charges, chances are very good one of the powders that meets your velocity criteria shows a “C” beside the maximum charge and/or gives one of the highest velocities. The “C” means a lightly compressed charge of powder. That is an ideal situation, as maximum or near maximum charge weights that yield from 95% to 103% load density tend to give the most uniform velocities, as well as top accuracy.

I’ve yet to see a benchrest shooter whose load does not completely fill the case, as well as give top velocity. The same holds true for a varmint shooter, case full or darn close to it. Along with that particular powder, the powders listed closest to it on either side will likely be in that 95% to 103% range as well. This is a great place to start. Simply start with the beginning load for that combination and carefully work your way into the maximum, at all times watching for case head pressure signs. You can save a lot of shooting by carefully going up in 1/2-grain increments at a time (in mid- to large-capacity cases). Fire only two rounds of each charge level, each pair at a different target. Shoot slow enough to not overheat the barrel. Some of these two-shot groups will show a willingness to group closely. When you find shots that group tightest, load several rounds and then shoot five-shot groups for verification.

I do not have one rifle that doesn’t group the best somewhere near the max load. Should this not provide the accuracy required, either change primer brands and repeat or try one of the powders on either side of the one you just tested. Chances are very good one of these will lead you to a load that meets your expectations."

quote:

Originally posted by custombolt:
Saeed. Just to be clear. The Dr. Frankenstein comment was a compliment. Nothing derogatory was intended. I enjoy your posts of thinking outside the box.

Actually, sometimes I wish I WAS Dr. Frankenstein!

There are a few people I would love to experiment on

quote:

Originally posted by Ackley Improved User:
This is what the experts at Hodgdons powder company recommend...IMO this is very good advice.

"Choosing a Powder for a New Cartridge: You just purchased your new hunting rifle in a cartridge where you have no loading experience. What powder do you choose? When you look at reload data, the list of powders is usually long, and any one of them might work great. But here is the trick to hone in quickly on the ones that may work best.

First, choose the bullet for your intended use. Review the reload data to find the velocity level you wish to achieve. As you look at the powder charges, chances are very good one of the powders that meets your velocity criteria shows a “C” beside the maximum charge and/or gives one of the highest velocities. The “C” means a lightly compressed charge of powder. That is an ideal situation, as maximum or near maximum charge weights that yield from 95% to 103% load density tend to give the most uniform velocities, as well as top accuracy.

I’ve yet to see a benchrest shooter whose load does not completely fill the case, as well as give top velocity. The same holds true for a varmint shooter, case full or darn close to it. Along with that particular powder, the powders listed closest to it on either side will likely be in that 95% to 103% range as well. This is a great place to start. Simply start with the beginning load for that combination and carefully work your way into the maximum, at all times watching for case head pressure signs. You can save a lot of shooting by carefully going up in 1/2-grain increments at a time (in mid- to large-capacity cases). Fire only two rounds of each charge level, each pair at a different target. Shoot slow enough to not overheat the barrel. Some of these two-shot groups will show a willingness to group closely. When you find shots that group tightest, load several rounds and then shoot five-shot groups for verification.

I do not have one rifle that doesn’t group the best somewhere near the max load. Should this not provide the accuracy required, either change primer brands and repeat or try one of the powders on either side of the one you just tested. Chances are very good one of these will lead you to a load that meets your expectations."

EXCELLENT advice. That's precisely what I am conveying to my Grandson.

I can appreciate that lots of the Guys don't want to spend money on internal ballistic calculators and some have disdain for the theoretical output vs actual on the ground experience.

I have found, after checking and cross checking, that the ballistic calculators yield chillingly precise results time after time with a small number of anomalies that are not, as yet, understood in larger case volumes.

True also that the powders with the faster burn rates are definitely SAFE to load, within reason, and also yield remarkably good accuracy with modest pressures, - when used in moderation intelligently and cautiously.

However, as a precaution, when loading the fast powders, the relatively small grain volume could easily be double charged with still significant case volume empty. And the results absolutely catastrophic.

Further, unless the fellows actually have internal ballistic calculators they cannot see the VAST amount of other information also calculates such as amount of powder burned IN THE BARREL, multitudes of other info that will probably be "Greek" in any event. It's really Egg Head specific.

Why the differences in burn rates ?

Pistols have very short cases with small volumes compared to rifle cases. The barrels are short comparatively . Sometimes 2" vs 24" - 26 " to burn powder. AND pistols are not bottle necked but rather open barrel bore large in size.

Shotgun shells are crowded with fillers/spacers and shot, leaving little relative space for powder. Too they are open bore with lots of free space to dissipate pressure.

Thus these conditions call for quick burning powders.

Personally I follow the powder company's recommendations. I'm a cautious conservative by nature and character.

Some posters take exception to my cautious counseling to young guys and seem to get their knickers in a knot.

I can only say it's a free country and re-loaders are certainly entitled to venture wherever, so long as they take personal responsibility for their adventures.

Nothing is more akin to my thought process than the last 2 posts (Ackley User quote inclusive) right down to the double charge.
I had an overflow once in a 7X57 case. I think the words that came to mind were dumb ass.
No foul came of it. However, this seemingly harmless incident reminded me to take it slow and check everything. Rushing into something that is potentially dangerous will only make you dead or injured "sooner" if you make a big mistake.

Back to pistol powder experimentation........Not to say that experimenting with unconventional powders with inherent large air spaces wrong, in my view it is just more for "advanced loaders" since it is a whole other "animal". Getting fast powders with a short power stroke to do the job of reduced charge slow powders with a much longer power stroke doesn't seem like something that can be accomplished overnight.

For those who load comparatively modern cartridges or cartridges which have been in constant production over a long period of time, such as the 45-70, 45 Colt and others of that ilk, I can't agree more. There is data available for such cartridges that has been tested to the Nth degree. Loads are available that cover the spectrum of their capabilities from mild to hot with more than adequate case fill. Good case fill is always desirable. However.....

There is more than a few of us who, by choice, prefer old, obsolete and obscure cartridges chambered in old firearms. Firearms in which the metallurgy is not of the standards of today, whose actions may well be past their prime in strength. Many of the cartridges themselves haven't seen production in over 100 years and data is nonexistent. One can often find the ballistics of those cartridges which, with enough knowledge and experience, offers up several clues as to what powder and what charge can safely be tried. We often use reduced loads which consequently result in less than optimum case fill. Some may require a filler. For me this is done in deference to the age and strength of the firearm in question and I expect others feel much the same. We admire and prize those old rifles and the last thing we want to do is destroy one through inattention and ignorance. We still want to "hear them go bang" and wring the best possible accuracy from them.

I also expect most of us, in these times, either have or have access to one of the several ballistics programs and utilize them. Ultimately, however, I imagine most of us rely on our knowledge and experience and use the programs more as a check on our choice/decision of a load. In the past such programs were not available and we relied on what we knew, had learned and other means to come up with starting loads that probably did not offer a very high percentage of case fill. Those men I know who delve into such cartridges, to include myself, have yet to blow up a vintage firearm or so much as ring a chamber. That comes down to one thing, attention to detail. If a person slops together their loads it is best they stay with book recipes and cartridges for which good, safe data is available. If they are the particular kind then those old firearms and cartridges offer an excellent and rewarding field of endeavor.

That is why I did not vote...and why my answer, "it depends".

Perhaps it is that the above is not pertinent to the original post in the sense that few use those old cartridges in those old firearms. However, I believe it is pertinent in regard to case fill as it is a consideration.

Thanks for that very interesting "expansion" on the subject. CB

I think I have arrived !

Fine now means specificity and many obviously have very focused, laser sharp insight.

I also have to agree that electing the King of Rifles is not in the cards.

If only it was as easy as this.

https://www.youtube.com/watch?v=FqrTEQ_1h68

quote:

Originally posted by Saeed:

quote:

Originally posted by custombolt:
Saeed. Just to be clear. The Dr. Frankenstein comment was a compliment. Nothing derogatory was intended. I enjoy your posts of thinking outside the box.

Actually, sometimes I wish I WAS Dr. Frankenstein!

There are a few people I would love to experiment on

Although I voted for #1, I would suggest that you add the word normally..Nomally best accuracy is arrived at with a powder charge that comes about half way up the neck, and has a little compaction, but this sort of thing is not written in stone..Case volume can be important or it can be worthless to a degree. you have to play with these things to determine what your gun likes, not what you like or believe.