compression?

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bruce m
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compression?

Post by bruce m »

i have tried compressing powder until it bulges the cases so badly that they will no longer fit the chamber.
when digging out the powder, it is obvious that the powder is compressed much more in the top 1/2 of the charge, and this is where the case bulges too.
strangely enough, the granules are not crunched into powder, but are still granular.
has anyone had experience with pouring 1/2 the charge and compressing, then the second 1/2 and compressing again?
this technique is little mentioned, so is either a waste of time or is too much trouble.
the bottom 1/2 could be compressed quite hard, as the case walls are much thicker down there.
keep safe,
bruce.
ventum est amicus meus
Coltsmoke
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Re: compression?

Post by Coltsmoke »

I know that Dan T. had one load he used that method of compression on and he said the accuracy was great.
Normal isn't coming back, but Jesus is.
martinibelgian
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Re: compression?

Post by martinibelgian »

I'm still wondering about compression myself - it usually is not a parameter you can change by itself, being linked with other other changes (thicker/more wads, more powder, smaller cases,...), so does compression change something, or is it the change in other parameters? In reloading, for me compression is always a result, not a goal by itself. I just put a specific powder weight in the case, and compression is actually a variable, depending on e.g. powder lot or brand. In other words, for me compression depends on powder quantity.
martinibelgian
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Re: compression?

Post by martinibelgian »

double post - sorry
bruce m
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Re: compression?

Post by bruce m »

thanks guys,
not many have tried this, or are too scared to admit to it.
or maybe it works so well it is top secret :?:
keep safe,
bruce.
ventum est amicus meus
hepburnman
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Re: compression?

Post by hepburnman »

I heavily compress my powder charges (>0.300"). After sometime using the same charge weight. etc., I noticed that my cases were bulging whereas they hadn't before. I contributed some of this to air being trapped in the case during compression. I use tightly fitting poly-wads. I now compress the powder with a newspaper wad over the powder to keep the granules from sticking to the compression plug. This lets the air escape. I then seat the poly-wad when I finger seat the bullet (I use no neck tension).
Kenny Wasserburger
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Re: compression?

Post by Kenny Wasserburger »

I compress Goex FG .385 with a veg fiber wad, with a poly wad you can bulge the cases.

This is in a 45-110. It works.


KW
We'll raise up our Glasses against Evil Forces, Singing, Whiskey for my men, Beer for my horses.

Wyoming Territory Sharps Shooter
Kenny Wasserburger
Posts: 4728
Joined: Tue Sep 24, 2002 3:53 pm
Location: Gillette, Wyoming

Re: compression?

Post by Kenny Wasserburger »

I compress Goex FG .385 with a veg fiber wad, with a poly wad you can bulge the cases.

This is in a 45-110. It works.


KW
We'll raise up our Glasses against Evil Forces, Singing, Whiskey for my men, Beer for my horses.

Wyoming Territory Sharps Shooter
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Kodiak
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Re: compression?

Post by Kodiak »

Load some cases with your favorite powder, place your favorite bullet on top of it and when you can shoot a MOA group @ 500 yards, that's how much compression you need!

My $0.02,
I don't always shoot well, but when I do there isn't any reason.
bruce m
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Re: compression?

Post by bruce m »

thanks guys.
interesting about the plastic wads and not veg or paper bulging cases.
im oz we cannot get goex, so i have to use swiss.
does goex compress more easily than swiss?
keep safe,
bruce.
ventum est amicus meus
Coltsmoke
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Location: GA.

Re: compression?

Post by Coltsmoke »

bruce I would say you don't hear about that type of compression because most people are able to work up a load just doing it the normal way, so why go to the extra time and trouble. I could see it if you were trying to gain more powder in your load, or maybe not having any success the normal way. If I remember correctly Dan T. was loading 50gr. and compressing it, then adding the rest of the charge and then compressing it. He was really pleased with the accuracy it produced. That is all the details I remember.
Normal isn't coming back, but Jesus is.
bruce m
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Re: compression?

Post by bruce m »

coltsmoke,
yes getting more in could be an advantage under certain circumstances.
however accuracy is more important, as the extra powder would not gain much speed.
i just wondered if a more uniform compression could be obtained by doing it double.
however it is not worth doing extra work for no gain.
like i say to other guys, try it yourself.
i should heed my own advice. :? :idea:
keep safe,
bruce.
ventum est amicus meus
hepburnman
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Re: compression?

Post by hepburnman »

When i am doing testing for an accurate reload I start with enough powder to just get a slight amount of compression (I load into the rifling) and then I increase the powder charge in 2 gr increments all the way up to where the compression is so much that it starts to bulge the case. For all my rifles (40-65 and 45-70) I have found an accurate reload at somewhere near the slight amount of compression powder charge and then also somewhere near the maximum amount of compression powder charge. The slight compression reload gets used for the chickens (with a lighter bullet) and the heavy compression reload is used on everything else with a heavy bullet.
beltfed
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Location: Central Wi

Re: compression?

Post by beltfed »

Bruce,
I get Excellent accuracy and velocity with Swiss 1 1/2-
compressing only 0.050-0.1" in my 40-65 and 40-72
beltfed/arnie
bruce m
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Re: compression?

Post by bruce m »

arnie,
i get similar results in the 40/72. but with 0.1 to 0.15 compression, with both swiss 1.0 and 1.5.
we are similar but not quite the same - i wonder why?
this at least happens to work well with pp bullets, as you can bring the over powder wad to the top of the case with powder, compress, and finger seat the bullet ready to go.
the 45/2.4 seems to work with similar compression, 0.14 being what i use.
do shorter cases need less compression in depth to get the same compression in compression terms?
because the compressed powder is at the top of the column, a greater % of the column height will have compressed powder in the shorter case.
does compression work because it modifies ignition?
compressing the bottom 1/2 of the charge first might slow down ignition to beneficial or detrimental results re accuracy.
keep safe,
bruce.
ventum est amicus meus
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