Swiss powder compression question

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opencountry
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Swiss powder compression question

Post by opencountry » Sat Mar 06, 2021 12:21 pm

As a general rule am I right in thinking Swiss 1 and 1.5 require a lesser compression value than Goex Fg powder?
Years ago I ran a ladder-test using Swiss 1.5 in my 45-90 shooting postell bullets, 75.0 to 80.0 grains (78.0 being the best). In your opinion was it the weight of powder that made the difference, or the compression value? Or both combined? I realize Goex powders require considerably more compression that do Swiss powders. And, what would be a good ballpark compression value for Swiss 1.5 in the 45-90 shooting pp bullets? And, if you have experience, in the 45-110 with pp using Swiss Fg?

Robert
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Distant Thunder
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Re: Swiss powder compression question

Post by Distant Thunder » Sat Mar 06, 2021 2:39 pm

Robert,

It was true prior to some time in 2013 that with Swiss you started with something like 1/16 inch compression and worked up from there and the sweet spot was usually found by about .150" compression.
Then in 2013 something changed, Swiss 1 1/2, which had always done well with less compression than the typical Goex 2f loads, got "fluffier". At least some of those fluffier lots did better, actually very well in my experience, with some what more compression like 3/16" or more.

I do not know how more recent lots of Swiss are. I've only shot a few random lots after 2013.

With Goex 2f I have always started with about .200" compression and worked up from there with something around .250" being the sweet spot.

Something I found with the pre-2013 lots of Swiss 1 1/2 is that there is a second sweet spot up around .300" compression. I don't have enough experience with newer lots of Swiss 1 1/2 to say anything about them in this regard.

As to whether it is the powder charge weight or the amount of compression that matters I can only guess. I would lean toward it being the compression.

In .45 caliber I only have experience with the 2.1" and the 2.4" cases.

YMMV
Jim Kluskens
aka Distant Thunder

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bruce m
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Re: Swiss powder compression question

Post by bruce m » Sat Mar 06, 2021 5:45 pm

generally speaking, i really like swiss 1.0 1and 1.5 for pp target loads for this reason.
with the lots i have had, they seem to shoot well enough at about 0.080 to 0.125 compression.
this then allows the case to be droptubed with enough powder so whatever wad comes to the top of the case neck just enough to start a compression plug, and compress so that the bullet is 0.080 to 0.125 in the case depending on what shoots best.
such charges of swiss are very dense and allow quite a tight bullet to slide into the bore without further compressing powder and or altering cartridge overall length.
i have taken compression to the stage where the cases bulge enough to be difficult chambering, to no benefit over the above mentioned.
the small ammount of compression and then just seating the bullets by hand makes loading ammo so simple.
with that ammo you just go out and focus on the wind.
another thing about swiss is that it often shoots well just droptubed.
this comes in handy when breech seating.
just droptube the case to where the wad is level with the top of the neck.
then start tuning with the airgap.
as you slowly increase the airgap, almost suddenly the group tightens, then as you go further it will open up again.
when i say open up again, i mean to about as good as fixed ammo.
bruce.
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Re: Swiss powder compression question

Post by opencountry » Sun Mar 07, 2021 8:12 pm

Bruce, thank you! I see everything you are saying. But, what is the ‘air gap’, please? Is it the compression value?

Robert
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...from 'Fiddler on the Roof'

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Re: Swiss powder compression question

Post by bruce m » Sun Mar 07, 2021 10:20 pm

robert,
here is how to tune a load when breech seating.
firstly all your cases should have similar capacity.
this is because the charge is how much powder you can droptube into the cases such that a finger seated wad is dead level with the top of the case neck.
having cases trimmed to the same length is a given.
however consistent you are in droptubing, it is very hard the get exact column height, but pressing any high wads with your finger or a pencil will get heights the same.
you will need a breech seater.
start out seating a bullet into the rifling so that its base will just touch the wad when you chamber a charged case.
shoot groups with this load.
then start adjusting the breech seater about 0.010" further out and keep shooting groups.
as you keep going you will suddenly find the groups start closing up, and then open up again.
where they shoot best is the place to adjust the breech seater to.
what you will more than likely have is a gap between the wad and the base of the bullet, and this is what i refer to as the airgap.
god only knows why this happens. but i suspect it is either something to do with the bullets' relationship to the rifling, and or ignition.
my own personal experience with this has been purely with bore diameter bullets.
when they are seated, i can look down the barrel and see light around the bullet between the bore.
bullets loaded thus do not seem to bump up as hard as with fixed ammo, but still make good confetti.
i would rate 16:1 alloy with breech seated as about the same in bumpup as 12:1 in fixed ammo.
i mention seeing light around the bullet because some might raise the subject of ringing barrels.
i believe any sudden pressure cannot form there as it will blow down the rifling grooves until the wad hits the bullet base.
anyway i have never ringed a barrel in 40 and 45 cal with 85 to 90 gns swiss in 40, and 98 to 100 gns in 45/2.4"
major hinman suggested that most of the creedmoor shooters were loading their rifles in this manner at the end of the era.
in my limited experience, 40 and 45 cals seem to like around 1/8"airgap38 about 1/2 that and 32/40 a bit less again.
all the scheutzen shooters around here breech seat greasers, and i have met none of them who has ringed a barrel.
one of the biggest problems with breech seating in long range is the time it takes.
in the day they did not string shoot, so had ample time to wipe and breech seat between shots.
bruce.
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Re: Swiss powder compression question

Post by opencountry » Sun Mar 07, 2021 11:40 pm

Thank you, Bruce, for describing something I’ve never known of before. It’s interesting.
I’m certain I won’t be loading in this manner because I’m more interested in finger-seating patched bullets in the casings as I have been doing for awhile. I’ve had good luck using Goex Fg powder, but I’m never satisfied until I try every option, including using Swiss Fg, to minimize group size at all ranges. Thank you, sir, for your input.

Much appreciated,
Robert
"The rabbi that praises himself has a congregation of one."
...from 'Fiddler on the Roof'

bruce m
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Re: Swiss powder compression question

Post by bruce m » Sun Mar 07, 2021 11:47 pm

robert,
good luck trying stuff.
it is all about the never ending journey.
bruce.
ventum est amicus meus

ian45662
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Re: Swiss powder compression question

Post by ian45662 » Mon Mar 08, 2021 4:25 am

I have been having good luck with around .160.

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Re: Swiss powder compression question

Post by opencountry » Mon Mar 08, 2021 8:13 am

ian45662 wrote:
Mon Mar 08, 2021 4:25 am
I have been having good luck with around .160.
Thanks. .160”

Robert
"The rabbi that praises himself has a congregation of one."
...from 'Fiddler on the Roof'

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Re: Swiss powder compression question

Post by Woody » Mon Mar 08, 2021 4:39 pm

Robert,

Ian and I are shooting the same lot of Swiss. He shoots PP and I'm a greaser. My experience with the 2018 lot is less is better. I'm zero to .050 inch depending on rifle.

Woody
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Re: Swiss powder compression question

Post by bruce m » Mon Mar 08, 2021 5:53 pm

woody,
you raise a good point.
there is rarely an actual compression, but more a zone of compression that suits.
it pays to find the beginning and end of the zone, so you can go in about the middle.
you raise another point when you say "depending on the rifle".
bruce.
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semtav
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Re: Swiss powder compression question

Post by semtav » Mon Mar 08, 2021 7:21 pm

My 07 lot of 1F likes .200 compression with PP bullets

John Bly
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Re: Swiss powder compression question

Post by John Bly » Mon Mar 08, 2021 8:12 pm

My current lot of 1 1/2 Swiss likes minimum compression, 0 to .050". I think it is a 2015 lot. I haven't looked at any since last fall so I would have to confirm the year.
"Perfection consists not so much in doing extraordinary things as in doing ordinary things extraordinarily well"

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Re: Swiss powder compression question

Post by opencountry » Mon Mar 08, 2021 8:26 pm

I’ve decided to load, and have already started, cases with 105 grains of Swiss 1Fg. and compressing from .100” to .350” in .050” increments, four shots each. 16-1 530 gr. money bullet, wrapped with 100% cotton 9 lb. onion skin paper, seated 1/8”. I use a .030” vegi-fiber over powder to compress with, and .060” poly wads for fillers, and an 1/8” cork wad under the bullet. It’s getting up into 60’s and 70’s this week, so I’m looking forward to finding something I like. If I need to I’ll work up from the 105 grain load closer to 110, or load down to 100 grains. I’m sure I’ll find a great load, and at least have a good time trying. Btw, I just bought this Swiss 1Fg, and 1.5 this year (2021).
Thanks everyone,
Robert
"The rabbi that praises himself has a congregation of one."
...from 'Fiddler on the Roof'

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Re: Swiss powder compression question

Post by opencountry » Mon Mar 08, 2021 10:03 pm

And, if I need to try less compression I’ll do this too until I find a good load for target work.
R
"The rabbi that praises himself has a congregation of one."
...from 'Fiddler on the Roof'

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