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Jul 28th, 2025
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Joined: Dec 2006
Posts: 629 Likes: 1
Sidelock
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OP
Sidelock
Joined: Dec 2006
Posts: 629 Likes: 1 |
I have reloaded some 20 ga low pressures for a damascus gun based on this formula:
Win Universal shell (same with Win AA/HS according to the cut profile of the shell) Rem 209P, 800X 16.5 gr. and RXP20ga wad with 7/8 oz of lead at pressures of 7500 psi and velocity of 1200 fps.
Is it OK to assume that if I drop the load to 3/4 oz and/or the powder charge to 15 gr. the pressures will be lower?
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Joined: Jan 2002
Posts: 2,752
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 2,752 |
I would stay with published loads or ones that have been pressure tested.
Substantially reduced powder charges can produce erratic ignition. If you are seeking even lower pressures, you might just reduce the shot charge, but even then, you wont KNOW how much the pressures have dropped.
Be careful no matter what.
Starting from the top though, whats wrong with 7500 psi?
Regards
GKT
Texas Declaration of Independence 1836 -The Indictment against the dictatorship, Para.16:"It has demanded us to deliver up our arms, which are essential to our defence, the rightful property of freemen, and formidable only to tyrannical governments."
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Joined: Jan 2009
Posts: 150
Sidelock
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Sidelock
Joined: Jan 2009
Posts: 150 |
I am no expert at reloading, but have used the above formula for some time. I understand that 800x works best with a heavy load on top of it. When you drop the load weight too much it can result in irregular ignition.
What you talk about in theory is generally true, if you drop either the powder or the weight it usually gives a lower pressure. The devil is in the details though. You really don't want a squib leaving a wad in the barrel, or irregular ignition causing goofy pressure spikes.
Since you are talking about using this load in a damascus barrel, I recommend making up some 3/4oz loads and sending them to Tom Armbrust for pressure testing. He does them for a very reasonable rate. The cost of testing 3 shells would be negligible compared to a ruined barrel.
FWIW, 7500psi seems to be about the lowest pressure you can get with 20gauge. There are some Federal hull loads with 4756, and some Remmie loads with 20/28 and unique that give low pressures, but not really better than the one you are using.
The benefit of another combo is better metering of powder, as 800x requires weighing each drop.
Rob.
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Joined: Dec 2006
Posts: 629 Likes: 1
Sidelock
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OP
Sidelock
Joined: Dec 2006
Posts: 629 Likes: 1 |
Thanks guys,
It seems that with reloads it's better to stick with what has been measured.
I thought that beyond the logical approach there might be odd things that happen to mess up one's day.
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Joined: Dec 2006
Posts: 629 Likes: 1
Sidelock
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OP
Sidelock
Joined: Dec 2006
Posts: 629 Likes: 1 |
A few low pressure loads from the Lyman 5th edition:
Cheddite, 800X 17gr., Rem 209P, RXP20 7/8 oz at 6600 psi and 1200 fps.
Fiocchi hull, SR 7625 17.5gr., CCI209, Fed20S1 at 6800psi and 1206fps.
Fiocchi hull, 800X 17gr., CCI209, Fed20S1 at 7100psi and 1211fps.
Some of these loads make me think there has been a printing error.
I found same recipe listed at 7000psi and 7500psi on the Lyman and Hodgdon site...
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