Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Temperature Learning Experience
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="J E Custom" data-source="post: 1211664" data-attributes="member: 2736"><p>Extreme is a term used first by Hodgdon and is designed to control the heat sensitivity of certain</p><p>powders. Hodgdon still makes some powders that are not "extreme" powders. All Powders are not created equal so they must be treated differently. Some powders are very predictable and increase in pressure very linear, other powders will increase in pressure as more powder is added, then all of a sudden the pressure will spike/go critical and max pressure will be exceeded by the addition of only 2/10ths of a grain. so we need to understand the characteristics of each powder we use to stay out of trouble. IT's like gasoline,</p><p>you cant change the octane by putting it in another car but you can change the performance. </p><p></p><p>Other powder manufactures make powders that are designed to reduce the effects of heat on the burn rate, and we tend to call these powders "Extreme" because of the first name given to powders with the ability to lower the velocity/pressure spread.</p><p></p><p>The cartridge has nothing to do with the powders ability to be more consistent with temperature differences because the powders coating/treatment is the same. differences in case capacity causes different powders to react differently, but the powders ability to reduce the effect of heat/cold remains the same .</p><p></p><p>I have used all of the Extreme powders in many different cartridges and found them to be very predictable/consistent and to maintain velocity very well. as stated earlier, some of my rifles shoot better with other powders that are not temperature stable and velocity swings are as high as 175ft/sec depending on the temperature so I have learned to live with it and avoid pressure situations.</p><p></p><p>Extreme powders can be over loaded just like any powder. Some powders will/may go critical and increase the pressure suddenly with only .05 grains more powder, so when this point is reached it is recommended that you back off at least 1+ grain to avoid this situation. </p><p></p><p>Varget tends to give the 223 the highest velocity within SAMMI pressures but It can be over loaded </p><p>like any other powder, but still remains stable if loaded to SAMMI pressures with different temperature spreads.</p><p></p><p>Where a powder might have a 10 ft/sec shift in a 308 in a 50o temperature change, it is true that a smaller/larger case may have a 15 ft/sec shift with the same extreme powder. BUT other "NON- Extreme powders may/will shift 150 ft/sec through a 50o range.</p><p></p><p>Temperature controlled powder can only help with Temperature swings not with over pressure loads. We all try to get more than we should from a cartridge (It is the nature of our sport) but this can lead to problems with any type of powder. </p><p></p><p>Just my opinion</p><p></p><p>J E CUSTOM</p></blockquote><p></p>
[QUOTE="J E Custom, post: 1211664, member: 2736"] Extreme is a term used first by Hodgdon and is designed to control the heat sensitivity of certain powders. Hodgdon still makes some powders that are not "extreme" powders. All Powders are not created equal so they must be treated differently. Some powders are very predictable and increase in pressure very linear, other powders will increase in pressure as more powder is added, then all of a sudden the pressure will spike/go critical and max pressure will be exceeded by the addition of only 2/10ths of a grain. so we need to understand the characteristics of each powder we use to stay out of trouble. IT's like gasoline, you cant change the octane by putting it in another car but you can change the performance. Other powder manufactures make powders that are designed to reduce the effects of heat on the burn rate, and we tend to call these powders "Extreme" because of the first name given to powders with the ability to lower the velocity/pressure spread. The cartridge has nothing to do with the powders ability to be more consistent with temperature differences because the powders coating/treatment is the same. differences in case capacity causes different powders to react differently, but the powders ability to reduce the effect of heat/cold remains the same . I have used all of the Extreme powders in many different cartridges and found them to be very predictable/consistent and to maintain velocity very well. as stated earlier, some of my rifles shoot better with other powders that are not temperature stable and velocity swings are as high as 175ft/sec depending on the temperature so I have learned to live with it and avoid pressure situations. Extreme powders can be over loaded just like any powder. Some powders will/may go critical and increase the pressure suddenly with only .05 grains more powder, so when this point is reached it is recommended that you back off at least 1+ grain to avoid this situation. Varget tends to give the 223 the highest velocity within SAMMI pressures but It can be over loaded like any other powder, but still remains stable if loaded to SAMMI pressures with different temperature spreads. Where a powder might have a 10 ft/sec shift in a 308 in a 50o temperature change, it is true that a smaller/larger case may have a 15 ft/sec shift with the same extreme powder. BUT other "NON- Extreme powders may/will shift 150 ft/sec through a 50o range. Temperature controlled powder can only help with Temperature swings not with over pressure loads. We all try to get more than we should from a cartridge (It is the nature of our sport) but this can lead to problems with any type of powder. Just my opinion J E CUSTOM [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Temperature Learning Experience
Top