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
Rifles, Bullets, Barrels & Ballistics
7 rum
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="DocDoc" data-source="post: 1224828" data-attributes="member: 69144"><p>Appreciate JE Custom and his wisdom, but I think he is a little off on his estimates of % increase in 7mm RM to STW to RUM. They are running about 3000 fps so a 20% increase in velocity would be about 600 fps increase. I did not think that was reasonable so I went to the Berger manual. Barrel lengths are all 26 inches. Max should all have pressures about the same.</p><p></p><p>7 mm RM</p><p>168 gr Berger about 3000 fps max</p><p>180 gr Berger about 2800 fps max</p><p></p><p>7mm WBY</p><p>168 Berger about 3050 fps max</p><p>180 Berger about 2950 fps max</p><p></p><p>7 mm STW</p><p>168 Berger about 3050 fps max</p><p>180 Berger about 2950 fps max</p><p></p><p>7 mm RUM</p><p>168 Berger about 3067 fps max</p><p>180 Berger about 2988 fps max.</p><p></p><p>It looks to me like getting much over 7mm RM you are into the area of diminishing returns and not a lot of velocity increase for the powder burned. I do not see even a 10% increase.</p></blockquote><p></p>
[QUOTE="DocDoc, post: 1224828, member: 69144"] Appreciate JE Custom and his wisdom, but I think he is a little off on his estimates of % increase in 7mm RM to STW to RUM. They are running about 3000 fps so a 20% increase in velocity would be about 600 fps increase. I did not think that was reasonable so I went to the Berger manual. Barrel lengths are all 26 inches. Max should all have pressures about the same. 7 mm RM 168 gr Berger about 3000 fps max 180 gr Berger about 2800 fps max 7mm WBY 168 Berger about 3050 fps max 180 Berger about 2950 fps max 7 mm STW 168 Berger about 3050 fps max 180 Berger about 2950 fps max 7 mm RUM 168 Berger about 3067 fps max 180 Berger about 2988 fps max. It looks to me like getting much over 7mm RM you are into the area of diminishing returns and not a lot of velocity increase for the powder burned. I do not see even a 10% increase. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
7 rum
Top