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
7mm Rem. Mag. load help
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="SakoShooterSD" data-source="post: 515036" data-attributes="member: 33931"><p>I have the 150's seated about 0.011" off the lands, according to my RCBS Freebore tool. </p><p>I didn't have the freebore/headspace/micrometer tool when I did my very limited C.O.A.L. test; i based my COAL choice on a comparison of just 3 different 4-shot groups. I only tested COAL of 3.300" (over SAAMI spec!), 3.285 and 3.270 . . . and the longest COAL (which I now can calculate as having put the bullet just about on the lands) ended up giving a slightly better group. I decided to stay in SAAMI spec, to allow for a little margin, since this is a hunting/field rifle . . . and so my subsequent loads have been done with COAL of about 3.290, and have produced very good groups. (at 11 / 1000's off the lands)</p><p></p><p>Regarding the 140 gr bullets vs. 150 gr . . .</p><p>I would bet that you can find a powder and charge that will work just as well for the 150's as for the 140's, and save your self a little $ on buying the TTSX (@ 62 cents) instead of the MRX (@ $1.18). -- Oh, I see Barnes now has 140 gr TTSX. </p><p></p><p>Seat the bullets 10/1000's off the lands, and use your Retumbo to do an Audette/Ladder test with the 150 gr bullets, in 0.2 gr charge increments, shooting at 300 yds. </p><p></p><p>Then do the same with IMR4831, or another powder of your choice (H1000?)</p><p></p><p>I bet you will find at least two good loads, with just 30 or 50 shots fired, and can then fine tune from there, and verify drop at different distances.</p><p></p><p>I am going to try the ladder test for the first time -- it seems like a very efficient way to narrow in on optimum powder charge, without inadvertently skipping over a node. It also seems like it will give you a better idea of the sensitivity of your gun to powder (pressure) variations, and could point you to a more robust solution, as opposed to just the tightest group. </p><p>I'll let you know my results, and hope you will post yours! We almost certainly won't get the same optimum load, but one can often learn a little by hearing about other people's development efforts. </p><p></p><p>Good luck! And let us know what you get.</p></blockquote><p></p>
[QUOTE="SakoShooterSD, post: 515036, member: 33931"] I have the 150's seated about 0.011" off the lands, according to my RCBS Freebore tool. I didn't have the freebore/headspace/micrometer tool when I did my very limited C.O.A.L. test; i based my COAL choice on a comparison of just 3 different 4-shot groups. I only tested COAL of 3.300" (over SAAMI spec!), 3.285 and 3.270 . . . and the longest COAL (which I now can calculate as having put the bullet just about on the lands) ended up giving a slightly better group. I decided to stay in SAAMI spec, to allow for a little margin, since this is a hunting/field rifle . . . and so my subsequent loads have been done with COAL of about 3.290, and have produced very good groups. (at 11 / 1000's off the lands) Regarding the 140 gr bullets vs. 150 gr . . . I would bet that you can find a powder and charge that will work just as well for the 150's as for the 140's, and save your self a little $ on buying the TTSX (@ 62 cents) instead of the MRX (@ $1.18). -- Oh, I see Barnes now has 140 gr TTSX. Seat the bullets 10/1000's off the lands, and use your Retumbo to do an Audette/Ladder test with the 150 gr bullets, in 0.2 gr charge increments, shooting at 300 yds. Then do the same with IMR4831, or another powder of your choice (H1000?) I bet you will find at least two good loads, with just 30 or 50 shots fired, and can then fine tune from there, and verify drop at different distances. I am going to try the ladder test for the first time -- it seems like a very efficient way to narrow in on optimum powder charge, without inadvertently skipping over a node. It also seems like it will give you a better idea of the sensitivity of your gun to powder (pressure) variations, and could point you to a more robust solution, as opposed to just the tightest group. I'll let you know my results, and hope you will post yours! We almost certainly won't get the same optimum load, but one can often learn a little by hearing about other people's development efforts. Good luck! And let us know what you get. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
7mm Rem. Mag. load help
Top