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
7mm SAUM Wildcat!
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="calinb" data-source="post: 644273" data-attributes="member: 31242"><p>I ran QL on the GT with the same numbers as before (2.840 COAL) but with a 26" barrel instead of 28". The difference in velocity is less than 50 fps! Given that a shorter barrel implies higher pressure for the same velocity (and reduced barrel life?), I ran IMR 7828 SSC at 2878 fps to see how much the pressure dropped with a 28" barrel. It only went down from 64542 psi. to 61240 psi.</p><p></p><p>[ATTACH]8798[/ATTACH]</p><p></p><p>I just talked to Dave at PTG today and ordered a custom 7mm-300 RCM reamer. After making up the dummy cartridge and discussing my measurements with him, Dave recommended a 0.188 freebore and 0.315 neck, which will require neck turning. Even though the Hornady brass necks seem pretty good after a measuring a small sample, I didn't want to risk going for a no-turn fit.</p><p></p><p>Dave said 0.188 FB is known to work well with the 180 Berger VLDs and Hybrids and he recommended sticking with 0.188 until the 195 design is finished. He said a PTG throating reamer will work perfectly for a length adjustment later.</p><p></p><p>I'm sure others have taken the 7mm RCM path before me, but I can't find any online performance reports. According to 6mmbr.com, just about any 7mm cartridge can shoot the Bergers well, if setup right. I'm not anticipating any problems with the RCM, though it's obviously not a terribly popular parent case.</p><p></p><p>After reading <a href="http://www.longrangehunting.com/forums/../articles/barrel-weight-1.php" target="_blank">http://www.longrangehunting.com/articles/barrel-weight-1.php</a>, I think I'll order a Krieger Light Palma in 1:8. I'm not taking any chances on 8.5 and the 195 Bergers. I'll probably order the standard 28" because I can always cut it down. Krieger appears to be more conservative than some other vendors. They won't makes a stainless 7mm in a #4 contour (#5 is their minimum) nor will they flute a Light Palma, which is okay by me. I've purchased from Krieger twice in the past and find them great to work with, despite the wait for delivery. I once had to send them a larger than normal AR barrel extension and a wrench socket tool that I'd machined to fit it to get a new barrel made for my Oly 243 WSSM upper. It worked out fine.</p></blockquote><p></p>
[QUOTE="calinb, post: 644273, member: 31242"] I ran QL on the GT with the same numbers as before (2.840 COAL) but with a 26" barrel instead of 28". The difference in velocity is less than 50 fps! Given that a shorter barrel implies higher pressure for the same velocity (and reduced barrel life?), I ran IMR 7828 SSC at 2878 fps to see how much the pressure dropped with a 28" barrel. It only went down from 64542 psi. to 61240 psi. [ATTACH]8798.vB[/ATTACH] I just talked to Dave at PTG today and ordered a custom 7mm-300 RCM reamer. After making up the dummy cartridge and discussing my measurements with him, Dave recommended a 0.188 freebore and 0.315 neck, which will require neck turning. Even though the Hornady brass necks seem pretty good after a measuring a small sample, I didn't want to risk going for a no-turn fit. Dave said 0.188 FB is known to work well with the 180 Berger VLDs and Hybrids and he recommended sticking with 0.188 until the 195 design is finished. He said a PTG throating reamer will work perfectly for a length adjustment later. I'm sure others have taken the 7mm RCM path before me, but I can't find any online performance reports. According to 6mmbr.com, just about any 7mm cartridge can shoot the Bergers well, if setup right. I'm not anticipating any problems with the RCM, though it's obviously not a terribly popular parent case. After reading [URL="http://www.longrangehunting.com/forums/../articles/barrel-weight-1.php"]http://www.longrangehunting.com/articles/barrel-weight-1.php[/URL], I think I'll order a Krieger Light Palma in 1:8. I'm not taking any chances on 8.5 and the 195 Bergers. I'll probably order the standard 28" because I can always cut it down. Krieger appears to be more conservative than some other vendors. They won't makes a stainless 7mm in a #4 contour (#5 is their minimum) nor will they flute a Light Palma, which is okay by me. I've purchased from Krieger twice in the past and find them great to work with, despite the wait for delivery. I once had to send them a larger than normal AR barrel extension and a wrench socket tool that I'd machined to fit it to get a new barrel made for my Oly 243 WSSM upper. It worked out fine. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
7mm SAUM Wildcat!
Top