|
Forum Rules | Firearms Safety | Firearms Photos | Links | Library | Lost Password | Email Changes |
Register | FAQ | Calendar | Search | Today's Posts | Mark Forums Read |
|
Thread Tools | Search this Thread |
July 30, 2013, 01:10 PM | #1 |
Member
Join Date: February 5, 2013
Posts: 22
|
7mm rem mag 180gr reloading and twist rate
Hi guys,
I just picked up some sierra 180gr match kings for 7mm rem mag and noticed that on the box it says min twist rate is 8" or faster. Ive got a 700adl and remington tells me the twist is 9 1/4". How much of an issue do you guys think this will be if I decide to reload these? Thanks |
July 30, 2013, 01:23 PM | #2 |
Senior Member
Join Date: August 1, 2010
Posts: 641
|
It should work.
Measure the length of the bullet and go to the stability calculator at jbmballistics.com. |
July 30, 2013, 03:07 PM | #3 |
Member
Join Date: February 5, 2013
Posts: 22
|
Thanks for the info, i checked out their site and found the stability calculated at 1.785. I dont understand the scale that this number lies on. Is this considered good or bad or inbetween?
Thanks |
July 30, 2013, 03:19 PM | #4 |
Senior Member
Join Date: August 1, 2010
Posts: 641
|
The JBM site says,
"Stability value should be in the range of 1.3 to 2.0 to ensure bullet stability." Just out of curiosity, how long is that bullet, and what velocity do you expect? |
July 30, 2013, 03:33 PM | #5 |
Member
Join Date: February 5, 2013
Posts: 22
|
the bullet is 1 and 7/16'' and i left it at 3000fps, but in reality it will probably be about a 100 or so lower than that.
|
July 30, 2013, 03:48 PM | #6 |
Member
Join Date: February 5, 2013
Posts: 22
|
im curious what the value represents. they give a range in which stability is acceptable, but what are the effects of a low value as well as a high value?
|
July 30, 2013, 07:43 PM | #7 |
Senior Member
Join Date: January 27, 2010
Location: AR
Posts: 1,401
|
3000fps out of a 7mag with a 180gr bullet......... That is pushing it.
|
July 30, 2013, 07:54 PM | #8 |
Junior member
Join Date: December 20, 2012
Location: The "Gunshine State"
Posts: 1,981
|
That is WAY more than just pushing it...........
My Sierra manual ( a few years old) doesn't even list a 180gr, but they do show MAX loads for 175 @2900 and that is from a 26" barrel, not your typical 24 |
Thread Tools | Search this Thread |
|
|