Visit the SWFA.com site to check out our current specials. |
Chrono 7mm Mag Loads? |
Post Reply | Page 12> |
Author | |
Trays 7940
Optics Master Joined: August/09/2009 Location: Texas Status: Offline Points: 1149 |
Post Options
Thanks(0)
Posted: August/14/2009 at 22:17 |
Just got a chrongraph and took it to the range with my 7mm Mag loads. For the longest I thought my rounds were moving at 3050 to 3100fps. I found out, today, they are only moving at 2808fps. Looking at all of my reloading books, they show 63g of RL22 will move a 160 nosler Accubond at 3000fps +/-. These are max loads.
I would like to shoot my 7mm Mag above 3000fps but I don't want to add more powder and blow up my rifle... or me.
Anyone have a handload for a 7mm Mag 160g chronoed at 3000 +?
|
|
Steelbenz
Optics Jedi Knight ROLL TIDE ROLL Joined: January/03/2006 Location: Heart of Dixie Status: Offline Points: 5153 |
Post Options
Thanks(0)
|
Trays 7940 what barrel length did the manufacture use to produce the 3050-3100FPS? Next question, are you getting high pressure signs showing on your cases? At where are you getting your load data?
edited for fat fingers!!! LOL Edited by Steelbenz - August/14/2009 at 22:38 |
|
"Don't argue with a fool! From a distance you can't really tell who's who!"
|
|
sakomato
Optics Master Joined: February/28/2008 Location: Houston Status: Offline Points: 1166 |
Post Options
Thanks(0)
|
Alliant powders (the manufacturer of RL22) lists 65 gr as max with the 160 gr bullet
Speer lists 65 gr RL22 as max with their 160 gr bullets
Sierra lists 65.2 RL22 as max with their 160 gr bullets
Swift bullets lists 65.5 gr RL22 as max with their 160 gr bullets
Barnes bullets lists 63 gr RL22 as max with their 160 gr X bullets
Nosler lists 63 gr RL22 as max with the 160 gr bullet
I got this information out of the 7 mag booklet called One Book / One Caliber from www.loadbooks.com . Steve's pages also listed 66 gr RL22 as max with the 160 gr bullets.
If you have a large jump to the lands that will also lower the velociy.
I don't have a lot of experience with the 7 mags and have only reloaded for 3 of them. In one of them that I did the most work on, a Browning A bolt, I had to get up to 65.5 gr RL22 to get 3000 fps. About 3050 fps with the 160 gr bullet is max with the 160 gr bullet in the 7 mags. That is where the extractor groove brass flow marks start showing up on the case heads and the bolt starts to get stiff.
By contrast my 280AI will hit 3100 fps with the 160's with nary a sign of pressure.
WORK UP TO THESE LEVELS POSTED. EACH GUN IS DIFFERENT AND YOUR GUN COULD DEVELOP PRESSURE EARLIER THAN MINE. LOOK FOR PRESSURE SIGNS AS YOU WORK UP.
|
|
Guns only have 2 enemies, rust and politicians
|
|
Roy Finn
MODERATOR Steiner Junkie Joined: April/05/2004 Location: United States Status: Offline Points: 4856 |
Post Options
Thanks(0)
|
That's cruel, but kinda funny. |
|
pyro6999
Optics Retard OT TITAN Joined: December/22/2006 Location: North Dakota Status: Offline Points: 22034 |
Post Options
Thanks(0)
|
i suppose that has something to do with the belt???
|
|
They call me "Boots"
375H&H Mag: Yeah, it kills stuff "extra dead" 343 we will never forget God Bless Chris Ledoux "good ride cowboy" |
|
sakomato
Optics Master Joined: February/28/2008 Location: Houston Status: Offline Points: 1166 |
Post Options
Thanks(0)
|
Hey pyro, I must confess that I feel about 7 mags like you feel about 270's.
|
|
Guns only have 2 enemies, rust and politicians
|
|
pyro6999
Optics Retard OT TITAN Joined: December/22/2006 Location: North Dakota Status: Offline Points: 22034 |
Post Options
Thanks(0)
|
really? how come?
|
|
They call me "Boots"
375H&H Mag: Yeah, it kills stuff "extra dead" 343 we will never forget God Bless Chris Ledoux "good ride cowboy" |
|
Trays 7940
Optics Master Joined: August/09/2009 Location: Texas Status: Offline Points: 1149 |
Post Options
Thanks(0)
|
I set everything up like the Nosler book had.
They used a 24" barrel.
I have a Remington 700 with a 24" barrel. I have no signs of pressure, at this time.
My COAL is 3.290
Fed 215 primers
Winchester cases
160g Accubond Bullets
63g RL22 powder
I might try not seatting the bullet so far down... or maybe I need to seat them farther down?
Maybe I got some bad powder...
|
|
300S&W
Optics God Joined: January/27/2008 Location: Burlington,WV Status: Offline Points: 10592 |
Post Options
Thanks(0)
|
T,
The trouble is Nosler uses pressure bbls that are at minimum SAAMI specs so they reach higher pressures/velocities with less powder than your production bbl does.
|
|
"I ain't got time to bleed!"
|
|
Roy Finn
MODERATOR Steiner Junkie Joined: April/05/2004 Location: United States Status: Offline Points: 4856 |
Post Options
Thanks(0)
|
Bingo!!!!!!
|
|
pyro6999
Optics Retard OT TITAN Joined: December/22/2006 Location: North Dakota Status: Offline Points: 22034 |
Post Options
Thanks(0)
|
they do that for marketing reasons i assume, since in this country speed sells. |
|
They call me "Boots"
375H&H Mag: Yeah, it kills stuff "extra dead" 343 we will never forget God Bless Chris Ledoux "good ride cowboy" |
|
300S&W
Optics God Joined: January/27/2008 Location: Burlington,WV Status: Offline Points: 10592 |
Post Options
Thanks(0)
|
To be honest I believe all reload data is developed using SAAMI minimum spec bbls. It's just that Nosler publishes the data obtained using them where as the others(maybe not all)publish data that they obtained by shooting their pressure bbl loads in production or sometimes custom rifles.
|
|
"I ain't got time to bleed!"
|
|
Roy Finn
MODERATOR Steiner Junkie Joined: April/05/2004 Location: United States Status: Offline Points: 4856 |
Post Options
Thanks(0)
|
I have to wonder if the loads listed in Nosler manuals and others, is throttled back because of the rifles chambered for the 7 mag such as levers and autos.
|
|
pyro6999
Optics Retard OT TITAN Joined: December/22/2006 Location: North Dakota Status: Offline Points: 22034 |
Post Options
Thanks(0)
|
i would assume yes roy, although if you look at stuff like the 45-70 they have separate pages for old actions etc. and new ones. |
|
They call me "Boots"
375H&H Mag: Yeah, it kills stuff "extra dead" 343 we will never forget God Bless Chris Ledoux "good ride cowboy" |
|
300S&W
Optics God Joined: January/27/2008 Location: Burlington,WV Status: Offline Points: 10592 |
Post Options
Thanks(0)
|
Good point pyro. I guess all the load developers would have to do is add a warning with the data that the loads are to be used in modern bolt action rifles(not that older actions would matter).
|
|
"I ain't got time to bleed!"
|
|
Roy Finn
MODERATOR Steiner Junkie Joined: April/05/2004 Location: United States Status: Offline Points: 4856 |
Post Options
Thanks(0)
|
Safety and CYA is always at play.
Trays, I have an old issue of Handloader magazine with an article named "Handloads that Work" by John Barsness that listed a load of 66 grs of R-22 or H-4831 using 160's for a velocity "slightly over 3000 in a 24 inch barrel". |
|
pyro6999
Optics Retard OT TITAN Joined: December/22/2006 Location: North Dakota Status: Offline Points: 22034 |
Post Options
Thanks(0)
|
in the case of the 45-70 i could see where that would matter, other than that i totally agree earl. the other point they need to make is in the case of the the .257 roberts vs the .257 roberts+P there is a slight difference. it seems to me that most of the manuals i have now are pretty good about not giving a lawyer load. they seem to get you about as close to true max as one would dare, obviously working up to your rifles maximum's is the safest bet.
|
|
They call me "Boots"
375H&H Mag: Yeah, it kills stuff "extra dead" 343 we will never forget God Bless Chris Ledoux "good ride cowboy" |
|
300S&W
Optics God Joined: January/27/2008 Location: Burlington,WV Status: Offline Points: 10592 |
Post Options
Thanks(0)
|
No doubt,Roy! Probably just as well to. Really though,just how much more velocity can they or even need to eek out of the popular rounds? Listen to some of the stories of the WSM's and the pressure signs with factory ammo. Just makes no sense.
Pyro,TO ME Noslers velocities are the max. After all,the loads they develop and equipment they use follow SAAMI standards. Edited by 300S&W - August/15/2009 at 11:51 |
|
"I ain't got time to bleed!"
|
|
pyro6999
Optics Retard OT TITAN Joined: December/22/2006 Location: North Dakota Status: Offline Points: 22034 |
Post Options
Thanks(0)
|
i hear you earl, when i first bought the nosler book and started thumbing through its pages i thought to myself "damn these guys are loading em plenty hot" when i started to load my .375H&H even some of the loads in the hornady manual were as full as full could be.
|
|
They call me "Boots"
375H&H Mag: Yeah, it kills stuff "extra dead" 343 we will never forget God Bless Chris Ledoux "good ride cowboy" |
|
Big Squeeze
Optics Master Extraordinaire GOOGLE NINJA Joined: August/30/2007 Location: Anaheim, Calif. Status: Offline Points: 3143 |
Post Options
Thanks(0)
|
If you`re not showing pressure signs using 63 gr, then keep going up carefully 1/2 gr at a time until you start to see signs of pressure. Then back off 1/2 grain and consider that as max for your rifle and then chrony that loading. You just need a little extra powder to get closer to the 3000 fps mark. Some rifles need a little extra powder to get book velocities. You may also have a slightly slower bore.
Using the RL22, try different bullets, chrony them and then compare those velocities with the Nosler A/Bs.
Another good source for re-load info is on the "reloadersnest" site (rifle section), where posters have submitted loads, the components used and their chrony results in most cases. I have duplicated a few loads from that site and posted them there.
|
|
Post Reply | Page 12> |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |