7mm Rem. Mag. load help
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yes it is and I have ordered most of what was said on this thread and some from others . the lowest I went was with Barnes 140gr and on the high side Berger's at 180gr and then the Nosler Accubond - Swift - Hornady amax - . going to try 2 wights in each manufacture . I'm thinking I will find the right one for my riffle .
boomtube
Well-Known Member
"I just got a a-bolt in 7mm Rem. Mag. what loads are going to do good."
Popular question from new guys. Ah, if only our life were so easy then the loading manuals would only need to print one load for each caliber, giving the correct amount of what powder and bullet ... but that isn't what they do.
Popular question from new guys. Ah, if only our life were so easy then the loading manuals would only need to print one load for each caliber, giving the correct amount of what powder and bullet ... but that isn't what they do.
GOOD ?? I hope I do them all good . after the .243 and a major tune up on the .270 I think I can do it and come up with the best load and best bullet for both 7,s and possibly they will be the same load .
I have never relay looked at the bullets that have been used with the 7 rm . I,m supprised at the gram's of bullets being used . looks like most on this site use 160gr to 170gr . I would of thought 170 to 190 . found out today a buddy loads 138gr in his weatherby . one of my 7 rm must shoot lead free and it looks like most lean torwd the TTSX 140gr . I just found this to be on the light side .
The main reason there's hundreds of printed loads for a given bullet in a given cartridge is easy to understand. 99% of them are developed by someone shooting a rifle resting atop something on a bench, holding the rifle and pulling the trigger themselves typically shooting a couple of 5-shot groups. There's two big problems with this.
First, unless one shoots at least 20 shots per test group, the statistical confidence level it represents real accuracy at least 80% of the time won't be attained. One 20-shot test group's about 4 times better than four 5-shot ones averaged.
Second, maybe 1 in 1000 people can shoot a rifle with a 2-pound or heavier trigger with more than 10 foot-pounds of recoil held against their shoulder as it rests on something atop a bench exactly the same for each shot. Everyone else's non-repeatable technique opens up groups considerably.
Why else would there be hundreds of loads listed for that bullet-cartridge combination? To say nothing of the wide range of rifle quality used to develop loads in the first place along with a wide range of reloading tools and techniques used.
I am working up a load with 168 berger, norma brass, retumbo and win large rifle primers. I have gotten into the 1/2" group range at 200 yds. Does anyone see a benefit to trying a Fed 210 match primer? Anyone think they are more consistent than the WLR primer?
While many folks feel primers that are the most consistant (uniform?) produce the best accuracy, I decided years ago to try some that were the mildest.
A friend did some tests shooting BB's from a 17 caliber barrel using primed cases only. The BB's were shot through a chronograph recording their speed. Hot primers shot 'em the fastest, mildest ones shot 'em the slowest. Some of the medium ones produced the most uniform velocity.
Those shooting the most accurate in loaded ammo were the mildest ones. Even if their velocity spread shooting BB's was not all that great, they seemed to more uniformly ignite the powder and produce the lowest muzzle velocity spread.
I've used RWS 5341 primers wearing out three 30 caliber magnum barrels for long range matches. Tried a couple "match" primers and also the RWS magnum large rifle primer, the hottest one made. None shot test groups at 1000 yards as small as the mild RWS ones.
I and others have also got great results from Remington .308 Win. cases pocketed for small rifle primers. Remington 7.5's did very well indeed. Watched a guy set a National record using this case and primer holding 48 grains of IMR4350 under a Sierra 200-gr. HPMK. He put 20 record shots in a 4 inch group a bit off center in the 6-inch X ring at 600 yards. One shot leaked out for a 200-19X score. Not too shabby with aperture sights, an almost worn out barrel and small, mild rifle primers.
Nowadays, I'd recommend Wolf primers; they seem to be the favorite of follks shooting accurate rifles off their shoulder in competition.
A friend did some tests shooting BB's from a 17 caliber barrel using primed cases only. The BB's were shot through a chronograph recording their speed. Hot primers shot 'em the fastest, mildest ones shot 'em the slowest. Some of the medium ones produced the most uniform velocity.
Those shooting the most accurate in loaded ammo were the mildest ones. Even if their velocity spread shooting BB's was not all that great, they seemed to more uniformly ignite the powder and produce the lowest muzzle velocity spread.
I've used RWS 5341 primers wearing out three 30 caliber magnum barrels for long range matches. Tried a couple "match" primers and also the RWS magnum large rifle primer, the hottest one made. None shot test groups at 1000 yards as small as the mild RWS ones.
I and others have also got great results from Remington .308 Win. cases pocketed for small rifle primers. Remington 7.5's did very well indeed. Watched a guy set a National record using this case and primer holding 48 grains of IMR4350 under a Sierra 200-gr. HPMK. He put 20 record shots in a 4 inch group a bit off center in the 6-inch X ring at 600 yards. One shot leaked out for a 200-19X score. Not too shabby with aperture sights, an almost worn out barrel and small, mild rifle primers.
Nowadays, I'd recommend Wolf primers; they seem to be the favorite of follks shooting accurate rifles off their shoulder in competition.
for one of the 7 rm's like I said must be lead free !! ( I'm in a lead free hunting zone ) so is the 140 ttsx to light ?? what is the input on this .. it will not be my 1000 yard shooter but might get a chance at a dear at 800 or a bear at 800 is 140 to light ??
I would say that 140 is to light. The better the BC the more energy you will have down range for the kill. BC naturally goes up with heavier bullets. For long shots out to 800 yards, you want the highest BC bullet you can shoot. Run a 140 bullet, compared to a 168 bullet, in your ballistics program and see what you 800 yard energy is.
boomtube
Well-Known Member
Bart B.: "Why else would there be hundreds of loads listed for that bullet-cartridge combination?"
Well, you write of some interesting side issues but, putting any possible effects of recoil and trigger pull on the potential accuracy of a load aside, the reason there are 'hundreds of loads listed for that bullet-cartridge combination" is because there are many possible usable combos and no one has any way in the world of predicting what may work well in any particular rifle.
Well, you write of some interesting side issues but, putting any possible effects of recoil and trigger pull on the potential accuracy of a load aside, the reason there are 'hundreds of loads listed for that bullet-cartridge combination" is because there are many possible usable combos and no one has any way in the world of predicting what may work well in any particular rifle.
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