7mm Rem. Mag. not living up to it's billing
- Thread starter Lefty Dick
- Start date
Gibbs:
It aint all that great in any of the loads I've worked so far, I made a optics change, and will do one more kick at it in a couple of weeks. But I kinda think the whole barrel issue is going only one way.
Straight to the scrap metal bin.
It aint all that great in any of the loads I've worked so far, I made a optics change, and will do one more kick at it in a couple of weeks. But I kinda think the whole barrel issue is going only one way.
Straight to the scrap metal bin.
Your experiences with Remington's 7 mag are common for those issues as before I got a left handed .300 Win mag.and sold my 7's ,I too had the same results with bullets in that weight group although I did not have a chrono in those days(1975-1981),many, many readers of the various gun rags like Guns & Ammo and Shooting Times expresseed that very same sentiment.Much of the problem was actually created by Remington in that the powder used in Remingtons factory loadings was not available to handloaders untill IMR-7828 became available to handloaders.The other common misconception was that few shooters knew in fact that the Remington "7" mag was not designed for bullets heavier than the 140 grainers as that is where the cartridge really shined ballistically.The other main issue with the cartridge was that of greatly varying of freebore lengths from one rifle maker to another.To my best recollection there is no other cartridge to this day that had that much tolerance stretching where freebore is concerned.This resulted in many different overall cartridge lengths especially where bullets 160 grains and over were used.
OK, the best that you can realesticly hope for in a sporter is about 1". Yes a lot will do better then that down to .5" off the bench but most sporters will do about 1".Lefty #### said:
If you are doing worse then that then yes I agree with you.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Factory barrels can be quite rough which increases pressure issues with overbore cartridges. The 7RM's I have played with all shot the fastest and best with Re25. In fact, my savage will push a moly 162gr Amax over 3100fps with sub MOA accuracy.
Another rifle with a match barrel will not come close to 2900fps with the same components. yet accuracy is fantastic at 1km.
I started playing with Retumbo and it showed alot of promise. H1000 was 'fast' in my rifles (bizarre but true). Never played with the IMR powders but a friend shoots IMR4831 with lighter bullets and his browning spits them out fast.
Jerry
Another rifle with a match barrel will not come close to 2900fps with the same components. yet accuracy is fantastic at 1km.
I started playing with Retumbo and it showed alot of promise. H1000 was 'fast' in my rifles (bizarre but true). Never played with the IMR powders but a friend shoots IMR4831 with lighter bullets and his browning spits them out fast.
Jerry
Gibbs:
I htink the 7RM can be just as accurate as any other cartridge...
Here is a load work up wiht a Rugerr 77MK II S/S
Action and barrel stock Ruger
Bell& Carlson stock, bedded.
Timney trigger.
140gr TSX
IMR 7828
Fed 215M primer
3 shots, 1 grain of powder apart:
14 shots, 1 grain of powder apart. Squares on target are 1".
This rifle shoots well with 140 gr Accubonds, 175gr Partitions, 160gr X bullets, 139 gr Hornadys...
I htink the 7RM can be just as accurate as any other cartridge...
Here is a load work up wiht a Rugerr 77MK II S/S
Action and barrel stock Ruger
Bell& Carlson stock, bedded.
Timney trigger.
140gr TSX
IMR 7828
Fed 215M primer
3 shots, 1 grain of powder apart:
14 shots, 1 grain of powder apart. Squares on target are 1".
This rifle shoots well with 140 gr Accubonds, 175gr Partitions, 160gr X bullets, 139 gr Hornadys...
SuperCub said:
Well damn if I aint doing exactly that.
And I'm tickled that all of you are getting such wonderful #'s with your 7's, and yes I know a lot of them don't live up to the billing, but If I wanted 150's at 2900, I'd have bought a 24" bbl., 270Win. I'd at least get 2800, and do it with 10grs. less powder. That being said with a lot of predjudice towards the 7, I have over the course of 15 or so years had opportunity to chrony many 7 mags, from other guys, and suspected I'd end up here, but I did'nt think it would be such a crappy ending. I also knew that this rifle was just an action donor, for a project, but hey I got to tinker, and unless the accuracy comes around I reckon it will be rebarrel time sooner as opposed to later.
As for the barrel right now I have'nt gotten anything sub 2" out of it yet, and that's on 5 shot strings.
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Gatehouse that is great accuracy and great shooting by you.
That is also a lot better then most sporters I have seen shoot, although not by much!
Half a inch!!
I am interested, how did you decide WHAT load to use in the end!!
That is also a lot better then most sporters I have seen shoot, although not by much!
Half a inch!!I am interested, how did you decide WHAT load to use in the end!!
Gibbs505 said:Gatehouse that is great accuracy and great shooting by you.
That is also a lot better then most sporters I have seen shoot, although not by much!
I am interested, how did you decide WHAT load to use in the end!!
Withthis load it was easy. Find max and load them up...All the charges went rigth next to/above each other..they just piled on top.
I have yet to shoot a group over 1.5" at 200 yards with this load, and moslty they are under an inch, although to be fiar, I have only shot 5 groups at 200...
Lefty, I hear what you're saying and I have sympathy.
On the other hand, I've loaded for a couple of 7s over the years. (In fact, that's how I learned about reloading).
My first rifle was an old Sako. With 61.5 grains of IMR 4831 and a Hornady 162 BTSP, I was breaking about 2,850, but accuracy was excellent. Before the barrel finally gave up the ghost, I was getting 2,850 to 2,900 with 175 Hornadys pushed by 64 grains of H4831SC.
I also loaded for a buddy's Sako. I was shocked to find that 160 Partitions pushed by the same 61.5 grains of IMR 4831 was clocking 3,050 out of his rifle. This just goes to show how wide the velocities can be with different rifles in this cartridge. (Incidentally, this has been the magic combination for accuracy in my experience in a 7 Mag. If this load (with a decent 160-grain bullet) doesn't print small groups, then something is wrong with the rifle.)
My question for you is what is your seating depth? In my experience, Remington 700s have looooong throats, and bullets need to be seated way, way out if you hope to reach the classic 0.020" off the lands. Seating depth can make a significant difference in velocity and accuracy, and that might be a factor in your case.
However, your velocities (with the stated charges) seem very low, by any standard. If I were you, I'd tinker a bit more, but after a while it's just not worth it anymore.
The truth is that even with the velocities you're getting, the rifle will work on any game animal -- but as you've recognized, what's the point? You already have another proven rifle that performs at this level.
If you want to re-barrel the Remington, I'd still suggest a 7mm Remington Magnum. I wouldn't let this experience sour you on the cartridge. It just plain works, and with a bit of careful loading, you should be able to safely reach 2,950 to 3,000 with a 160-grain bullet.
At the end of the day, though, it's all about what turns you on and gives you confidence. If you think your rifle is anything less than the Angel of Death, for whatever reason, it will not work for you in a hunting situation. That's why these days I'm enamoured with the .300 Winchester Magnum and that's where I plan to stay for a while (as far as "magnums" go, that is).
On the other hand, I've loaded for a couple of 7s over the years. (In fact, that's how I learned about reloading).
My first rifle was an old Sako. With 61.5 grains of IMR 4831 and a Hornady 162 BTSP, I was breaking about 2,850, but accuracy was excellent. Before the barrel finally gave up the ghost, I was getting 2,850 to 2,900 with 175 Hornadys pushed by 64 grains of H4831SC.
I also loaded for a buddy's Sako. I was shocked to find that 160 Partitions pushed by the same 61.5 grains of IMR 4831 was clocking 3,050 out of his rifle. This just goes to show how wide the velocities can be with different rifles in this cartridge. (Incidentally, this has been the magic combination for accuracy in my experience in a 7 Mag. If this load (with a decent 160-grain bullet) doesn't print small groups, then something is wrong with the rifle.)
My question for you is what is your seating depth? In my experience, Remington 700s have looooong throats, and bullets need to be seated way, way out if you hope to reach the classic 0.020" off the lands. Seating depth can make a significant difference in velocity and accuracy, and that might be a factor in your case.
However, your velocities (with the stated charges) seem very low, by any standard. If I were you, I'd tinker a bit more, but after a while it's just not worth it anymore.
The truth is that even with the velocities you're getting, the rifle will work on any game animal -- but as you've recognized, what's the point? You already have another proven rifle that performs at this level.
If you want to re-barrel the Remington, I'd still suggest a 7mm Remington Magnum. I wouldn't let this experience sour you on the cartridge. It just plain works, and with a bit of careful loading, you should be able to safely reach 2,950 to 3,000 with a 160-grain bullet.
At the end of the day, though, it's all about what turns you on and gives you confidence. If you think your rifle is anything less than the Angel of Death, for whatever reason, it will not work for you in a hunting situation. That's why these days I'm enamoured with the .300 Winchester Magnum and that's where I plan to stay for a while (as far as "magnums" go, that is).
john-brennan
CGN frequent flyer
- Location
- Vancouver Island B.C.
I was out on the weekendand did sometesting with 66gr H4831 with a Smith barrel on my 7RM and was getting 3130-3150fps everytime with 160gr partition golds, have used H870 and was getting 3070fps, then Retumbo 71gr and was getting 3200fps. so i believe the barrel seems to be the problem. My rifle is custom built by Bill Leeper and the guy who had it before me was getting similar results with R22 and R25.
Lefty, have you considered casting your chamber; it might just need the throat extended. If the throat is good, I would try fire lapping the bore.
I sold a guy a Browning BBR in 7 RM that he wanted to replace a Weatherby that went off a pack horse and down a montainside, never to be seen again. He insisted on stoking it to 7mm WBy specs, and got away with it, the velocity was there and the accuracy was great. I don't know though, whether it is still shooting that good; I didn'twant to be around if something went wrong!
When/if you're up here fto sandbag our next rifle rodeo, I'll show you my BSA in 7 Mag. It gets advertised velocities out of a 25" barrel, and still groups okay even though the rifling looks pretty dark and rough! Go figure.
Could it be that you're shooting it sinister handed, with the hand of darkness, etc?
I sold a guy a Browning BBR in 7 RM that he wanted to replace a Weatherby that went off a pack horse and down a montainside, never to be seen again. He insisted on stoking it to 7mm WBy specs, and got away with it, the velocity was there and the accuracy was great. I don't know though, whether it is still shooting that good; I didn'twant to be around if something went wrong!
When/if you're up here fto sandbag our next rifle rodeo, I'll show you my BSA in 7 Mag. It gets advertised velocities out of a 25" barrel, and still groups okay even though the rifling looks pretty dark and rough! Go figure.
Could it be that you're shooting it sinister handed, with the hand of darkness, etc?
My 700 Classic is uncommonly accurate for a factory barrel. I am surprised when I get three-shot groups that are over 1" I have used this one at 1000 yards for Hunter class at Burns Lake for the past 5 or 6 years, and expect to see groups in the 8-9" area, if I do my part. That is shooting the 150 Ballistic Tip Federal Premium load. Handloaded, It will do slightly better, but handloads are not allowed in that class. Regards, Eagleye.
