Well I started to work up some loads in a used 7 Rem Mag a Ruger 77 tang saftey style with a 24" barrel. Using R22 and the 140 Nosler Partition I am only able to generate 3050 ft/sec's with book maximum loads. Various books suggest that I should be able to get 3250 ft/sec's. But my 35P says different. When venturing into the beyond the book range (with "safe" primer reading and other voodoo,) I get all the way to 3130 ft/sec's. Interestingly, the rifle really shoot well with the hot ones. To spare the obvious response, yes it is the rifle not the shooter which is slow...

308,

I share your dilemma. I've shot two Savage 110's (one circa 1965, the other maybe 10 years later) that aren't as spritely as they should be. It seems, however, that I loose less velocity the heavier the bullet--175 partitions are only about 200 fps slower than what I'd hope, while 150's are 400! fps slower.

I think Allen Day has commented on this before, you might PM him for some help.

friar

edit p.s. I was using the Nosler #5 Manual, which lists the 7 Rem Mag with a 24" barrel. Both rifles I mentioned above are this length barrel.

first of all the book velocities are usually taken with longer barrels, and second they are usually exaggerated

Every rifle I own is slow.

I've checked hundreds of loads from the dozen or so rifle calibers I load for over multiple chronographs and used multi screen chronographs to calculate actual BC using computer programs that compensate for the distance of the screens to true muzzle velocities and not one load will achieve any load listed in any of my reloading manuals.

My 7 Rem mag is one of the worst in this.

I'm going with a 27" Krieger barrel in my next rifle and I'm hoping that one will do it.

There is a lot of variation in velocities with the 7Mag. If I used book maximums in mine, I'd sell it and buy a .270 as they will go 3000 fps with 140's. You should be able to get 3200.

quote:

Originally posted by 308Sako:
Well I started to work up some loads in a used 7 Rem Mag a Ruger 77 tang saftey style with a 24" barrel. Using R22 and the 140 Nosler Partition I am only able to generate 3050 ft/sec's with book maximum loads. Various books suggest that I should be able to get 3250 ft/sec's. But my 35P says different. When venturing into the beyond the book rang (with "safe" primer reading and other voodoo,) I get all the way to 3130 ft/sec's. Interestingly, the rifle really shoot well with the hot ones. To spare the obvious response, yes it is the rifle not the shooter which is slow...

I see numerous problems here:
-slow powder (RL-22) used in a short tube
-light to mid-weight bullets used with a slow powder
-last, but not least, lact of an actual known maximum load.
I would try RL-19, and I think improvements would be immediate. Better yet, try VV-N-160.

I tried every slow burning powder in my 7m/m and couldn't break 3100FPS, that was until I went back to the 4350 burning rate. The slower powders will do much better with the 175s in 7m/m. That's been my experience anyway.

quote:

Originally posted by 308Sako:
Well I started to work up some loads in a used 7 Rem Mag a Ruger 77 tang saftey style with a 24" barrel. Using R22 and the 140 Nosler Partition I am only able to generate 3050 ft/sec's with book maximum loads. Various books suggest that I should be able to get 3250 ft/sec's. But my 35P says different. When venturing into the beyond the book range (with "safe" primer reading and other voodoo,) I get all the way to 3130 ft/sec's. Interestingly, the rifle really shoot well with the hot ones. To spare the obvious response, yes it is the rifle not the shooter which is slow...

Maybe the answer to your question is the rifle is a tang safety model. Bear with me. In an early RIFLE or HANDLOADER Magazine, I forget which, a fellow was getting some phenomenal velocities using some of the newer powders of the day. The rifle was a Ruger tang safety in 7x57 Mauser BTW. When he tried IMR-4350, he was again able to load up to the very high for the cartridge velocities. He had a chamber cast made and also slugged the bore. The end result was the chamber was the maximum allowable according to SAAMI specs and the bore was .295", rather than the standard .284". There may have been a batch of those barrels in the various 7mm caliber as I also had a tang safety with the oversized bore, although my chamber was closer to the mid level of SAAMI standards. I could still get away with loads well over book max, just not as high as the fellow in the magazine.
A fat chamber and a loose bore would reduce velocity with normal loads.
I'm not saying this might be your case as wll, but it might be worth looking into.
Paul B.

The book is a good guide, but your chrono & pressure signs will tell you what's what. Rugers tend to be longer throated, at least the #1s are. You may also have fired this rifle a lot & worn the throat a bit. I would drop to H4831sc for the 140gr bullets, just a wee bit faster, but nothing wrong w/ exceeding this ot that book data, all rifles are diff. When you need to back off is when you are getting way over a book vel. This usually, buy not always means higher pressure.

I had no problems reaching 3200fps in my own rifles using r-22 and 140gr bullets.The powder charge was above that listed in some manuals but within the range listed in other manuals.As an example of variances in manuals, one of my manuals lists a maximun velocity of 3340fps usin 67.5gr of r-22 while another manual lists 3209fps using 70gr of r-22.Both rifles are listed as having 24" barrels.That is why I don't blindly trust the max loads in the manuals.They may be too hot for some rifles,and yet very mild in others.

I also have a Ruger tang safety in 7mm Mag with the standard 24 inch tube.

I get a little over 3200fps with a 140gr bullet and 68.5gr of Vihtavuori N560 powder. This is a pressure tested load direct from Vihtavuori's manual. You can download it as a pdf file from their website (and their listed velocity was obtained with a 24inch tube too). Download in case I made a typo!

[URL=Vihtavuori Reloading Guide]http://www.lapua.com/[/URL]

Work up to this load though -- in some other calibres I've found that Vihtavuori's max load to be too hot to allow 6 loadings of a case in my rifles. This is my conservative criteria (primers seating easily after 6 loads) for when high presure is exceeding the elastic limits of the brass.

I will admit that I've tried a lot of other powders, and that VV N560 is the only one to break 3100fps (let alone 3200fps!) in my 24 inch barrel and still let me load a case at least 6 times.

John

quote:

There is a lot of variation in velocities with the 7Mag. If I used book maximums in mine, I'd sell it and buy a .270 as they will go 3000 fps with 140's. You should be able to get 3200

Better yet, get a 280 Rem. you can get 3150fps w/RL22, a bit more w/Norma MRP (if you can find it )

A 280 will do @ least 100fps better than a 270 w/any given bullet weight.

7mm's seem to have more bore diameter variance than most calibers. I had 1 7 mag that comfortably shot about 3grs more powder than the listed max load to reach the same velocity as the listed max load, remember Velocity is a pressure sign.
I had another 7 (a 7 Dakota) that would acheive the listed velocities with about 4 grs less than the maximum load.
I could only concluded that the 7 Mag had a large toleranced bore and the 7 Dakota had a low end of tolerance bore.
Both shoot well and reach the listed velocities. A third 7 mag won't reach quite the velocities I've seen in the others but shoots so well 100 fps slower who cares? If your gun shoots well and shows no other pressure signs at the velocities you need I wouldn't worry too much about it even if your load varies the max powder charge. If you are loading to 150-200fps more than the maximum listed velocity - then you should worry...............DJ

My hunting buddy in Wyoming has anolder Colt Saur in 7MM mag and he was always bragging about what an elk rifle it was with 154 grain Hornady Spire points and a bunch of IMR4931. This rifle has retractable locking lugs and as soon as you hit a certain point the bolt is really hard to open. Last year wa we sighted in another friend shows up with a new chrony and we test our hunting loads. My 30-06 hunting load with 180 grain bullet gets 2850 fps, My 270 with 150 grain Hornady gets 2910 fps and his 7MM mag with 154 grain Hornady gets 2850 with a load 1 grain under what it takes to make opening the bolt hard. This in no way reduces the effectiveness of his rifle on elk and I wish he had never chronyd his as he is gettin a custom 30-06 Springield built now.

Obviously the gent didn't need a new rifle he just needed a new load.

Unless of course he might of been jonesing for a new play toy...

MD

quote:

Originally posted by 308Sako:
Well I started to work up some loads in a used 7 Rem Mag a Ruger 77 tang saftey style with a 24" barrel. Using R22 and the 140 Nosler Partition I am only able to generate 3050 ft/sec's with book maximum loads. Various books suggest that I should be able to get 3250 ft/sec's. But my 35P says different. When venturing into the beyond the book range (with "safe" primer reading and other voodoo,) I get all the way to 3130 ft/sec's. Interestingly, the rifle really shoot well with the hot ones. To spare the obvious response, yes it is the rifle not the shooter which is slow...

Yes, something in your system is slow - perhaps the rifle, perhaps the LOT OF RE 22 you have!

It is not beyond the realm of possibility to get over 3300 FPS with a 140-grain bullet, and over 3000 FPS with a 175-grain bullet in the 7mm Remington Magnum, and do so safely!

What is a maximum load in some rifles may be very much OVER maximum in others, and vice-versa. Book maximum loads are maximum in the rifle in which they were developed ONLY!

Another sugjestion is !
Play around with different primers. I added 75 FPS with my stw when i went from winchester lr mags to federal mag primers.
I bet you can play around with powders and primers and get your velocity up there where you want it.
I have a 7 mag and while it is a very good cartridge, some people seem to hold it out as some kind of awsome power house. I have argued with people who make rediculas claims, such as with a 7 mag you never have to hold over !
Usualy I can talk them out of there folly by poiting out that at some point gavity will allways over come led.
But back to your problem. Try other powders and primers and you will get what you are looking for ! i am prety sure...tj3006

Sako: Interesting post. I too have a M77 7mag. I just traded for and will be trying some 160 gr. handloads. Just got done tearing apart the trigger and polishing bearing surfaces. Dropped from 4.5 to 3 lbs, and crisp!
Anyway, I was trying to find a factory load which shot well from this rifle and came up with the Remington CorLokt Ultras. Hopefully I will chrony them soon as a comparison load.
Just curious how far off the lands that you set up your bullet? I usually start all my reloads at .010" off the lands measured with a Stoney Point tool.

Sako I have had several Rugers over the years and found that most of them had quite long throats,and yeilded rather low velocities for what was listed as max loads in most manuals. I have a 280 that came within 100fps of the 7mm rem mag. The 7mm mag was sold and I still have the 280. I don't have my load data in front of me but I do remember I obtained the top velocity with that Ruger using a max charge of 7828. You may want to try that.

Gentlemen, most helpful input... thank you all. First I like to start my bullets with very light contact to the lands for consistancy and hopefully accurate results with new brass. Second, I am using he Fed 215 primers. Third, the best velocity in my second attempts was 3114 with R22 @ 69.5 grs. And 3154 with 71 grs of IMR 7828. I do believe that Big Green developed that powder for the 7 Mag, but most likely with heavy bullets in mind. I will try a lighter powder and will also move off the lands about .030 or so. The 70.5 gr of 7828 was an incredibly accurate load, I will try it again just to see if it was a fluke. Also some 140 Accubonds haave arrived so may be they will do better. I note a significant amount of powder fouling, so possibly the bore is a bit large. I do not know the history of this rifle but the bore feels even when clean and a tight patch is pushed through. Rifling is sharp, and bullets seated long are cut evenly on the ogive. Thanks again for the input one and all.

308- hey have you shot that same load over the clock on different days?

I've done enough clocking with enough clocks to know that trying a load one time is not the way to go.

Also have you tried it over more than one clock?

Thx

MD

Seating into the lands is a likely culprit for problems. I think that on a hunting rifle it's a big mistake to have your bullets touching the lands. A variance in Ogive (which is common) can result in a seating that will be harder into the lands etc.. You only have to clean the powder out of an action after the bullet got stuck in the lands once to see the error of into the lands seating on a hunting rifle. Try from .005 to .050 off the lands and you'll get good accuracy and fewer funky pressure problems......DJ

My M70 Classic 24" barrel, shoots 3150 fps with 70 grs. RL22 and a 139 gr. Hornady. Yeah, maybe not the fastest one out there, but that load is extremely accurate in that rifle, so I like it!

P.S.
I've clocked Remington factory 140's at over 3200 fps in that rifle, so I don't know that it is a slow rifle, actually.

I've used the 71 gr of RL22 with a 140 grain for 3246 fps in mine. I also have to load 66 with a 175 Nosler partition to get 2901 fps. A lot of books will show that velocity with 62-63 grains of RL22, not in mine.