Home Forums Hunting & Shooting Ask The Gunwriters Factory 140 gr Load in .275 Rigby

CCC -

Thanks. I've been in your area and thoroughly enjoyed the scenery. Spent some time in/around Santa Rosa on Rt 66. Actually crossed N M on I-40. Beautiful especially compared to W Texas between Ft Worth and E P.

How did the cowboys ever ride a horse to E P?? Beats me.

We saw a lot of antelope (lopes for the KOOL). There are several places I'd love to hunt. I know there's some good elk hunting in N, NM.

Congrats - Rev Mike.

We are supposed to have a lot of feral hogs, have seen a lot of sign, but haven't been able to put an eyeball on em.

Thanks. Give it some time and I'm betting you'll start seeing the critters leaving the sign. If you have access to a feeder, and it's legal, throw out a bit of corn and either sit in a stand or set up a camera. They'll eventually show.

From what I understand - at least as far as wildlife biologists are concerned - 60% of the annual breed has to be culled just for the population to remain static. When you consider that a sow has two, and sometimes three, litters per year, and generally has between 5-8 piglets per litter, and can start breeding long before turning a year old, well, that's a lot of pigs. And once they get some size on them they really have no natural predators. There isn't much in the woods that wants to take on a 200 pound boar. Except me.

Makes you feel better and stronger!

An Idaho buddy of mine was obsessed with getting 3000 fps out of 165's from a .30-06. I asked him why, and he replied: "All those zeroes!"

Which makes as much sense as a lot of other things rifle loonies do.

On the contrary, 200 fps in a 7x57 makes bugger all difference to how it kills.

The 7x57 one-shot dead mule deer and elk over this way have not testified regarding that 200 fps difference affecting killing power. How does one calculate such?

I always thought that 3000 fps fig for that 275/ 7 x 57 Rigby load came from a type writer. Ross Seyfried some years go writing about the HV 275 Rigby model, said that the sights on his rifle shot right under the sights, out to 400 yards with 50 gr of IMR-4350 and a 140 gr Nosler Partition. he said that load gave 2800 fps and no extraction problems. I myself been shooting this load in my 7 x 57 and the others that I had had since 1968 or so. Never needed more. You want more that that, you can get it, just go to a 280 or 7mm RM. Or a 270 and 130 gr SP's, there is not a whole lot of difference unless you are compelled to shoot at targets in the next zip code. A light 7 x 57 is one of the most useful hunting cartridges on the planet. Thou its pretty much a hand loaders deal now a days.

Stop and consider if the creature would be any more dead if the projectile were going 200 fps quicker...question answered.

If not then ask yourself why.

+1

Or what a 140 at 2500 fps would do......

Can't say about the 140 at 2500 but, I can vouch for a 139 at 2550:

Started taking them with the 7x57 in 1963 - may have considered such a question somewhere along the way, but not likely. As ever, no deader with even 1000 more fps.

I owned a genuine John Rigby in .275 until recently and it really liked the various 140 X bullets at around 2940ish, so with the longer barrels that were on these rifles a century ago, 3,000 isn't much of a stretch.
JW

As promised in an earlier post on this thread, I have done more shooting with Big Game powder behind the 140 g. Nosler Partition bullet in my 7X57.

For years I ran a load of H205 with the Partition bullet that got well over 2900 fps. But when I substituted the 140 grain Nolser BT once; the velocity was over 3,000 fps and I got marks on the brass . (Used that load for a long time with 139 g. Hormady and the 140 Partition. Brass lasted 10 or more loadings, bolt lift was easy.)

Consequently, when the OP mentioned that some sources gave 3,000 fps for the 140 g. bullet, it seemed possible to me.

Today I chronographed a load using 50 grains of Big Game, using two different lots of powder, with the 140 Partition, WW cases and Winchester large rifle primers, OAL = 3.12".

I can find no manual data for Big Game in 7X57, so use 7mm-08 data as a starting point. Nosler gives 47.5 g. of Big Game for 2953 fps with the 140 g. bullet in their 26" long barrel. Ramshot shows 48 grains of BG with the 139 g. Hornady bullet for 2842 fps. in their 24" long barrel at 56,660 psi of pressure.

Nosler shows case capacity of 48.6 g. of water with the 140 bullet in the 7mm-08, and 52.5 g. of water with the 140 g. bullet in the 7X57. So the 7X57 case has more volume than the 7mm-08 (no news there).

Rifle is a 7X57 custom M98 Mauser, action made in 1934 by FN, Douglas 22" barrel. Rifle has a long throat.

Results: Four shots with each lot of powder. Temperature was 56 degrees F. Overcast skies so the ProChrono digital chronograph had good conditions for measuring velocity.

Lot #1: 2969, 2976, 2949, 2969 fps.

Lot #2: 2936, 2930, 2962, 2949 fps.

A month ago I started at 48 g. and worked up to 50.5 g. of powder in 1/2 g. increments using powder from Lot #1. This is when I saw the 50.5 g. load record 3003 and 3030 fps on the chronograph .

Now lest the flaming and derogatory remarks start; let me say that I do not feel I was pushing things too far. I am only 2 to 2.5 grains above published 7mm-08 loads at 56,660 psi with a rifle with larger case volume and a long throat. - Of course I have no way to be certain because I don't have pressure testing equipment. - But going 2 to 2.5 grains above 7mm-08 data seems reasonable. At no point did I experience a change in bolt lift or see marks the case or anything else to suggest too high of pressures.

DISCLAIMER: IN NO WAY DO I SUGGEST THESE LOADS ARE SAFE IN ANOTHER RIFLE. THESE ARE MY RESULTS ONLY AND ONLY PERTAIN TO MY PARTICULAR RIFLE. AS ALWAYS WORK UP CAREFULLY FROM BELOW.

Thanks, that is good information.

I'm not arguing for or against this, just asking a simple question: Since there is a lot more reloading data in new manuals for 7-08 than there is for 7x57, how safe is it to start at the low end of 7-08 data and work from there for 7x57 loads in a modern rifle (M98, M70, M1999, M77, etc)?

That's a good question. I have a Winchester reloading booklet that they give out and the highest pressure load they show for the 7x57 is 44,500 C.U.P. for the 175 gr. bullet. Yet for the .270 Win. for example they show 49,500 C.U.P./60,P.S.I. for pressures. (I used the .270 because they only show C.U.P. data for the 7x57.) For the 7-08 they only show P.S.I. figures, the highest being 58,300 P.S.I. I've read elsewhere that the 7x57 is loaded to about 50,000 P.S.I. which if correct means the 7-08 is loaded to at least an 8,300 P.S.I. advantage. NOw if a modern rifle like M70, M700 and M77 are strong enough for the 60KPSI level of the .270 Win., why can't the 7x57 be loaded tp that same 60KPSI level. I doubt they make the M70, M700 and M77 chambered to the 7x57 using weaker materials. I have three rifles in 7x57, an M70 FWT, Ruger #1A and a custom Mauser with a match grade barrel and chamber. I have a load with W760 asnd the 140 gr. Ballistic tip that does an honest 2800 FPS from the M70 and #1 but is way too hot for the Mauser, probably because of the tight tolerences in that rifle. Dinking around one day I loaded up Winchester's data for the 175 gr. bullet using the Hornady round nose, a "Karamojo" Bell load as it were. Velocity from the #1 was 2310 FPS, the M70 was 2340 FPS and the Mauser 2450 FPS. The first two rifles have 22" barrels and the Mauser a 23" barrel, not enough longer to kick the velocity up that much IMHO. That load shot at one inch or less depending on the rifle. I don't have my notes handy so the velocity figures are from memory.
It wouldn't surprise me none if those guys that shoot to get their data from the loading manuals have worked up properly tested 60KPSI level handloads for their 7x57s. the sad part is they ain't sharing.
Now to get around to your question, with the greater case capacity of the 7x57 vs the 7-08, the starting load would have to be less than the max load for the 7-08 so should be no problem. The only place where there might be a problem is if you have a very tight rifle like my Mauser and frankly, even then a 7-08 starting load should be OK. Might be close to max for that particular rifle though. I like W760 for the 7x57 but it raises pressure quite fast in that Mauser. I may have to try a different powder for that one.
Paul B.

Following Nosler's on-line data for grains of water in each case with the same bullets, the 7X57 has about 8% more capacity than the 7mm-08. My loads cited above were about 5% higher than published 7mm-08 data. So I felt I was within the range of reasonable expectations.

There is no reason that a 7X57 chambered in a strong action cannot match 7mm-08 pressures, or even 270 and 6mm Remington pressures of 65,000 psi. I would not even consider it in anything other than a good 98 Mauser or equivalent action. It goes without saying that good brass and consistent primers are also factors.

Hodgdon on-line data gives good pressure information for their powders. Denton Bramwell has a conversion formula for converting CUP to psi. I use that to try to get all of the data into the same format so extrapolations are on common terms. But this is just to get into the ball-park. Then I start at what should be a safe level and then work up in 1/2 grain increments with the chronograph and watching how the rifle acts. At home I examine the cases with a magnifying glass to check for shiny spots on the head.

I also like to track the change in velocity with each increment. If the increase declines; then I take that to mean I've reached the point of diminishing returns in adding powder. An example of this is my 9.3X62 data on another thread. Adding more powder didn't add much more velocity even though there were no pressure signs.

Paul, I have a custom Mauser in 257 with a tight chamber and I have to be very careful with it because even some factory loads and commonly published hand-loads make the bolt stiff to open. This rifle averages 100 fps more than another 257 I own using the same loads. In the second I have to exceed book charges to reach book velocities. In the first, I stop short of book charges, but by then have usually reached book velocities (given differences in barrel lengths, etc.)

Every rifle seems to be a law unto itself, so work up carefully, use a chronograph and pay attention!

It sounds like a good way to get a lot more 7x57 loads than are currently in the reloading manuals.