160 Grain A-Frames out of a HS .275 Rigby?

375 Ruger Fan said:

I have a M70 and a couple Ruger No 1 in 7x57. I handload 160 gr Swift A Frames and find that is the sweet spot for bullet weight for this caliber. Taken lots of PG and deer.

View attachment 790353

Click to expand...

I like that chart! What is a CCI #34 primer?

Does anyone have a good way to measure the throat length without doing a chamber casting?

Fixfire said:

@migrabill if not too late, can you have your cartridge ordered delayed until the issue is resolved?? I feel for ya. I like keeping all my guns as “original” as possible. Reaming would be last resort.

Click to expand...

Reaming would be the very first thing I would do. My HS barrel is labeled 275 / 7x57. Reaming to SAAMI spec for 7x57 in my mind adds value as I now have a versatile rifle from whitetail to eland. We are looking hard here at a lot of ways here to work around something that has a very easy solution.

Hedge774 said:

Thank you very much!

Click to expand...

As I mentioned twice just get a competent gunsmith to open the HS throat like myself and many others have done then it will easily handle 175 grains. About $300

LeftySixgun said:

Does anyone have a good way to measure the throat length without doing a chamber casting?

Click to expand...

You get close by blacking bullets and then backing off loa until it just clears the lands. Then backing off for your desired ‘jump’ and you know where to set loa.

WAB said:

You get close by blacking bullets and then backing off loa until it just clears the lands. Then backing off for your desired ‘jump’ and you know where to set loa.

Click to expand...

Obviously you do this with a dummy round.

roverandbrew said:

Reaming would be the very first thing I would do. My HS barrel is labeled 275 / 7x57. Reaming to SAAMI spec for 7x57 in my mind adds value as I now have a versatile rifle from whitetail to eland. We are looking hard here at a lot of ways here to work around something that has a very easy solution.

Click to expand...

Not disagreeing, I was responding to the OP’s desire to keep it original - which I can appreciate.

Hi Lefty,

I do the measure of the distance to the lands on ALL the bullets I use in my rifles and take the notes.
What I actually measure is the cartridge OAL with 0 jump to the lands with all the bullets. As my rifles are all hunting rifles, I don´t like less than 1 mm, roughly 0,04" of jump to the lands.
To do this I use the cleaning rod (or a similar object). With a cleaning rod is necessary to put something to block the threaded end of it. In mine I use a .22 LR case that fit perfect. So there is a level surface at the end.
1- With a closed bolt but mounted firing pin (so the firing pin point don´t interfere), I introduce the rod from the muzzle until it touchs firmly the bolt face. Mark a circle at that position on the rod at the barrel muzzle plane.
2- Without the bolt I introduce the bullet by the chamber until it makes contact, firmly, with the lands.
3- Put the rod by the barrel muzzle gently to make contact with the bullet tip. Mark again a circle on the rod at the barrel muzzle plane.
4- The distance between these marks is the OAL with 0 travel to the land WITH THAT BULLET. Done!

The limiting dimentions or factors for the OAL cartridge in any rifle are three:

1- That max OAL with each bullet or,
2- The magazine lenght.
3- The bullet shape.

In a Standard M98 Mauser action like Argentine 1909, VZ24, standard FN or Mark X ones, usually the limiting factor for the OAL of the 7x57 with almost all bullets is the magazine but, just in case, I measure the OAL with 0 jump.
About bullet shape: is an accepted rule, I agree with it, that the bullet must be make contact with the neck of the case not less, aproximately, than 1 caliber lenght. So with some extreme boat tail ones, the jump to the lands will be much greater than that 1 mm-0,04".
Some of my most accurate loads are with Sierra Game King 160 grs, with a very long jump to the lands!!!
And at the other extreme, I can load the great 175 Nosler Partition with the base of the bullet at the neck/shoulder point of the case! The OAL with that 1 mm / 0.04" jump is 82,5 mm, almost 3,25"!!

Having said all this, I prefer the original long free bore of the 7 mm Mauser.

Good luck!

WAB said:

If your plan is to use the rifle in the African bush on plains game, you are giving up a lot of capability by not using 175 gr A-Frames. I am surprised that they cannot be loaded to the same overall length as any other bullet, just giving up some powder capacity. What overall length keeps you off the lands with an A-Frame in your rifle?

If this is an absolute non-starter, I would have Rigby ream it out to your desired spec. They are very customer focused and I am sure would do this for you. Keep in mind that the magazine can also be a limiter so don’t bother reaming past the allowable length in the magazine.

I load 175 A Frames to 2,300 fps in my .275/7x57’s for Africa. I don’t know that I have ever recovered a bullet as everything is pass through. That includes zebra, wildebeest and kudu, so not just small stuff.

Click to expand...

I have learned that it shoots the 156 Normas very well. On African plains game, I really don't think I am giving up that much going from a 160 to a 156.

Fixfire said:

@migrabill if not too late, can you have your cartridge ordered delayed until the issue is resolved?? I feel for ya. I like keeping all my guns as “original” as possible. Reaming would be last resort.

Click to expand...

I have asked if they started the order and I am waiting to hear back. If they haven't, I am going to have them use 158 Norma. If they have, then the 160 A-Frames will be for my Ruger No1 7x57. And I agree, I am not running a reamer through a brand new Rigby.

I must say that the original Rigbys and Sporting Mauser from Oberndorf pre WWII were made with the Intermediate lenght Mauser actions, which have a 5 mm shorter magazines!
So, in this case, probably the limiting OAL factor will be the magazine!

I’m a little lost on this thread. If you want to shoot a heavier bullet with a different ogive, why can’t you just measure the desired overall length needed and load to that length? You may take up some case capacity by doing so but powder selection should resolve any issues. What am I missing?

.

Been there, seen it & had a gunsmith (Shiller in Bavaria) open her up for me so that I can use a variety of factory 7x57 in various weights. The rifle was stamped .275 Rigby / 7x57 & whilst the .275 ammo (Hornadys) was no problem, she would not digest most of the German factory 7x57 that I wanted to shoot.

Upside of opening her up is that I can now shoot a wide variety of factory bullet weights to suit the situation.

Downside of opening her up was that - it being a material change - the rifle had to be submitted for proof, hence she now has a German Ulm proof stamp as well. Does this detract, not IMO & I am not planning on parting with my Rigby HS so I believe the upside far outweighs the down,





I did however find it somewhat strange that this is how Rigby built the rifle, but it was a pretty straight forward & not so expensive fix.

.

WAB said:

I’m a little lost on this thread. If you want to shoot a heavier bullet with a different ogive, why can’t you just measure the desired overall length needed and load to that length? You may take up some case capacity by doing so but powder selection should resolve any issues. What am I missing?

Click to expand...

Hi WAB,
Of course, you are right. Most users not even think about these minutiae...I want to maximize the cartridge potential with a standard lenght M98 and the original CIP barrels.

WAB said:

I’m a little lost on this thread. If you want to shoot a heavier bullet with a different ogive, why can’t you just measure the desired overall length needed and load to that length? You may take up some case capacity by doing so but powder selection should resolve any issues. What am I missing?

Click to expand...

Perhaps that I have never reloaded in my life and I am buying commercial ammo?

migrabill said:

I have asked if they started the order and I am waiting to hear back. If they haven't, I am going to have them use 158 Norma. If they have, then the 160 A-Frames will be for my Ruger No1 7x57. And I agree, I am not running a reamer through a brand new Rigby.

Click to expand...

Did you know if Rigby is building your 275 all you have to do is call and ask them to open up the throat to accept up to 175 grain bullets?

Rare Breed said:

Did you know if Rigby is building your 275 all you have to do is call and ask them to open up the throat to accept up to 175 grain bullets?

Click to expand...

No. I purchased it from JD Oitfitters in Oklahoma. It’s really not a biggie. I’m going to shoot 156 Norma’s through it. I have my Ruger No 1 in 7x57 to shoot the higher grains. 275 Rigby in 156 grain will take any African plains game with the possible exception of Eland, and I will never have Eland on my list.

My HS in 275 is even hard to close on cheap factory 140 grain.

I have spoken to Rigby about this. The recommendation (if I wanted it opened) was to send it to a qualified gunsmith in the US.

The current state of import/ export laws is that it would have to be fully imported and exported back to the US if I wanted Rigby to do the work. Unless I was there hunting with it and just dropped it by.

Mine does cycle quality factory ammo 140-150 gains no problem so I’ve held off for now.

migrabill said:

Perhaps that I have never reloaded in my life and I am buying commercial ammo?

Click to expand...

But it sounds like you are having hendershots load ammo for you? If so, they can solve this problem for you.

It's funny for me how after 127 years my Rigby .275 is the opposite issue.

Not regulated for the HV 140 gr. So I have a hard time finding some practice 173gr up in Canada. I will end up learning and reloading for it