175 Grain Bullet in Normal No Alterations 275 Rigby HS

[Rare Breed]

Before I begin reloading my new 275 Highland Stalker Rigby just wanted to check with those that have one if a 175 grain bullet will still enable me to chamber a round in the normal 275 Rigby? I seem to remember Joe @Red Leg saying for him to be able to do that he had to have them make an alteration to the chamber when they built his? Appreciate the help. I also have 156 grains and 140 grains I can use but wanted to check on the 175 grains.

Thanks!!!

 

[rookhawk]

Every rifle barrel off the lathe is different. (dull reamers sharpened undersize, fresh reamers, over/under throated that day, etc.)

What you need is a Hornady OAL gauge: https://www.hornady.com/modified-cases#!/

And you need a Hornady 7x57 brass OAL cartridge for it: https://www.midsouthshooterssupply.com/item/00005a7x57/lock-n-load-a-7x57-mauser-modified-case

That will let you place your desired bullet into the gauge, push it into the chamber, thrust the bullet forward in the case until it hits the lands, and then withdraw the fake cartridge. You'd then measure it to figure out the true OAL of the potential ammunition if it were loaded to touch the lands. You want at least .020" off the lands to prevent a pressure spike, or more if it gets more accurate shorter, or more if it is still longer than the maximum COAL of 3.045", or shorter if it won't feed from your internal magazine.

With the measured facts, you'll know if you can use a 175gr bullet of a given type, and if so just how deep in the case it would require. (which would inform you if you're accidentally creating compressed loads)

 

[franzfmdavis]

Just as an example for comparison, I have a 2017 Highlander Stalker and was not able to load 175g Northfork Semi Spitzer round. I sent it to JJ Peredeau who opened up the throat in the rifle. The cost to do it exclusive of shipping was less than $300.

 

[YancyW]

It could also depend on the bullet, so make sure you give several a try. However, opening it up a bit is a very simple task for any good gunsmith.

 

[rookhawk]

@franzfmdavis to play devil's advocate, you didn't have to lengthen the throat on your rifle, but doing so gave you some advantages.

The consequence of not lengthening would mean you'd have less powder capacity in your loads because the bullet would be set deeper, taking away capacity.

If someone was going to load 175gr without a long throat, you'd look at a chart like below and you'd pay special interest in the powders with the asterisk "most accurate" at starting velocities. The net result would be loads that are running 150fps to 200fps slower than the potential loads for a long-throated 275 Rigby.

 

[PARA45]

You may have to check your chamber to see if the 175 grs will fit. Hornady has this tool, that I believe would help you to see if the 175s will fit your chamber.

Lock‑N‑Load® O.A.L. Gauges & Modified Cases - Hornady Manufacturing, Inc

Lock-N-Load® O.A.L. Gauges Regulating seating depth and the resulting jump to the rifling is widely regarded as fundamental to improved accuracy. A few thousandths of an inch change between the bullet and the rifling can make the difference betw...

www.hornady.com

 

[franzfmdavis]

@franzfmdavis to play devil's advocate, you didn't have to lengthen the throat on your rifle, but doing so gave you some advantages.

The consequence of not lengthening would mean you'd have less powder capacity in your loads because the bullet would be set deeper, taking away capacity.

If someone was going to load 175gr without a long throat, you'd look at a chart like below and you'd pay special interest in the powders with the asterisk "most accurate" at starting velocities. The net result would be loads that are running 150fps to 200fps slower than the potential loads for a long-throated 275 Rigby.

View attachment 675717

That’s good to know for future reference!

When I was looking into it, I spoke with a tech at Rigby and with JJ Peredeau, both of whom recommended that I lengthen the throat. Rigby also mentioned that they offer throat lengthening as a customization on new rifles. None of them offered the other option you described above.

I did ask whether there would be any negative impact on using smaller bullets, such as the 140, after the throat was lengthened and they said no.

In retrospect, I am still happy that I lengthen it because I subsequently had the flexibility to develop a load using the 175 grain Northfork bullet that will hit the same point of impact at 100y as the 140g Hornady bullet at 100y, allowing me to use my scope and irons for either bullet.

I can imagine that if I was restricted in fps due to reduced case capacity, that may have become more difficult or not possible?

 

[rookhawk]

That’s good to know for future reference!

When I was looking into it, I spoke with a tech at Rigby and with JJ Peredeau, both of whom recommended that I lengthen the throat. Rigby also mentioned that they offer throat lengthening as a customization on new rifles. None of them offered the other option you described above.

I did ask whether there would be any negative impact on using smaller bullets, such as the 140, after the throat was lengthened and they said no.

In retrospect, I am still happy that I lengthen it because I subsequently had the flexibility to develop a load using the 175 grain Northfork bullet that will hit the same point of impact at 100y as the 140g Hornady bullet at 100y, allowing me to use my scope and irons for either bullet.

I can imagine that if I was restricted in fps due to reduced case capacity, that may have become more difficult or not possible?

Oh, I definitely think you did the correct thing by lengthening, but you didn't have to, it was just a good idea to do so.

To split hairs, the theoretical downside of lengthening is that your rifle is not likely to shoot 140gr and smaller bullets with a level of precision to win Olympic Gold at 1000 meters because of the additional freebore now created. In practice, your rifle and every other hunting rifle on this forum is not designed to win Olympic Gold so who cares?

As to whether you could make the 140gr and the 175gr the same velocity without lengthening? Sure, but if its 2100fps with a 175gr you'd probably have to make a real sluggish 140gr load to get same POI...as in <2000fps I'd imagine.

 

[franzfmdavis]

I have been using factory loaded 140g Hornady 275 Rigby ammo, and then hand loading 175g North Fork in the spent factory Hornady cases.

The average Chrono speed for my 175g is 2,387 with 41g H4350 and an overall cartridge length of 3.040”. The tips on the NF semi spritzers are different lengths so its best to measure off the ogive.

On an unrelated note for those of you who are going to be reloading these, please note that the S&B 7 x 57 cases require a different shell holder (Lee Universal 2A) than the Hornady 275 Rigby (Lee Universal 2). There is a different rim thickness between the two cases.

 

[rookhawk]

I have been using factory loaded 140g Hornady 275 Rigby ammo, and then hand loading 175g North Fork in the spent factory Hornady cases.

The average Chrono speed for my 175g is 2,387 with 41g H4350 and an overall cartridge length of 3.040”. The tips on the NF semi spritzers are different lengths so its best to measure off the ogive.

On an unrelated note for those of you who are going to be reloading these, please note that the S&B 7 x 57 cases require a different shell holder (Lee Universal 2A) than the Hornady 275 Rigby (Lee Universal 2). There is a different rim thickness between the two cases.

sorry for the threadjack, but wanted to thank @franzfmdavis twice. A.) I was losing my mind last week trying to handload using S&B brass and my lee priming tool shellholder wouldn't work! and B.) I am playing with NF 160gr bullets right now so I appreciated the ogive measurement recommendation.

 

[Rare Breed]

LOL! JJ told me he no longer likes to work on bolt action rifles, but I am his best customer after sending him now 8 DRs. He will be opening up my new 275 Rigby throat so I can easily shoot any 175 grain bullets. Thanks everyone so much for your help!!!

 

[rookhawk]

LOL! JJ told me he no longer likes to work on bolt action rifles, but I am his best customer after sending him now 8 DRs. He will be opening up my new 275 Rigby throat so I can easily shoot any 175 grain bullets. Thanks everyone so much for your help!!!

Check the throat length with the gauge in the first post before you send it. It may be good-to-go now, if it isn't you'll want that tool for handloading anyway.

 

[franzfmdavis]

sorry for the threadjack, but wanted to thank @franzfmdavis twice. A.) I was losing my mind last week trying to handload using S&B brass and my lee priming tool shellholder wouldn't work! and B.) I am playing with NF 160gr bullets right now so I appreciated the ogive measurement recommendation.

This may be the first time I’ve been able to share useful information with you It has most definitely been the other way around most often and very much appreciated!

 

[Sika98k]

175gr Nosler Partitions run perfectly through my Rigby 275. Zero issues.

 

[roverandbrew]

Before I begin reloading my new 275 Highland Stalker Rigby just wanted to check with those that have one if a 175 grain bullet will still enable me to chamber a round in the normal 275 Rigby? I seem to remember Joe @Red Leg saying for him to be able to do that he had to have them make an alteration to the chamber when they built his? Appreciate the help. I also have 156 grains and 140 grains I can use but wanted to check on the 175 grains.

Thanks!!!

My 275 HS initially would not chamber a 175 Grain. 156 Oryx was the largest. I had it reamed out to 7x57 SAAMI spec in order to shoot the larger bullets.