7mm rum to 28

[HuntTx777]

First off let me just say hello to everyone as I'm new to this site. I've spent the past few days reading as much as possible and there is an infinite amount of knowledge here so I think this will be an easy one for ya'll.

Currently I have a like new early build 7mm rum sendero that I would like to have re chambered to 28 in the future. So to be short I would just really like to know what all would be involved in the process of having this done if I bring it to a smith. Every rifle I own has had some type of work done to it but I have never altered anything from it's original chambering.

TIA !

 

[MudRunner2005]

First off let me just say hello to everyone as I'm new to this site. I've spent the past few days reading as much as possible and there is an infinite amount of knowledge here so I think this will be an easy one for ya'll.

Currently I have a like new early build 7mm rum sendero that I would like to have re chambered to 28 in the future. So to be short I would just really like to know what all would be involved in the process of having this done if I bring it to a smith. Every rifle I own has had some type of work done to it but I have never altered anything from it's original chambering.

TIA !

You will have to have it rebarreled with a proper 1:8 twist 26"-28" barrel (I recommend the Bartlein 5R 1:8 28" Rem Varmint/Sendero) to push the big heavy high-BC long range bullets like the Berger 180 Hybrids and 195 Elite Hunters. You cannot rechamber that factory barrel without cutting an inch or better off the chamber-end (tennon) that's threaded, because the .28 Nosler is a much shorter case than the 7mm RUM.

Might as well just have a new and proper barrel blank chambered for .28 Nosler and installed onto your action. If you do that, it will be a very simple process. Remove the old barrel, blueprint the action. Then thread the new barrel blank and set the shoulder for the lug, chamber the new barrel blank, headspace the chamber to your action, install the new barrel.

That simple.

 

[HuntTx777]

Well that sure makes everything easier for me. Guess it's just as simple as picking a barrel and trying to find a good smith locally as I'm not sure if mine is still taking new work. Thanks for the quick reply!

 

[MudRunner2005]

Well that sure makes everything easier for me. Guess it's just as simple as picking a barrel and trying to find a good smith locally as I'm not sure if mine is still taking new work. Thanks for the quick reply!

Yep, pretty much. The 26/28/30 Nosler cartridges are based on a shortened 7mm RUM case. So, any factory rifle that was a RUM cartridge originally, is a great donor for a 26/28/30 Nosler build. I have two 7mm STW's. One is an original 2002 Sendero SF that I special ordered new. The other is a custom that was built out of a 700 CDL that was factory chambered for 7RUM. I am thinking about building a .28 Nosler just to diversify my collection a bit more. That CDL 7RUM action would be the perfect donor, because it needs no mods, and has already been blueprinted. Basically just ordering a new blank, having it chambered, threaded, and headspaced, and go hit the range.

 

[Wedgy]

Decide which bullet if you are going to shoot the 180 or 195 and have it throated for that.

 

[Deleted member 25294]

Also give some thought to replacing your barrel with a "Remage"
Setup. Same concept as the savage pre fit with a barrel nut.
I recently put a pre fit barrel on my 700 in 28 nosler and it's an exceptional performer for just over $300.

 

[MudRunner2005]

Don't fall prey to trendy unnecessary stuff... You don't HAVE to custom throat anything, and you don't have to have a barrel nut. The stock Remington crush design works just fine, especially if you're already taking it to a gunsmith.

 

[Rich Coyle]

You might do a little math. Measure the RUM and a .28. Take the difference off the chamber end.

 

[HuntTx777]

Honestly this rifle has roughly 35-40 rounds down the pipe, my problem is the issue with getting my hands on readily available AMMO. Currently I'm shooting 175 ABLR and at 100yds I'm getting pretty decent groups but taken out to 200 everything seems to open up, it has certainly taken my confidence away as a hunting rifle at this time.

 

[Deleted member 25294]

Don't fall prey to trendy unnecessary stuff... You don't HAVE to custom throat anything, and you don't have to have a barrel nut. The stock Remington crush design works just fine, especially if you're already taking it to a gunsmith.

Nobody said he has to custom throat it but one would significantly reduce the potential of the 28 nosler by going with a saami spec. And if you're going through the expense you might as well do it right.
And the barrel nut is just a cheaper alternative to a traditional barrel swap should a guy choose to go that route.
This is not about trends we are simply sharing our experience and suggesting a few options....

 

[TwoMore]

You might do a little math. Measure the RUM and a .28. Take the difference off the chamber end.

It depends on how big the original chambering is, if it is a loose chamber alot of times the reamer wont touch the original surface, only from the shoulder on to how much you ream deeper and it leaves a step out from the original shoulder to the rear of the chamber, some factory jobs the reamer was no where near centerline and ends up boring the hole wide so just taking up 3/8 inch wont do it

 

[Rich Coyle]

It depends on how big the original chambering is, if it is a loose chamber alot of times the reamer wont touch the original surface, only from the shoulder on to how much you ream deeper and it leaves a step out from the original shoulder to the rear of the chamber, some factory jobs the reamer was no where near centerline and ends up boring the hole wide so just taking up 3/8 inch wont do it

No reamer necessary with the system I suggested. Whack the barrel off leaving the chamber the length of the .28 Nosler. Turn the shoulder back to correct headspace and go shooting.

 

[TwoMore]

ok I see now, lightbulb

 

[Swamplord]

No reamer necessary with the system I suggested. Whack the barrel off leaving the chamber the length of the .28 Nosler. Turn the shoulder back to correct headspace and go shooting.

the 28 Nosler has a 35 degree shoulder angle and the 7mm RUM is 25 degrees, will require some work on the 28 Nosler brass to fit chamber, better off installing a new barrel and using a 28 Nosler reamer