Gunsmithing Reaming 260 Rem to 6.5 SAUM

[gregt]

Hi Fellas, I just had a 6.5 SAUM reamer arrive from PTG. I've got a Savage here chambered in 260 Rem that I want to rechamber using the new reamer (I've got a magnum bolt head I'm going to fit up as well). I've been wondering if it's a problem given that I already have a chamber around the same length and the reamer will be cutting for a while without the pilot in the bore of the barrel.

My plan is to set the barrel up initially off the neck and rear of the current chamber then check that the chamber is concentric to the bore. Hopefully it will all be good and not a problem. My concern is that if the reamer runs off cutting the initial part of the chamber then I'm going to have an issue when the pilot moves into the bore of the barrel. I'm using a floating reamer holder which has worked really well before but I have always been cutting a fresh barrel so the pilot has been in the bore right from the start.

Any tips or tricks that improve my chances? The barrel is a factory Savage large shank 260 that I've trimmed down to fit a small shank action. This is a budget build to give this cartridge a try before starting on a new rifle. Would I be better sacrificing a bit of barrel length (it's 26" now) and just chopping off and rethreading the barrel so I can start fresh with the pilot running in the bore? There's plenty of barrel there to do it if that's the safest option.

 

[bapayton]

260 to 6.5

I'm not an expert but in looking at some reamer prints I would cut off at about 1/2" to make sure you're cutting a complete new throat then I would indicate and pre bore to make sure you are cutting straight. That's just in case the factory chamber is off center. In fact if you don't pre bore the reamer shoulder will be doing the majority of the cutting unsupported which isn't a good thing for an accurate chamber or reamer longevity. I did something similar with a 270 Winchester to 270-7mm Rem Mag wildcat. I pre bored enough to make sure the reamer body was supported and the reamer cut smooth as could be.

 

[SSC]

If you have it to cut, it would be best in this situation to make sure that pilot is riding in the bore before any cutting is done. Sure you can do it like you have it now, but if you need to ask the questions then just play it safe and cut of however much needed to for the pilot to do its job. I can assure the loss of velocity will be a much better option than spending time and money cutting the chamber multiple times to get it right. Now if you want the practice then go for it and just bore out what you need.

 

[gregt]

Thanks Fellas, I took the safe route and lopped off the original chamber and set it up and cut the threads and the chamber all in the same setup. It's still 24" which is supposedly a good length for one of these. I'll flip it around and thread the front end for a brake and I should be up and shooting next week.

 

[Boltfluter]

Greg,

Looking forward to your report.

Paul

 

[gregt]

Thanks Paul, I got the bolt head machined and fitted yesterday and tracked down some powder today, only a hundred or so km away, we're having the same problems here with powder that it seems you are in the US which is weird given that ADI makes H1000 powder here.

I just finished making a stock for it and have some Alpha 308 mags here I might be able to modify and get them to feed. I'm really looking forward to giving it a run.

 

[trailrider121]

Did you ever get the barrel reamed? Outcome?

 

[gregt]

Yep I got it done, it came out really well. I put a few rounds through it, I had some pressure problems, maybe turned the necks a little too big or it was just too much powder in there. I popped a primer and ended up with the ejector jammed down in the bolt face so I'm waiting on a new one of those. I just got hold of 150 Remington 7mm SAUM cases so I can get them ready in the meantime. This is really just a bits and pieces rifle to see if I like it but it's looking like it'll be fun.

 

[trailrider121]

That's awesome. Rifle looks great, and hope it performs for you. I'm thinking of building a 6.5 saum next.