Advice on custom chamber options or just stick with SAAMI

All, i have a savage 111 trophy hunter XP chambered in 7mm Rem Mag
building this gun and looking to possibly use the carbon fiber PROOF barrel as this is for long range hunting lighter weight im curious if performance is going to be equal to an all steel krieger type.

My questions is for a custom chamber should i just be more concerned with other than the obvious things like facing the action to the barrel and bolt so its all in perfect alignment
but should i be focused on the neck of the chamber and any other regions of suggestions?
or do people think saami is good...? i do all my loading for this gun and we will set it up for the physical max i can fit in the magazine its a DBM AICS style mag currently running hornady eldx 162 gr and the nosler long range accubond 175gr and havent gotten into berger vlds yet

When it comes to belted mags and SAAMI spec reamers, I always go for NON SAAMI spec reamers either of the Match variety or custom.
Preferable for belted cases is a reamer that minimises shoulder dimensions keeping forward movement below .016".
There is the 'A191' print the US Marines developed for the 300WM chamber they use. It keeps the shoulder expansion to a minimum and maximises the belts headspace control.
If you get a custom reamer, look at these dimensions and follow a similar pattern, including the throat length. Give your gunsmith the bullets you plan on using, this can help determine what throat dimension is preferable.

Cheers.

If you really want a custom chamber load some dummy rounds to mag length, a mag length where they feed 100%, measure base-ogive, and cut your throat .020" longer than that. Would probably spec out a match chamber too and follow those dimensions. For a custom chamber, you need a custom reamer. That's usually $200 and 6-8 weeks.

I have a custom chamber on a .260 and then a saami chamber on a creedmoor. they both work but I am pretty well limited to 142 smks in the custom chamber. I can get other bullets to shoot but I have to single feed and some are only .150-.220" into the case.

Schnyd112 said:

If you really want a custom chamber load some dummy rounds to mag length, a mag length where they feed 100%, measure base-ogive, and cut your throat .020" longer than that. Would probably spec out a match chamber too and follow those dimensions. For a custom chamber, you need a custom reamer. That's usually $200 and 6-8 weeks.

I have a custom chamber on a .260 and then a saami chamber on a creedmoor. they both work but I am pretty well limited to 142 smks in the custom chamber. I can get other bullets to shoot but I have to single feed and some are only .150-.220" into the case.

Click to expand...

I really would love to try a custom chamber I'm just not experienced enough to determine what will yield results for this cartridge... that's why I question if saami as some have stated perform very well for their long range shooting or if custom is hands down a better option

AZlongrangehunting said:

I really would love to try a custom chamber I'm just not experienced enough to determine what will yield results for this cartridge... that's why I question if saami as some have stated perform very well for their long range shooting or if custom is hands down a better option

Click to expand...

I can't give you that answer for a 7rm. I do not know what you may gain from a match chamber and custom throat. My .260 definitely outperforms a saami chamber loaded to mag length, but I do a lot more case prep to make sure it all feeds and fires properly. I need to turn necks before chambering, trim after every other firing, anneal every 3, and I cannot use off the shelf ammo. Is it worth it? In my case I believe it is.

If you buy a reamer, take care of it. Have it sharpened after each chambering. The benefit is, if you shoot out a barrel you can run the same reamer into your new barrel and have a good idea of where to start for load development. A custom reamer, unless it is a sought after design, is not worth much as far as resale value.

AZlongrangehunting said:

All, i have a savage 111 trophy hunter XP chambered in 7mm Rem Mag
building this gun and looking to possibly use the carbon fiber PROOF barrel as this is for long range hunting lighter weight im curious if performance is going to be equal to an all steel krieger type.

My questions is for a custom chamber should i just be more concerned with other than the obvious things like facing the action to the barrel and bolt so its all in perfect alignment
but should i be focused on the neck of the chamber and any other regions of suggestions?
or do people think saami is good...? i do all my loading for this gun and we will set it up for the physical max i can fit in the magazine its a DBM AICS style mag currently running hornady eldx 162 gr and the nosler long range accubond 175gr and havent gotten into berger vlds yet

Click to expand...

You're going custom so take it from a recovering belted mag owner...
The absolute best thing you can do is go 7mm wsm throated long for 180's.
You don't need to buy a reamer, load some dummy rounds and have your savage pre fit throated accordingly.
Just do yourself a favor and research the 7wsm, trust me you'll be glad you did!

blackaj said:

You're going custom so take it from a recovering belted mag owner...
The absolute best thing you can do is go 7mm wsm throated long for 180's.
You don't need to buy a reamer, load some dummy rounds and have your savage pre fit throated accordingly.
Just do yourself a favor and research the 7wsm, trust me you'll be glad you did!

Click to expand...

7 shortmag anything, be it Winchester wsm, rem Saum or Sherman shortmag is my dream hunter cartridge. Still haven't made it to a custom hunting rifle yet, but I can't argue with your statement. 180's at 2900+ is bad medicine for just about anything walking this earth.

Absolutely
I can guarantee a 7 wsm throated properly will push 180's over 3000 fps with ease.

Schnyd112 said:

I can't give you that answer for a 7rm. I do not know what you may gain from a match chamber and custom throat. My .260 definitely outperforms a saami chamber loaded to mag length, but I do a lot more case prep to make sure it all feeds and fires properly. I need to turn necks before chambering, trim after every other firing, anneal every 3, and I cannot use off the shelf ammo. Is it worth it? In my case I believe it is.

If you buy a reamer, take care of it. Have it sharpened after each chambering. The benefit is, if you shoot out a barrel you can run the same reamer into your new barrel and have a good idea of where to start for load development. A custom reamer, unless it is a sought after design, is not worth much as far as resale value.

Click to expand...

I'm not a gunsmith but, I don't believe that a reamer has to be sharpened after each use. Used properly, most metal cutting tools I use last a good long while.

I've been a custom smith for over 30 yrs. I build mostly compatition rifles. I own maybe 6 factory spec reamers out of my whole lot. Reamer are absolutely not sharpened every use. You wouldn't make any money if you had to do that. Plus your reamer will be gone for 2 plus months at a time. All I do is scrape the cutting edge down with a thin razor blade to remove any metal that might be stuck to the edge. On a fresh reamer I do this every cut because they tend to do it more. As far as you wanting to know what reamer specs to use I would measure the brass you want to use with a bullet seated. Then add .004 to this neck diameter for a hunting rifle. Get the reamer with no freebore. Get a throating reamer for it. Then you can make your chamber fit for any bullet you choose to use and fit your mag box. All my chambers are cut to fit the rifle the customer brings me with there dummy rounds. On match chambers I always set the freebore long enough to get the bearing surface above the neck shoulder junction. That way donuts can't hurt your accuracy. You can do this on a 7 mag up to about a 150 gn bullet and fit a standard box magazine. If you want heavier bullets to fit to match spec you can add a Wyatt's extended mag box. Easy fix. So here is where I'm gonna get thrashed. On a hunting rifle with a factory chamber you will easily get 1/2 moa accuracy. And that will kill as far as you are capable of shooting comfortably. Also the belt doesn't do a dang thing after the first firing as long as you set you sizing die to bump .003 or less. Reloaders wear mag brass out in 3 firing if you just set the die down on the shellholder and crush your shoulders back all the way. Any questions just ask. Shep

predator 22 said:

I'm not a gunsmith but, I don't believe that a reamer has to be sharpened after each use. Used properly, most metal cutting tools I use last a good long while.

Click to expand...

It probably doesn't but I have seen one, for a 6 creed, trashed after 3 barrels. It would still cut but you could see the cracks in it. I had another smith tell me that probably would not have happened if it were sharpened after each chamber.

OP is not a gunsmith. If he has a barrel cut and sends the reamer off to be sharpened it could take 6 months and he still wouldn't miss it. He isn't cutting other people's barrels with it.

The simple answer to the OPs question is it depends are the cartridge. The 300 Win is not bad for 215 Bergers. The 7 Rem mag is not bad(not optimal) for most 180s. The short mags I would want a reamer throated for 180s long and I would do it on a long action. The Nosler line of cartridges are far from optimal in SAAMI form. The PRCs are pretty good. Like I said it depends.

Reach out to Dave Manson at Manson custom reamers, he is very knowledgeable and great to talk to.
These type of questions are right up his alley!

Schnyd112 said:

It probably doesn't but I have seen one, for a 6 creed, trashed after 3 barrels. It would still cut but you could see the cracks in it. I had another smith tell me that probably would not have happened if it were sharpened after each chamber.

OP is not a gunsmith. If he has a barrel cut and sends the reamer off to be sharpened it could take 6 months and he still wouldn't miss it. He isn't cutting other people's barrels with it.

Click to expand...

That's odd. I've never seen tool steel crack, seen it break, but not crack. I'm not a expert on steels but I would guess if he had cracks it was probably because it didn't get tempered correctly. Again just a guess.