7mm SAUM SAAMI ???

[bobinpa]

If a barrel is chambered in 7mm SAUM with a SAAMI spec reamer, what is the freebore?
Based on the SAAMI freebore, what is the heaviest bullet that you can realistically use? OR to put it another way, what weight class bullets work best with a SAAMI spec reamer freebore?

Thanks in advance!

 

[std7mag]

I'm coming up with a freebore of 0.2177", if i'm reading the drawing correctly.

 

[bobinpa]

Thanks for the reply. If that's correct, what bullet should I be looking to buy and try?

 

[davidjoe]

I don’t think you’ll be limited to any weight bullet with a SAMMI reamer. I shoot 195 EOL’s and 190 A-Tips with a standard spec reamer, neither with any additional throating. I use saums in LR F-Class. Twist rate might be a limitation with the heavies.

 

[Coyotefurharvester]

I don't remember any bullet over 160 in factory Rem ammo, but that was hunting ammo. Long range targets whole different selection process.

 

[Edd]

Thanks for the reply. If that's correct, what bullet should I be looking to buy and try?

The SAAMI freebore is .090".

There are a lot of bullets that will work. Is there a certain style bullet that you prefer?

 

[bobinpa]

I have a chance to buy a new custom rifle in 7mm SAUM. It has an 8 twist Bartlein, heavy Palma barrel and the chamber is a SAAMI spec. Being that it is a SAAMI spec chamber I was just curious if I would be limited on bullets that I could use. I would like to run something in the 180 class but wasn't sure if that would work. I understand I could do it, but I didn't want to have to seat them "too" deep to do it. I am trying to figure out if I can run a 180 and not limit my case capacity.

 

[Edd]

What is your magazine length?

 

[bobinpa]

No mag. It's a single shot.

 

[J.d. Popkes]

Make a dummy round with a 180 in the rifle before you buy it. Find the touch number.

 

[bobinpa]

Make a dummy round with a 180 in the rifle before you buy it. Find the touch number.

I'd like to but I have no 7mm bullets. That was my reason for this thread. I'm trying to determine which bullets "should" work, so I know what to buy.

 

[bobinpa]

I don’t think you’ll be limited to any weight bullet with a SAMMI reamer. I shoot 195 EOL’s and 190 A-Tips with a standard spec reamer, neither with any additional throating. I use saums in LR F-Class. Twist rate might be a limitation with the heavies.

I appreciate the info. Based on what you are saying I should be able to run whatever I want, correct?

 

[bobinpa]

The SAAMI freebore is .090".

There are a lot of bullets that will work. Is there a certain style bullet that you prefer?

This is a paper punching rig and maybe some long range varmints. I'm planning to try some of the Berger 180s.

 

[J.d. Popkes]

I'd like to but I have no 7mm bullets. That was my reason for this thread. I'm trying to determine which bullets "should" work, so I know what to buy.

These days I’d buy the bullets before the rifle. If it’s a good deal and you like it just buy it. In a couple years when you get 180 hybrids just throat it to your liking. Surely it isn’t too long now. Buy it. Rifle is the cheap part.

 

[Edd]

This is a paper punching rig and maybe some long range varmints. I'm planning to try some of the Berger 180s.

A Berger 180 gr Hybrid Target should be a perfect fit for a SAAMI chamber.

 

[davidjoe]

I appreciate the info. Based on what you are saying I should be able to run whatever I want, correct?

That’s correct. The 190 A-Tip is about the longest bullet out there. The 197 SMK is probably longer, but it requires an unusually fast twist rate.

I jump the 190 A-Tips considerably. I realize the Hornady podcast guys don’t believe they are seating depth sensitive, but I think they need a long jump for best accuracy. Also, jumping bullets keeps the peak pressure lower. I am not giving up necessary case volume because a saum is capable of holding plenty of powder to either open its primer pockets, or blow up bullets, and so you can’t use it all, anyway.

You can see the OAL on the left side is shorter, despite their being longer. Does seating into the donut hurt accuracy? For me, no, but I don’t do things that exacerbate donuts through brass migration, like turning or trimming necks, nor do I ream the throats, so that may not be universally true.

Also, I use body dies as opposed to full length dies, so I am altering the necks as little as possible. I size down the top of the neck only, which gives sufficient neck tension to reliably extract a loaded round while minimally working the brass.

 

[rhovee]

You need .200-.230 FB for 180 class bullets to be in the neck only

 

[bobinpa]

You need .200-.230 FB for 180 class bullets to be in the neck only

Thanks! If the freebore on a SAAMI spec reamer is in fact .2177" then I should be good to go, correct?

 

[Sandstorm]

( Your good to go sir..)..May want to reconsider this and get yourself a uni Throater
and create your extra freebore if needed, and may well need it with the 180's and still
be above the donut so to speak.

 

[rhovee]

But min SAAMI freebore is .090 like previously mentioned.