6.5 saum v 6.5 saum improved

[JQuaglino]

I am looking at building a 6.5 saum so already headed down the "wildcat" route and was wondering if should just go deeper and make it a 6.5 saum improved. I understand how the change in the bullet for 280 to 280 AI made the cartridge better. As I understand it a 6.5 saum generally has a shoulder angle of 60 degrees, but if made it improved does that change it to 40 degrees? Also anyone know what the general velocity gain is from improving a cartridge? Like a % pump, since it will depend on the case capacity. With all that being said I am not the biggest gun guru so I might be out of my element on this topic, but looking to gain some insight. Thanks in advance.

 

[ATL]

If you want short action 6.5 magnum performance I recommend keeping it simple with the 6.5 PRC.

 

[wildwilderness]

If you want to go 6.5 improved you should go 6.5 Sherman Short! It’s all been done and easy to get dies, brass etc. For the 6.5 SAUM just go with Gap 4s and once again it’s all set up.

The %gain is based off how bad the original case design was. Older cases like the 280, which was a 30-06 based round had lots of taper and low shoulder angle for feeding in unreliable condition, military etc. Newer designs like the short magnums, SAUM are already optimized so improving get little fps gain.

Some nominal gain like longer case life and less case trim are pluses, though minor.

If you want more than that go 6.5 wsm

 

[wind gypsy]

Improving a 6.5 saum would be an unnecessary headache IMO. Traditional cases with a lot of taper and 20 degree shoulders make more sense to improve ala 280ai. There’s so many good cases out there wildcatting in general seems a waste of time for most bullet diameters.

 

[JQuaglino]

If you want short action 6.5 magnum performance I recommend keeping it simple with the 6.5 PRC.

I hear what you are saying but i want to build something that is going to force me to reload, i keep saying im going to do it and then I buy a box of ammo

 

[Plowboy85]

I have had multiple 6.5 SAUMs, there are a handful of 6.5s that will outperform it as far as speed/energy goes but at considerable powder and barrel life. I have no love for the PRC and no real reason as to why I except the fanboys. Sure the 40deg Sherman shoulders look sexy but it doesbt bring much to the table vs the standard SAUM. I see no real reason to buy a short action when the mediums/XMs being so well supported with bottom metals and stocks therefore I don’t see the fad for the Sherman’s PRC unless I had an action I was trying to repurpose. TS completed my newest 6.5 saum in the fall and it has the Hawkins hunter DBM and is flawless. Make damn sure you get a freebore that allows you to take advantage of the action COAL. Buy enough brass and powder yo burn out the barrel and never look back.

 

[Ryan Avery]

I am looking at building a 6.5 saum so already headed down the "wildcat" route and was wondering if should just go deeper and make it a 6.5 saum improved. I understand how the change in the bullet for 280 to 280 AI made the cartridge better. As I understand it a 6.5 saum generally has a shoulder angle of 60 degrees, but if made it improved does that change it to 40 degrees? Also anyone know what the general velocity gain is from improving a cartridge? Like a % pump, since it will depend on the case capacity. With all that being said I am not the biggest gun guru so I might be out of my element on this topic, but looking to gain some insight. Thanks in advance.

The 6.5 SAUM has a 30-degree shoulder angle. The Saum I improved gave me about 60 FPS. Not worth the effort, IMO. Now, what about a 6.5 SAUM IMP +P??

But really, everyone should be building a 6UM. LOL

 

[Shooter264]

6.5 saum +P gained me right at 100fps in a 19.5” bbl.

 

[Ryan Avery]

6.5 saum +P gained me right at 100fps in a 19.5” bbl.

I wonder if the IMP+p would give you that additional 60 FPS. My gut says no.

What powder and bullet did you use?

 

[Shooter264]

I wonder if the IMP+p would give you that additional 60 FPS. My gut says no.

What powder and bullet did you use?

N565 and a 140 elite hunter. With the 140 actual speed to pressure the gain was 148
Fps but stable velocity node was at the 100fps gain. My bbl had 275 rounds on it before I sent it in and velocity with a 140 EH was right at 2925, after +P, I’m running the same bullet @ 3030. Saw same 100fps w the 156 Berger as well.

 

[Plowboy85]

6.5 saum +P gained me right at 100fps in a 19.5” bbl.

Who done your chambering?

 

[Ryan Avery]

Who done your chambering?

If you want to +P it, you have to go through Defensive Edge or Unknown Munitions

 

[Shooter264]

correct, sent my bbl into Defensive Edge to have the +P done. Original saum chamber was done by another smith

 

[SouthPaw]

If you want to +P it, you have to go through Defensive Edge or Unknown Munitions

Approximate rate for just the +P service? I didn't find the info on UM website about this service.

Sent from my SM-G986U using Tapatalk

 

[Shooter264]

Approximate rate for just the +P service? I didn't find the info on UM website about this service.

Sent from my SM-G986U using Tapatalk

If I remember right it was around $200

 

[Ryan Avery]

Approximate rate for just the +P service? I didn't find the info on UM website about this service.

Sent from my SM-G986U using Tapatalk

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[B23]

Just doesn't seem like the squeeze would be worth the juice and for me, Improving a SAUM case would be about like improving a 284 case, not much gain. I have a few that Shawn has done his +P throat to with one of those being my 6.5-284. Shawn didn't build the gun but from new I took it out to him and had him +P it. It has a Shilen 8tw finished at 26in and shoots the 140 Berger's pretty fricken fast for a 6.5-284.

I would do a +P SAUM of any caliber before I'd do a "improved" SAUM.

 

[Plowboy85]

6.5 saum +P gained me right at 100fps in a 19.5” bbl.

Out of curiosity was the charge the same or did you increase it when pressure dropped due to the throating.

 

[Shooter264]

Out of curiosity was the charge the same or did you increase it when pressure dropped due to the throating.

No, you’ll have to add more powder after you +p. You’ll find you will add 3-4 more grains of powder to get the same pressure signs on your case as you did prior to +p. I was right at 3 grains more to gain 100fps.

 

[JQuaglino]

The 6.5 SAUM has a 30-degree shoulder angle. The Saum I improved gave me about 60 FPS. Not worth the effort, IMO. Now, what about a 6.5 SAUM IMP +P??

But really, everyone should be building a 6UM. LOL

Thats what I had in mind but im not sure I might be diving too deep down a rabbit hole. Maybe I just go 6.5 saum +P. I talked to Jake about the 6UM and Im having a hard time building a custom rifle at a 243 caliber at this junction in my life. I did read your feed on it and it was attention grabbing. I do appreciate the IMP design of bullets and I thought while im at building a reloading only cartridge, I could just keep going and make it super niche. I am a bit worried it might be more trouble then its worth, hence why I started this thread in hopes of gaining some others' perspectives on it.