7prc vs 7saum for Sako 85 Long

penguinofsleep · Jul 27, 2024

EDIT3: Primarily looking to see if anyone has first hand experience with 7 SAUM feeding reliably in a Sako 85 with factory double stack long action mag / action at this point. Everything else is pretty much figured out.

See post #8 for feeding experience with 7RM as well.

EDIT4: Missed the obvious answer... oops. Thread resolved. Will post results later if people want to know.
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Not building immediately, but trying to decide between a 7PRC and 7SAUM for a Sako 85 hunting rifle and would like feedback on 3 things:
Key question - 1. Will 7 SAUM run in a Sako 85 long action (with Sako long action mags, originally 7RM). Anyone with experience know if 7 SAUM runs / feeds reliably in these?

2. How much of a difference is there in velocity between the two (assume 24"/24.5" barrel for both)? Can't find a lot of mfg published 7 PRC data, but looking online it seems a 180gr bullet (180 just as an arbitrary example) will go about 2800-2900 in SAUM and 2900-3000 in PRC?
3. Is one significantly easier to reload for or run on vs the other (ex: accepts more powders, wider nodes, etc.) or easier to keep running in a rifle (ex: doesn't need to be cleaned every 50 rounds to prevent carbon ring, oddities with brass, etc.)

Edit: Forgot to mention, lack of factory ammo availability for both is not a concern (reloading). Already have 7SAUM brass / components / dies (i.e. intermittent 7 SAUM component availability will not be a problem). Do not have 7 PRC anything yet, so if it's all "close enough" and 7 SAUM will feed reliably in a Sako 85 LA, then I'm probably going to go SAUM just to save myself money on additional equipment.

Edit2:
Plan on using copper / solids in the 150 - 170 weight range.

fdkay · Jul 27, 2024

The 7 saum is an awesome, dead cartridge with no factory ammo suuport.
The PRC is a well designed cartridge that has SOME support.
The SAUM would need to be throated long to seat the heavies further out.

FuhQ · Jul 27, 2024

7 PRC on a long action and you can seat the heavies as long as you want. Ballistically, it's pretty much identical to a 7mm RemMag pushed to modern pressures with modern components, which is one of the best hunting cartridges ever made.

It is a little bit shorter than a 7mmRM, but case capacities are nearly the same thanks to the very low (straight) taper of the case walls. But this shortness comes into play allowing you to seat heavies farther into the lands while maintaining magazine lengths.

Here's a pic I took of one of my 7 PRC cases next to a 7mm RM cases.

oldnewguy · Jul 27, 2024

This is from Berger (so I would assume it's QL numbers)

Screenshot_20230726_144830_Yahoo Mail.jpg

Screenshot_20230726_144817_Yahoo Mail.jpg

Screenshot_20230726_144803_Yahoo Mail.jpg

oldnewguy · Jul 27, 2024

The PRC numbers are from 26" barrel, and the SAUM are 24"

Tikka595II · Jul 27, 2024

I don't have a sako 85 but i did basically the same thing with a tikka 695 (long action) 7 rem mag turned into a 7mm Rsaum it feeds fine so I don't see any reason for you to have problems as long as you don't short throat it. My 7mm saum has a 26 inch barrel a soft load with 162 amax/eld is around 2950fps i also can PUSH the 180eld to the same speed but it is harsh/winter only load so i will probably rework it to 2875fps for more consistent results. I will update with c.o.a.l etc when i get home/ time

penguinofsleep · Jul 27, 2024

Looks like I'm only losing 100-150 FPS going SAUM instead of PRC. Difference in drop for a few different projectiles in a ballistic calculator is <5" at 450-500 yards (minimum v around 1950/2000 for bullet expansion, not because I'm only taking 500yd shots).

Guess it will come down to feeding / function.

Also saw on Backfire that 7PRC is somewhat prone to carbon rings, seemingly mostly in earlier production runs of factory barrels mostly due to mfgs wanting to be on the low end of chamber tolerances (i.e. tighter) but not necessarily due to bad chamber design. Anyone have similar experiences?

penguinofsleep · Jul 27, 2024

Tikka595II said:
I don't have a sako 85 but i did basically the same thing with a tikka 695 (long action) 7 rem mag turned into a 7mm Rsaum it feeds fine so I don't see any reason for you to have problems as long as you don't short throat it. My 7mm saum has a 26 inch barrel a soft load with 162 amax/eld is around 2950fps i also can PUSH the 180eld to the same speed but it is harsh/winter only load so i will probably rework it to 2875fps for more consistent results. I will update with c.o.a.l etc when i get home/ time

I think the 695 is more like a T3 with a similar type of single stack / single feed?

Wondering because the 85 is double stack with L/R feeding and I do occasionally have minor problems feeding the 7RM - about 1/8 rounds - I'm not 100% sure why. Nothing ever completely jams up, but sometimes half way through feeding, the front of the entire round won't point up enough and gets a little stuck on the way in (where it gets a little stuck will vary each time too) or the front will point up enough but hit other surfaces on the way in. Easily fixed by pushing harder on the bolt but at the same time beating up some of the projectiles + brass this way is not ideal for anything. However, 6.5x55 (medium length action) and 300WM (long action) have both been fine in the Sako 85 for me and IIRC the 300WM and 7RM have similar enough case taper / shoulder angle / OAL IIRC so not 100% sure why.

lash · Jul 27, 2024

Both are great choices, but since you already have the dies etc for 7SAUM, just make sure you go to a known smith who knows to throat it long for the 180s. Make up a few dummy cartridges to send in if you need to.

Tikka595II · Jul 27, 2024

penguinofsleep said:
I think the 695 is more like a T3 with a similar type of single stack / single feed?

Wondering because the 85 is double stack with L/R feeding and I do occasionally have problems feeding the 7RM - about 1/8 rounds

Yes it is single stack. I did see that the 85 is a double stack and wondered how it ran normally.

FuhQ · Jul 27, 2024

penguinofsleep said:
Looks like I'm only losing 100-150 FPS going SAUM instead of PRC. Difference in drop for a few different projectiles in a ballistic calculator is <5" at 450-500 yards (minimum v around 1950/2000 for bullet expansion, not because I'm only taking 500yd shots).

Guess it will come down to feeding / function.

Also saw on Backfire that 7PRC is somewhat prone to carbon rings, seemingly mostly in earlier production runs of factory barrels mostly due to mfgs wanting to be on the low end of chamber tolerances (i.e. tighter) but not necessarily due to bad chamber design. Anyone have similar experiences?

Please take everything you see on YouTube and the internet with a grain of salt... Most of these people get paid to sell you shit, or push their own opinions as facts, when reality might be completely 180º different.

NewsShooter · Jul 27, 2024

Either would run fine, I'd go with the PRC just because it's being currently produced. You can buy factory ammo for it now. I have a 7 Saum throated long for 180's, runs fine in a Tikka with waters mags.

Ronws · Jul 27, 2024

I agree with what @NewsShooter said.

7 PRC is good for hunting and some long range targets. You push heavy for caliber bullets at decent speeds. Even if the modernly the 175 gr is averaging 2800 fps, bullet performance and precision are more important than ultimate velocity.

But some guys like to tinker and 7 SAUM is usable as a hunting cartridge, as well. Just depends on how much work.

And I agree with @FuhQ as well. Jim is not the ultimate source. He is a clickbait king and stages things for dramatic effect. Like his recent vide about the Howa 1500 Superlite. Shot 4 inches. Then he tightened a loose action screw and got less than 1 inches for 3 shots.

But he would not do that for another budget rifle that he hates with a purple passion.

So, again, it's tough to separate the wheat from the chaff but I have not heard of rings from 7 PRC and mine has not had problems. Then, again, I give it a thorough cleaning and oiling (and grease for the bolt and lugs.)

FuhQ · Jul 27, 2024

Ronws said:
I agree with what @NewsShooter said.

7 PRC is good for hunting and some long range targets. You push heavy for caliber bullets at decent speeds. Even if the modernly the 175 gr is averaging 2800 fps, bullet performance and precision are more important than ultimate velocity.

But some guys like to tinker and 7 SAUM is usable as a hunting cartridge, as well. Just depends on how much work.

And I agree with @FuhQ as well. Jim is not the ultimate source. He is a clickbait king and stages things for dramatic effect. Like his recent vide about the Howa 1500 Superlite. Shot 4 inches. Then he tightened a loose action screw and got less than 1 inches for 3 shots.

But he would not do that for another budget rifle that he hates with a purple passion.

So, again, it's tough to separate the wheat from the chaff but I have not heard of rings from 7 PRC and mine has not had problems. Then, again, I give it a thorough cleaning and oiling (and grease for the bolt and lugs.)

That HACKfire dude is a joke. So are so many "guntubers" like DickCock45 and his Fudd video about how Trump and the NRgAy banning bumpstocks was a good thing (I think he deleted that video not long after he uploaded it from all the backlash he caught), and Clickbait Ranch doing stupid shit just to get clicks and views, and 22Shillster and his CCI "stangers"... Partly why I stopped watching IV8888's videos and MAC's videos...They became a 10 minute infomercial, and then 5 minutes of actual shooting or sharing about the gun or scope itself.

Kiba · Jul 27, 2024

A friend has a 7 SAUM long throated on a long action that I did load development for and I recently built myself a 7 PRC.

The 7 SAUM is awesome round... his rifle is extremely accurate with 180 VLDs and 145gr monos (older build, not fast enough twist for the 170-180gr 7mm monos) and quite powder efficient for the performance. Load development was easy, everything I tried shot fantastic. Negatives are brass can be very tough to get sometimes, and it's also very tough to find factory ammo... and factory 7 SAUM ammo isn't nearly as ideal as handloads with heavies loaded long.

The 7 PRC I just put together also shoots great with both lead and monos, just as well as my friend's 7 SAUM, and has the advantage of easy to find brass and good factory ammo. Load development was easy for both lead and the monos. Uses a bit more powder than the SAUM for the same performance, but the slightly larger case capacity of the PRC means I can squeeze a little more performance out of the PRC than the SAUM before encountering pressure signs.

I almost went SAUM on my build to avoid having to buy another set of dies and more brass but decided to go 7 PRC for easily available brass and the option of decent factory ammo, such as you go somewhere on a hunting trip and realize you forgot your handloads at home and then have to run to a store and find some factory ammo. Pretty easy to find 7 PRC ammo nowadays, not so easy with a 7 SAUM.

penguinofsleep · Jul 27, 2024

FuhQ said:
Please take everything you see on YouTube and the internet with a grain of salt... Most of these people get paid to sell you shit, or push their own opinions as facts, when reality might be completely 180º different.

Agreed.

OTOH, it did remind me of how a few people I used to shoot with had some individual rifles or some of the group had (the same) particular wildcats cartridges between them that were particularly prone to carbon rings or had other similar idiosyncrasies that weren't often mentioned by public at large (but even then, they also acknowledged it could have been a mfg issue, etc.). Figured I'd ask here given all this.

penguinofsleep · Jul 27, 2024

Anyways, it seems like everyone isn't saying anything really bad about either cartridge.

Guess it's just going to come down to if I get any feedback regarding reliability / feeding.

FuhQ · Jul 27, 2024

penguinofsleep said:
Agreed.

OTOH, it did remind me of how a few people I used to shoot with had some individual rifles or some of the group had (the same) particular wildcats cartridges between them that were particularly prone to carbon rings or had other similar idiosyncrasies that weren't often mentioned by public at large (but even then, they also acknowledged it could have been a mfg issue, etc.). Figured I'd ask here given all this.

I can tell you how to help avoid carbon rings... Don't trim your brass any farther than you actually have to. If you leave too big of gap between the case mouth and the leade, then you will develop a carbon ring. If that gap is full of brass, there won't be room for a carbon ring to form.

I know, it's SUPER scientific...

jbuck88 · Jul 28, 2024

I don’t think there is a wrong answer.

They are so close that you just need to decide one and commit. If I was picking something based on a guess it'll be supported by mainstream I'd go PRC. However, I have a short action and I'll be going saum as soon as my shoulder won't take the 300wsm.

If you want a factory magnum the 7rum, 28 nosler and 7 stw should work just fine.

Ronws · Jul 28, 2024

FuhQ said:
That HACKfire dude is a joke. So are so many "guntubers" like DickCock45 and his Fudd video about how Trump and the NRgAy banning bumpstocks was a good thing (I think he deleted that video not long after he uploaded it from all the backlash he caught), and Clickbait Ranch doing stupid shit just to get clicks and views, and 22Shillster and his CCI "stangers"... Partly why I stopped watching IV8888's videos and MAC's videos...They became a 10 minute infomercial, and then 5 minutes of actual shooting or sharing about the gun or scope itself.

You are not wrong. Especially for those guys that claim that youtube videos are their primary occupation. The only way to make money is live reads. That being said, I would say that as a clickbait king, I do like the recoil pad that he is marketing.

Which makes him a salesman.

FuhQ · Jul 28, 2024

Ronws said:
You are not wrong. Especially for those guys that claim that youtube videos are their primary occupation. The only way to make money is live reads. That being said, I would say that as a clickbait king, I do like the recoil pad that he is marketing.

Which makes him a salesman.

Oh sometimes the products themselves might be legit good products, but you gotta wade through the paid shill BS to figure out which ones are snake oil, and which ones are solid and legit purchases. That's why I do tons of research before I buy MOST things. Occasionally I'll hop on a bandwagon early if the product interests me and I think it might be worth the money... They're not always winners (Arken), but sometimes they end up being better than I imagined (Otter Creek suppressors) and being a diamond in the rough.

penguinofsleep · Sep 5, 2024

Bump to see if anyone else has feedback since the build got delayed.

Primarily looking to see if 7 SAUM feeds reliably in a Sako 85 with factory double stack long action mag / action.

NewsShooter · Sep 5, 2024

I would guess that it would, do you have the Sako and mags, I could send you a few pieces of brass with 180's seated to about 3.2 that you could try yourself.

penguinofsleep · Sep 5, 2024

NewsShooter said:
I would guess that it would, do you have the Sako and mags, I could send you a few pieces of brass with 180's seated to about 3.2 that you could try yourself.

When I miss the super obvious answer this whole time... despite doing this already to check other stuff... thanks.

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7prc vs 7saum for Sako 85 Long

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