Oh god, not another caliber debate thread.

Okay I ran some numbers thru Quickload...I'm actually very surprised...either QL is goofy this morning, I did something wrong or this is true...

My version doesn't have the 175 ELD so I used the 162 AMAX and Reloader 33 powder for all of them and a 24" barrel.

7mm WSM - 3122 fps, 62311 psi.
7mm Rem Mag - 3113 fps, 62149 psi.
7mm Dakota - 3140 fps, 61636 psi.
7mm Wby - 3149 fps, 62917 psi.
7mm STW - 3095 fps, 62440 psi.
7mm/300 Wby - 3165 fps, 62237 psi.
7mm RUM - 3053 fps, 62462 psi.
Lazz Firebird - 3170 fps, 62290 psi.

I have noticed my version of QL is about 150-200 fps slower then real life, but still that's a pretty neat comparison. Of course some tweaking powder and barrel lengths will change things a lot too.

Rich Coyle said:

Exactly. From my drag racing days.....there's no substitute for cubic inches.

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That's a popular cliche but it isn't true either. One substitute that is applicable to this discussion is airflow. You can make the chamber as large as you want but the pressure has to flow through a 7mm orifice. The flow capacity of that orifice seems to be maxed out at about a 7mm STW chamber size.

I have a hard time buying into that, I am sure there is some validity if we are set at one duration , but we are not, we have the options of different throat configs to reduce pressures and longer duration's to accelerate the bullets, if this were true there would be no Allen mags along with others. slow the pressure down but hit it longer to transfer the energy or build it to higher pressures

adam32 said:

Okay I ran some numbers thru Quickload...I'm actually very surprised...either QL is goofy this morning, I did something wrong or this is true...

My version doesn't have the 175 ELD so I used the 162 AMAX and Reloader 33 powder for all of them and a 24" barrel.

7mm WSM - 3122 fps, 62311 psi.
7mm Rem Mag - 3113 fps, 62149 psi.
7mm Dakota - 3140 fps, 61636 psi.
7mm Wby - 3149 fps, 62917 psi.
7mm STW - 3095 fps, 62440 psi.
7mm/300 Wby - 3165 fps, 62237 psi.
7mm RUM - 3053 fps, 62462 psi.
Lazz Firebird - 3170 fps, 62290 psi.

I have noticed my version of QL is about 150-200 fps slower then real life, but still that's a pretty neat comparison. Of course some tweaking powder and barrel lengths will change things a lot too.

Click to expand...

look at that WSM gettin it

adam32 said:

Okay I ran some numbers thru Quickload...I'm actually very surprised...either QL is goofy this morning, I did something wrong or this is true...

My version doesn't have the 175 ELD so I used the 162 AMAX and Reloader 33 powder for all of them and a 24" barrel.

7mm WSM - 3122 fps, 62311 psi.
7mm Rem Mag - 3113 fps, 62149 psi.
7mm Dakota - 3140 fps, 61636 psi.
7mm Wby - 3149 fps, 62917 psi.
7mm STW - 3095 fps, 62440 psi.
7mm/300 Wby - 3165 fps, 62237 psi.
7mm RUM - 3053 fps, 62462 psi.
Lazz Firebird - 3170 fps, 62290 psi.

I have noticed my version of QL is about 150-200 fps slower then real life, but still that's a pretty neat comparison. Of course some tweaking powder and barrel lengths will change things a lot too.

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I'm far from an expert...FAAARRRRRR!

But did you really do justice to the larger capacity cases with that short of a barrel?

I was reading some "stuff" on another site where they were trimming a barrel in one inch increments and there are a lot of calibers that would do better with barrels a lot longer than the factory cut.

The two that stood out was the 7.62x39 (because I was actually looking for that one) and the 6.5 Creedmoor.

7.62x39 was designed for 16" barrels (AK-47) up to 20" (SKS) but the best velocity was from a 21" or 22". The 6.5 Creedmoor was best velocity was 27".

In your above data I would assume there was a lot of unburnt powder flying down range that a longer barrel could have made good use of.

I would like to see you run your numbers with a 28" tube just to see if any of your samples calibers really shined.

CaptnC said:

I'm far from an expert...FAAARRRRRR!

But did you really do justice to the larger capacity cases with that short of a barrel?

I was reading some "stuff" on another site where they were trimming a barrel in one inch increments and there are a lot of calibers that would do better with barrels a lot longer than the factory cut.

The two that stood out was the 7.62x39 (because I was actually looking for that one) and the 6.5 Creedmoor.

7.62x39 was designed for 16" barrels (AK-47) up to 20" (SKS) but the best velocity was from a 21" or 22". The 6.5 Creedmoor was best velocity was 27".

In your above data I would assume there was a lot of unburnt powder flying down range that a longer barrel could have made good use of.

I would like to see you run your numbers with a 28" tube just to see if any of your samples calibers really shined.

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I did 24" because that's what was wanted in previous posts.

Yes, a 26-30" barrel will make the bigger cases much faster.

adam32 said:

I did 24" because that's what was wanted in previous posts.

Yes, a 26-30" barrel will make the bigger cases much faster.

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I would be interested is seeing how much change Quickload shows with a 28 inch barrel on the 7 STW and the 7 RUM.

Edd said:

I would be interested is seeing how much change Quickload shows with a 28 inch barrel on the 7 STW and the 7 RUM.

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I'll check it Tuesday when I get to work again.

I would be curious if using the heavier bullets, the 195 grain Berger for instance fare.

I have two 7 Rem Mag and 3 7RUM all Remintong 700. All stock rifles minus trigger upgrades. The RUM shoot circles around the 7RM s shooting factory loads. One of the 7RUM is a VTR 26" barrel that I just had to buy because it is different. It shoots .250 3shot groups factory ammo all day. Cannot believe this gun, it is my most accurate I have ever owned.
Buy and shoot what you want. Just stock up plenty of brass from the start and enjoy your gun or guns.

By the way, if I were to run across a nice 7STW or a 28 Nosler I would buy it and add it to the arsenal. Part of the fun is developing the load and building the gun to your wants and needs.

adam32 said:

I did 24" because that's what was wanted in previous posts.

Yes, a 26-30" barrel will make the bigger cases much faster.

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Yea buddy 30 inch rum ai 195 eol hit a node at 3200 and lettin it rip, although I would not build this setup for 700- yards , I think the wsm and a 7mm RM own it out to 1000 at 70 grains a pop with the RM owning the brass availability, or even the 7mm-300 wm with just neck sizing. the brass is so much cheaper than Weatherby so that would hinder that chamber but if that were not an issue, it is a great chamber . I wont lie, I am just as guilty of the testosterone thing lol, I couldn't stand not to have the biggest 7. I built an STW back before Remington chambered it and used 8 mm mag brass and when they came out with the ultra I chambered that one to it, and it was a waist of time shooting 140 grainers, it did do a lil better with 168s and 180s , shoots the 168 3300 and the 180s 3200. Now that they have some bigger bullets , slower powders ,and I have followed the bigger cartridges, I am liking the RUM. The biggest hurdle is brass life, the pockets are not that strong so you have to load under ejector marks, I am in the process of sizing down some Bertram edge brass ( I also shoot an Edge) that brass is tougher than rem brass, just to see if I can run a lil pressure. Maybe someone with a bit more experience will chime in and tell me if I am just walking down the wrong trail.

Edd said:

Did you read what Mudrunner wrote? He almost got something right. The difference between a 7mm RUM and a 28 Nosler from a 24 or 26 inch barrel will be negligible. I think a 28 Nosler is the best choice.

I think a 7mm RUM is a poor choice regardless of the criteria but under certain conditions it would deliver more velocity than a 28 Nosler.

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You know what, I think that's the closest thing that I'll ever get to it, so I'll take that as a compliment Edd.

smithjasona1978 said:

Anybody ever heard of a company called Weatherby?
They have a pretty fast 7mm.

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smithjasona1978 said:

Oh and the wby been around since about ww2. Components won't go away.

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Yeah, and Roy's cartridge design technology was out of date by Korea...