7Mag in My Future- Help me decide

[gethuntin]

Allright i was going to build a budget 7 mag, but decided i have enough cabelas points to just purchase the gun. I have it narrowed down to the Tikka T3 mainly bc i have two and i do like them. I would like stainless so i would be limited to the lite model with the synthetic stock- which i am not excited about in a 7mag. I have the laminate which is about impossible to find.

Also thought about the Sako A7

But what i dont know much about is the Weatherby Series 2 i see they are Gaurunteed 1"MOA. I have not handled one how is the stock it looks better than an average plastic stock.is there any good aftermarket stocks and triggers?
How do they feed, one knock on 700's for me is they dont feed like a tikka.
Anyone have reviews on the weatherby?

 

[Matt Cashell]

The Weatherby Vanguard 2 is a Howa. I would say feeding is comparable to a Rem 700. Accuracy is very good. They are a bit heavier.

The Tikka or Sako would work great.

I like Savage for out-of-the-box rifles. And I like Remingtons for "customizing."

 

[gethuntin]

i just found out the vanguard isnt free floated- anyone free float one without losing accuracy?

 

[big10hunter]

You might want to take barrel length into acct with 7 Mag. A lot will argue it does not matter, but to get the most out of all that powder you should be thinking about a 26" barrel. I don't want to argue, so no one get upset, but you are burning unused powder outside of the barrel in 23 or 24 inch barrel. That's why for a mountain rifle I decided to stick with a wsm. Just my 2cents.

 

[Justin Crossley]

I would also go with a 26" barrel for a 7mm Rem Mag.
With the new AccuBonds coming out soon I think it makes the .270 short mag tough to beat in a Tikka T3.

 

[Matt Cashell]

You might want to take barrel length into acct with 7 Mag. A lot will argue it does not matter, but to get the most out of all that powder you should be thinking about a 26" barrel. I don't want to argue, so no one get upset, but you are burning unused powder outside of the barrel in 23 or 24 inch barrel. That's why for a mountain rifle I decided to stick with a wsm. Just my 2cents.

I load the same 7 RM load for my Buddy's 26 in. Winchester that I do for my 24 in. Savage, and the difference is a towering 42 fps (average). So I guess it is one of those "Is it worth it to you" things.

 

[Justin Crossley]

BB, what is your load?
When I sat down with my gunsmith before I built my 6.5, he told me I wouldn't get much more speed by going from a 24" to a 26" barrel. Then we started looking at some other powders and we found that from 24" to 25" I would see 100 fps more. From 25" to 26" I would also see about the same increase. From 26" to 27" I was looking at about 50 fps and from then on I wouldn't get much more out of it. I ended up with a 26" barrel.

I still think the 24" barrel will work just fine for a 7mm mag. My best friend just bought a Tikka in that caliber.

 

[Matt Cashell]

BB, what is your load?
When I sat down with my gunsmith before I built my 6.5, he told me I wouldn't get much more speed by going from a 24" to a 26" barrel. Then we started looking at some other powders and we found that from 24" to 25" I would see 100 fps more. From 25" to 26" I would also see about the same increase. From 26" to 27" I was looking at about 50 fps and from then on I wouldn't get much more out of it. I ended up with a 26" barrel.

I still think the 24" barrel will work just fine for a 7mm mag. My best friend just bought a Tikka in that caliber.

Justin,

Were you actually shooting and cutting a barrel? Or were you using a ballistics estimation program?

The load is 160 Accubonds over Retumbo and FED 215s, Nosler brass.

 

[Matt Cashell]

There have been a number of cutdown tests done and many had similar results to this one with the 300 WM:

http://www.tacticaloperations.com/SWATbarrel/

An excerpt:

"To find the answers, Tac Ops took a 26-inch barreled .300 Win. Mag. and chopped the barrel down in one-inch increments as they previously did with the .308 Winchester. Ten rounds of Federal Match 190-grain BTHP Gold Medal were fired from each increment. No velocity was lost from 26 inches to 22 inches. Velocity loss started to occur only after they went below 22 inches."

 

[Whisky]

Interesting data on some real life testing....

For a long time I have wondered about how barrel length affected velocity. I had always been told you need a certain length barrel for certain calibers. I have read when folks compared one gun to another with different lengths but I always thought that was not an apples to apples comparision. So I did a few test myself.
All these were Shilen barrels. I used the same brass through out the whole test. All weighed to with 1 grain. Bullets were tested on the Juenke machine. Powder charges were weighed to .1 grain. The same rest, chronograph, Redding press, primers all from the same lot, bullets for the same box, same lathe, same crowning tool, same cutoff tool, and each rifle done from start to finish on the same day. Ambient temperature was the same because I shoot from inside the shop. I held the rifle the same way on the rest every time. I shot ten rounds first to break in the barrel. Then cleaned with Sweets and fired one fouling shot. Then shot five rounds and took the average. I used a midrange load fron the Nosler book, not too hot but certainly not a reduced load. Here is what I got.

22-250 Hodgdon 380 34 grains Federal GM210M Remington brass 55 grain Ballistic Tip
27 inches 3469 fps
26 3451
25 3425
24 3407
56 fps from highest to lowest

270 Winchester Hodgdon 4350 54 grains Federal GM210M Winchester brass 130 grain Sierra
27 inches 3115 fps
26 3093
25 3071
24 3054
23 3035
22 3027
21 3001
114 fps from highest to lowest

300 Winchester mag Federal GM215M Winchester brass 74 grains of Reloder 22 180 grain Partition
27 inches 3055 fps
26 3031
25 3024
24 3003
23 2984
22 2960
95 fps from highest to lowest

340 Weatherby Federal GM215M 250 grain Sierra
81 grains Reloder 22 Wby brass
27 inches 2837 fps
26 2817
25 2809
24 2791
23 2777
22 2755
21 2731
106 fps from highest to lowest

I think I will do a little more thinking before I recommend a barrel length in the future. What do you folks think ?
Charlie



.338 Winchester & .257 Roberts

Here is the info about the 338 Win and the 257 Roberts.
338 Win mag
Winchester brass
Federal GM215M primers
Reloder 19....73 grains
250 grain Partitions
27 inches.....2806 fps
26 inches.....2787 fps
25 inches.....2761 fps
24 inches.....2743 fps
23 inches.....2716 fps
22 inches.....2697 fps
21 inches.....2676 fps
20 inches.....2656 fps
150 fps from 27 inches to 21 inches

257 Roberts
Federal GM210M primers
Remington brass
H-4350....45 grains
120 grain Partitions
27 inches.....2860 fps
26 inches.....2834 fps
26 inches.....2815 fps
25 inches.....2815 fps
24 inches.....2798 fps
23 inches.....2775 fps
22 inches.....2760 fps
21 inches.....2739 fps
20 inches.....2717 fps
143 fps from 27 inches to 20 inches

I want to test this on the next 450 Marlin I build and on a 222 Remington. If I get the same results with those, in my mind the test is over. I think this will be enough data to support the findings. Are there any folks out there who have a degree in this sort of thing ? Maybe explain how many data points would be needed to be able to say this would work with the majority of calibers ? Someone with experience in statistical (spell check) quality control?
Charlie



--------------------
Sisk Rifles
400 County Road 2340
Dayton, Tx 77535
www.siskguns.com
charliesiskguns.com
1-936-258-4984

The data and opinions contained in these posts are the results of experiences with my equipment, componentry, and testing methodology ONLY. As your equipment, componentry, and methodology is different, NO CONCLUSIONS SHOULD BE DRAWN FROM ANY DATA PRESENTED, nor should any data presented form the basis for any load development. DO NOT, UNDER ANY CIRCUMSTANCES, ATTEMPT TO REPLICATE THESE RESULTS, as doing so could be extremely dangerous.

Also, when I cut my 308 down I lost 19 fps/inch....I'll soon have a 6.5 SLR comparison at some point this Spring. I suspect it will be ~20 fps/inch too.

 

[Matt Cashell]

Yeah Whisky,

I think barrel length gets a lot more press than it deserves. There has been a lot of barrel length testing on accuracy also, and shorter barrels tend to shoot better. You know shorter = stiffer.

It's not the length it's how you ... Oh never mind.

 

[Whisky]

Yeah Whisky,

You know shorter = stiffer.

It's not the length it's how you ... Oh never mind.

Anyways, I agree.....There are very few situations where I would sacrifice handiness for a few more FPS. If I was a comp shooter and had rifles built strictly for that purpose, that would be one example. But I'm not a comp shooter... Another may be if/when I build something in the 338 flavor. That rifle would likely be used 10x more shooting rocks and steel than in hunting situations. And if I did bring it hunting, it would only be under certain conditions (like not packing it in 4 miles). Also, obviously it would be an ELR rifle, so the extra FPS would be nice for them ranges.

When it comes to a dedicated field/hunting rifle though, I will take "handy dandy" over a few more FPS every time.

 

[Justin Crossley]

Justin,

Were you actually shooting and cutting a barrel? Or were you using a ballistics estimation program?

The load is 160 Accubonds over Retumbo and FED 215s, Nosler brass.

Just using his program. I'm not saying that with some loads, you won't see much increase, but from what I've read (not tested) you can get more velocity from a longer barrel with some powders. I would think that if you were using heavier bullets like the 168 or 180 grain, you would see more of a difference because of the slower powders?
I know a lot of the guys that shoot the big .30 and .338 mags use 30" barrels for the same reason.

 

[big10hunter]

Weatherby would argue barrel length...all their mags have long barrel. Even Remy slaps on 2" more for mags. BB, from a lot of your posts I know you are educated of rifles, so I'm not arguing. Just saying I have read a lot and all loads are different. A lot of the loads above r not big powder burners. 7rem and the RUM's are. I believe you need a lot of barrel to Burn that powder. Also the reason the newer powders are more efficient in wsms, I think.

 

[philw]

Weatherby would argue barrel length...all their mags have long barrel.

No they don't, Weatherby makes plenty of rifles in their magnum chamberings with 24" barrels, I have one in the safe. I also have a custom 7 mm Mashburn Super (a little hotter than a standard 7 RM) with a 24" barrel that shoots 150's at 3300 fps. into tiny groups.

Personally, 24" is about as long as I want in a barrel, and if I have to give up 50 fps vs. a 26" I'll take it.

 

[Shrek]

Looking at most of these test I am left wondering about slower powders. All of the test whisky quoted are with powders and bullets that are mild charges right in the middle of the applicable powder range. The 308 federal match is made for average barrels which for the 308 run from 20"to 22" on most factory barrels . It makes sense that velocity loss was flat down to 20" and little velocity loss down to 18". I think the true worth of a long barrel will not show up if you do not try to take advantage of it. Midrange to fast for caliber powders and midrange to light bullets will not benefit from a long barrel. Take the 300 win mag and load it with max charge of retumbo under a 210gr berger vld and I would like to see the velocity loss per in starting at 28". I'm thinking it would be more significant but I could be wrong.
As for a 7mm rem mag for dragging all over a mountain I think the 24" barrel is plenty. My 7mm wsm comes factory with a 23.5" barrel and when I rebarrel it I might go with a 26" barrel to grab another 50 to 70 fps ? On a fluted #3 barrel an extra 2.5" on the skinny end isn't a ton of weight.

 

[Matt Cashell]

Justin, Big10, DaveIJ,

The OP was asking about factory 7RM rifles, which typically come in 24 inch barrel configuration. I was trying to make the point that a 26 inch barrel isn't required for good performance with that cartridge. I would actually recommend a 24 inch barrel for a 7 RM for hunting anyway. The OP won't be shooting 180 grain pills out of a factory tube either.

But as long as were speculating on heavy loads and bullets (which this post was not about), I would speculate that even with crazy overbore cartridges like the 7 RUM, and super slow powders, you still aren't going to see anywhere around 100 fps/inch. It would be a great experiment though.

Charlie Sisk knows his stuff, and I think his testing is pretty reliable. I also think RL22 and 180 gr. bullets in a 300 WM isn't really midrange to light for bullets and midrange to fast for powder with that cartridge. Even jumping to 210s and RL25 or H1000, I don't think you are going to shoot way past Sisk's 20 Fps per inch gain.

 

[Shrek]

Matt , I agree the the 24" barrel is plenty for a light carry rifle. That said , the difference in velocity is small but the weight penalty is small also when adding two inches. On a #3 pacnor it's 2.56 oz according to their calculator.

 

[philw]

i just found out the vanguard isnt free floated- anyone free float one without losing accuracy?

Mine is a Vanguard MOA and I did free float it without losing accuracy.

 

[Matt Cashell]

Matt , I agree the the 24" barrel is plenty for a light carry rifle. That said , the difference in velocity is small but the weight penalty is small also when adding two inches. On a #3 pacnor it's 2.56 oz according to their calculator.

I am with you Dave, not too much weight there. I am sure there are plenty of ouce counters here on Rokslide that would disagree with us, though!

It is the extra 2 inches of length that can be a bother, especially if you are using Scabbards. My 26 in. Sendero has the butt sticking about an inch out the end, when sunk in the scabbard.

I guess my point is there are a few factory 26 in. options out there, but the OP doesn't need to worry about it, IMO, when selecting a hunting 7RM.