I don’t think I could tell a difference between 6.5CM and 7-08 if I were blindfolded. Could pretty easily tell between either of them and a .308 though, esp with 168grs or higher. I think most people need about 15-20% change in recoil energy to win the Pepsi Challenge with any consistency.
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Why shouldn't I build a 7-08?
- Thread starter Rickt301
- Start date
Well 7-08 it is. 500 yards is a long way to shoot at an animal that is shaped and furred like a bear making it's features hard to define. Plus with the bear walking on the side of a steep hill broadside might not mean the same thing it does on level ground. Going for a 1-8 twist I have an older Model Seven Remington in 7-08 I picked up a couple years ago cheap. It shoots ok and I love how light it is to carry. Getting 2740 fps using H414 and the 145 gr. Speer SPBT. I like a bit more weight and barrel for longer shots. I thought about putting a longer barrel on it and getting a different stock but why not have two rifles set up for different purposes.
Hey RT.. What twist are you shooting to get the 180s working? And what sort of MV are you getting? Unfortunately here in the UK, Hodgdon powders are a thing of the past.. I'm sure there are plenty of Vihtavuori substitutes. I've had a 7-08 for the last 10 years but haven't got a fast enough twist on it for slippery 162s or bigger.
A friend has recently got a 7-08 and we have been comparing the drops, terminal energy and windage of the 7-08 with a 150gn ELD versus a 6.5x285 with a 143 ELD. Even a fairly pedestrian 6.5 wins hands down on the 7-08 when its 'balls to the wall'.. What have you found with the 180gn bullets? What MVs are achievable?
Mines a short barrel for hunting, so decent MVs are tricky to get, just starting on a quest with a double based N540 to see if i can squirt them a bit quicker!!
comparing a 7-08 to a 6.5-284 isn't exactly fair. it's a 10 grain difference in H4350 powder charges
i run an 8 twist and 180s get to 2750-2800
short barrel id probably still be looking lighter weight
Sorry b6graham, I should have maybe been more specific, My 6.5x284 runs 143 ELD-X at 2745fps with 48.5gn N160 from a 21" 1:8 twist. The 7-08 should run the 150gn ELD-X at 2700fps with N540 (I'll know more after a trip to the range today)..
The point being is that for a similar speed and a similar weight, the 6.5s just do so much better. I compared a 162 ELD-X out of my 7x64 with a MV of 2650 versus a 6.5 143 ELD-X at 2745 and the windage at 1000 was within a gnats cock.
My conclusion (and its just my thoughts) is that unless you can launch those bigger 7mm bullets up around 2800-3000, theres not a whole heap to be gained out of the 140-147gn 6.5 bullets launched 2700-2900.
And my 2p ( or 2 cents for you guys) to the OP.. i love my 7-08, seriously accurate gun and easy to load for out to 800. definitely better than the .308 but if i had my time again (and don't let my 7-08 hear this!!), I'd have gone .260 or even the .260 ackley.
If i was hell-bent on shooting 7mm bullets, I'd be going into a long action with .284 win, .280, 7RM..
I'm shooting an 1/9 twist, throated for the 180s. With h4350, it's around around 2650-2700. Varget or rl17 will get a hundred fps or so more.
The 7/08 or ackley version will have better barrel life, same wind or a touch better and significantly better terminal ballistics over a 6.5.
That's why I went with it. You'll have to weigh out the pros and cons of the two, but for me a 7mm is my flavor of choice.
that's what i meant. comparing a 284 parent case versus a much smaller one
that's like saying a 22 creed smokes a 6ARC (6grendel). 22creed is bigger case and smaller bullet like the 6.5-284, versus the bigger 6mm ARC which has a much smaller case
look at a 162 at 2850-2900 which is possible with a short action 284, a 7SAW and a 7-08AI
You're right, I get what you're saying, but i wasn't really comparing the casings, just a similar weight bullet at a similar speed in both 6.5 and 7mm. not scientific at all, i know.. I guess my point to my buddy is that why are you trying to 'lob' a big bullet out of a small case just because the BC is better at the detriment of MV. At some point, MV becomes more important that BC. Notwithstanding stability and twists. In his (and my) instance, we're both shooting 21" barrels which really doesn't help with the velocities. I've just got back from the range after trying some N540 in the 7-08 with 150 ELD-X and at viht's max load, I got 2627fps average against a book of 2700fps. Thats a butt ton under your 180gn speeds.
look up a 168 from a 7mm and a 168 from a 308 at the same speed
the 7mm wins. with same weight the smaller caliber will be superior because BC and sectional density
max load in a book is a fare. you need to find it in you rifle. but i will say that data makes sense. normal load data is 24 or 26" barrels. subtract 20fps per inch.
with the 162s i used 41.4gr varget to get 2850. never tried H4350
not sure where varget equivalent is from VV
the 7mm wins. with same weight the smaller caliber will be superior because BC and sectional density
max load in a book is a fare. you need to find it in you rifle. but i will say that data makes sense. normal load data is 24 or 26" barrels. subtract 20fps per inch.
with the 162s i used 41.4gr varget to get 2850. never tried H4350
not sure where varget equivalent is from VV
Powder selection is important. Try to find something in the xbr 8208 or Varget burn range. There is no reason you should be that slow with a 150gr. My non ackley 7/08 with 162s and 25" tube did 2700 with minimal pressure. You should be at 2750-2800 with those and the shorter barrel
1. Because you want one , 2. They are fun , you don't already own 9 of them and besides the 10th one is the charm or a backups is always a good thing to have . 3. Because you can own it while you still can . Its more fun that a 22lr well it has more power and when is more power ever a bad thing ... Girls will like you more you will instantly attract others to you , who will wish to be like you , Ok maybe most of that is a line of bs but the first 3 seem like good reasons to me .
Ok then the hard question, Criterion has a "Heavy Sporter", "light Varmint" and "varmint" contour. I am going to have to lug this thing around up and down some hills so will the heavier contours really help me that much? Will they have a real accuracy edge over a heavy sporter contour. I do want a 26 inch barrel and my stock is cut for the Remington varmint contour.
I had to HBN coat the 162s to get them going fast enough to stabilize in my 1-9tw 7-08. 1-8tw won't hurt your 162s and should stabilize 180s. 40gr Varget under 162gr HBN coated were super accurate. A tad slow, but it was a good trade for my uses. Other powders did fine as well, H414, RL17 were a couple of my go-to powders and were what I used for hunting because they would hold under 1 MOA and gave more velocity.
Lol
A 1-8 would be perfectly fine with 190’s at 7-08 speeds
162’s are probably stable with a 1-9 at 7BR speeds.
I’ve seen QL data get them into the 2500’s safely which is the speed I did the stability calculation at.
A 190 in 7-08 will be just a bit slower than a 290 in 308 and there’s plenty of info on that combo.
OP is better off going 1:8 and shooting the 168 ABLRs or one of the new 175gr variants. If he was looking to push a 190 then he'd be better served to make 7WSM.
Thanks b2lee for posting that video.
It got me thinking... when they compared the 7 mag to the 7-08 (9% increase in performance and 41% more powder), i wonder what the results would be if you shot a 7mm 175/180 grain bullet from a 6.5PRC necked up and a 300PRC necked down and compared the two as they did.
Love the 7-08!
It got me thinking... when they compared the 7 mag to the 7-08 (9% increase in performance and 41% more powder), i wonder what the results would be if you shot a 7mm 175/180 grain bullet from a 6.5PRC necked up and a 300PRC necked down and compared the two as they did.
Love the 7-08!
I totally agree about the lighter bullet but totally disagree with the need for a 1-8.
My point wasn’t to promote 190’s in a 7-08 but to show that a fast twist isn’t necessary.
1-9 is more than enough.
Not in my experience. Roughly 15,000 rounds loaded and fired through three separate 7-08 barrels all on the same long action. Even with the extra mag capacity the 180's and heavier only held consistently under .75 MOA in the 1-8tw
JBM calculates a 190gr at 2500 has a stability of 1.271 @ 1-9 and shows it as questionable.
Though, for the OPs stated purpose a 1-9 will be very suitable.
You point to 190s and say that 1-9 is "more then enough"
You obviously didn't read your last post.
Your reading what you want.
I said the 190 would be fine with a 1-8 at 7-08 velocities implying it’s overkill for 168 and lighter Bullets.
That 1-9 is more than enough for common 7-08 bullets.
To the OP:
According to Quick Load 47.7gr H4350 is roughly 81,497 PSI in a 7-08 with 180gr Berger VLD loaded at 2.960 COAL. Do not try this. This guy is either full of shit or has a magic wand he waves before pulling the trigger on that load.
Well, I guess if you also have a magic wand to wave before risking your face and forearm, then go ahead.
Edit to add: It's also 115% of case fill.
I couldn’t get that much H4350 into my 260 without 130’s with some serious drama.
I should've said, this is for my 7/08 ackley. But here is the fireforming load. I didn't mean to mislead. Apologies.
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I ran my initial loads on my new 7 saum barrel at 2700 with the last of my 180ELDM’s.
My 1810 plate got punished with them.
None blew up at that speed.
I haven't had issues with them at all. I run them closer to 2900 or so in my 280 Ackley with a 9 twist and no issues. Seems under 2950 they are fine.
I have to admit I am super curious about your 7-08AI. What's the case capacity, barrel length and COAL on that 7-08 AI?
I only ask because when you AI a 7-08 you only gain about 3.3gr of case capacity and based on what you've provided and extrapolating out that you might be loading as long as 2.960 that still leaves you with 70,000 PSI to get a 180gr ELDM to 2700fps from a 26" tube.
Edit to add: That does bring you down to about 107% case fill though, so it becoming more conceivable.
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I'm not sure about the pressure, but I'm not seeing anything excessive. I know that pressure isn't always easy to read though.
25" McGowan 1/9 heavy varmint
Shot about 800 rounds with the standard 7/08 then reset as a 7/08 ackley.
Originally throated @ 2.960 with 180s eldm
Neck is .3185 allowing for sizing down lake city brass and still having clearance.
Edit- no clue what the freebore was, I can't remember, but I am jumping them a ways. Probably .070 when loaded at 2.96.
Barrel has 2.5 or 3k on it.
Xbr 8208 gets me 2800-2850 with 162s
I can check my load data but I was getting 2700-2770 with sierra 175s and various powders.
180s I tried with h4350 and that's it.
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I get different numbers from my Magneto Speed than QL gives all the time. They vary quite a bit when you get into the AI stuff.
That velocity makes a lot more sense to me now. QL has no way to determine throat erosion, neck tension, gain twist or any number of other variables and is really just a guide for where to start exercising more caution.
Was not trying to say that there's no circumstance that 180s will stabilize in a 1-9tw, the point to the posts was that a standard 7-08 that the OP was looking to build would get about 2500 - 2580 FPS and a 1.204 - 1.217 stability index from JBM is not the place to start looking for consistent accuracy. He said he's not looking to go that heavy anyway so a 1-9tw will suit his needs. If you're going to try and lob heavy bullets from a case as small as a 7-08 then an 1-8tw is better suited. HBN coat them, point the tips or do something else to make them go faster (bigger cartridge) and a 1-9tw fits the bill again.
Good luck with your AI.
That's a fair point, 180s that slow should have a 8 twist, but it could work with an 9 twist.
I love my ackley, great cartridge. Thanks for running some numbers too!
Well gentlemen I have to admit I ordered a 1-8 twist 260 remington barrel. I hemmed and Hawed around looking at BC's, velocities, remaining energies and wind defeating properties. I also shot a very accurate 260 out to 700 yards and was just smitten with the cartridge. The bizarre part is I justified this by also beginning a build on a 280 AI using a Shilen barrel on a 1903A3 Springfield action for the bear hunt. There just might be an actual affliction called rifle loonyism. I think the 7-08 just made too much sense.
I chose the 7mm08 about 15 years ago. I like a shorter (20") barrel.
After researching it and running ballistic charts till my eyes bled I remember the real-world muzzle speeds made more sense for 7mm08 than smaller calibers with the same length barrel. The advantage over the 308 was clear as well.
I'm in the process of building my forever rifle, did a lot of soul searching, and decided that I'm staying with the 7mm08 despite all the fanfare around newer options.
I can change barrels myself, so it's not really that much of a commitment, but anyhow, that's what I think of the caliber.
By the way, my low-pressure super accurate load gives me a hair over 2600fps. When I was pushing it a little more I was at 2680, but it didn't group as well at distance (more spread in speeds).
Edited to add: That's with 162 grain bullets.
After researching it and running ballistic charts till my eyes bled I remember the real-world muzzle speeds made more sense for 7mm08 than smaller calibers with the same length barrel. The advantage over the 308 was clear as well.
I'm in the process of building my forever rifle, did a lot of soul searching, and decided that I'm staying with the 7mm08 despite all the fanfare around newer options.
I can change barrels myself, so it's not really that much of a commitment, but anyhow, that's what I think of the caliber.
By the way, my low-pressure super accurate load gives me a hair over 2600fps. When I was pushing it a little more I was at 2680, but it didn't group as well at distance (more spread in speeds).
Edited to add: That's with 162 grain bullets.
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The 7-08 I have is a Model 7 with the short pencil barrel, 18 inches I think. Shoots great and gets 2745 fps running the Speer 145 gr. BTSP. Top load of H414 and a magnum primer. My "summer" load uses I4350 under the 140 grain Partition pushed to 2600 fps. Mostly for feral hogs.
I've shot my 7SAW in temperatures ranging from ZERO to 100 degrees and have noticed no primer issues at all, I'm using H4350 and FED Match primers behind Berger 175 Elite Hunters as with any powder temp will cause POI variances but I've never had one not POP!
Alpha factory brass and no fire forming sold me on this cartridge, I use it on everything New Mexico has to offer and am very pleased with terminal performance so far!
Alpha factory brass and no fire forming sold me on this cartridge, I use it on everything New Mexico has to offer and am very pleased with terminal performance so far!
@wjm308 a bit of a messy thread but 180 ELD-Ms from mag length 7mm08AI sounds promising, should think the 7mmSAW should also handle 180gr bullets.
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