Any 7mm-08 Ackley Shooters?

[gunsbam45]

I've got a rifle Bob Jourdan built for me as a study model back in 2010 when he brought me over to show me how to re-barrel rifles, true actions etc. Bob had not done but one or two in the caliber, but did have the loading dies and reamer, so I went with that caliber in a 9 twist Hart bench rest grade sporter weight barrel target crowned full length at 26". To my shame it hasn't been touched since test firing. I'm trying to decide whether to hang onto it and load for it, or sell it. Does anyone have load data for the 7mm-08 Ackley?

[potatojudge]

I don't see a reason to get rid of it at all. Not saying the AI version gains you much- it does very little in the 308 family of cases- but even if you just load to 7-08 data you've got a great gun. Is the magazine box length standard short action or extended? Is it throated for mag length rounds? That 9 twist should be perfect for 160-175 grain bullets, like the excellent 168 Berger VLD (or VLD hunter), but you could get some 120 ballistic tips to some impressive RPMs which isn't a bad thing deer hunting.

RL17 usually gives top velocity in the 7-08 I you can find some, and with that barrel length in an AI the gun is built for max velocity.

If you've already got the dies and if the gun feeds well, there is no real downside to having the AI version of a great round.

[gunsbam45]

I was thinking that Bob said that twist was good up to 140 grain bullets, but others have told me recently the 9 twist should work with longer bullets. I was into the Remington mountain rifles then, so I bought a Mountain LSS in 7mm-08 and we trued the action and re-barreled it with a Hart sporter weight, which is a tad heavier barrel than the Remington factory sporter barrels. I remember the disappointment he expressed when we went to true the action. He wanted me to see the reason for squaring everything, but this one turned out to be the straightest 700 he'd seen. You had to be there, but it was funny. The LSS barrel that came off was the pencil contour of the mountain rifles. I actually have no idea how it feeds. We took it to the Bartlesville range since Bob lived in town, and test fired it into the berm there. I put a set of Leupold Dual Dovetail rings and bases on it and ordered in a scope, but the scope didn't quite work with the medium rings, and it got lost in the shuffle when I started getting into the big bore revolver world. I remember buying two boxes of 7mm-08 cartridges to fire form brass, but never got that far. I don't even have the ammo anymore. It's still sitting in the safe next to the seating length gauge Bob made for me with the reamer we used for the barrel. I found this picture of it on my phone. He also taught me how to do his mini scroll finish, but we can't find the notes on the lathe speed now. The reason I left the barrel at 26" was the balance of the rifle. It really just felt right for me off hand. Seems like my thinking at the time was by going Ackley on the 7mm-08 I'd have a 7mm bullet running at 270 Winchester velocities on a short action rifle, but it's been awhile. I all but put my rifles away until about 3 springs or so ago when I picked up a Kimber Montana in .223 and started working the coyotes over again. I like it so well I'm seriously considering getting another one in 6.$ )&$%#@^&$# simply because I'm now spoiled from a super light rifle with no recoil. I also wonder what would be the best route to go for dies on the 7mm-08 Ackley. I think Bob's dies came from RCBS but I can't remember for sure now.

[potatojudge]

That's a clean looking rifle.

9 twist will for certain stabilize bullets in the 160 class. I think my factory M48 in 28 Nosler is a 9 twist and the standard load for the 28 is a 175 grain bullet, apples to oranges a bit but 9 does not top out at 140 in any rifle AFAIK.

I had put rifles away also until I got a Montana in 7-08. Who says we can't hunt with them all? No shame in getting another in a better deer caliber.

Dies for the 7-08 AI aren't a problem, but inexpensive ones are. New they're $150 for non bushing dies, $220 for bushing dies. Custom cut Whidden dies are $200ish. Don't find them used often.

[bradshaw]

gunsbam69 and potatojudge.... a note on 7mm twist:

From the physics angle, bullet length is more critical than weight in determining twist rate.

Example, Dan Wesson M-40 .357 Maximum
* 1:14 twist----stabilizes both Hornady .358 200 grain Round Nose and the longer 200 grain Spire Point.
* 1:16 twist----stabilizes Hornady .358 200 Round Nose, but not the longer 200 grain Spire Point.

Streamlined rifle projectiles are much more twist-sensitive than the pumkim balls we throw from sixguns. and the high ballistic coefficients exacerbate another factor seldom discussed in in accurate flight----bore uniformity. And bore uniformity becomes more critical when we boattail the bullet.

In handgun silhouette we learned the huge difference between the 7mm with 1:9 vs 1:10 twist. the first T/C Contender 7mm TCU (7mm/.223 with 40-degree shoulder, a.k.a. 7mm Thompson/Center Ugalde) barrels I tried were 1:10 and I called Warren Center to pronounce them useless of silhouette. Same happened with the first Pachmayr Dominator 7mm IHMSA (bolt action, single shot conversion for 1911 frame). Upon shooting the Dominator @ 100 yards, I measured the twist----1:10”----then called Carl Cupp at Pachmayr. “I knew you’d catch that,” said Carl. Pachmayr sent a 1:9”, which shot straight, even with Sierra 160 SBT (Spitzer Boat Tail).

The Sierra 7mm 168 MatchKing (boattail hollow point) has a very gradual boattail, which makes twist and bore uniformity much more critical than the blunter boattail on the Sierra 160 SBT. (The Sierra .308 168 MatchKing BTHP has a blunter, more forgiving, boattail than the Sierra 7mm 168 MatchKing.)

Following an IHMSA match at Richard Dietz’s range in New Braunfels, Texas, a bunch of us gathered on the adjacent NRA Rifle Silhouette range. A few scoffs from the rifle silhouetters faded when Jim Whitcomb got into Creedmoor and put 4x4 shots from his Wichita center-grip 7mm IHMSA into the area of a modest desert plate on the chest of a swinger ram @ 500 meters (550 yards). Whitcomb’s load consisted of Sierra 168 MatchKing over H4895. Sights: Bo-Mar rear; globe front, with thin post. Whit’s Wichita sported 1:9” twist.

This shooter followed with his XP-100 7mm/308x1-3/4” with Douglas Premium 1:9” (pistol built by sharpshooter Skip Talbot). Position: Creedmoor. Load: Sierra 140 SP flat base seated over 33/H4895 in formed & reamed .308 Lake City 1968 brass. Sights: Micro rear with custom notch; .75” blade front. 4x4 shots stitched into the ram’s head @ 500 meters you could cover with a coffee cup. The rifle silhouetters got an education in pistol accuracy that day.

No need to worry about Remington’s 7mm 1:9-1/4” twist.
David Bradshaw

[potatojudge]

bergerbullets.com/twist-rate-calculator/

This gives a good ballpark for stability.

All copper bullets are another story, and require a faster twist than their bimetal counterparts. I'd recommend the 168 Berger hunters for this rifle.

[gunsbam45]

Some great info and experience there David. I haven't done any loading for rifles, just big bore revolvers, so would be new to the game, but I do understand the amount of bullet in the groove vs actual length effect of rifling twist. I've done a fair amount of research on .20 caliber twist rates for hide hunting purposes, but not much else. Good just to know from both of you guys it'll handle some of the heavier bullets. A 168 grain bullet in 7mm is no joke. I'm curious what kind of velocity would be likely from the 26" barrel running that weight of bullet. Seems like we figured a 140 should run in the 3000 to 3100 FPS range, but I don't trust my memory that far back.

[bradshaw]

Dec 28, 2022 22:01:28 GMT -5 gunsbam45 said:

Some great info and experience there David. I haven't done any loading for rifles, just big bore revolvers, so would be new to the game, but I do understand the amount of bullet in the groove vs actual length effect of rifling twist. I've done a fair amount of research on .20 caliber twist rates for hide hunting purposes, but not much else. Good just to know from both of you guys it'll handle some of the heavier bullets. A 168 grain bullet in 7mm is no joke. I'm curious what kind of velocity would be likely from the 26" barrel running that weight of bullet. Seems like we figured a 140 should run in the 3000 to 3100 FPS range, but I don't trust my memory that far back.

*****

Hornady 175 Spire Point (pre-Interlock)

* 7mm IHMSA----As 7mm’s on the heavy end go, the Hornady 175 Spire Point stabilized @ 1,800 fps from my XP-100 in factory 14-7/8” bbl with 1:9.25” twist. Factory 7mm BR Remington reamed to 7mm IHMSA. 7mm IHMSA (aka 7mm International) is formed from .300 Savage with long neck and 38-degree shoulder. For rechambering 7mm BR the reamer matches straighter BR body than tapered-case .300 Savage. Dropped into an H-S Precision Fiberthane center-grip stock, my XP 7mm IHMSA happened to be a super-shooter. Last shots fired on eve of departure for International Championship, center-punched a black cardboard chicken, 3x3 = 5/8” @ 200 meters. Hornady 175 SP over 30.8/H4895 stick powder. (Bo-Mar narrow notch rear sight; Redfield Olympic Globe front with .075” post.) Same pistol and load won the Florida Sun Shoot sudden death shootoff with three heart shots through miniature plaster ET dolls @ 200 meters.

* 7mm-08 Remington----Remington 1980 M700 Varmint Special. Bull 24” bbl, hammer forged 1:9.25” twist. Epoxy full float. Hornady 175 SP over 40/Winchester 760 ball powder produces 2,400 fps. (Hodgdon 414 is re-labeled 760.) The old Leupold Vari-X III 6.5-20x AO (Adjustable Objective) steers these bullets into a half-inch or so @ 100 yards. Certainly no more accurate than the above XP-100 7mm IHMSA.

* 7mm-08 Remington----with over 700 clean matches, IHMSA All-American Russell Troup holds the record for perfect scores in handgun silhouette. Troup’s weapon of choice in Unlimited, his Wichita 7mm-08.

* 7x57mm Mauser----original Remington Rolling Block. The Hornady 175 SP gave impressive accuracy from the 30 or 31-inch (?) barrel. Don’t remember my mild charge of IMR or H4895. Rather rough bore, with fast twist, deep rifling. Excellent mild-mannered deer load.
David Bradshaw

[swc123]

David, 2800fps with a 175gr bullet from a 24" barrelled 7mm-08 is a bit optimistic, perhaps 2600fps is more realistic?

[bradshaw]

Dec 29, 2022 10:40:06 GMT -5 swc123 said:

David, 2800fps with a 175gr bullet from a 24" barrelled 7mm-08 is a bit optimistic, perhaps 2600fps is more realistic?

*****

swc123.... thanks for catching that. Actually, my M700 7mm-08 records the Hornady 175 SP a hair over 2,400 fps for the Varmint Special 24" bbl.

The 175 SP @ 2,800 fps is the work of a 7mm Rem Mag, not the 7-08!

In working up XP-100 (14-7/8” bbl, 1:9.25” RH twist) 7mm-08 loads for Sierra, the Oehler chronograph recorded the Sierra 140 SP @ 2,700 fps with a full case of Winchester 748 ball powder. Velocity above other powders and too high to format in the Sierra manual.
David Bradshaw

[bigbrowndog]

A new powder Im Having good success with in 7-08 is Win StaBall 6.5. The Hodgdon site lists very impressive data, and I’m getting 2600fps with a 150ELDX from a 14.5” XP.

Trapr

[x101airborne]

Gunsbam, do you still have the factory barrel? Interested if it is for sale.

Bigbrowndog, That 6.5 Sta-ball is a powder I am looking to get into. From what I have read it could be a big game changer.

[gunsbam45]

Sorry 101, the original mountain contour barrel is gone.

[potatojudge]

I’ve started loading my M77 in 7x57 with 6.5 StaBall powder using 7-08 data

It’s nice to have a rifle powder meter so well

Accuracy has been excellent with 160 partitions. Haven’t chronographed it.

I picked up 8lbs when that’s all that was available and glad I did.

[bigbrowndog]

Yep I’d love to find another 8# for what I gave for the first 8.

Trapr