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hhunter318
April 26, 2012, 12:46 PM
So what's the largest caliber you would feel comfortable chambering to a Win. Model 70 Action? Safari load or crazy big bore wildcat, anything. Even something big enough that it has to be single loaded.

mrawesome22
April 26, 2012, 02:40 PM
Modern cartridges are loaded to a certain MAP measured in PSI or CUP.

A huge cartridge that fires a giant projectile could quite possibly have a lower MAP spec (maximum average pressure) than a much smaller cartridge firing a tiny projectile.

You'd just have to look up the tested failing PSI of a M70 action.

I know the M700 action has been tested to beyond 200k PSI and no modern cartridge that would fit in the action even comes close to reaching that MAP. Most are in the 50-70k PSI range.

I imagine the M70 action is close, if not stronger.

EDIT: In other words, just because there is more recoil, doesn't necessarily mean the pressure generated is higher.

Heavier projectile equals more recoil. Take a 12gauge slug for example. Huge 1oz. slug (437.5gr), generating lots of recoil, but MAP is only around 10k PSI.

kraigwy
April 26, 2012, 04:28 PM
I have several Model 70s, from 243 to 375 H&H.

I also have a 1000 yard rifle I built on a Model 70. It's a 300 WM and a single shot.

The Model 70 will handle what ever you choose to use unless you get stupid with reloading.

But its not the size that determines strenght, but the round itself.

For example, the 243 Win pressures are in the 58K range, the 375 H&H are in the 52K range. The 458 WM is also in the 52K range.

My 270 Win has more pressure then my '06, both are Winchesters.

Beter example: I have a Model 70 in 243, and a Model 70 in 257 Roberts. Compare the 243 Win using a 100 grn bullet, its in the 57-58K range. The 257 Roberts, using a 100 grn bullet is in the 42-43k range, both have about the same velocity, the 257 uses more powder (assuming you're using the same powder).

There is a lot more to pressure then the size of the bullet, but as to the Model 70 action it will take anything any other normal action will take.

PetahW
April 27, 2012, 09:21 AM
Since the Model 70 is based on the 1903 Springfield, a Mauser 98 derivation itself, it's unsupported case head will determine it's limitations - which would be somewhat lower than an action that features a fully wrapped/supported casehead, like the Model 700's "Three rings of steel" wrapping the case head (bolt face/lip, barrel hood, receiver ring).

(I'm NOT espousing the Rem 700, here - just using it as an example)

.

Scorch
April 27, 2012, 11:41 AM
To answer the original question, the largest cartridge I have seen a Model 70 chambered for is 416 Rigby.

kraigwy
April 27, 2012, 11:46 AM
the largest cartridge I have seen a Model 70 chambered for is 416 Rigby

How did they do that? I didn't know Winchester made an action long enough for the Rigby round.

The 416 Rigby is a low pressure round, The Model 70 will take the pressure no problem, but I didn't know they had a Model 70 long enough.

I had to make my 416 Rigby on a Remington 1917 Enfield action.

Scorch
April 27, 2012, 02:07 PM
How did they do that?
Modify the bolt stop, lengthen the magazine box forward and to the rear, open the feed rails. The magazine holds 2 rounds. Opening the bolt face leaves a very thin ring of metal at the top of the bolt (pre-64 action).

kraigwy
April 27, 2012, 02:23 PM
Dern, now if I only had one more Model 70 action.

Greyhorse
April 27, 2012, 05:37 PM
The following paragraph was copied from ..... http://www.ogca.com/WRM_collecting_winchester_pre.htm

The pre-64 Model 70 Winchesters were produced in 18 catalogued calibers as follows: .22 Hornet, .220 Swift, .243 Winchester, .250 Savage, .257 Roberts, .264 Winchester Magnum, .270 Winchester, 7X57MM, .300 Savage, .308 Winchester, .30-06, .300 Winchester Magnum, .35 Remington, .358 Winchester, .375 H&H Magnum, and .458 Winchester Magnum. Also, a very few were produced in 7.65MM and 9X57 MM prior to World War II in an attempt to lure foreign market.

RaySendero
April 28, 2012, 07:49 PM
Greyhorse wrote:

The pre-64 Model 70 Winchesters were produced in 18 catalogued calibers as follows: .22 Hornet, .220 Swift, .243 Winchester, .250 Savage, .257 Roberts, .264 Winchester Magnum, .270 Winchester, 7X57MM, .300 Savage, .308 Winchester, .30-06, .300 Winchester Magnum, .35 Remington, .358 Winchester, .375 H&H Magnum, and .458 Winchester Magnum. Also, a very few were produced in 7.65MM and 9X57 MM prior to World War II in an attempt to lure foreign market.

Did the 375HH fit the same action length as the others?

Scorch
April 29, 2012, 02:15 AM
Did the 375HH fit the same action length as the others?
Yes. Model 70s were designed and introduced to give American buyers the option of 300 H&H and 375 H&H without going to a magnum Mauser action, which at the time cost as much as a new car (about the same as now, actually).

RaySendero
April 29, 2012, 11:29 AM
So:
1) All those cartridges in the above list use just the one size action?
2) How many different bolt sizes were there?

longfellow
April 30, 2012, 01:30 PM
Don't forget the larger bolt face of the magnums (and however many other face diamteres there are out there). It is about 42% larger so when that pressure that folks say is all you need to think about, is converted to force, you have almost fifty percent MORE force applied to the bolt face if it is comming from a magnum cartridge.
Then I'd look at sheer forces, the sizes of radii to accurately apply stress concentration factors and moment dimensions, and alloys and heat treatments. Which action is stronger? We have no clue.

Winchester_73
April 30, 2012, 03:31 PM
The following paragraph was copied from ..... http://www.ogca.com/WRM_collecting_winchester_pre.htm

The pre-64 Model 70 Winchesters were produced in 18 catalogued calibers as follows: .22 Hornet, .220 Swift, .243 Winchester, .250 Savage, .257 Roberts, .264 Winchester Magnum, .270 Winchester, 7X57MM, .300 Savage, .308 Winchester, .30-06, .300 Winchester Magnum, .35 Remington, .358 Winchester, .375 H&H Magnum, and .458 Winchester Magnum. Also, a very few were produced in 7.65MM and 9X57 MM prior to World War II in an attempt to lure foreign market.

Don't forget the 300 H&H and the 338 win mag!

WildBill45
April 30, 2012, 04:38 PM
They make them now for .458 Win. and Remington .416 I believe....

http://www.winchesterguns.com/products/catalog/detail.asp?family=001C&mid=535116

RaySendero
April 30, 2012, 09:45 PM
longfellow wrote:

Don't forget the larger bolt face of the magnums (and however many other face diamteres there are out there).



Well...I was hopeing someone knew and would jump right in with the answer.

LOL - Now I have to count! :(

I count 4:

1) 0.532" all those with "magnum" in name

2) 0.473" all the rest from 220 Swift through to the 358 Win including the 7.65 and the 9x57 Mausers

3) Except the 35 Rem and

3) That 22 hornet :confused: - Surely it wasn't produced on a std long action!?

Bart B.
May 4, 2012, 06:26 AM
Note the H&H magnum pre-'64 Win. 70's had an extra long magazine port to handle the longer cartridges but the action length overall was the same. I had one in .300 H&H that Roy Weatherby's shop rechambered to .300 Weatherby Magnum. For short cartridges such as the .308 Win. and even the .22 Hornet, a spacer at the back of the magazine was used as well as the bolt stop and ejector were longer so when the bolt was opened and pulled back, it would stop just behind the case head.

Winchester built for a special contract twenty pre-'64 actions for the .300 H&H Magnum without the magazine port; they were solid bottom receivers except for the ejector slot. All were sold to the US Army Marksmanship Unit in the 1950's for use in their 1000 yard match rifles chambered for that H&H round. I've seen a few of them and they are really heavy. They were said to have special heat treatment making them 20% stronger than the standard commercial version.

Some years ago, I read an article comparing the Win. 70 to the Rem 700 for strength. It said the Win. 70 receiver and bolt were good for pressures up to 120,000 CUP (165,000 PSI) and the Rem 700's were rated at 140,000 CUP (195,000 PSI). But cartridge brass is good for only 65,000 CUP (81,000 PSI) before it stretches past its elasticity limit.

thallub
May 4, 2012, 07:28 AM
Since the Model 70 is based on the 1903 Springfield, a Mauser 98 derivation itself, it's unsupported case head will determine it's limitations - which would be somewhat lower than an action that features a fully wrapped/supported casehead, like the Model 700's "Three rings of steel" wrapping the case head (bolt face/lip, barrel hood, receiver ring).

Good post.
i was the left handed guy sitting at a shooting bench when the right hander at the bench on my right had a .270 case head separate. The follower, spring and floorplate were blown out of the gun, the stock was splintered and the receiver cracked. The guys face was badly peppered; his hand, forearm and wrist were lacerated.

Presently i own seven pre-64 Winchester model 70 rifles. My cases are carefully inspected when reloading ammo for those guns.

Bart B.
May 4, 2012, 07:36 AM
I've seen two Rem. 700 actions that held a ruptured case head. They held most of the brass case head parts but none of the gas.

I'll bet two bucks that .270 case that ruptured in an M70 had already got partial head separation from improperly sized cases and/or way too hot of loads. It would have blown in a R700, too, but little brass would have left.

thallub
May 4, 2012, 09:14 AM
i was pretty lucky that day. All the right hand positions were taken when the owner of that model 70 showed up. He asked if it was ok to shoot my bench and i told him yes. There was a cease fire to check targets: The shooter at the bench on my right picked up his gun and gear and left the range. The model 70 shooter moved to the vacated bench.

If the shooter had been at my bench i would gotten sprayed with high pressure gas and brass particles and may have gotten hit with the extractor which was never found.

Clark
May 4, 2012, 11:36 PM
Modern bolt actions get some changes to the bolt when I get a belted magnum up to around 107kpsi.

Worked up slowly, the trouble can be lapped out, and the rifle is still good.

I buy dozens of guns to overload per year, but I actually only wreck a few.