Pressure tolerances, pump vs. lever

jaysouth

New member
I assume that most published loads for .35 Remington contemplate use in a lever action carbine.

Can the Remington 760 handle more pressure. An academic question to be sure because my best performing .35 Rem load is a cast bullet at far below max pressure and velocity.

But who knows, I might need a max load to take on feral elephants or mastadons digging up my flower beds.
 
The Browning BLR lever rifle will handle more pressure than any pump that is now on the market.

The one pump that could match the BLR in this area was the BPR, a pump version of the BAR that is no longer in production.

All made by Browning.
 
I would use the most caution for earlier offerings such as Rem's Model 8 auto and Model 14 pump. Both Marlin's (relatively) modern levers and Rem's modern pumps handle much hotter rounds than the 35 Rem. For either I'd use the normal caution working up to published max... then feel safe...
 
Can the Remington 760 handle more pressure.

I tend to think they would be about the same. I sold off my Remington 7600 so I can not review the method it locked up the bolt. But my rifle was in 30-06 so I tend to think it might be able to.

But, and this is a big BUT. I am not sure if Remington built in greater pressure tolerances in their 760 & 7600 series rifles. I think the factory might be able to answer your question better. I do own, use and reload for a Marlin 336 in 35 Remington but I would never go over Max published loads for it. I am just not that adventurous. (LOL)

Good luck and stay safe.
Jim
 
all rifles can be blown up with the right or wrong loads, whats more important is how they handle the hot gases. the remington 760-7600 series will channel the gases down and will not allow the gases to get to the shooters face and i think the browning pump would do the same, the only lever actions i think would do the same thing is thw winchester 88 and sako finnwolf that i can think of off hand. any lever action with the bolt comming out the rear of the reciever will let gases from a blow up back. how many here have been stung with gases from a blown primer in a bolt action and i think with a blow up alot of gases with be flowing rear wards in a hurry. eastbank.
 
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The Rem 760/7600's bolt has rotating locking lugs which can contain more pressure than most (non-BLR) leverguns.

The problem with that is that the 760/etc don't have enough extraction camming power to handle the removal of cartridge cases that were fired with pressures too high.

FWIW, there's more than a few folks out there, who've tried, and ended up trying to hammer out the empties.


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The problem with the rotary bolt pumps like the Remington, and the rotary bolt levers like the browning and the old Win 88 are not weakness. They are plenty strong. The problem is lack of cam leverage for primary extraction.
You see, when you use hotter loads the extraction can be harder to start.

A bolt action has a great deal of mechanical advantage to start that extraction whereas most other actions do not.

So a pump or lever can take hotter loads safely, but function may be impaired even though it’s safe to fire them without fear of the gun “blowing up”
 
PetahW pretty much nailed it.

You see, there is pressure, and there is pressure. The Rem series pump and autoloaders, the Browning BLR, and a few other front locking designs will handle a higher pressure than the "traditional" rear locking designs like the old Winchesters/Marlins, etc.

But in this case, "handle more pressure" means that the actions will take a higher pressure before stretching, or blowing up. It does not mean the guns will work properly with higher than standard pressure rounds.

Modern brass (in a properly supported chamber) doesn't let go until well above the max working pressure for ALL cartridges. Somewhere well above 60K psi if I remember right.

Well before you get to that point, cases swell and stick in the chamber. And it is at this point that the pump, lever and semis have troubles, compared to the bolt gun.

There are two phases to extracting fired cases. The first phase (Primary extraction) is pulling the fired case away from the chamber walls. The second phase is pulling it out of the chamber so it can be ejected.

With normal pressure loads, the brass springs back from the chamber walls a tiny bit, allowing normal extraction. Primary extraction normally occurs when the camming action of the bolt head unlocking moves the bolt head back slightly, pulling the fired case with it. This breaks the remaining grip of the case on the chamber, and allows it to be easily withdrawn, then ejected.

Now, when you shoot an overpressure load (above proper working pressure, but still well below the level at which the case, or the gun might let go), the brass is, in effect, hammer welded into the chamber. While the case still springs back away from the steel slightly, due to the high pressure, it is still gripping the chamber much more tightly than it should.

The mechanical force needed to rotate the bolt head is increased, when this happens. Lever, pump, and semis all rely on mechanical force inline with the bore, a portion of which is being converted to perpendicular rotational force to unlock, and the rest of it to move the bolt to the real after it unlocks.

A bolt action, with a large bolt handle, perpendicular to the bore allows the shooter to exert a LOT more rotational force on the bolt than the other designs, overcoming the increased adhesion of brass swollen from too high pressure. And, of course, there is a point where too much pressure will defeat even the bolt action's ability to extract the fired case.

This is why, when you are working for the ablsoute maximum pressure ammo usable, the bolt gun has an edge over other designs. Note that here we are talking about above standard pressures, but well below the pressure range where damage to the gun could result.

The standard "max" pressures, including "max loads" in reloading data is that pressure level which 1) is inline with industry standards for the cartridge, AND provides normal working function for the gun.

Individual gun tolerances being a variable, listed max loads are below the point of extraction trouble (or any other trouble) in the test guns. So they should be safe and work properly in all guns, BUT may not be. Highly unlikely to blow up any gun in sound mechanical condition, but very likely to cause functioning issues. That's why one ALWAYS starts low, and works up in small steps until the max for your particular gun & ammo combination is reached (if you go that far).

A hot load that functions fine in one gun might be too hot, and give sticky extraction in another. Even identical models of guns can have variations in how much pressure they will take before giving extraction troubles.

The standard pressure signs used by reloaders (flattened primers, cratered primers, expanded case heads, etc) can all occur at different points in different guns. Sometimes some of these occur in a particular gun below max working pressure, because of the tolerances of the gun, AND the ammo (particularly the brass case).

Some guns and ammo combinations can reach, and even exceed the listed "max" levels without showing any of the usual pressure signs. That is why the listed loads, and fired case pressure signs are all guidelines, not rules or laws. Arrrr!(pirate voice)

There is one pressure sign that absolutely should never be ignored, and that is sticky extraction. And sticky extraction can happen at a point below listed max levels, if the combination of brass, load and gun that YOU are using line up just right. Some lots of brass are softer than others. This means they are prone to stick at lower pressure than "harder" cases would. Again, this is why the max listed loads are guidelines.

No matter what pressure it happens at in your gun (and it can vary with different batches of ammo), when you get sticky extraction, STOP. DO NOT INCREASE the load any further. BE a good idea to back off a bit from that point, too.

If it takes noticeably more force to work the pump on your 760, you're done. Not matter what pressure level you are at, at that point, tis time to stop, and back off slightly. If you want, or need more, tis time to go to a different cartridge.
 
Remington factory ammo should be serviceable in any clean MDL 760-7600. I fired a friends in 30-06 and it functioned flawlessly and was very accurate also, he had trigger work done, and Wow!

I reloaded for BAR, 300WM, and used small base dies, which may still be available from RCBS, made for just this problem, RCBS also published separate load data for high pressure centerfire, such as BLR, Rem pumps and semi's, and BARs. All the 300WM loads that I did functioned fine and for 1977 were adequately accurate.

These rifles should be fine at factory pressures, but have to be reloaded to pressures slightly lower than pressures endured by most modern bolt action rifles.

Also, I have heard, but no experience of, that small base dies stress the brass in resizing it to a smaller diameter, more than conventional dies, and possibly reduce case life.
 
that small base dies stress the brass in resizing it to a smaller diameter, more than conventional dies, and possibly reduce case life.

Brass work hardens. Like most metals. The more it is worked (stretched, compressed) the harder it gets, until it cracks. With cases, pressure from firing works them one way, resizing works them the other way. Annealing extends the life by returning the brass to a softer state.

But you don't anneal case heads, those need to be "hard" compared to the rest of the case. Small base dies work the case more than standard dies, but the question really is, does it make a practical difference in the case life?

OR are the other factors (and there are several) going to override the effect of small base dies vs standard, on case life? Personally, I don't have anything that needs small base dies to work, but even if I did, I think that one or two fewer loads in case life is an acceptable trade for ammo that feeds and functions in a specific rifle. Just my opinion, and worth what you paid for it.;)
 
The lack of cam action works two ways. I was at a range one day and a guy next to me was sighting in a new rifle. He told me his 760 had let him down the year before and he got rid of it. He went to shoot at a deer and the bolt was not fully locked and it would not fire. He then proceeded to tell me that he had just taken up reloading and was neck sizing his loads. I asked if he neck sized for the 760 and he said yes. It was obvious to me the bolt was not able to seat the cartridge.
 
Let me restate my question:

If I load a .35 rem to max for a Marlin 336, how much higher can I load it for a Remington 760?

Or,

If I load a 200 gr. bullet to 2,000 fps for my 336, can I load the same bullet in the same case to 2,400 for the Remington pump?
 
jaysouth said:
Let me restate my question:

If I load a .35 rem to max for a Marlin 336, how much higher can I load it for a Remington 760?


Not much, if at all - the best practice would be to work up a load for the 760 in small increments until either high-pressure indicators (like flat primers, etc) arise, or when fired case extraction becomes unattainable via manipulating the slide handle normally.

Each gun is a story unto itself, especially when handloading.


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My answer to the 2,000 FPS in a Marlin vs 2400 FPS in a Rem pump is this.... just buy a BLR in .358 instead of the 760. If you already own a 760, have it rechambered to .358. Simple as that. :D

Or, if you want to walk on the dark side.....have your .35 Rem rechamberd to the fine .356 Win. I own two 336ERs and they are GREAT rifles! Your 336 so rechambered becomes, for all intents and purposes, a 336ER.
 
You won't find a 2400 FPS .35 Rem. load in any reloading manual ! So I guess you'd be on your own . I get a kick out of questions , such as yours . Are you really a reloader , your question would indicate that you aren't ? Or you're a very inexperienced one !
 
My answer to the 2,000 FPS in a Marlin vs 2400 FPS in a Rem pump is this.... just buy a BLR in .358 instead of the 760. If you already own a 760, have it rechambered to .358. Simple as that.

Or, if you want to walk on the dark side.....have your .35 Rem rechamberd to the fine .356 Win. I own two 336ERs and they are GREAT rifles! Your 336 so rechambered becomes, for all intents and purposes, a 336ER.

No its not as simple as that. The 760 in 35 remington is cut for a .460 case head on the bolt face and the .358 winchester has a .473 bolt face. This may cause a problem readjusting the extractor and the ejector.

One other problem with the 35 remington is that it is almost a straight sided case and works best with faster burning powders. and it doesn't have the case capacity to hold enough extra powder for a meaningful increase in velocity. I would never advise anyone to exceed the load data in a reloading manual.
 
oldsap said "You won't find a 2400 FPS .35 Rem. load in any reloading manual ! So I guess you'd be on your own . I get a kick out of questions , such as yours . Are you really a reloader , your question would indicate that you aren't ? Or you're a very inexperienced one"

Oldsap, I have been reloading in a very safe and responsible manner for 50 years. I pose a simple question about which gun will take higher pressures and you insult me. I am trying to illustrate my question with a hypothetical and you attack me.

The 760 Remington that is chambered for .35 Remington is exactly the same frame that is chambered for .30-06 and .35 Whelan. I know it is a stronger action than a Marlin and I am trying to get some idea of proportionality.

Sorry I offended you.
 
I learned the hard way to not "push" the Marlin 45-70 lever action. The action opened on firing. It did not feel too good on my fingers and knuckles.:) I am thankful I did not get hit in the face with the bolt. I still cant figure out why it did not hit me.
 
@ratshooter:
"Quote:
My answer to the 2,000 FPS in a Marlin vs 2400 FPS in a Rem pump is this.... just buy a BLR in .358 instead of the 760. If you already own a 760, have it rechambered to .358. Simple as that.

Or, if you want to walk on the dark side.....have your .35 Rem rechamberd to the fine .356 Win. I own two 336ERs and they are GREAT rifles! Your 336 so rechambered becomes, for all intents and purposes, a 336ER.

No its not as simple as that. The 760 in 35 remington is cut for a .460 case head on the bolt face and the .358 winchester has a .473 bolt face. This may cause a problem readjusting the extractor and the ejector.

One other problem with the 35 remington is that it is almost a straight sided case and works best with faster burning powders. and it doesn't have the case capacity to hold enough extra powder for a meaningful increase in velocity. I would never advise anyone to exceed the load data in a reloading manual.


Ratshooter, I have a 7600P in .308 with 16.5 inch barrel. In the woods with limited ranges, this is THE deer gun. I also have 760 Carbine in .308, which was a very limited run. For about $350, I can have either of them rebored to .358, which is a great cartridge especially for cast bullets. However, I cannot justify the cost versus the increased functionality for hunting deer where I hunt. If I were going to go West and hunt bigger game, I would consider it. However, from my deer stand, a .308 is too much gun. Whether shooting a 30-30 or 308 or 30-06, my 'deer' load is a 165 cast bullet with a big meplat launched at 1700 fps. At 25-50 yards, it kills whitetails like a lightning bolt.
 
Ratshooter, I have a 7600P in .308 with 16.5 inch barrel. In the woods with limited ranges, this is THE deer gun. I also have 760 Carbine in .308, which was a very limited run. For about $350, I can have either of them rebored to .358, which is a great cartridge especially for cast bullets. However, I cannot justify the cost versus the increased functionality for hunting deer where I hunt. If I were going to go West and hunt bigger game, I would consider it. However, from my deer stand, a .308 is too much gun. Whether shooting a 30-30 or 308 or 30-06, my 'deer' load is a 165 cast bullet with a big meplat launched at 1700 fps. At 25-50 yards, it kills whitetails like a lightning bolt.

I guess I don't get it. You are killing deer at 50 yards with a cast bullet load and doing a good job of it. But you might want to rechamber your gun to a 358 for hunting in the west where the ranges are long?

The 358 is not a long range round. Your 308 would do just as well if not better. Especially if it had a longer barrel. If you go west consider a new gun in a better round. If you are hunting elk start with a 30-06 and go up from there. Even a 270 is is a good elk round with premium bullets. A 7mag is a superb round. And the couple I have shot didn't seem any worse for recoil than a 30-06. Cartridges don't kill game. Bullets do. And the world is full of good bullets.
 
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