7mm saum in 7mm rem mag

1899 said:
My book says 4.3gr more capacity for the 7mm Wby, plus it has a 4000 PSI higher operating pressure (65,000 vs 61,000). On paper it gives the Weatherby a fair edge.
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Add in the half inch of free bore on the Weatherby and you see where the extra speed comes from. You could freebore the 7RM and of course load to the same pressure and you likely would not notice a difference worth talking about. If that extra speed is so important, rebarrel and use the 7mm/300 with freebore and polygonal rifling with the extra pressure loads, 140g barnes all copper bullets. Where does it stop? I think just buying a Rem 700 in 7mm ultra would be cheaper. If money is not a concern, then 7mm Ultra with freebore and polygonal rifling loaded with said bullet, you would have a large, hungry 22-250. Have you looked at sabot technology if speed is your only goal?
 
stubblejumper and ROA........I said SLIGHT pressure indicators not high pressure indicators...........meaning flattened primers but no ejector marks......100% safe loads and any load you can get 4-5 loadings from a case is SAFE in that particular rifle. You really need to learn to read your brass...........ROA you may buy your rifles anywhere you choose but a steady diet of loads that even blow primers has no ill effect on the rifle. Our MODERN firearms are capable of withstanding a steady diet of 100,000 psi loads with no ill effects and will withstand pressures in excess of 150,000 psi without catastrophic failure. I have done testing of a 700 action that withstood something in the range of 200,000 psi without setting lugs or stretching threads. I had to remove the barrel to open the bolt and drill the brass from the ejector and replace the ejector assy as well as the extractor but beyond that the action was sound and the headspace did not expand even 1 thou. I did this intentionally and it was done safely, I was just curious how much a 700 action would REALLY take, I did not go beyond this experiment and I rebarreled this rifle to a 264 WM which I still have today and shoot occasionally.
I have said this before here, and will say it again, you cannot hurt a modern rifle as long as we use brass for the containment medium of the pressure to drive the projectile down the barrel. The brass is the weak link by about 300% and until someone comes up with a better medium of holding the powder and containing the pressure required to drive the projectile down the barrel, our firearms are totally safe from damage.
I don't care if you believe me or not but I've been doing this for more than 40 years and have done things that no one in their right mind would do in a normal situation. I've done this in a quest for knowledge and to further my knowledge of internal and external ballistics as well to debunk some of the old wives tales that still plague the firearms and reloading industry, even today.
Loading manuals, even ones that publish so called pressures with loads, are approved by the corporate lawyers before they ever go to print. With the US being the litigious bunch they are, loading manuals are published with both hands over their a$$, and are deemed to be safe with the cheapest and worst piece of junk ever chambered in that caliber. Think about that for a minute............it is fact. SAAMI is bound by the same parameters when determining the max working pressure for a given cartridge. God help the powers that determine these maximums should any rifle ever factory chambered should fail with a SAAMI factory load. What does this say to you? Not all actions and complete rifles are created equal so, all data is rounded down to the weakest action ever made for that cartridge with the mandatory built in safety margin.
So you know what ROA you live and load by what ever ethics and standards that make you comfortable, but I know without a doubt what a 700 or similar action is capable of withstanding because I've actually done it myself and I'm not relying on propaganda for my information. My loads are governed but the limits of the brass case, which when maxed out is still just a fraction of what the action is capable of without any undue damage or wear. One more thing which I have said before and will reiterate again, I've seen more damage to quality rifles from a lack of lube on the locking lugs than I ever have or will from high intensity loads.
 
I only work with pressure vessels and piping every day and have seen them fail for a multitude of reasons, nearly being killed a few times, so what would I know... Anyways, I am not one to take advice from tinkerers and toy makers in this matter.

I would highly recommend for others reading this to keep pressures to reasonably sane levels, I think that most other experienced people would agree.
 
Republic of Alberta said:
I would highly recommend for others reading this to keep pressures to reasonably sane levels, I think that most other experienced people would agree.
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We all know that brass will fail before a rifle action. We all know that an action can take much higher pressure than SAAMI pressures, otherwise guns would be blowing up all the time, and they are not. But who really cares? We have lots of cartridges that can kill anything we want using SAAMI pressures, so why bother with high pressure loads that are running at the edge of brass tolerances? We all want our rifles and ammunition to be reliable, and that's easy to do without risking a sticky bolt at the wrong time, or worse.

There isn't any need to run full throttle all the time, when you can just use a bigger cartridge.
 
Republic of Alberta said:
I only work with pressure vessels and piping every day and have seen them fail for a multitude of reasons, nearly being killed a few times, so what would I know... Anyways, I am not one to take advice from tinkerers and toy makers in this matter.

I would highly recommend for others reading this to keep pressures to reasonably sane levels, I think that most other experienced people would agree.
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No one here is advocating the use of loads that exceed "reasonably sane levels", are you implying that a load which can be used 4-5 times in the same brass case is other than "reasonably sane"? If so, what criteria do you use to determine a "reasonably sane" load?
As far as a "tinkerer and toymaker", young man, I hold three Journeyman Certificates in my area of expertize as well as a commercial Pilots license and have been doing gunsmithing for nearly 40 years, "tinkerer and toymaker indeed". I have learned from some very accomplished and respected gunsmiths, one of whom spent months learning his talents from none other than PO Ackley. One more thing ROA that you must keep in mind, rifles aren't built by welders or the lowest bidder, unlike your pressure vessels and piping.
"I think most other experienced people would agree"............really? So you are saying you are more experienced than I, at this game? I'd be interested in reading your internal and external ballistics research and gunsmithing resume. How many cartridges have you designed, had reamers made for, and actually built and developed loads for? How many barrel blanks have you drilled, reamed, rifled and contoured? How many varied forms of powder ignition have you experimented with? How many duplex powder loads have you tested? How many 2 and 3 mix powder loads have you experimented with? Every single "EXPERIENCED" person I know says that if you can get 4-5 reloads from a case the load is safe, and in fact Bob Hagel, who has published books on just this matter, says that he gets 3 loads from a single case and deems this absolutely acceptable. Which makes me curious as to just where you get your wealth of experience and opinions from, the internet?
May I suggest that before you deem yourself qualified to advise other people as to the intricacies of wildcatting and acceptable pressure loads you may need to do a little more research and practical experience yourself !!!!!
 
Easy girls!
I dont think it's a good idea to get too far into discussing advanced or extreme handloading in this forum. We always assume we are above average intelligence, but that still leaves those that are willing to take risks without understanding what they are doing or the consequences of a mistake. I have had hot 338 loads that used the cases 6-8 times with no issues. I have had 270wby loads that left primer pockets loose with no other signs of pressure on the first loading. I have ha a 300win load that worked well in cold conditions but left sticky bolt in summer weather. I have had pressure spikes with nothing more than a switch to magnum primers.
I am no expert but better safe than sorry.
 
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snoopycda said:
Easy girls!
I dont think it's a good idea to get too far into discussing advanced or extreme handloading in this forum. We always assume we are above average intelligence, but that still leaves those that are willing to take risks without understanding what they are doing or the consequences of a mistake. I have had hot 338 loads that used the cases 6-8 times with no issues. I have had 270wby loads that left primer pockets loose with no other signs of pressure on the first loading. I have ha a 300win load that worked well in cold conditions but left sticky bolt in summer weather. I have had pressure spikes with nothing more than a switch to magnum primers.
I am no expert but better safe than sorry.
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This. c-fbmi, you clearly have enough experience that you should know better than to speak of subjecting rifles to 200,000psi on a forum like this. I just think statements like that could cause inexperienced reloaders to quit giving reloading the respect it deserves because they hear people say they are operating with a 500% safety margin. I agree with the fact that we can let the case tell us when the load is maxed out and that using signs like flat primers, primer cratering, sticky bolt lift will keep us within the safe margins of reloading, plus why would anyone want to shoot a rifle that sticks the bolt or pierces primers?

To the OP, the 7RM has pretty good ballistic potential, I'm still not clear on why you need more from it. If you want to go long range then you could switch to something like a 7saum, not for velocity but for barrel life so you can practice more. If you've found something that you can't seem to knock down with it then you should get into a .338 or bigger projectile.
 
ROA.........what I do for my own personal knowledge is for me to decide, what you will never see in this forum or any other is me posting a powder charge..........I will name powder, case, cartridge, primer and bullet but NEVER a charge weight. That is for each individual to work up responsibly in his or her own rifle to their own limits and comfort levels. I advocate safe reloading and following proper protocols when loading at all times, and always have, and for you to imply otherwise is just ridiculous.
What irks me is when I post my findings for a wildcat, which I have built and worked up loads for, only to be ridiculed by the likes of you. You did the same thing, quite nastily, on my thread regarding the 9.3 X 300 WM and now here you are again, berating me for posting my findings, after extensive load development, for the 7mm X 300 WM. Have you even seen a rifle in either one of these cartridges, or are you just relying on your vast inexperience to question my findings?
As with any scientific experiment I don't go into these projects with any preconceived notions, I work with powders that have been known to work well given the case capacity to bore ratio and appropriate bullets. I make up test loads starting at a conservative level and work up charges with no more than a 2% increase per step and then I shoot them through the best chronographs on the market. Not one Oehler 35P but 2 of them, all the while keeping my ammo at 25 deg C so there are no summer surprizes. My maximum loads must allow me to use my cases multiple times. After doing all this, I may share this experience with someone who asks, as in this case. Only to get jumped on and berated by people like you, whom I doubt have even seen a rifle in 7mm X 300 WM let alone built one and done extensive load development for one.
Lastly, ROC, I have no problem showing how my mind works, thanks!!!! After more than 40 years of wildcatting and load development I have all 10 digits and both eyes and not one scar that is in any way related to my experiments or load development.

To 07blackwater, I would respond why not? With that mentality we would all still be shooting 30-30s and 45-70s. Why the 30-378 Wby..........'cause someone wanted to make a 180 gn 30 cal bullet go faster than 2700 fps, why the 220 Swift....'cause someone wanted to make a 22 cal bullet go faster than what the hornet would provide in the day. Without the desire to try new things or make bullets go faster the entire field of ballistics would wither and die and I'm afraid our sport with it.
 
cdn shooter.....Although I would possibly agree with the questionability of mentioning that here on this forum, this information is out there in print several times by several people . PO Ackley, in his books relates his experiences in researching the catastrophic failure point of several actions. My intent would never be for loaders to lose respect for the power they release when they pull a trigger but more to show we are so limited by the brass case that our rifles are very safe when loading practices allow the multiple use of this brass case.
 
Something as simple as going to a bullet with a higher BC can dramatically change your downrange performance.....
 
If someone feels that it is a smart idea to load their firearm to 100,000psi, more power to them, as long as they aren't doing it near me. I have an engineering background, where I studied applied mechanics , statics,dynamics, fluid mechanics, as well as metallurgy courses, and I also hold two trades tickets. In my studies , and on the job, I have seen first hand what happens when something lets go due to metal fatigue, and I will not tempt fate by repeatedly exposing a firearm to chamber pressures well in excess of what it is designed to be used at, when I am holding it next to my face.
 
Neilm said:
If you want more than the 7RM take a look at the 7mm Dakota.
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This.

I actually looked at doing this on a dumoulin that was chambered in 7 RM. It can be done if you are interested, with a bit of work to the bolt face by a good gunsmith.

I thought the cost was unjustified given the small difference in performance. I am certain no animal would ever know the difference.
 
OK, I am not asking this to preach to anybody, just asking. If you look at back thrust, say of a .300 Win Mag at 61,000 PSI you get - .156 sq.in (inside case area) x 61,000 PSI = 9516 lbs. Increase the pressure to 75,000 PSI and you get 11,700 lbs of back thrust. How much surface area of the bolt lugs are in contact with the receiver? What is the Rockwell Hardness on the action and bolt? And given that, what is the yield strength? And forget even about yield strength, what about the pressure required for lug set-back?

Maybe one of you can explain the findings from this write-up:
http://www.varmintal.net/abolt.htm
 
If something can't be done with a 162 Amax at 3100 fps then it can't be done.

That said a 7SAUM in a short action is a handy tool to have. Zinging 162s at 2950.
 
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