just wondering how often, in a new rifle, that the max load listed in the manual is too hot? haven't loaded any that high yet, but curious because i want to know when i should be getting worried about pressures. I don't have anybody to show me, except this site and the few manuals i have. never acyaully experienced signs of high pressure, so i'm a little nervous.
how conservative are manuals?
- Thread starter bruno
- Start date
bruno; good to be cautious. Problem is, there are so many variables when one is reloading. [i.e. Barrel groove/bore diameter, chamber dimensions, freebore, throat erosion, bullet diameter, bullet hardness, powder lot burn rate, primer type, case capacity (varies between makers) bullet seating depth] the list goes on. In my personal experience, spanning some 45 years, most manual loads listed as maximum are recorded with a small amount of room for safety. That being said, Certain manuals in the past have listed some very "hot" loads as maximum. Most of the later ones have safety as the primary concern. You cannot assume that your rifle will accept loads beyond those listed as maximum in any given manual. If you do not have a chronograph, buy one. This is the best tool you can have to get some idea of how close you are to a max load in your rifle. I'll give an example: In most 24" barrelled 270 Winchesters, the maximum you can expect to get safely with a 130 grain bullet is about 3100 fps (+-50) If you are checking bullet speed and find that 60 grains of H4831SC is giving you only 2910 fps, you may be able to move up carefully a bit to come closer to that velocity, as long as no other pressure signs are apparent. I measure all my brass at the base with a VERNIER MICROMETER (measures to .0001") If I detect ANY base expansion in addition to the .0005"-.0007" allowed on the first firing of new brass, I consider that load too hot, and back off. Other factors to watch for are: sticky extraction, primers that are very flat, or cases that grow in length a lot each time they are fired. But the chronograph has usually already told me that I am on the warm side by the velocity readings. Again an example: I once inadvertently dumped a powder charge in an R-P 7x57 case that I had worked up in Winchester brass. (the R-P brass has a considerably smaller capacity than WW brass in 7x57). I was chronographing the loads as I shot them from my Ruger #1 SS Rifle. The bullet was the 150 Partition with old Norma 205 powder. Figures read like this: 2790, 2785, 2792, 2779, 2973! Guess which was the R-P case! When I opened the underlever, the primer fell out of the case. I kept the case and the figures as a reminder to watch my cases. Experience is a great thing, but you don't get any without experimenting a bit. The manuals are a guide, but a good guide usually. Seldom in our litigious age, will you find a max load in a manual that is actually too hot. The caution still applies....start lower and work up. I use 6% as the amount to lower a given max for a starting load. It has always worked for me. Hope all this gibberish has helped a bit. Regards, Eagleye.
- Location
- Vancouver Island BC
Eagleye has some words of wisdom there for sure. For example, my 300 Win mag reaches max book velocities 2.5 grains before book max loading is reached. I'm getting 2930 fps with a 190 BTSP Hornady, so I don't worry about getting another 20 fps that the manual states. I have a good accurate load with the velocity I want with no pressure signs.
These loads were worked up slowly, I burned almost a pound of IMR 4831 doing so. Rather be safe than sorry.........
These loads were worked up slowly, I burned almost a pound of IMR 4831 doing so. Rather be safe than sorry.........
- Location
- The Conservative part of Ontario
That's an excellent system, and the one most guys use.
As to the Manuals, Hogdon was quoted as saying that their max loads were really ten percent under.
That said, my Wife has a BLR that shows pressure sign with minimum loads, and is very hard to open if loaded heavier.
The first time I loaded for it, I blew a primer. Very tight chamber.
As to the Manuals, Hogdon was quoted as saying that their max loads were really ten percent under.
That said, my Wife has a BLR that shows pressure sign with minimum loads, and is very hard to open if loaded heavier.
The first time I loaded for it, I blew a primer. Very tight chamber.
Never assume that just because the velocity matches the manual,that the load is safe in your gun.Some guns will not safely reach published book velocities,while others will safely exceed the book velocity.Be aware that identical loads often produce velocities that vary by over 100fps in different manuals,even with identical barrel lengths.
I have found that the newer manuals list milder loads, but not always.
Ultimately, it's your gun (and the sum of the components) that determines the load. Many will accept heavier loads, but sometimes accuracy is sacrificed. I'd much rather have 100fps less and an load that is consistent and accurate year in & year out.
.
I don't load a lot of rifle... So my "words of wisdom" are more just sound advice...
Hot is not all that. Just becuase it doesn't seem that hot... getting a good,safe, accurate load is far more important... Having a blowed up gun and a hot load ain't great...
Ok enough of the same theme... The books are conversative but only becuase they have to be.. The loads will be used as a guideline for 20 hour and 50 year old guns... in new to worn shape. so many different purposes... as well the gun you have may not be the one they worked up the load in so what people say as min load may be too hot for their gun may be true..
I've had sequentially numbered guns on a couple occasions and had one that won't shoot what the other loves... and some that are great with the same load... I have a standard load for 45 but I have one gun that refuses to cycle nicely with it... no matter what I do... I will not put anything then as 12 lb spring in it because the gun will get beaten up.. So work up a load start from mins and work whichever way the gun tells you to go.. look for signs of over pressure, make sure the load is consistent...
Hot is not all that. Just becuase it doesn't seem that hot... getting a good,safe, accurate load is far more important... Having a blowed up gun and a hot load ain't great...
Ok enough of the same theme... The books are conversative but only becuase they have to be.. The loads will be used as a guideline for 20 hour and 50 year old guns... in new to worn shape. so many different purposes... as well the gun you have may not be the one they worked up the load in so what people say as min load may be too hot for their gun may be true..
I've had sequentially numbered guns on a couple occasions and had one that won't shoot what the other loves... and some that are great with the same load... I have a standard load for 45 but I have one gun that refuses to cycle nicely with it... no matter what I do... I will not put anything then as 12 lb spring in it because the gun will get beaten up.. So work up a load start from mins and work whichever way the gun tells you to go.. look for signs of over pressure, make sure the load is consistent...
Aside from dollar savings, the biggest advantage reloading has in my opinion is that you get to design a particular load for your rifle and your application. To me accuracy is far more important than reaching some magical velocity number. Join a dedicated forum of reloaders, ask questions and listen. One of my favourites is:
http://reloaders.gunloads.com/index.php
The guys there have a wealth of knowledge and won't steer you wrong.
Good Luck with your reloading and be safe.
Bob
http://reloaders.gunloads.com/index.php
The guys there have a wealth of knowledge and won't steer you wrong.
Good Luck with your reloading and be safe.
Bob
- Location
- The Conservative part of Ontario
Always value a second opinion on a load, or even a third.
Never load from internet data taken from a forum, such as this one, (But not specifically) without checking it against at least one manual.
Never load from internet data taken from a forum, such as this one, (But not specifically) without checking it against at least one manual.
One of the changes are the ease of wiring a strain gauge set-up to a rifle barrel.You can do it yourself with a laptop and few hundred dollars. So the newer manuals tend to be more accurate in their max pressure then the older methods of measuring copper pellets or brass cases. Also they will set their max according to standards of the agency,the Americian SAAMI or the European CIP.Check out the CIP numbers for the 8x57 JS
Use a chrony ,but be aware there are no fast barrels,but there are slow ones. I had high pressure, low velocity 264WM.
Use a chrony ,but be aware there are no fast barrels,but there are slow ones. I had high pressure, low velocity 264WM.
The books are not conservative. They are accurate - for the rifles they tested in. The problem is that each rifle is quite different. The labs try to make sure that their test rifles are not the big sloppy ones that tolerate lots of powder. Each company has a "library" of many different rifles in each caliber, and they try their loads in all of them before publishing. It is a major undertaking.
At one time in the distant past part of my job decription was testing ammo in the "library" guns. other than shooting 45 acp in the Thompson it was a boring job...
A couple of considerations. Many rifles, especialy quality bolt action rifles will shoot ammo way over the pressure limit without showing pressure signs - until the day the wrong combination of circumstances... For this reason, I suggest you impose a pressure limit of not exceeding the book "max" if you have worked up to that limit with no problems.
The caution about starting low and working up is very real, especally with a new rifle. some rifles develop a lot more pressure than others. I once had occassion to shoot a 6.5 x 55 that blew the primer very, very badly with a "Start" load. The same load was mild in another rifle.
Sometimes I hear shooters (usually hunters) say they made some ammo using the book max, without any work up. This is not a safe approach. The book cannot give you a "safe" load for your rifle. It can only suggest a probable safe range to try. Only you can determine that.
Here is what I do with a brand new rifle. I load 10 rounds, starting with a load under the start load, and load them in 1 grain increments, up to the book max. I label each case with a felt marker. I shoot these across a Chrony, noting the results. Sometimes I have to stop before shooting all 10.
This info gives me a starting point for doing some load development in the velocity range I want.
At one time in the distant past part of my job decription was testing ammo in the "library" guns. other than shooting 45 acp in the Thompson it was a boring job...
A couple of considerations. Many rifles, especialy quality bolt action rifles will shoot ammo way over the pressure limit without showing pressure signs - until the day the wrong combination of circumstances... For this reason, I suggest you impose a pressure limit of not exceeding the book "max" if you have worked up to that limit with no problems.
The caution about starting low and working up is very real, especally with a new rifle. some rifles develop a lot more pressure than others. I once had occassion to shoot a 6.5 x 55 that blew the primer very, very badly with a "Start" load. The same load was mild in another rifle.
Sometimes I hear shooters (usually hunters) say they made some ammo using the book max, without any work up. This is not a safe approach. The book cannot give you a "safe" load for your rifle. It can only suggest a probable safe range to try. Only you can determine that.
Here is what I do with a brand new rifle. I load 10 rounds, starting with a load under the start load, and load them in 1 grain increments, up to the book max. I label each case with a felt marker. I shoot these across a Chrony, noting the results. Sometimes I have to stop before shooting all 10.
This info gives me a starting point for doing some load development in the velocity range I want.
you won't, as every rifle is different, and manufacturers won't tell you due to liability issues- what you will find is a pressure load for a cartridge- esp in the lyman book, and that's in one of their pressure guns- otherwise some fool is going to load it full of powder or something so that it peaks at chamber pressure and the rifle fails, the locking lugs fail, and the bolt comes flying back- question- was it the chamber or the brass that failed-? you'll never know - trust me, the same goes for everybody- start low, work your way up, and when you see pressure signs or reach the maximum, QUIT- chances are your accuracy load isn't up at max levels anyway, which is really the load you want
IF you want to go faster buy a bigger gun. When it comes to reloading the fastest seldom is the bestest. Your eyes and fingers though, and you can always dictate what load was the maximum for your gun plus one grain from the hospital.
Take Care
Bob
Take Care
Bob
the very fact that you don't give us a caliber and refer to it as a "remmy super mag" tells us you haven't done much research- caliber, then designation, as in 338 winchester magnum or remington 7mm ultra magnum
or whatever- if you want more speed and or more power, you have one of 2 things-either stretch the case or shrink the bullet- for instance the 338 win mag is based on the 458 win mag but a 338 diameter bullet-hence, greater speed with a lighter bullet- but you can also reach a point were the velocity causes the bullet to "break up" - ie come apart, shed the jacket, etc
If it's a 7mmRUM,They tend to shy away from the giving data for the 7mmRUM,it was just too hairy.My 264 is tame and well behaved in comparrision.You are likely going to have to wire that rifle. Good luck and wear your safety glasses.
