The "pet" loads you are referencing might be safe loads in the rifle for which they were developed - you cannot "assume" they will be safe in your rifle. You need to work up your load, not start at a point that is over the published maximum. You aren't quite ready to load for your .308 until you understand that principle.
Pet Loads Over Maximum Load Recommendation
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The "pet" loads you are referencing might be safe loads in the rifle for which they were developed - you cannot "assume" they will be safe in your rifle. You need to work up your load, not start at a point that is over the published maximum. You aren't quite ready to load for your .308 until you understand that principle.
Maybe I start to flinch or something? When I'm developing loads I generally go 1gr below max and work my way up in .2gr increments to the max (Hodgdon's) and then go up to .5gr over max to see what that is like. 3-5 rounds for each load tested at 100 for accuracy.
I just did some load testing of 300gr TSXs in my 375 H&H using from 64.0-71.5gr H4895. Book says about 61-67gr. Most accurate loading was 69.0gr. So really as long as your not going over pressure the load is whatever the heck your rifle likes. A safe load is whatever doesn't overpressure YOUR rifle as every gun has different chamber and bore tolerances.
Really just start with the book data and if it doesn't work out for you consider going higher. If you do make sure to check for pressure signs on EVERY shot. If you see them, start to think of stopping and pulling the rest of your cartridges apart.
Really just start with the book data and if it doesn't work out for you consider going higher. If you do make sure to check for pressure signs on EVERY shot. If you see them, start to think of stopping and pulling the rest of your cartridges apart.
Max loads are a tricky thing, every rifle has a different maximum load. I`ve seen factory loads in a 22-250 the locked up the bolt. also some time ago saw some 30-06 factory stuff that blew primers. I start at a reasonable rate and work up to my rifles max load, remember that loads worked up in the colder temps of fall or winter can be over the safe range in the hotter temps.
You got it. Go higher and the bolt will stick.
As has often been pointed out, rifles are not all the same. I have had two 243 bolt rifles, where one could easily take a certain load and was very accurate with it, while the other 243 would stick the bolt on those loads.
The exact same was with two 30-06 rifles I once had.
The point is, keep loading heavier and eventually the bolt will stick. This is perfectly normal and is the first real, certain clue that the load used was too heavy for that rifle.
The loads that stick the bolt will likely expand the primer chambers also, but a fairly light sticking bolt will not likely expand a pocket on the first shot. It will take several such loads to ruin the case by expanding the pocket until a new primer goes in too easily.
If a single load will expand the primer pocket beyond further use, that load is in the extreme danger area.
Remember this rule well: 5% more velocity means roughly 10% higher pressure!
For example:
308 Win 175gr SMK 2600fps at 58000 PSI
308 Win 168gr SMK 2730fps at 63800 PSI
The only real advantage of hot load is that many powders burn more uniformly at 60000+ PSI, so a hot load is often a more accurate load.
Alex
For example:
308 Win 175gr SMK 2600fps at 58000 PSI
308 Win 168gr SMK 2730fps at 63800 PSI
The only real advantage of hot load is that many powders burn more uniformly at 60000+ PSI, so a hot load is often a more accurate load.
Alex
Not a dumb question.
Being a handloader, you have already taken personal responsibility for your own decisions.
It comes down to willingness to experiment, and common sense .... do you feel you have enough knowledge of the symptoms of high pressure?, and also the ways of measuring how close to absolute max, in that particular firearm, you currently are?.
My approach(and not suggesting that it's the best, or the only way to do it).
- Begin with a good supply of components from the same lot, 'specially powder. Stay within those lots for the entire work up.
- Stay with the same brand primers (they react to pressure differently, one from another, eg: Federal flattens more than CCI.)
- use only previously fireformed, neck sized brass. Zero headspace.
- change nothing but the powder charge from one load to the next.(I go up in .2 of a grain increments, weighed out on two different scales.)
- Keep meticulous and detailed records.
- Max-handload only when you're stone cold sober, and in the unharried mood to take your time and concentrate, ... allow no distractions/interuptions.
To measure relative pressure:
- Case head expansion. My favorite. Done by measuring the web of a case, just above the extractor groove, before and after firing, with a blade micrometer.
My personal cut-off point is .0002"(two tenths of a thou.) expansion.
Much more than that .... you'll likely be tossing that brass pretty soon when the primer pockets go slack.
Different brass brands will measure to different specs, at similar pressures.
I mostly use Lapua.
- Case stretch. When the previously fireformed case grows in length by 2 - 3 thou. or more(measured after neck sizing) ... the pressure is getting up there, ... it's time to back off.
I've seen 12 thou. happen when way 'over the top'. Not recommended.
- Bolt lift. When drag gets noticable, or more than how factory loads normally feel .... back off. Maybe switch to a slower powder, if you want to go even faster.
- Primer appearance. This can be tricky. Not a reliable indicator if any headspace is present.
Assuming fireformed, necksized, zero headspace cases .... when half of the radius disappears, or the firing pin indent starts to go away, it's time to back off, IMO.
When the above 4 parameters are used in concert, one indicator overlaying the other, some sense of where one is at, pressure wise, may become apparent.
This is the internet, plenty of B.S. out there. The above is personal opinion.
I claim no authority on this topic.
It was after reading H4831's posts a few years ago that I first started looking for loads above max. It was also suggested to me by a lady shooter with much more experience reloading than me. Typically, if I find an accuracy node below max and the velocity is reasonable I don't go higher. But I have had occasion where I have had to go higher. For example the Hodgsons data for IMR XBR 8208 and 80 grain bullet is practically anaemic in my oppinion. Even with the bullets stuffed into the lands I am well over their stated max load in my rifle.
It is always a good idea to start with the minimum load with any new rifle. I recently started reloading 338 LM. I decided I would start with the bullets into the lands. Not far off minimum load I was getting sticky bolt lift and slight brass flow (light rings from the ejector). I started seating bullets off the lands and now max loads show no pressure. The primer pockets on those brass are still good after 4 firings btw. Lapua brass is tuff.
It is always a good idea to start with the minimum load with any new rifle. I recently started reloading 338 LM. I decided I would start with the bullets into the lands. Not far off minimum load I was getting sticky bolt lift and slight brass flow (light rings from the ejector). I started seating bullets off the lands and now max loads show no pressure. The primer pockets on those brass are still good after 4 firings btw. Lapua brass is tuff.
This sir is almost words to words the procedure i use for my load devellopement except i use Hornady brass now, both my Nemesis loads the 208 Match and the 178 Match are over the max and none of the above criterias were even close... Thank for posting it... JP.
If you find a load that works well, there is no need to keep going. Yes, in some rifles it is possible to get 100 fps over the max reccomended load, but why bother if you have a load that meets your velocity and accuracy requirements below that. The lower pressure you shoot at the longer the brass lasts. I have a 7mm rem mag that I only use hunting that has a rather hot load, but I shoot it very little. Calculate the energy and the trajectory and you will find that 100 fps is of little or no value.
Many things have changed since the 60's. Variations in powder lots spring to mind.
Loads listed in manuals have been worked up in those specific barrels/chambers. Yours may or may not be different, only way to tell is to work up a load in your rifle. Be aware that all guns do not show signs of pressure equally.
