Grouping of "good load" vs "bad load"

I know that certain guns like certain loads to produce best accuracy.  I believe that most would even say that each particular gun (even between guns of the same make, model, and caliber) can have a different load that it likes.

guns and loads produce cones of fire -- a 3 dimension radial dispersion. a worn NFA barrel can go to 5" in the cone of fire. It depends on the shooters need, a cone of fire of 1" would not work for a target shooter, but be fine for hunting, 2" would not work for hunting (as an example) but works great on NFA Ak-47's

I've had/seen rifles that are capable of MOA, that with the wrong load open up to the 4"-8" range.  Though most rifles I have will group almost any load to 3".  I've had two extremely finicky rifles, one a Ruger MKII in 7mm and the other a Remington 700 in 300RUM.  The Ruger I never did figure out so I got ride of it. The Ultra Mag (a friends gun) we finally figured out and got a respectable load which groups about 1.5".

I took a peak at my range log book, as an example of pattern changing with load. In my old 03-A3 30-06, with the 165-gr Hornady SST, 100yds, results were:

Thanks, Terry - Thats what I was looking for.

robbie wrote: Thanks, Terry - Thats what I was looking for. Soooooooo   -    If one is shooting 3-4 inch groups (at 100 yds), don't blame the load or waste time looking for a better load.  Guess that leaves scope, mount, or personal error. Thanks

I wouldn't neccisarily believe that either..... I had a rifle shooting 2.5-3" pretty consistantly. I changed powders, and now it shoots the good loads to less than a 1/2". The bad loads with the same powder go to 1"-1.5". I would consider trying at least changing one thing in the loading, and see what happens. Maybe that gun hates that bullet, or powder. I'm no reloading expert, but have seen this happen.

If you were to look in a Reloading Manual and it tells you the most accurate powder for the particular grain of bullet you want to load. What is that really telling you? Does it mean thats what they found for the rifle that THEY tested? Certainly they are not saying that is the most accurate powder/bullet combo on that page for all rifles of that particular caliber, right?

almost all of them are just saying that max. accuracy never comes at the max of pressure (and thus velocity). because so many avenues can give results, there is obviously no deterministic solution, if there were , every one would be doing it.

I do not understand what you mean Dale.. Lets go to my Barnes book as an example, lets say its says for a 7mm 150gr TTSX BT for the "MOST ACCURATE LOAD" use IMR 4831.. That must mean they tested all those powders on that page (maybe 15 of em) with the TTSX 150gr. bullet.. The IMR 4831 was the most accurate it says....So why would you bother trying the RL 19 or RL 22 or whatever other powder there is on the page?

JF4545 wrote: If you were to look in a Reloading Manual and it tells you the most accurate powder for the particular grain of bullet you want to load. What is that really telling you? Does it mean thats what they found for the rifle that THEY tested? Certainly they are not saying that is the most accurate powder/bullet combo on that page for all rifles of that particular caliber, right?

Thanks Trays!

Also;

the load matters to a certain extent. some custom rifles will shoot everything you feed them pretty well. problem is that it will only shoot a load or two exceptionally well. imo the better the quality of the barrel the better it will shoot whatever you feed it. now, you must recognize that you have to match the twist up with the proper weights to make it work.
   the load i use in my 6.5rem mag is the nosler books fastest load for the 130gr accubond, and it is certainly not the most accurate load they cited, the same went for the load i used with 120gr tsx's, the fastest load in the book was the one. you move to my .264 and it hated pretty much everything i fed it. then i bought some h-1000 and things started to change, and now i use a middle of the road weight charge for it. my .300win mag really liked a bunch of imr 4831, where my .300wsm was more of a middle of the road. my dads 30-06 likes 58gr of imr 4831, my 30-06 wouldnt shoot that load into a 6" plate @100, but i load up 50.5 gr of imr 4064 and i have a beautiful 1" group every time. in other words you simply cannot predict what will work and what wont, you just gotta try it.

I've never wanted to test too many powders and haven't had to. Basically, I start out by looking for the powders that produce the highest velocities for the bullet weight/type and cartridge that I'm using and just load test with those. Like Dale says most loads do not obtain the best accuracy at the highest pressures so I know choosing these powders I have room to back off.

Re: loads that shoot good at 100 yards but not out at longer distances. I haven't experienced this. But maybe that's because all my loads are with high BC boat tails. If a load shoots well at 300 yards it shoots well at 100 yards. Same applies in reverse. I also zero at 100 yards because there's less variation from wind and you can see the target better. If you plan to shoot at long distances, once you have that zero in you can check to your real world results out as far as you can shoot against a ballistics program like JBM.

most loading information in published sources are based upon guys who "might" shoot a 1000 rds thru their guns in the course of the ownership of the gun. This amounts to a relatively small amount of powder. So the powder companies go to a great deal of trouble making sure that canister powders are can to can as uniform as they companies can make them. I've gotten exceptionally accuracy from military surplus powders, bought in bulk, 50 lbs at a time in some cases , and adjust everything according to that lot of powder and primers. Variations in lots even in canister powders purchased one at a time over a long period of time can show quite a spread. Personally I have no idea why reloading books put in most accurate load-- I don't have any idea what it means.

Dale Clifford wrote: most loading information in published sources are based upon guys who "might" shoot a 1000 rds thru their guns in the course of the ownership of the gun. This amounts to a relatively small amount of powder. So the powder companies go to a great deal of trouble making sure that canister powders are can to can as uniform as they companies can make them. I've gotten exceptionally accuracy from military surplus powders, bought in bulk, 50 lbs at a time in some cases , and adjust everything according to that lot of powder and primers. Variations in lots even in canister powders purchased one at a time over a long period of time can show quite a spread. Personally I have no idea why reloading books put in most accurate load-- I don't have any idea what it means.

all very good points and all are very true.

Yes, Very good information GuysIm glad I asked those questions. I used to think it was always me, my shooting. Which Im sure is true to a point, but just as often its the load and if the rifle likes it or not it seems...My sons Mod 70 Winchester 7mm Mag. is not picky but all my rifles seem to be pretty fussy...

after shooting and reloading for a while -- you will gain an intuition, why and how to adjust for the variations you are seeing. Sometimes one can put together a load and a gun and this bad feeling develops-- are you willing to put the cost of load development or just walk away. Having done this with literally hundreds of guns, I would say that 95% of most problems is the stock.

Dale,

robbie wrote: My question is how much difference does the load make?  Lets say the perfect load will produce groups the size of a quarter, or a 1" pattern.  How bad could a non-favorable load be?  Would it shoot a 1.5" group?  2"?  5"?

robbie wrote: Lets say the perfect load will produce groups the size of a quarter, or a 1" pattern.  How bad could a non-favorable load be?  Would it shoot a 1.5" group?  2"?  5"?    Thanks

There is no "rule of thumb" here.  There are too many variables involved.  If you are shooting a bullet that is totally incompatible with your barrel twist, for example, groups can open up to shotgun patterns. 

here too, autoloaders have their own quirks, that may or may not work. In regards to the stock, its difficult for a company to place a barreled action in a stock so that it is just so. As an example a loose stock or even one torqued in too much can cause as many problems in working up a good load as the variables of powder and bullet. The orginal post, and in reading it, one assumes that these variables are have been taken care of so that the load work is the only remaing problem. This is rarely the case, sometimes the stock has too much flex in the forend, or is too soft and the action is torquing in the stock.