Author Topic: Pressure work up & range time (Read 514 times)

Toolpush · « **on:** September 17, 2003, 06:04:00 PM »

How do you work up the ramp from your starting load: IE how many rounds at how many stages to you reload before going to the range?

If you need a caliber to discuss this make it the 300 Win Mag. Bullet weight 180 Gr. Powders IMR 4350, Re 22, H1000, H4831, & IMR 7828.

This is not a fun combo to spend a lot of time trying to get to group well. Yes I try to set the sand bags where it kicks them first. The rifle is a SS Ruger 77 with a composite stock. Not real heavy!

Since these loads of powder will be in the 75-80gr bracket. When one backs off just 5%, 3.5 - 4 grains and loads in 1 gr increments, 3 rounds each that will make 15 rounds per powder times 5 powders equals 75 rounds. I don't believe in getting a barrel too hot. If you could fire 3 rounds every 20 minutes that would be 8+ hrs on the range! Not to mention that this was for trying 1 bullet. Help me if I don't try 2 or 3.

I can admit that I am not tough enough to take that much punishment for that long and still shoot good groups. I doubt that many people can! I don't need to develop a flinch.

One fellow I know says he would back off 2.5% load in .5 grain increments and load 1 round each. Shoot the over a chronograph, carefully measuring each round and watching for pressure sign as you go. That would make 5 rounds each powder. Then go home with the data and load three - 5 rounds of the loads that gave the best performance in relation to pressure sign. Back to the range to see if they would group well. If you choose 2-3 of the powders that would be another 6 - 15 rounds. With a little luck I could have a good load in 31 - 40 Rounds. This is sounding tempting to be honest my shoulder is getting mighty sore.

Blast away guys I'm at a crossroads! I have been reloading for 25 years. I have never stuck a bolt much less blown up a gun. Is there other shortcuts that I should consider? This is getting painful, expensive and time consuming!

Thanks in advance for your opinions and advice
Toolpush

Graybeard · « **Reply #1 on:** September 17, 2003, 06:30:13 PM »

Please be aware that what I am about to say is WHAT I PERSONALLY do. It is NOT a recommendation that you do like wise. How you do it is your decision and your responsibility.

I long ago stopped working up in increments of a few tenths of a grain or a grain or whatever at a time. I found I hardly ever got decent accuracy at the lower levels anyway. And what if I did get best accuracy at the starting load? Would I shoot a .30-06 at .30-30 velocity just because it was accurate? My answer is no.

So what I do is to compare several load manuals to get a feel for what they agree is a max load. If one book is well above the rest I discount it and do not consider it further in my decision making process. Once I've determined what set of powders deliver maximum velocity for the given round under consideration I pick 2-4 of them I have on hand and load up six rounds of each powder at about 1-1.5 grains less than what the books tell me is max.

I check this load across the chrono for consistentcy and if it is consistent and velocity is about what books say I should expect and accuracy is pretty good I consider it for further work. Any that are not consistent or which five really rotten accuracy I generally do not work with further.

I do NOT strive for the absolute Nth degree of accuracy in hunting loads. I want one that is consistent and shoots groups inside of 1.5" and preferably well under that from a rifle with proven accuracy potential of less. If it is a new rifle you have a double problem. You don't really know if an inaccurate result is the gun or load.

If a load is consistent and gives low Sd and velocity is right up there where book says it should be you can then fiddle with things like seating depth and primer or change powder charge by 1/10 grain or whatever you like to get a tad better groups if you feel you just must.

But using this procedure I find it easy to get groups with my rifles that shoot from 0.4" to under an inch with at least one bullet powder combo that are selected as above. When I do that is my load and I don't really mess around much more with it.

I only fiddle around playing with the ones that have light recoil. I have a rotator cuff that needs surgery badly and danged if I've gonna fiddle around with guns with recoil about the level of a .243 trying to find a more accurate load when I have one that shoots sub MOA for a hunting rifle.

GB

Dand · « **Reply #2 on:** September 17, 2003, 10:47:23 PM »

I did much the same with my guns. I think I have 12 load manuals and I'l often read all of them on a particular cartridge. I have also relied heavily on Ken Water's Pet Loads and his commentaries on best loads - especially powder selection. Since more new powders and cartridges are showing up - some of his stuff is dated. But in 3 of my rifles, loads Ken recommended as good and accurate have worked very well in my guns. He also shares a lot of loading techniques and warnings where needed.

TOOL PUSH - don't leave out IMR 4831 for the 300 win mag - its my favorite. Good balance between 4350 and H 4831. I have been curious to try H4831 short cut and may try AA3100 one of these days but like you say, the 300 win isn't a round to spend the afternoon burning up 50-70 rounds. I've done 40+ a couple times but hurt for a while afterwards - twitch, flinch. Shoulder muscles quit doing what I told them to.

Jack Crevalle · « **Reply #3 on:** September 18, 2003, 01:43:46 AM »

I was was trying to work up loads for several .30 cartridges using 5 round
trials between increments. I found that I couldn't get consistant results.
I re-read the Speer manual that said to get some kind of statistically
reliable result, you need a minimum of seven rounds, so I use a minimum
of ten if I have the brass to do so, but no fewer than eight.

The manual also says that bench shooting imparts more recoil to the
shooter than off hand. I'll believe it. They recommend the use of a
shoulder pad.

WD45 · « **Reply #4 on:** September 18, 2003, 02:17:27 AM »

300 win mag..... I put that one in the dentist gun category.
Most of your fillings are jarred loose after about 20 rounds which makes your dentist very happy :-D
I agree with grey beard. You dont need to spend your entire life working up a good hunting round that will give you acceptable accuracy at the farthest distance you will be shooting that rhino

Crayfish · « **Reply #5 on:** September 18, 2003, 05:37:24 AM »

I sort of follow Greybeard's method, except with maybe a little more caution built in. I don't start at the min load but will start somewhere in the middle. I don't care about the bottom end loads, either. I will start in the middle and load 3-5 rounds in 1gr increments (this is for medium to large capacity cases mind you) up to the max book load. These give me a feel for what the gun likes.

I also pick one powder and bullet that I think should do the trick thru asking questions and reading the load books ... I don't go to the range with a whole bunch of options. I concentrate on getting the most from the few rounds that I've loaded. If none of these groups look promising, I'll move on to another powder. If still nothing, I'll scrap the bullet and start over. If I can't find a suitable load after 2 different powders I assume that bullet and my gun are not compatible (ie. 180gr Barnes XBT's in my Rem 700 300WinMag!!).

Once I find some likely looking candidates, I'll narrow the gap and work up another batch in .5gr increments around the load(s) that gave me good groups ... unless of course I got great accuracy from one of my 1gr increment loads. Once I hit on something that looks good, I'll usually load up 10 of that load and give it a good test to make sure the results are repeatable.

In my 300WinMag, I found the best accuracy with most bullets at 1gr below max (71gr of IMR4350, I believe). The bullet my gun seemed to like the best was the 180gr Hornady SP (flatbase). I shot groups as small as 0.38" with this combination.

Good luck ... Crayfish

Iowegan · « **Reply #6 on:** September 18, 2003, 11:40:36 AM »

The first thing I do when working up a load is to buy a box of factory ammo in the desired bullet weight. Then I sight in the gun and shoot a few groups for accuracy. The last 5 rounds go over the chronograph. This sets a base line for hand loading. I have found, like Graybeard, most loads dial in at the higher end of the chart. I try to find book loads that deliver about the same velocity at the factory loads. Engineers that design guns and ammo don't just pull numbers out of the sky, they actually test the guns for optimum performance. That means best bullet weight and velocity to match the twist rate. Once you find the loads that emulate factory loads, you can refine them with different brand bullets (same weight), different seating depths, and tweaking the powder charge a little. I almost always end up with a load that is more accurate than factory stuff and just as powerful.

Toolpush · « **Reply #7 on:** September 23, 2003, 12:15:41 AM »

Greybeard that was just the answer I never expected to have gotten from you. I thank you for your frankness. Yes I know that what I pull the trigger on is my own doing so thank you for not being lawyer dodgy. I have always had good luck in besting factory accuracy but rarely have matched the velocity 100%. I guess there is just a little more confidence a rifle that will shoot under an inch for me. In most cases I have achieved this. But this one is Kicking me hard enough that It took the fun out of it.

A good friend said that this stock is known to be a hard kicker, the gun isn't all the heavy, and a 300 win mag is not a wimpy cartridge. DUH Go ahead and laugh at me guys. Yes I'm cryin calfrope on this one. This one kicks hard enough to make me rethink a couple three things. LOL

Thanks for input guys. I'll go with my buddies method tomorrow and see what happens. Yes I'll carry my mic and magnifying glass and study each round before going up another half grain. Then when I get done I'll load 5 of what seems to look good and see if they will group to my satisfaction. I hope a part of my reloading technique is about to change.