.45 acp - working up a load advice

[dmftoy1]

Ok, I've decided on my bullet, primer and powder and located a few different sets of load data for this combination. My goal is to get the most accurate load for my kimber that will cycle the action reliably with a 16lb recoil spring.

So, now for the questions:

1. How many rounds do you typically load/fire of a given combination to determine reliability/accuracy? (assuming I'll be shooting from a sandbag rest)

2. How many variations do you try in a session?

My thoughts are to load 3 21 round batches (in a single session) varying each batch by .2 grains (using Accurate No. 5). Whichever shoots the best groups without and failures to feed or failures to eject is what I'll settle on.

Any and all critiques of my plan are appreciated.

Have a good one,
Dave

PS - I don't have a chrono right now.

 

[rbwillnj]

I would start off by shooting 10-15 rounds just to fowl the barrel. Should be with the same bullet and powder you want to test, but your not trying for groups here.

Then shoot maybe 3 five shoot groups off the sandbag. If you think you did a good job of squeezing of the rounds, that should be enough to give you an initial indication of the accuracy.

I read in some magazine that your best 3 shot group off a sandbag is about equivalent to a five shot group from a Ransom Rest. Don't know if that's true, but I know I can never do as well off sandbags as I can with my Ransom Rest.

Next, do some shooting, maybe 50 - 100 rounds, then do three more five shoot groups and see if they came close to your first five shot groups.

A load can look pretty good to start with, but if you get extensive leading, it can go to heck after a while.

 

[ClarkEMyers]

Let us know if it really makes a difference?

I don't see any mention at all of cases? Do you have a pick for that as well?

My own experience has been that trying for small differences in a .45 ACP is either a waste of time or terribly time consuming. Many people insist on much larger lots for reliability testing as well. I believe it will be very hard to achieve statistically significant differences measuring the performance difference with small changes in powder charges. A .2 grain spread is much the same as simply dropping charges from a measure (+/- .1=.2 extreme spread) will give.

I'd bet that short of a Ransom Rest (note that a Ransom Rest may have issues with a 1911) and much larger lots of ammunition any real differences will be lost in the noise. On the other hand it does pay to pick the best load and if the loads all test OK then so much the better.

I did weigh all my bullets and powder charges for match ammunition but I just picked a popular load (Saeco 130 with 3.5 Bullseye and Alox/Beeswax) and found it entirely satisfactory - except today I wouldn't shoot it indoors.

 

[Kamicosmos]

When I develop loads, I do 5 rounds of a charge, then 5 rounds at like .2-.5 more powder. I do up 30 rounds or so, which is 6 different charges. Shoot your 5 rounds, let the gun cool off a bit, and work your way through the 30 rounds. Helps if you have a note pad and a chrono.

I like to think: 3 shots indicate what the gun can do with that load, 5 shots indicates what the gun and SHOOTER can do. Which is why I do 5 round groups.

 

[HSMITH]

I inventory quite a few powders, so I load 10 rounds or so AT the velocity level I am looking for, 10 a hair under and 10 a hair over. I will do this with 2 or 3 powders at a time since it is very time consuming to test different loads. I don't bother with sandbags or any rests unless the load shoots good, I just shoot them at 15 yards or so to get a feel for how they shoot. I know when a load is shooting well, and if it is I will shoot some groups at 25 yards, otherwise as long as no pressure signs are present I burn them up to get the brass back and move on.

I have never picked a powder and then tried to make it work. I pick powders that will do what I want according to the manuals, and load a couple sets close to what I want out of the ammunition. Either it works or it doesn't. If it does I stick with it until testing proves something else is better. If it doesn't I put it on the bench until the next round of tests come up.

 

[dmftoy1]

Thanks guys!

As far as brass goes I'm just sorting what I have into lots by headstamp and picking a batch to work with that I knew I bought at the same time. When I find a load I like I'll probably do nothing but load up 500-1k at a time and shoot them.

I hadn't thought about the .2 grains being within the +/- of the powder measure. I guess I'll just try some load at 850 fps (according to the manual) and see how it shoots, maybe some at 800fps also. (those seem to be about .2 gr apart from what I can see.)

Have a good one,
Dave

 

[rbwillnj]

I have checked the accuracy of my Powder Charges on several occasions, and they have been dead on. I have done most of my work with a Lee AutoDisk. Its such a simple device I figured I shouldn't trust it, but everytime I have checked the weights of my charges compared to the Lee chart it has been right on. I have also checked for charge to charge consistancy, it that has been right on too.

When I did the Ransom rest testing for my 45, I prepareded loads with 3.5, 3.8, 4.0, 4.3. 4.5 and 4.8 grains of bullseye under a 200 grain LSWC. I used those loads because that's what an AutoDisk drops. I started at the low end and worked up. I got maybe 2.5" groups at 25 yards with 3.5 Bullseye. They got smaller with 3.8 grains, gave me 1" groups at 4.0 grains, and started getting bigger again as the loads went higher.

I did the same thing using charges of W231, basically got the same results, but I got my 1" groups at 4.3 grains.

 

[Sunray]

"...3 21 round batches..." will take far too long. Begin with the 'starting load' from your manual, load 5 rounds. No powder thrower. Weigh each load. Then go up by half a grain, loading 5 of each load and keeping them separate until you get to the 'max load'. Taper crimping only. Go shooting. Take slow deliberate shots off your rest, shooting for group only. Change targets for each string of 5 and allow time for the barrel to cool between strings. When you find the most accurate load, adjust your sights using that load. Or you can go back to the load previous to the best half grain increments and go up by 1/10th of a grain to find the absolute best load. Not really necessary for a handgun though.
If you change any component, you must start over. Same proceedure for rifle reloading.