Cold bore shot load development.

[K22]

I have tried ball powder in the past and it didn't seem to temperature stable? Maby it was just me . I have a charge master and it's pretty accurate.. as far as a crimp I have the Lee factory crimp die . Don't need a crimp ring on bullet . Probably wouldn't take much of a crimp to hole it

I found the same to be the case with Ball Powders, namely H380, H335 and BLC2, especially in hot weather, 90's. In fact, I had pressure surges with H380 in the 22 250 in the field with a medium load.

Not familiar with the Lee crimp die but sounds like it would work if you wanted to crimp a bullet that does not have a cannelure.

 

[cjmac]

I found the same to be the case with Ball Powders, namely H380, H335 and BLC2, especially in hot weather, 90's. In fact, I had pressure surges with H380 in the 22 250 in the field with a medium load.

Not familiar with the Lee crimp die but sounds like it would work if you wanted to crimp a bullet that does not have a cannelure.

308 Winchester or 303 Savage Factory Crimp Die

Lee 308 Winchester or 303 Savage Factory Crimp Die crimps the bullet in place more firmly than any other tool. Tests demonstrate that even bullets which have no crimp groove will shoot more accurately. A firm crimp improves accuracy because pressure must build to a higher level before the bullet...

leeprecision.com

A must for auto loading rifles

 

[Doom]

Thought you were mentioning me for a second.,,,

My point was that, for hunters, things like ladder tests are less important than practicing what you'll be using the rifle for. If you're only going to take one or two shots on an outing, it doesn't matter what size group you can put 10 or 20 rounds into. As long as you can hit with those 2 shots, you're pretty much done.

I agree. Those first two shots need to be repeatable. Depending on the intended distance I'm not sure any load development in the classic sense is necessary. Beyond the 400-500 yd range I would start looking at velocity stability as a guide also.

 

[searcher]

As others implied or otherwise commented, you are not really trying to tune the rifle or load to the cold shot, but rather, you just want to know where the first shot will land - and whether it is repeatable and accurate. If you are firing from a clean bore, how much your first shot can stray can be heavily influenced by traces of bore preservative, oil, etc., in your bore. My hunting rifles average about 1/8" to 3/4" +/- difference on the first shot (depending on the rifle) from a clean barrel with a slight amount of lube in the barrel. Whether you plan on shooting from a clean or fouled bore, you just want to know that your round will hit a certain place on that first shot. Just shoot your rifle one shot, let cool, shoot one shot, etc. If you will be shooting from a clean barrel, you will need to clean the barrel between each shot, trying to leave oil residue as my may have when cleaned at home. You may find that your rifle is so close on the first shot to subsequent shots - that you needn't worry about any of this.

Record how much you may need to hold off. I'd hold off on the first round when hunting, as if you need to fire additional rounds, you can aim right on for them without any holdoff. If you find that the amount the first shot strays is very negligible, I'd not even worry about it unless you shoot at very long distances (big game). I'd not want to dial the difference in my scope for the first shot, as if I have to shoot again - that comes quick, and I don't want to have adjust my turret after the first shot or try to remember a different corrective holdoff to where my bullets will normally impact after that first shot.

 

[mikecr]

The fouling is vital to this.
To ensure that my 1st and following cold bore shots are together, I clean barrels to dry white metal, and then dry pre-foul with a burnishing of Tungsten Disulfide (WS2).
My bullets are WS2 coated as well.

Ambient temperature is very important.
You need a load within a reasonable temperature window as developed.
That is, different winter ammo from summer ammo.

I first hot load develop for precision at 500 or 600yds (depending on bullet).
Then I shift to cold bore accuracy at 200yds, with 10min shot rate.
I do this because 200yds happens to be my worst range, and a 10min shot rate is the worst I've seen with any gun so far. I tweak the load to reach my hot bore precision MV, and tweak around that for tightest accuracy.
Then I validate cold bore accuracy at more hunting ranges.

The gun will either be CB accurate, or it will not. There is no predicting this.
I've had excellent hot bore precision (grouping) guns that were not cold bore accurate enough for my hunting.
I've had terrible grouping guns that were incredibly cold bore accurate.
I'm a groundhog hunter