Can you force a load on a rifle?

Hear me out....

I have 4 .54 caliber rifles that shoot the same load super accurately. They are all slightly different in barrel length and twist. 2 are 1:70, 1 is 1:60 and 1 is 1:24. The length varies from 38" barrel down to 26" barrel. Nonetheless, they all are perfectly happy with the same load - 80 grains FFFg Goex, .530 swaged ball, .018 pillow ticking with 7:1 Ballistol/Water dry lube. (One is a flintlock that uses FFFFg Goex for pan prime, the others using CCI #11 caps).

So there is one more .54 caliber rifle. This one is 1:66, 28.5" barrel. I have moved the components around and substituted some for others to develop the best load for this rifle. With the above components the only variance is that this rifle wants 100 grains of powder. The difference between amounts of powder in 5-grain increments related to accuracy is significant. The groups are ok but right at 100 grains they shrink considerably, like one expanding hole at 50-yards and 3" or less at 100-yards.

I can live with the load needed to get the most accuracy from this rifle but I have to wonder...…. is there something I could do to get it to be more accurate with my "standard" load? It would be convenient to have the same load working in all the same caliber rifles.
Again, I am ok with giving it what it wants. I am just seeking tips, advice, recipes or remedies that might work to get it more accurate with 20 grains less powder.

Is there such a remedy or am I just wasting time looking for it?

Thanks in advance!

Don't know if this will work, but sometimes a felt wad over the powder before the patched ball will tighten up groups. It has worked for me on a couple of rifles. I suspect the depth of the rifling may have something to do with your accuracy issues at lower powder charges. The heavier charge "bumps up" the ball to better fill the grooves. Have you tried a ,535 ball?

You could try a thicker patch, but then you would be changing your "standard load".

Use 100 in all if one load is important to you.

First thing I would do if a percussion gun is check the barrel is not touching or bearing down on the lock.

Try bedding your barrel AND tang with bedding compound or epoxy around the bearing points. Do not overtighten the tang screw when seating the barrel assembly into the stock. It won't hurt and certainly can help to improve your gun's accuracy.

You might want to loosen the tang screw now and tighten it just enough to insure that it isn't torquing the breech end of the barrel. Then shoot it with your favorite load and see if there is a difference. If yes, then bed the whole works and tighten the tang and barrel with the same torque. This should stabilize the barrel assembly from then on.

The first thing I would try is 100 grs in the other rifles and are how they respond.
I know match shooters who use a torque wrench on action screws... so they get the SAME amount of pressure on a specific action every time. You can try that on your lock/ tang screws.
Bedding the action/ barrel is standard practice on BR rifles... you may find it helps.
Also a business card at the end of the stock and barrel helps many "white powder" rifles by giving slight pressure up in the barrel. If it doesn't help simply remove it.
Good luck and let us know how you get on.

Obviously the standard load for the other rifles isn't destined to do as well in that rifle. An op wad, as mentioned above, could make a difference as could a thicker patch.

My impulse would be to try a grease lube like TOW's mink tallow before giving up. My own array of rifles is a lot more "forgiving" about powder charge when using grease rather than dry lubed patches. Might work, might not. But we're not talking about rocket science.

The difference in loads from what is written, only shows me a difference in flight-time.

I wondering how "secure" the barrel is in the stock? Also how were the rifles tested, meaning from a bench, from a bench with a rest, sandbagged on a bench, or locked into a Ransom Rest???

Bear with me.....

Because the 100 grain load should be about .03 seconds faster in flight time at 100 yards than the 80 grain loads, IF Goex data is to be believed. That's only 16% faster, but the groups dramatically tighten. It's much more than a 10%-15% improvement.

So I wonder if the barrel to stock fit, OR how the stock fits Sparkitoff, OR BOTH are a factor, and the faster exit speed from the muzzle with the 100 grains is enough for the bullet to be free before something bad happens due to recoil? Patocazador may have hit on the solution, already.

LD

This was from a bench with the end of wood rested on sandbags. I shot 5 5-shot groups with powder charges that showed potential. I also shot at 50-yards and 100-yards. There is noticeable improvement in group size when I use 100-grains of powder. This is a percussion rifle. In reviewing my notes I see that other types and brands of powder opened up the groups. The best is with FFFg and 100 grains of it, so I think you guys are on to something - the speed makes a difference. Maybe it is the pressure? I also just realized this is the shortest barrel of the .54's, so maybe they all like a certain velocity and this one needs more powder to get it due to shorter barrel? I am making a written plan for further experimentation based on the suggestions here to see what turns up. Again, I don't mind giving it what it wants but boy would it be convenient to have one "standard load" for all of my .54's, and a reduction in recoil is always welcome by me.
Thanks

Sparkitoff said:

I also just realized this is the shortest barrel of the .54's,

Click to expand...

It's possible that the higher powder charge = the same speed in the longer barrels but I doubt it's that significant.
Since you shot from what seems to be a good foundation for the stock and barrel, I'm still leaning on your barrel doing something from recoil. IF you had a less stable setting, I'd think the longer barrels were giving you an accuracy advantage due to the weight being "out front", or the longer sight radius , but that should not be consistent with four different sizes, and suddenly not work simply because the last rifle was an additional 2" or so shorter than the next shortest.

No, I think that larger split second of time with lower amounts of powder is allowing the barrel to move off of where you have the sights sitting. When you get to 100 grains, the ball is probably just popping out the muzzle as the "whatever" occurs, and it doesn't effect the ball's flight path.

LD

Every gun is different. You can get close when you open your expectations of accuracy. But the same for all for best? Good luck.

Well a longer barrel allows more time for the expanding gasses to propel the ball forward which increases muzzle velocity, an increase in the amount of powder charge will help to offset a shorter barrel length to a certain degree. I am surprised that it would take a 20 grain difference, that seems like a quite a bit to me. But without knowing the actual muzzle velocity and the rate of twist that the rifling is applying over that distance, it could very well be that a 20 percent increase is what is required to stabilize the ball prior to exiting the barrel. Have you compared chrono data from rifle to rifle at all?

My .54 is the same and it just starts at 100 gr. Barrels vary so much that one load is tough to use. Lube, ball size and patch thickness also changes with most barrels.