Working up a 38 cal (rifle) load

[BlackHillsBob]

im not a nay sayer but a tappered bore in a muzzleloader is wrong? who ever started that crap hooked a few shooters.

 

[smoothshooter]

I wouldn’t disparage FCI barrels in any way – too good a reputation and Charles Burton seems like a man who will do what it takes to get something right. However, I have a similar experience with a .54 FCI barrel. I’m quite sure it’s not the crown since the muzzle is coned. My patches are shredded regardless of lube or patch size. I recently used THICK denim and the patches still show seven small cuts whether using mink oil or spit and a light powder charge. I’ve tried running scotch bright down the bore – but I wouldn’t think this would be a problem with round bottom rifling. Maybe it needs an over the powder wad. I’ve done that in the past with other guns but never kept it up because I saw no discernible difference in accuracy.

Your problem is not in the bottom of the rifling, but at the top.

 

[Col. Batguano]

So I'm not the only guy to have the same issue with FCI barrels. Question; did they ever lap themselves in after X number of shots, and stop that bad behavior?

What did you mean by the "problem is with the top of the rifling rather than the bottom? I don't understand.

 

[SDSmlf]

What did you mean by the "problem is with the top of the rifling rather than the bottom? I don't understand.

The sharp corner where the groove is cut into the bore. Yellow arrows below point to corners at the ‘top’ of the rifling. If real sharp or if there is a burr you could cut patches. Have you pushed out a seated a patch and ball to see what the patch looks like?

 

[Rifleman1776]

im not a nay sayer but a tappered bore in a muzzleloader is wrong? who ever started that crap hooked a few shooters.

In fifty years of shooting ml and hanging around people involved in this avocation, I will admit I have heard mention of choked bores in rifles. But, I have never to my knowledge used or even seen one. Historically, all kinds of 'things' have been tried to improved accuracy in guns of all types. Personally, I do not know if a choked rifle bore in an ml is good or if the benefits are just imaginary. We have knowledgable people here who know what has been tried. I would like some of them to chime in. OTOH, my gut is telling me (and my gut is never wrong) the notion is pointless.

 

[Col. Batguano]

I think the reason for it comes from the fact that due t the nature of patched balls, they're going to be nowhere as tight as a bullet fired from a high velocity cartridge gun that gets swaged in to the rifling at 50,000 psi. Lots more gas blow-by. At our relatively low pressures (<20,000 psi) we need a softer projectile if it is going to obdurate at all. My hunch is that it only partway gets there, but is slightly squashed with the initial charge. When it gets to the choked part, it is engaged more fully by the tighter bore,and better accuracy is the intended result. It MIGHT slow down or even accelerate some due to the increased pressure due to the restriction. My hunch is though that it is slower.

My breech plug is pretty much permanent now (I used Red Loctite on it because it was pretty loose as I coould unscrew it with just firm finger pressure) so I don't really want to pull it. I would have to get a ball out the more conventional way, with a threaded ball puller. I can't make those CO2 dischargers work on flint guns, and I don't want to hook it up to a scuba yoke of my compressor to blast it out, though that certainly would work, as I can generate up to 5000 psi with it. So far after about 100 shots I haven't managed to dry ball (yet) but I'm sure I will soon enough.

 

[rich pierce]

GRRW barrels had some choke. Just 0.001” or 0.002” can make loading easier once short started. That’s the main feature I like and do on barrels where I recut or freshen the rifling. I heard that FCI barrels (Charlie Burton) are choked a bit but I’ve not verified that yet.

It’s very easy to put a slight choke in when re-cutting rifling but I am not sure how it’s done on new barrels.

It supposedly improves accuracy but plenty of un-choked rifle barrels shoot great.

 

[Eterry]

I'm still working up a load for my 38 cal Lehigh (48" FCI barrel). I started at 40 gr, FFFg, and have been going up by 5 gr at a time. So far I'm up to 50 gr FFFg and the .015" patches are still being shredded. .375" 83 gr. ball. RB rifling 1:48" ROT. FCI barrels are milled about .001"-.002" tighter at the crown than they are at the breech, so they're a bit tight to get started, even with a short starter. I tried using .018" patches ONE time, and I had to use a hammer all the way down the bore to get it in. 10 shot groups @ 25 yards (benched and sand bagged) are running 2 1/2"-3 1/4", which I think is too big,

What have you guys found to be your optimal RB loads in this, or calibers close to it (36 or 40)? I'm thinking that with a lighter ball it takes a greater powder charge to upset the ball (less mass) to get it to obdurate in to the rifling.

Thoughts?

Almost every new barrel I've dealt with would cut the patches for 100 rounds or so. I used that time to get used to her, busting cans, etc. If it continues I'd consider lapping the bore.

50 grs of fffg in your 38 prb is SIZZLING, around 2200-2300 fps according to data i have. If it were mine I'd drop back to 20grs, and work up from there, unless you're concerned about Zombie Squirrels!!

 

[jbwilliams3]

Your problem is not in the bottom of the rifling, but at the top.

That actually makes quite a bit of sense.

 

[Col. Batguano]

My recent outing I dropped down to 17 grains. It's probably still humping along at 1200 out of a 48" barrel. Accuracy was much better too. One thing I noticed (which is probably true for all flint guns) is that as fouling increased in the lock / frizzen area, the stiffer the frizzen became in flipping upwards, and the subsequent more klatches (failure to generate sparkI had. So a free-flipping frizzen would seem to be just as important as a sharp flint to generate sparks. That would be less of a concern with a roller frizzen, but this is a Large Siler, and the arm rests on the frizzen spring directly.