Knight disc .45 issues

[StorMay05]

I have an older Knight disc in .45, a superdisc I think, picked it up a few years ago from local shop who forgot about for over a decade. Anyways I’ve messed with it on and off over the past couple years and the accuracy was so-so but I chalked it up to mostly my lack of attention to it. Last year I decided I wanted to really get good groups and order a Swinglock die and bullets to size. Upon trying to size them I found the Swinglock die, even being opened as much as it could was too small to size them. The bullets would go down the muzzle no problem. It’s also when I realized that the first two inches of barrel are much tighter than the rest, even a bullet that is hard to start will go down with finger pressure after the first two inches.

Tried some .451 385grs from No Excuses today. Accuracy wasn’t great shooting 80-85 grs of T7 FFg. Dropped to 65 grs before I left and looked started to get sub-3” groups. Note this was with a fouled barrel which I’m not crazy about hunting with.

My questions are.
1. Any one else experienced the tight muzzle and looser bore or heard of this problem before? Any solutions to improve accuracy?

2. Would the 385 NE and 65 gen’s be good for elk at 100yds? I feel like it would but want so more experienced answers.

 

[lazydrifter]

Are you running a felt wad between your powder and your bullet?

 

[StorMay05]

I did when I was trying some Parker BE, unformed and knurled. Didn’t make much of a difference, haven’t tried them with the NE.

 

[sabotloader]

you may have a big problem shooting full bore bullets, if you notice tighter crown and a larger bore. The full bore will be sized to the tight crown then easily (to easily) slide the rest of the bore.

On the other hand it will probably shoot sabots very well.

Knight may help you out with your problem but you would need to contact them and discuss your problem.

 

[StorMay05]

I’ve reached out to them. Steve Bryan responded saying it could possibly be lap the crown end to open it slightly.

That’s the issue now .451s fit the muzzle with maybe 10 lbs of pressure, past that hardly any pressure at all.

I ran a No Excuses down the clean bore and was able to turn the muzzle down, bumped on the bench to see if the bullet would move and it slid out of the gun.

 

[sabotloader]

I’ve reached out to them. Steve Bryan responded saying it could possibly be lap the crown end to open it slightly.

That’s the issue now .451s fit the muzzle with maybe 10 lbs of pressure, past that hardly any pressure at all.

I ran a No Excuses down the clean bore and was able to turn the muzzle down, bumped on the bench to see if the bullet would move and it slid out of the gun.

Not Good!

Once the bullet is through the crown - just through the crown does it require the same loading pressure continually the rest of the way down the bore?

Steve is an excellent contact at Knight. I would ask him if he might take a look at the rifle. He just might,

mike

 

[StorMay05]

Not Good!

Once the bullet is through the crown - just through the crown does it require the same loading pressure continually the rest of the way down the bore?

Steve is an excellent contact at Knight. I would ask him if he might take a look at the rifle. He just might,

mike

More or less the same pressure, which is basically none. I’ve have several muzzleloaders an am pretty familiar with what the pressure should feel like and start and finish.

 

[sabotloader]

More or less the same pressure, which is basically none. I’ve have several muzzleloaders an am pretty familiar with what the pressure should feel like and start and finish.

Then I would say that Steve's suggestion might be right on the ball. You could take it to a gun smith, it would be an easy task for him to accomplish.

mike

 

[StorMay05]

Update on this. Before I looked for someone to lap it I decided to slug the bore at the muzzle and the breech to see how different the were. The muzzle was measuring just under .453, and the breech was .453 on the nose. I don’t have a mic so this with a caliper. Did double check the caliper readings with some .308 and .451 diameter bullets though, was on the money every time.

Tried getting a more aggressive knurl on both Parker BEs and the 385gr No Excuses it held better but accuracy was the same. Tried both being wrapped with Teflon tape, at the suggestion of a friend these held great but shot the same. May try some tracing paper patches later.

Finally being frustrated I squeezed a few BEs down in my reloading press to try and and bump them up in diameter. Little hard to start as usual but went down with good pressure, and held well to the powder. This did the trick! First group was about 1.3” at 120yds. Have done this a couple more times and is consistently around 1” groups at 100 yds. Tried some bumped up BEs with BH209 yesterday and was getting under 1”.

Bumped up some no excuses, and the accuracy was still not great. Maybe I’ll try patching a bumped up ones. But for now I’ve found one bullet the gun likes. Will probably try other bullets after hunting season.