keyhole issue

[DavePA]

New experience for me. I was helping my cousin and his son fine tune their inlines for an upcoming CO elk hunt. Both are shooting identical T/C .50 cal Encore rifles. QLAs have been removed and muzzles professionally re-crowned.

Load information:
No Excuses 460 gr cast
OxYoke felt wad all atop 777 powder (volume ranged from 80-90 grains)
Win 209 primers

Breech plug removed and bore cleaned every 3 shoots.

We experienced three different keyhole events on target from the 50-yard benchrest. Anyone have any ideas? Something is upsetting stability in this equation.

Coincidentally, same bullet from my T/C Triumph (albeit using 90 grs Blackhorn 209 powder) shoots great.

Thanks. Dave

 

[GM54-120]

How easy do they load in the Encores that are keyholing vs your Triumph?

Are all the bullets from the same batch of NoExcuses?....Could it be possible they got a batch that are harder?

How old is the can of Triple7?

Have they tried BH209 in theirs to see if the problem persists?

 

[DavePA]

Bullets loaded easily in both rifles along with my Triumph
All excuse bullets from the same box.
New can of 777.
Unfortunately, I ran out of BH209 to try
Thanks

 

[GM54-120]

For whatever reason, 1 of 2 things is happening
1) The conical is not obturating into the grooves so its not grabbing the lands.
2) Its grabbing the lands but hitting them too fast...i think this is highly unlikely with only 80-90gr of Triple7.

Since 90gr of BH209 works in yours. Try 100grV of Triple7 in theirs. Its a tad milder than BH209. Also try the Triple7 load in yours to see of the problem follows the powder. That would be the least expensive and easiest thing to try atm.

 

[fishhawk2700]

I would say load is to lite. My Encore liked heavy loads. Although my Encore didn't seem to like any load,(long story)heavier was better. I wouldn't be afraid of going to 120 by vol.

 

[52Bore]

I shot a 500gr pure lead bullet I made in my Encore with 75gr Swiss 2f using a hard card wad - it shot wonderful. I too cut off the QLA, same load group cut in 1/2.
Bullet hardness is my guess

 

[sdporter]

Which shots were keyholing? any rhyme or reason there? It looks like off the lower right side of the picture, tgere was a good group developing with round holes. Check the flash hole erosion and speed them up. That’s a long bullet in a 28 twist rifle.

 

[jlynch75]

I've gotten keyholing from my own 464gr pure lead bullets with my Whitelighting when I use 777/fff volumes over 75gns.

 

[sdporter]

That (to me) seems odd. I’ve never, that I can think of, had a longer bullet keyhole from any of my muzzleloaders. The absolute worst shooting bullet I’ve ever shot, was a 250 grain Maxi-Hunter from my 1:48 T/C Renegade. I was shooting it at a target on a 4x4 sheet of plywood at 75 yards. I hit the paper once and the plywood twice out of about 6-7 shots. Two of the tree holes were key holes. The first shot, hit dead on and smashed a clay pigeon I had hung on a nail in the center of the paper. I wasn’t cleaning between shots, I never had anyone teach me how to shoot a muzzleloader, so I had no idea the difference that might make (good or bad). I was probably 18-19 years old so about 30+ years ago. Haven’t shot them since.
May have to revisit those bullets again.

 

[edmehlig]

When I first started shooting White ML's I had purchased a can of Swiss 1F powder. If my memory serves me correctly. Being inexperienced at the time with ML's someone told me to shoot only 50gr of powder of 1F. So off I went. loaded her up and with a 465gr White PowerPunch bullet. I fired away. I think the range as it was many, many years ago was 50 yds. It might have been 25 yards? In any case, I seemed to be missing the target?? Then, all of a sudden I saw a large hole appear. I thought to myself gee, I wonder if I was putting them in the same hole all along??? NOPE! That bullet hit perfectly BROADSIDE where you even saw the bands of the bullet on the target. Again, I was inexperienced and was afraid to experiment by using hotter loads. So I stuck with the recommended loads that Doc suggested with Proydex P. It wasn't until a few years later, I started using 777-3F and now shooting Swiss 2F and 3F depending on the ML.
I sure do wish Modern Muzzleloading was around back in the early to mid 90's. It would have saved me a lot of growing pains.

 

[GM54-120]

So did you get a chance yet to try BH209 in theirs and the Triple7 load in yours? Knowing if the issue follows the powder will shed light on the cause.

 

[Valkyrie]

Those 460's are available in multiple diameters. From the web site; "Sized at .504, .503, .502, .501 and .500 enabling a perfect fit for all guns". Do you think you may have got undersized slugs for your barrels??