It's been hard to start and seat bullets in my Marlin MLS-50, with the sole exception of Hornady 44 caliber XTP bullets in Hornady green 50 caliber sabots,. Only problem is that they pattern rather than group. So it doesn't get shot much.

Hornady 250 grain SSTs shoot pretty well with 80 grains of Triple 7 and CCI percussion caps, but the barrel is so tight I sometimes have to use a mallet (I know I'm going to really catch it now) to get the bullet seated.

Pure lead cast bullets (Lee), lubed, same thing.

Would switching to some version of a Minie ball be worth considering at this point? If so, any suggestions for a particular one? Thanks!

My Pedersoli Hawken Hunter was so tight that any bullet larger than exactly .500 was hard to seat. There's lots of variations in actual ".50 Caliber" bullet diameters. I once tried to seat a Hornady Great Plains bullet (which calipered at .510 but was labled 50 caliber) and I had to use a mallet to get it seated in a clean, unfired barrel. That was the only one I ever fired.

Based on good advice I got here, I ended up buying a No Excuses Bullets sizing pack. Each pack is a tube of 5 bullets, with diameters of .500, .501, .502, .503 and .504. You want a bullet that is snug and won't move after it is seated on the powder, but not so tight that you you have to bang it down the barrel. And which you can get one or two more bullets down the barrel without unreasonable force after firing the first load. For me, the .500 was the only size that worked well. Even if it seems it is going down the barrel easier than you are used to, as long as it doesn't unseat off the powder with test thump or two, it will be fine. The bullet will obturate (bellow out) and fill the rifling when fired.

https://www.muzzleloading-bullets.com/product/50-caliber-sizing-pack/

https://www.muzzleloading-bullets.com/sizing-pack-instructions/

I suggest you buy a pack of felt wads in .54 caliber and put that on top of your powder charge and seat the bullet on that.

https://www.midwayusa.com/product/2509115162?pid=115162

Remember, this is a sizing pack and may not be the bullet weight you decide to go with later. So don't worry about accuracy. You are seeking the proper diameter, first.

Try powerbelts, load easily

Have you tried different charge weights and different powders for accuracy? That bullet/sabot combo has never not worked in a host of different inlines that we've used and with several different powders, including Holy Black. We've always been around 100 or 105 grain charges for good accuracy at 100 yards. We had to switch to T/C sabots because Hornady quit selling those green sabots in 100 count bags.


Are you sure you have a sabot matched to the bullet diameter? I'm digging back into the memory bank, but if I recall, the 250 SST is a .452 diameter bullet and needed a thinner sabot. I buy stuff in bulk, so I've always had to match up bullets and sabots. Again, if I recall correctly, the 250 SST was hard to load for us too, so we went back to the 240 XTPs.

I should have caught onto matching the bullet and sabot before. The SSTs I have mike at 0.450" and the black sabots @ 0.495". Together they come out @ 0.505". The 44 caliber XTPs I had were 180 grains and are 0.428" in diameter.

Thanks for the heads-up on the bullet sizing pack; I'll definitely get one of those.

I have some Cerrosafe; probably ought to get an actual bore measurement with it.

Steve: You can measure bore diameter with an oval egg lead sinker with longitudinal hole. A size 7 is .530 in diameter. Use a 1/2" brass or copper ground rod close to bore size driven by a large hammer. If you use a small hammer you will just swage the sinker and stick it in the bore. Clean the bore first and lightly lube with WD-40 or other low viscosity lube. Measure slug with a micrometer.

When I had an MLS-50 I used Blackbelt (Powerbelt) bullets, 405gr IIRC. Loaded easy, were accurate and put a whoopin' on whitetail. I subscribe to Doc Whites method of slip fit pure lead bullets. You can accomplish that with the No Excuses bullets. I hate forcing down hard to load sabots needed for jacketed bullets.

Thanks; had forgotten that; it's been a while since I slugged a bore. Comes down to whether I find the sinkers or the cerrosafe first

Any way to pick out thinner sabots so I can shoot up the rest of my SSTs?

Your best bet may be to buy a pack of Harvester Crush Rib sabots to match your bullets. The Crush Rib sabots are available in packs of 50 and have about 50% less resistance when loading.

No mention of the bore. The plastic sabots can often leave a sticky in the bore. I have a Hawken flintlock that the original owner shot the sabots. It took me quite a while with brush and solvent before I was able to get it cleaned out.
I found the BoreRech for black powder to do a great job.

Measure your bore and then shoot the appropriate size No Excuses bullet. Thank me later