Rpair muzzleloading nipple

I blew a nipple out of a 25 yr old Lyman Great Plains Hunter after shooting a 265 grain sabot with 80 grains of Goex. That's all within factory specs. I then went from a 6mm to a 7mm oversized nipple and re-tapped the snail. It works with a reduced round ball load, but am not sure about a full power load with sabot. The new nipple doesn't feel as secure (tight) as the original nipple. The new nipple feels sloppy screwing down after cleaning.
I've heard of just re-threading the snail by using incremental stainless steel nipples until one size over size is reached.
Any recommendations? Or alternatives?

Thanks for the help. I'll take it one step at a time until I find what is going to work. I checked with Lyman. They will not supply me with a new breech plug. I would have to buy a pre-assembled plug and barrel. They had a recall a few years ago because a breech plug blew out of a factory gun.

If you have a serial numbered gun made in 2017, they will replace the barrel. As for my problem no.

The gun smith at Track of the Wolf retired a couple of years ago. I tried their oversize repair with tap and the oversize repair from Dixie. I also had a local blacksmith pressure fit a liner. All of them blew out within 4 shots. I picked up a T/C Hawkins at an estate sale for $100. I think that is the cheapest repair yet.

It's one year later and had a blacksmith weld over the entire snail area. He then re-drilled the nipple hole and annealed it.
Now he re-tapped it for the original size nipple. Everything looks good. The nipple hole is off center a little, but all I had to do is cut away some more of the front rim of the hammer. I fired a couple of caps and the fire channel appears to be clear and I blew a leaf around the yard. Can't wait to site it in again. At 6 degrees this a.m. I'll wait for some warmer weather.

Armorer 101 said:

I like the buying the TC Hawken repair method…… I tried the snail weld on my old 50 gun and it just blew the end of the snail off, 2nd shot, hope you have better luck than I.

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IT'S BEEN FIXED. A friend welded over the nipple hole, then annealed the weld and re-tapped it for the Lyman size nipple. Previously, a guy pressure fit a stainless steel ring but that only lasted for 5 shots.