What Options are there for Smokeless Builds?

[willraygreen]

I have been lurking around here for quite some time, and this site helped my decide a smokeless muzzleloader was something I wanted. Last year, I let a local gunsmith build me up a smokeless on my M70 Heavy Barrel Varmint platform. My understanding is that a guy named Richard Franklin is the guy who developed the system used with my gun. It is simply a 45 cal Kreiger barrel, tapped to accept a Knight breech plug and Knight nipple. The primer carrier is a cut off Laupau cartridge casing. The carrier, nipple, and breech plug are headspaced to the action for a snug fit when you close the bolt.
My barrel finished out around 28", and with 73 gr. 4198, it delivers a 275 gr BE right at 3000 fps while shooting MOA. My only complaint I have with the gun would be the "system". I have been thru a few nipples / primer carriers, as they inevitably "burn out". I would say I probably average 25 shots on a nipple. If a nipple goes, it usually takes a primer carrier with it by burning a small groove on the inside of the case around the flash hole.
I have read quite a bit on here, and seen references to different "systems" for smokeless muzzleloaders, but I wondered if someone could summarize the options available. I know there is the Savage, whether stock, or rebarrelled, but it appears there are a few guys making their own breech plugs, vent liners, etc, and building guns on 700 actions. What are the pros and cons of these systems? Where can I find more of the details?
My thought is that I might want to get a different breech plug/primer carrier for my gun if it can improve the reliability.

[Jon]

Will. I'm glad for your info. I've been looking at Richards b/p system with interest. He was saying 50 plus shots per nipple? I still think it is a simple and well thought out system. Every time you replace a nipple you are not only replaceing the surface the brass seats on but the vent at the same time? I'm looking for the same answers you are.

[willraygreen]

I have never gotten 50 shots, but then again, Richard didn't build my gun. I have added a 0.001" shim between the nipple and the breech to decrease the headspace. It takes a little more pressure to close the bolt, but I haven't blown another nipple yet. . . but I haven't shot but maybe 10 rounds since.

I guess in general, what is the purpose of a vent liner? In theory, why couldn't you take a gun chambered for 45-70, 500 SW, etc, load a primed cartridge case via the breech, then pour the powder and seat the bullet thru the muzzle? Other than the flash hole in the cartridge head, what plays the role of the vent liner in a traditional cartridge? Is it possible the vent liner is a "carry-over" from the true BP muzzleloader days, and not really required for some of these modern smokeless ML's?

[fishhawk]

First, most if not all states would not accept a gun as a muzzleloader that could also take a complete cartridge too. It would need some permanent block in the barrel that would not let a loaded cartridge in such as a collar to block the bullet. The ventliners primary function is a restriction for the full barrel pressure to not reach the primer. Adding a ventliner to your current setup might help your problem.

[willraygreen]

Isn't alot of cartridge brass capable of handling the pressures generated already? I have heard of a 45 cal muzzleloader built using a shortened 500SW cartridge as the primer carrier without any type of breech or nipple. If the brass is capable of handling the pressure, then a vent liner would not be required, right? In this gun, a 500 SW cartridge could not possible be loaded via the breech, so it is classified as a ML. I have never seen this gun/system, only heard of it.

In my ML, I assume the nipple is acting as the vent liner. It is a Knight Red Hot Musket Nipple, # 900012. The breech plug is # 900023. It is a simple system, and the weakest point is where the face of the nipple sandwiches against the inside of the cartridge head. I have thought many times about improving the contact area by making a custom nipple which keeps the 1/4" diameter all the way out to the cartridge head. Then there would be alot more surface contact to seal the pressure.

[muznut]

Safety issue loading a muzzle'loader with a live large rifle primmer and no plug or not a very deep vent? the reason you don't see flash hole growth in a cartridge case is because the plasma is going one direction out the barrel.