502-400-450-500-RF (HB) BP inline Comp / Hunter – 500 S&W

See the end of this post for Swedes’ preliminary Drawings – HP to follow

This is a continuation of a NOE 510-380-RF (HB) great plains for traditional BP group buy last year.

This is similar but for inlines

BP Hunting season is lurking – I have my Keith mould collection – so back to 50 cal BP inline wish.

I’ve talked with Al about modifying the 510-380-RF Great Plains to .502 diameter which is suitable to modern inlines and he is agreeable to the project.  He has limited time so we decided that I would do a makeup to the 510 GP drawing and get comments before he does a production drawing.

Points to ponder / consider and comment on:
Hornady developed the GP for traditional BP with larger bores and deeper groves.  Lyman also says their 50 cal Plains “fits most traditional muzzleloaders”

We have a very generous deer bag limit so a lot of data can be obtained quickly

We found the 44 Keith style 240g SWC in sabots worked MUCH better than the JHP normally used.
Bad news is somewhere between 500 and 1K sabots shot and your inline barrel sabot fouling build up is a disaster.  No amount of scrubbing or solvents will dissolve or remove sabot fouling.

With several fouled inlines that patterned instead of grouped there was plenty of experimentation.

We tried all the normal center gun cleaners.  Then Toluol, MEK, xlyene, ether, lighter fluid, paint stripper, and more on fired sabots.  All we got was nice clean sabots.

The GREAT news is Brownels Shotgun Wad Solvent WORKS both liquid and gel.  Swabbed out and left over night the sabot goo came out in globs.  Second application got only a little that was left.
Bores were shiny clean and original accuracy was back

The OLD Browning gun cleaner 8oz UPC 023614179412 that says” Removes lead, copper, plastic, carbon, powder fouling” does work although not as well as Brownels.  It has been discontinued for years – wish I’d bought more on close out CHEAP.

The 510 GP in pure lead doesn’t fill out well.  About 40:1 works well and is still soft enough for BP.  Beating a few .510 bullets with .485 groves into a 500 bore with .490 grooves deforms the nose and after about 2 shots you need a hammer to drive it through the fouling and seated on the powder – bad idea in BP.

The LEE REAL works fine and scrapes the fouling out on each reloading.  So we use a sharp trailing edge of the bullet as a fouling scraper.  Al thought that a sharp band trailing edge about .005 deep would release OK.

Wider, deeper grooves are needed to give the fouling a place to go as it is scraped off.

Hornady GP uses 4 grooves and is 380g.  Lyman Plains (508656) take is 3 groove 395g.  I like the 3 wider groove idea better because the wider groove gives fouling more area to pack in and displace grease.

I sweaged a number of the 510 -380 GP to 502.  This left almost no grease groove.  They were chucked up in a small HF lathe and grease grooves turned to about .475 x .055.  Lube was the Fryxell take on “Alox” using molygrease.  Accuracy was not too bad considering the deformed nose caused by the chuck and I’m sure they nutating about the CM because of the lousy machining.  BUT I achieved what I was looking for.  They started and rammed easily as long as I cared to keep stuffing them in.  Cleanup was a nothing with the normal hot soapy water.

I talked with various competitors at PB vendor booths at the NRA / AM in Louisville and most liked 400g or more for 50 cal inline twist.  Thus the weight of about 400g in the HB configuration.

The Keithesque profile of the nose is influenced by the effectiveness of the 44 Keith like240g SWC in the sabots.

There are two different brass ramrod tips proposed both with 10-32 threads.  The competition fits the nose and flairs to 0.495 to keep the nose centered.  The field tip is flat at 0.35 diameter as that is the ramrod diameters I have.  You got a smaller diameter one? Let’s hear about it.  The flat tip came from filing 10-32 brass screws flat and screwing them into my ramrods so they do not deform the meplat.  I also have a flat on the starter.

Up-Date [ preliminary drawings ]

Will be able to cast the following
502-500-SWC (PB)
502-470-SWC (HB)
502-420-SWC (PB)
502-390-SWC (HB)
502-339-SWC (PB)
502-309-SWC (HB)

First draft – changes can still be made!