Shooters Forum banner

Loading & Barrel lapping questions

7K views 24 replies 11 participants last post by  Starrbow 
#1 ·
Hello Gents-

I have been hunting with a TC Hawken - .50 cal muzzle loader here in CO for deer & elk for the past 8 yrs. Haven't bagged a critter every year but have thoroughly enjoyed the less crowded woods and hunting close.

CO doesn't allow the use of scopes, sabots, etc. but do allow the use of conical's. I've been using a Hornady Great Plains conical 405gr. FP over 95grs. Pyrodex select and a CCI #11 cap. Groups well for me at 50 yds. Of interest to some of you - I found this gun and others of my kids and friends to be very particular as to what bullet they preferred also. My Hawken & a Renegade both prefer the Hornady Great Plains bullets - either the 385gr HP or the 405gr. FP. My son's Thunderhawk prefers the TC Maxi-Hunter, another gun of a friend, TC Hawken, prefers the Buffalo Bullet. Same for a CVA in-line. Difference between the bullets they prefer vs. don't is drastic. 2" 50 yd groups vs. 5"+ !!!

Question 1) - just out of curiosity. I tend to be accuracy oriented and was wondering if any of you may have tried "fire-lapping" the bores of your muzzle loaders. It seems to me that the same benefits for clean-up and uniforming the bore that are ascribed to doing this with centerfires would also benefit the muzzle loader gun. Have been considering giving this a try.

Question 2) - Have any of you ever tried shooting paper patched bullets in your guns? I was pondering the possibility of using the old method of paper patching bullets and wondered if this might not be of benefit in shooting these conical bullets. Might also allow the use of slightly harder alloy (1:20) while still affording the clearance needed for loading.

Best regards-

Sky C.
Longmont, CO
 
See less See more
#2 ·
Sky,

Interesting you should ask about this subject. I've got some work to do, but an upcoming tech note will detail the process thoroughly. I've lapped five different muzzle-loaders to date for the project, and each one has shown remarkable strides in lack of fouling, increased accuracy, and a great diversity of projectiles and loads the guns will shoot well after fire-lapping.

Oversimplifying the process, you proceed as with firelapping any other gun in rolling your projectiles between steel plates coated with lapping compound to imbed the abrasive in the bullets, then load over BLACK POWDER (not Pyrodex) and shoot, cleaning between each shot with a clear water soaked cottin swab. The bullet MUST be a hollow based Mini design, and MUST be BHN 11-12 in hardness for this to work properly.

With a .58 Cal older CVA Mountain Rifle, lapping took round ball loads from 6-8" groups to under 2" using same patch, load and ball. Similar results with CVA Bobcat 50. TC Greyhawk 50, Knight MK85 54 cal and a CVA 45 cal.

Great stuff, and so simple. More to come!

God Bless,

Marshall
 
#3 ·
Marshall-

Thanks for the feedback. I'll be very interested to see the tech note.

In the meanwhile - I want to ask about the bullets you are using. Are these a product you sell? I couldn't find anything on the site - maybe just not looking in the right place... If you have offerings for .50 Cal ML bullets - I'm very interested to buy some and try them.

Also BHN 11-12; I understand the rationale from your other info but for a ML gun - with the harder bullet and especially once treated with lapping compound - doesn't it present a fit problem to get the bullet down the bore?

Mochas Gracias!
 
#5 ·
True, I don't have ML bullets listed on our offerings, other than the .44-325g LFNSS bullet designed specifically for sabots. I simply don't have the time to deal with yet another facet of Beartooth Bullets! It would necessitate buying yet another alloy and inventorying that for the few bullets that we would market, and I just don't see that penciling out on the bottom line.

About the lapping bullets, indeed they are somewhat difficult to load, I'll give you that, but my experience has shown that even very tight constrictions, such as under dovetail sights and wedge-pin holders that are dovetailed into the barrel (up to 0.006" constriction here on some guns) that the complete lapping process can be done on ML's in about 20 rounds! So, forcing a rather difficult bullet down the bore only 20 times max is a livable condition. However, the bullet hardness is crucial to proper lapping action.

I will be offering lapping bullets for .45, .50, .54, & .58 for those who ask. Sold in packs of 20 bullets each (the max needed for a lapping project.)

As for the why black vs. Pyrodex? Well, it seems that the Pyrodex, while producing similar pressures as Black Powder, still has the pressure curve characteristics of other conventional smokeless powders. Blackpowder delivers that instantaneous pressure that we're all accustomed to, and that's what is necessary to expand the skirt on those BHN 11-12 hollow-base minis used in lapping so that you get uniform lapping action throughout the length of the barrel. The guns lapped using Pyrodex seemed to get most lapping action after the first six inches of bullet travel. We use what works!

Looking forward to getting that article written.

God Bless,

Marshall
 
#6 ·
A very interesting topic - and truthfully, one I had never considered before. Having dropped a bore light down a muzzleloader, I can attest to the generally rough finish left in most of them.

Maybe this can be another project when the lapping slugs are available. My question though is this - forcing a tightly fitting lead bullet impregnated with lapping compound down the bore would effectively remove the coating from the bullet where it contacts the lands for the length of the bore, except for just the beginning at the muzzle where starting the bullet, wouldn't it? It would no doubt smooth the grooves satisfactorily, but what about the roughness of the lands?

Just my humble way of expressing my ignorance on the matter!
 
#7 ·
Interesting, but no, it appears that once the lapping compound is imbedded into the lead alloy bullet, when starting the bullet it just compressed the bullet a bit, not "scraping" anything off. The system actually works very, very well, and once you touch off the blackpowder charge, the skirt expands to fill the grooves, and you acheive a very uniform lapping action for the full length of the barrel. With properly designed HB Minnies, you really don't have that much contact with the lands when seating the lapping bullets.

I do know this, universally, in the ML's I've lapped the accuracy was makedly improved, the fouling greatly reduced and the ease of loading is indescribable!

Indeed, a good winter project!

God Bless,

Marshall
 
#9 ·
Rifle crowns get a certain press that would lead you to believe that there is a combination of voodoo, animal sacrifices, and long-distance phone calls to Miss Cleo involved in setting one up correctly.

Mostly, they just need to be EVEN. No big nicks, gouges, burrs, warts, rust pits, or other damage.

Other than that, the angles and exact dimensions are not terribly critical. The less muzzle pressure you have, the less the crown would affect accuracy. And muzzle-loaders would certainly have a very low gas pressure at the muzzle.

Most of them probably have burrs on them from the manufacturing process anyway, which would take forever to shoot out with soft lead bullets. You may be improving them to a tremendous extent without even realizing it.

I'm sure that starting out the bullet in the muzzle probably does put a little wear on the crown. As long as it is even, shouldn't be a big problem. Most crowns have a bit of a radius on them, anyway.

The bench-resters and long-range high-power shooters have their own specs, but that's a lot different than shooting a whitetail.
 
#11 ·
Sky,

I won't have slugging kits available, but the necessary HB Minnies for lapping. They are all be priced the same from 50-58 caliber, 20/box for $10.00 US. Just let me know what you need, and we'll get you taken care of! They are available now on request basis.

Thanks so much.

God Bless,

Marshall
 
#12 ·
Incoming e-mail about how to order two .50 sets and a .58 set. My three shoot pretty good as they are, but if I can improve them any at all it will be worth it, especially the .58, it has always been the problem child.
 
#14 ·
Lapping

Most of my muzzloaders, I wrap strip of a medium grit scotch brite pad around a bore brush, and polish for a hundred strokes raising the rod as I go along. Really helps as far as patched round balls are concerned takes the sharp edge off of the rifling and helps with patch cutting. Far as sabots are concerned I tried them but did not like the tupperware in the bore. I have a lyman mold that I had a enlongated .525 non grooved bullet mold made in the other side of it ( it is a rb mold on the original side, plenty of room ) Just had the NC mill operator do it at my tool room, now I use lubed cloth patches with this and they do shoot well, just some idle thoughts and way too much time on my hands. Take care and have fun. Swany
 
#15 ·
Hello All-

Got the minie's from Marshall but didn't have time to do the lapping prior to ML season. I was fortunate to have a cow elk trot into my shot at around 35 yds so now will have meat for the winter.

Bullet: Hornady Great Plains .50 cal - 410gr FPHB / 95 grs. Pyrodex Select. Elk shot through front shoulder quartering-on through lungs and body penetrating straight for approx. 30" and came to rest inside skin ahead of offside rear quarter. Bullet expanded to >.90 caliber w/retained weight of 404.6 grs. She went about 30 yds showing no sign of being hit (or even that I'd shot) - then lay down and expired. While I can't complain too much about performance - I was surprised that the bullet did not exit given that the distance was only 35 yds.

Will try to get out to establish baseline performance with good records keeping and then proceed to fire-lap as has been discussed in this thread concluding with re-assessing performance when done. Note: Got the "Technical Guide" re: cast bullets that Marshall sells - good stuff.

Marshall - If you're still following this thread... Is there a way to slug the bore of a ML rifle (breachplug on my Hawken doesn't detach as far as I know)? Thought it might be a good piece of info - pre & post lapping to have; especially for the purpose of spec'ing a mould downstream. Have thought about casting an oversize pure lead slug that I could make from a chunk of hardwood drilled to appropriate size for a mould, pounding it into the bore a little ways and then "ejecting it" with one of the silent ball dischargers. If there's a better or more accurate way - please share!

Best regards-

Sky C.
 
#16 ·
Sky,

Congrats on the cow elk! Hope one is as obliging for me in November on our Blackpowder elk hunt here in Idaho!

About slugging. What you suggest would work just fine, using the silent ball discharger. I don't have any oversize slugs for the ML's, but you've got me thinking, and it wouldn't take much to turn something simple on the lathe just to cast slugging plugs. Hmmmm, not yet, but I'll put my thinking cap on. Good idea, and I appreciate ideas like yours! In the interim period, you're definitely on the right track. Let us know what you do, and how the project progresses.

God Bless,

Marshall
 
#17 ·
Well, finally I got to lap the TC Big Bore .58. Twenty bullets later, the tight spots were gone, but would she shoot now? Before lapping a 3 shot group (if you can call it that) at 100 yards measured over 30 inches. Not exactly stellar performance. Lapping with 40 g. BP for the first 3 shots, then reducing to 30 gr. BP for the rest, took over three hours with all the cleaning between shots. After all 20 laps were down range I shot another 3 shot group with the Maxi-Hunters over 100 gr. Pyrodex, the same as the first group. Not good, but at least all three bullets were on the same target and measured a hair over 8 inches. In all fairness, these bullets and powder had been in some BC speed loaders for over three years so that may account for a lot of the group size. After fooling with that thing all morning, I was ready to pack it in. Maybe with some fresh powder it will shoot better as I remember it shooting a lot better than that before. At least now you can seat the bullet without making a couple of stops on the way down. I'll know more the next time out when I can shoot for group from the get-go and do more than just one group.
 
#18 ·
Sky C. said:
Hello Gents-

I have been hunting with a TC Hawken - .50 cal muzzle loader here in CO for deer & elk for the past 8 yrs. Haven't bagged a critter every year but have thoroughly enjoyed the less crowded woods and hunting close.

CO doesn't allow the use of scopes, sabots, etc. but do allow the use of conical's. I've been using a Hornady Great Plains conical 405gr. FP over 95grs. Pyrodex select and a CCI #11 cap. Groups well for me at 50 yds. Of interest to some of you - I found this gun and others of my kids and friends to be very particular as to what bullet they preferred also. My Hawken & a Renegade both prefer the Hornady Great Plains bullets - either the 385gr HP or the 405gr. FP. My son's Thunderhawk prefers the TC Maxi-Hunter, another gun of a friend, TC Hawken, prefers the Buffalo Bullet. Same for a CVA in-line. Difference between the bullets they prefer vs. don't is drastic. 2" 50 yd groups vs. 5"+ !!!

Question 1) - just out of curiosity. I tend to be accuracy oriented and was wondering if any of you may have tried "fire-lapping" the bores of your muzzle loaders. It seems to me that the same benefits for clean-up and uniforming the bore that are ascribed to doing this with centerfires would also benefit the muzzle loader gun. Have been considering giving this a try.

Question 2) - Have any of you ever tried shooting paper patched bullets in your guns? I was pondering the possibility of using the old method of paper patching bullets and wondered if this might not be of benefit in shooting these conical bullets. Might also allow the use of slightly harder alloy (1:20) while still affording the clearance needed for loading.

Best regards-

Sky C.
Longmont, CO
I have a .54 hawkin and usually shoot rb but wanted to try the conicals, well they did not impress me as far as shot groups were concerned, the patched round ball, 120gns of P pyrodex and 3" at 100yds impressed me. I still wanted a conical, I noticed buffalo ballets and got to thinking why not just bore out my rb mould (lyman) and have at it. When I took the mold out I noticed there was plenty of room for another mold on the other side, so I had a friend on a CNC mill bore the other side for a conical on the other side well, I my theory was to use a cloth patch on this also and have the advantage of the conical and the cleaning and lubing quality of the cloth patch. GUESS WHAT IT WORK WELL AND NO TUPPERWARE IN THE BORE.
 
#19 ·
lapping barrels?

Marshall,

I am glad to learn about lapping the barrel. I have not heard of this concept before and I am deeply interested in achieving the best possible accuracy from my muzzleloaders. Do you have bullets available that can be used to lap a .32 barrel? I have been doing most of my shooting with my .32 Cabela's Blue Ridge rifle lately. I have on two ocassions achieved groups that varied only 1/8 of an inch horizontally and 5/8 vertically at 25 yards, but the problem is that I have not achieved that same accuracy since. I have obviously come to the conclusion that I have missed something. Perhaps the barrel needs lapping. What do you think of the process of lapping a barrel by abrading it with scothbrite pads as described by another writer below this post?

I would be thankful for any new knowledge you could pass along to me.

I looked up Romans 1:16. I too am not ashamed.

Thank you.
 
#21 ·
Terry,

I don't have a hollow based mini for the .32's. However I'm sure that lapping the bore is possible and all muzzle-loaders I've experienced have benefitted from lapping. Just a thought. Might consider a .32 cal HBWC bullet... don't know for sure if it would work, but they are abundand and cheap! Would be worth looking into in my opinion.

Let us know what you find.

Thanks to all, and God Bless,
 
#22 ·
Marshall - Need your feedback... fire lapping

Well it's been a while but am finally getting around to doing the fire lapping project on my TC renegade. In fact - my buddy is doing his TC Renegade as well.

As we started the process - it was interesting to note how much different our two rifle bores felt when driving the lap impregnated WW slugs down the bore. His had a number of tight then loose spots which gradually improved as he proceeded to send about 16 slugs down the bore. By the end - there are still some constrictions but it is noticeably improved. FWIW - we used aluminum rod adequately wrapped and a 4lb. sledge to drive the slugs down the bore. They require quite a bit of "persuassion" to get them seated.

My bore was reasonably uniform to start without the tight/looses spots. I have only run 9 slugs down the bore so far.

Marshall - I note you posted your tech note on this procedure since the thread was last active. It raises some questions...

1) You note that it is important to "brush-lap" the barrel following the actual fire lapping. Could you do me a favor and explain why?

2) Barrel break-in following the lapping... Is this to condition the bore?

We have both stopped with the firelapping process - did not proceed to the "brush-lapping" yet but wanted to see about groups. We did short-stroke the bores good with our chosen lubes. Nothing to write home about yet. Did note that regular lead conicals were prone to sticking after the first shot trying to load into a fouled bore. Is this just a matter of getting the bore better seasoned you think? Just trying to get an idea of whether we've made enough progress by testing accuracy or whether we need more fire-lapping, etc.

Thanks-

Sky C.
 
#23 ·
Sky,

Actually what you call "brush-lap" isn't lapping at all, but an essential part of the process, giving a final polish to the bore. I guarantee that if you skip this step, your break-in process is going to be long, tedious and very frustrating. Whatever you do, don't skimp on this phase of the lapping operation, it is absolutely essential. And when I say one hundred strokes, as being a complete down and up stroke of the polishing bob, that's exactly what I mean.... no less!

THis step will not releive any constrictions, as the spongy bob merely follows the contours of the barrel. Too, if you have any contricitive points remaining in the barrel, continue lapping until they are gone. After that, then follow through with the polishing sequence.

Following the polishing, break-in should be a peice of cake! And yes, indeed the break-in process is to season the newly exposed raw barrel steel!

I hope this helps. Let us all know how your lapping projects work out!

God Bless,
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top