Who's got the answers? Although I'm an avid classic firearm enthusiast, I'm not a big shooter. About the only time that I shoot anything larger than a .22 cal. air rifle is to zero in a hunting rig. As a matter of fact, that's exactly what I went to do today with my new ultralight underhammer...but that's a whole other thread.
The subject of this thread is an earlier build...My .45 cal. Springfield Carbine. It's a hybrid of sorts, cobbled together with parts obtained from a mixture of other firearms.... A barrel band from a WWII Mauser, a trigger bow and plate from a dilapidated barn gun, a buttplate from a mini-fourteen...You name it.
I took her along today to evaluate her usefulness as a deer rifle and I'm not feeling any more "enlightened" than I felt before I left the house to head to the range.
The session began with a single squib shot followed by a dryball as I foolishly allowed myself to be distracted. After discovering that my .50 cal. bullet pulling worms don't fit down a .45 cal. barrel, I resorted to priming the bolster with the last, little bit of FFFF priming powder in the priming flask that luckily was in my tool kit. That took care of my problem.
The purists here are gonna hate me but I'm shootin' with Triple-7 pushin' .440 cal. lead balls wrapped up with .010 pre-lubed, linen patch because that's what I'll hunt with. The carbine is rifled at 1:66" and my questions revolve around inconsistent velocities. I'm reluctant to blame the propellant because I get very consistent pressures with it in other guns. The carbine however was stringing shots and my chronograph confirmed that I was getting a pretty good spread in my velocity.
I took 8 shots. Here's the string:
1295
1502
1552
1513
1696
1739
1746
1642
I thought that I was measuring carefully. I think that my issue was a change in force when tamping down the ball onto the charge.
1st Question: Could inconsistent seating pressure affect velocity enough to achieve an extreme spread in 8 shots of 451 fps?
2nd Question: Given that the average of the velocities shown above is 1626 fps and would yield a muzzle energy of 751 ft lbs, isn't this a little on the week side for even your average whitetail?
3rd Question: Assuming that you agree that 751 ft lbs is inadequate then I need to bump up the velocity of the 128 grain lead ball. Is 2000 fps goin' to be unstable shooting these little round balls ? I hope not because it'll mean a muzzle energy of 1137 ft lbs of energy.
Any light you can shed on these questions will be put to good use
You say it is "cobbled" together from various pieces and parts. What about the barrel? If it is used, what is the bore size? To say .45 doesn't mean a .440 ball will be correct. It sounds like your patching is to thin and then maybe the barrel is shot out.
I would try different loads. Change your ball size, patch thickness, (I agree with Papa, .010 sounds way too thin). And yes, your, let's call it COMPACTION will have an effect. However it is not unheard of, even with smokeless powder, to get varying velocities in ammo that is all loaded at the same time. Also, your LOWEST velocity is your first shot. You will notice a general increase as you build up fouling in the barrel. This would lead us back to a tighter ball/patch combo. Just some observations.
Makes good sense to me guys. The barrel is an unfired (until I fired it) barrel from what was originally gonna' be a H&R Springfield Stalker rifle that were made in the 70's. I purchased it as new from Numrich Arms a couple of decades ago. Don't know the diameter of the lands. I'll mic it up when I get home tonight. What's the rule of thumb for bullet diameter vs land diameter? Thicker pathching sounds like a good place to start. I'll be more consistent with seating pressure as well.
At what velocity should I expect a .45 roundball to begin to destabilize?
Razor 62
You seem to enjoy the science of shooting so try these for some reading pleasure.
http://home.insightbb.com/~bspen/math.html http://home.insightbb.com/~bspen/ballistics.html http://home.insightbb.com/~bspen/trajectories.html and http://home.insightbb.com/~bspen/onetrajectory.html. These may pique your interest.
doggoner
Thank you doggoner! This is priceless!!!
Seating pressure can sometimes have an affect on velocity, but. Your patch is really too thin. In my .45 I use .024" canvas for patches and get fine velocities and accuracy. A round ball can't become "unstable". The wind can blow it around and gravity can pull it to the ground but it won't ever "keyhole". Sub powders are inherently a bit harder to ignite than Black. First I recommend a thicker patch and see if that helps. If not then we can suggest the next variable.
A thicker patch it is then. I think I've got some old pillow ticking around somewhere.
Thanks Hanshi and to doggone, Dogshirt and Papa as well!
That's what I love about this bunch of folks,...Always willing and often eager to help a guy out on his way toward success.
Somehow I'm not upset about having to spend another day at the range... ;D
Quote from: Razor62 on August 20, 2020
Who's got the answers? Although I'm an avid classic firearm enthusiast, I'm not a big shooter. About the only time that I shoot anything larger than a .22 cal. air rifle is to zero in a hunting rig. As a matter of fact, that's exactly what I went to do today with my new ultralight underhammer...but that's a whole other thread.
The subject of this thread is an earlier build...My .45 cal. Springfield Carbine. It's a hybrid of sorts, cobbled together with parts obtained from a mixture of other firearms.... A barrel band from a WWII Mauser, a trigger bow and plate from a dilapidated barn gun, a buttplate from a mini-fourteen...You name it.
I took her along today to evaluate her usefulness as a deer rifle and I'm not feeling any more "enlightened" than I felt before I left the house to head to the range.
The session began with a single squib shot followed by a dryball as I foolishly allowed myself to be distracted. After discovering that my .50 cal. bullet pulling worms don't fit down a .45 cal. barrel, I resorted to priming the bolster with the last, little bit of FFFF priming powder in the priming flask that luckily was in my tool kit. That took care of my problem.
The purists here are gonna hate me but I'm shootin' with Triple-7 pushin' .440 cal. lead balls wrapped up with .010 pre-lubed, linen patch because that's what I'll hunt with. The carbine is rifled at 1:66" and my questions revolve around inconsistent velocities. I'm reluctant to blame the propellant because I get very consistent pressures with it in other guns. The carbine however was stringing shots and my chronograph confirmed that I was getting a pretty good spread in my velocity.
I took 8 shots. Here's the string:
1295
1502
1552
1513
1696
1739
1746
1642
I thought that I was measuring carefully. I think that my issue was a change in force when tamping down the ball onto the charge.
1st Question: Could inconsistent seating pressure affect velocity enough to achieve an extreme spread in 8 shots of 451 fps?
2nd Question: Given that the average of the velocities shown above is 1626 fps and would yield a muzzle energy of 751 ft lbs, isn't this a little on the week side for even your average whitetail?
3rd Question: Assuming that you agree that 751 ft lbs is inadequate then I need to bump up the velocity of the 128 grain lead ball. Is 2000 fps goin' to be unstable shooting these little round balls ? I hope not because it'll mean a muzzle energy of 1137 ft lbs of energy.
Any light you can shed on these questions will be put to good use
One thing Id like to add on all this is that the old rule of needing at least 1000 ft pd.s of energy generated by the bullet only applied to center fire shooting and has fallen out of favor since it's inception. The ability to put the bullet or round ball in this case where it needs to go in order to result in a quick and humane kill is more important than amount of remaining energy in the projectile. I'll also say that a RB is deadly out of proportion to it's diameter and weight but only within a shorter range compared with modern rounds. One of the reasons for using soft, pure lead for round balls in my humble opinion. One rule of thumb that I still think worthy of passing on is that for every yard you will have between you and your target, you should shoot one practice shot using your chosen hunting load. In other words, if the conditions where you hunt allow up to a 100 yard shot at your game animal then before you get out there you should have taken 100 practice shots at a target 100 yards away. I can't see as well as I used to so my self imposed limit is 80 yards. If the deer or hog or whatever is farther than that, I wait or pass on the shot. That's why I got into muzzle loaders for hunting as I have been shooting game for over 30 years, but now I hunt.
As far as your patching, try mattress ticking or as is sometimes called, pillow ticking. Make sure it's 100% cotton and bring your mic to the store to measure the thickness. Also, be sure to wash the ticking before using as it has starch in it to make it flat. Using it for patching without washing it first will give you widely varied results. Don't ask me how I know this, I just do...... rdfce
Most of all, be consistent when loading to eliminate all the variables. If you haven't read anything by Dutch Schoultz then you should.
http://blackpowderrifleaccuracy.com/
One more thing: With trippple 7 always use a magnum cap. It does make a difference.
We never heard any more about your findings. Did the thicker patch work?
Razor62, I'm also very interested in how your loading is coming along. I'll go ahead and list some things many folks do as well as a few points of my own.
In general, a rifle usually takes a ball .010" or sometimes .005" smaller than bore diameter. A patch of at least .015" and up seem to work well. I use heavy canvas material to cut my patches from (.024") and lube with Hoppes BP Lube for general shooting and TOW's mink oil for hunting. I use patches of about .012" to .015" in the smoothbore and one rifle I have. Since most of my rifles are flintlock I use black powder because it ignites easily unlike most substitutes - they usually do well in percussions.
I load fairly tight prb but they seat with little protest in my rifles. My .45s for instance get fired with either a .440" or .445" patched ball. A major benefit of tighter prb fit is the fact one can shoot all afternoon without swabbing the bore. I'd much rather shoot than continually have to wipe the bore out after each shot. In order to load these tight combinations you have to first polish the rifle crown so entry into the muzzle is smooth and doesn't tear the patch. Sandpaper and a thumb is really all you need to accomplish a smooth, rounded crown. It can also be done in, oh, 30 minutes or so. Patches are generally torn by sharp muzzles rather than sharp rifling.
Let's talk about ballistics. Work up your hunting load for accuracy - find and check your patches down range - and then, and only then, should you chronograph the load. Forget about velocities and go for accuracy and ballistic uniformity. At 100 yards a .45 prb started at 1800fps will not be much faster than one started at 1500fps. Muzzleloading velocities plateau at not much over the 2000fps range. I did have a .40 that when chronographed with a 60 grain charge of 3F BP averaged a whopping 2140fps, totally unexpected! It was a fine 100 yard load but I used only 40 grains for 95% of my shooting. My deer loads typically range from around 1600fps to around 1800fps and drop deer quickly, often where they were standing. The loads are very accurate and limited only by my shooting ability. The squirrel rifles, .32 & .36, are loaded to much lower velocities to make them less destructive on tiny game.
If you can come up with a can or two of real black powder, either 2F or 3F, you might have better results. Speed variations such as those you listed show that something is wrong; so check the bore for condition, bore diameter and polish that crown. Extreme velocity spreads should not exceed double digits in the lower ranges. Magnum caps are a good idea and I even prefer them with BP.
Can't think of anything else to suggest; but if you can find other experienced BP shooters or (best) a mentor, do it. If you have any other questions don't hesitate to PM me.
you mentioned what you were loading with , but never the powder charge , so it`s really not possible to give and real advice without all the info ! , but yeah , a .45 is fine for deer work with your powder charge / patch combo till you get something that`s consistent ! my first rifle was a cva kentucky flintlock kit that with a charge of 60 grains of 3 f and a tight ,but not overly tight patch would do 2 shot one hole groups at 50 yards , and just slightly larger at 100 yards !