key holed at fifty yards

[Misfire99]

Hi All
I have a new H&R handi-rifle in 45/70. I loaded up some laser-cast 500 grain bullets on top of 23 grains of AA5744. I only fired five of them but all were keyholing at fifty yards. Whats up with this??? The load of 23 grains of 5744 is the low end of the trap door loading so I don't think that the rifling is being stripped. The bullets mic out to .4585 and the twist rate is 1:20 I think.

How would you guys correct this problem? Would you drive the bullets faster? Use a lighter bullet? Or what.

I had no leading in the bore at all so I don't think there is any gas cutting and I don't think that the bullet is two small for the bore at .4585. One interesting factor is the group was very tight. Even though the bullet hits were keyholed they all were with in a couple of inches of each other. So maybey they were stabilized almost all the way to 50 yards. I have 250 of these bullets. I bought them from midway on a closeout sale. I have other bullets to try. A 405 grain jacketed soft point. A 300 grain jacketed hollow point. Some Postell 535 grain and some Schmittzer 480 grain. The Postell and Schmittzer are planed for my Sharps along with some PP bullets from the Bull Shop that are coming soon.

For my next move I'm leaning towards driving them faster. Something like 27 grains of 5744. This is the lower end of the loads for the Marlin and Winchester rifles. For those that don't reload for 45/70 there are three pressure levels for this round. One for the old trap door rifle that is <18000 psi. Another is for the Marlin and Winchester lever actions. The pressure levels for these rounds is <28000. And the high pressure loads for the Ruger number one and three. Also the Siamese Mauser re-chambered to 45/70. This pressure is <40000.

So how do you guys think I can solve this problem???

TIA

[dubber123]

I'd slug the bore. A 500 gr slug is alot to stabilize, but at only 50 yards you should be able to shoot it really slow and have no problems. After all, they shoot similar bullets to REALLY long range, and they only start at 1,200-1,300 fps. If thats a lower end trapdoor load, I doubt it's stripping, unless the bore is really big. Slug it, and if it's within spec, I'd drive them faster. My brothers Handi in 45-70 shoots 500's very well at slow speeds. let us know how it works for you.

[John Boy]

Misfire - check to see if the bullets are out of round. Also, see how they fly at 100

[gray wolf]

Have you checked the twist rate, hey I don't no nuthin but I think you need something like
1-20 for that bullet. wrong spin wrong velocity could = tumble.

Now for my educated guess----
barrel twist
lenght of bullet
speed of bullet

Hey I am learning --- i got to be right sometime

[leftiye]

My guess is that you're way too slow. Reason, no leading. Boolits either fit or are going too slow to lead. Not stripping the rifling unless way too small for grooves. Probly them long boolits need more spin to stabilize. I'd bet that just a little more speed would give some nice groups.

[Adam10mm]

Check with the Greenhill formula:

Length of bullet expressed in calibers, times the twist rate in calibers per turn, is 150.

LxT=150 and that answer is divided by bullet caliber

L= length of boolit in calibers
T= twist rate

So measure the length of the boolit. Divide that by bullet diameter. That is the length of the boolit in calibers (L). Now divide 150 by that number and that will give you T or the optimum rate of twist for the length boolit. Now to convert into inches, divide that number by the bullet diameter.

The NRA Firearms Fact book (p. 234) gives the 30cal M72 173gr bullet as an example.

The bullet is 4.21 calibers long (1.29668"). 150/4.21= 35.62. To convert calibers to inches divide by .308 and yet get 10.97 or roughly a 11" twist.

The rate of twist is related to the length of the bullet and velocity can have a minimal effect on stability.

[jack19512]

I cast for my H&R B/C 45/70 using the 500 gr. bullets, the 405 gr. bullets, and the 340 gr. bullets. All shoot well in my 45/70 but I prefer to shoot the 340 gr. bullets the best.

If memory serves me correctly I think I was pushing the 500 gr. bullets around 1100-1200 fps.

But, when I first started casting I was shooting 30 cal. cast bullets out of several rifles and I had one rifle that would keyhole at short range also. I was sizing the bullets to .308 diameter and after I used the bullets without sizing accuracy improved dramatically with no keyholeing. I think the bore was .311 or something close to that.

I should add that if I remember right(It's been a while) I didn't think I was driving them fast enough either so my problem could have been a combination of the two, size and velocity.

For my B/C 45/70 I size them .459 and they are doing quite well. On my last shoot I had a three shot group almost touching at a distance of 65 yards. I am just learning myself and have a long way to go.

[Misfire99]

Something is not adding up. I do the greenhill formula and it says I need at lest 1:24. I got 1:20. Sharps 45/70 are usually 1:18 and they shoot 500 grain bullets at really long ranges. Up to a thousand yards. If it's just twist rate I should be fine but I'm not.

The bullet I was shooting is .4585 in diameter and is 1.269 in length. Greenhill says that is 1:24, please check me if you would. And the formula say nothing about velocity. I'm scratching my head over this one. This is the first time I have had to deal with anything like this. Usually if I have a problem I have some idea why. Not now. I have twenty or so of these loaded up. I think I will pull the bullets and reload at 29 grains and see what happens. You know I was just thinking that it would be nice to have a hand press to load at the range. Now I need one and don't have one.

[pumpguy]

The bullet I was shooting is .4585 in diameter

I would definitely slug your barrell. I am thinking your diameter is to small. My 1895 likes .460. Worth a try anyway.

[Misfire99]

Hey Pumpguy where do you get .460 bullets? I have a Sharps and it slugs out to .4595. I would love some .460 bullets but I have been unable to find any or a mold that drops at .460. The bullets I am now using were sold as .459 but the ones I mic come out .4585. In some spots I might get .459 but mostly it.s .4585

I love the forty five seventy. I have a ArmSport Sharps copy and this Handi-rifle. I also have a Pedersoli on layaway at a pawn shop. The one in the pawn shop is beautiful. I got it for $750 with only 300 more to go. I can't wait for that one. It's nice and heavy too.

[44man]

I think a 500 gr boolit needs 1 in 18 to be stable. With 1 in 20, it needs speeded up.
That bore does need measured too. I tried Laser cast without any luck. You are stuck with the diameter too.
I also don't think the Greenhill works for BP guns.

[Scrounger]

I think the .45 caliber group buys done here are designed to come out at .460". You might also send a PM to a member here, Ranch Dog, who designs and sells custom Lee molds. He has a couple of molds that will drop .460" bullets for you.

[Three44s]

My guess is that you have bullets a little too small and too hard.

Laser Cast is typically pretty hard .... but also typically BIG so this is puzzling.

Within safe pressure ranges ...... I would try driving them faster to tighten things up. The reason you are not stripping is that you might be getting just enough action from your gas checks if they are GC bullets.

And it sounds like you have enough other rifles in that bore so if all else fails ....... you've got a back door!

Good luck

Three 44s

[9.3X62AL]

If your boolits fit the throat well, you might need more velocity to stabilize that critter. I believe the Greenhill Formula assumes a velocity of 1800-2200 FPS, with the "150 constant" changing as velocity lowers or rises above that spectrum.

The absence of leading tends to show good boolit fit. The close grouping of the tumbled boolits may indicate that instability began well downrange from the muzzle and close to the target--consistent with stability fall-off as spin slowed. When boolits cartwheel early in their flight, at 50 yards you'll need a 4 x 8 sheet of plywood-sized target to register all the hits. Don't ask how I know this. Another boolit type that takes a dive after very accurate and stable flight to 50 yards is the 38 Special hollow-based wadcutter--in the 1-18.75" twist of S&W revolvers, they will de-stabilize at about 60 yards pretty reliably when started at 750-775 FPS. In Colts with 1-16" twist, they will behave themselves to almost 75 yards before hitting the canvas like a bribed boxer. Short answer--I think they need to run faster.

I have used several 500-550 grain boolits in my Ruger #1, all fired from 1100-1400 FPS. They stayed point-forward in its 1-20" twist to 200 meters.

[joeb33050]

There's a guy at the range with a Pedersoli 45/70 Sharps. He's at the end of 1000 bought bullets. For a long time he's had no problems and sometimes scary accuracy at 100 yards, as I watch his target. Now and again, all of a sudden, he gets a keyhole; the bullet is pretty much perfectly sideways. Also, he's getting a lot of leading with 15 grains of Unique. He's used 5744 in the past. He thinks it's the Unique. The twist and dimensions and everything is correct. I've never seen this before, 10 nice round holes and one sideways. I thought maybe not enough powder in some, somehow, but there's no obvious "poof". It's got me stumped, him too. Never seen it before.

?????
joe brennan

[9.3X62AL]

The Curse Of The Store-Bought Boolit is alive and well........just kidding.

If the powder substitution of Unique is the only variable changed--and the boolits behaved without getting poetic using the 5744........the Pedersoli shooter may be correct. The ROOT CAUSE as to WHY Unique prompts this anomaly--and the pursuit of same--would make me nuts in short order.

Of course, driving me nuts is more of a chip putt than a long drive.......but I digress. My response to such a course of conduct would be to relegate the Unique to the mid-range magnum revolver cartridges from whence it came--and get me hence to the gunshop for more 5744.

[jack19512]

So far when shooting cast from my 45/70 I have found of the powders I have tried so far IMR 4198 seems to work the best for me so far. I am in the early stages of shooting cast so I need to try more powders. Of the 3 bullets I cast for my 45/70 none use the gas checks. Of the other rifles I cast for(.308) some have had better accuracy using the gas checks while others it doesn't seem to matter much.

[shotstring]

Yes to what everyone has said....and especially the velocity part. 1000 yard competition shooters have known for a long time that there is a velocity threshold that needs to be reached if you wish to stabilize a certain caliber bullet at 1000 yards rather than having it keyhole on arrival. Although you are not shooting 1000 yards, some sort of similar formula must certainly still be active. Too low a velocity, too short a barrel, incorrect rifling for projectile and distance, out of balance or unstable bullets and a host of other things come into play, but velocity is the easiest to correct and a good place to start.

[mooman76]

Misfire99
What alloy were you using?

[Dale53]

The original Trapdoor Springfield has a "1 in 22" twist. It will stabilize the Government 500 gr bullet (my Lyman mould throws this at 522 grs with 30/1 lead/tin) to 1000 yards.

I don't believe that you are driving this bullet fast enough. A chronograph would really be a help in this situation.

Most, not all, of my work with the 45/70 has been with black powder. I would look for 1100-1200 fps with the 500 gr bullet. I have worked with 4198 and RL-7 with smokeless in the 45/70 but have not worked with AA5744. I looked at the AA data and you are right at the starting load with 23.0 grs of 5744. I'd try a few more grains but would stay in the trapdoor class.

Keep us posted on your final solution.

One quick question. You state that the bullets were keyholing. Keyholing is where the bullet is absolutely sideways. If your bullets are "tipping" that is NOT keyholing. Long bullets, such as the .45 caliber 500 gr, often show some tipping (slightly elongated holes) at relatively short ranges before they settle down and fly right. If you are getting tipping this is NOT a concern. I would just move the range on down to 100 yards and try some more.

Dale53

[shotstring]

Misfire, at 1000 yards, 1,000 fps at bullet arrival on target seemed to be the necessary velocity to reliably prevent keyholing.

[35remington]

Shotstring, very, very few .45 caliber bullets will be making 1000 fps at that range. No blackpowder load will do it, and smokeless out of a .45-70 won't do it either.

Realistically, bullet velocities will be in the 750 to 900 fps range depending upon load, bullet shape and velocity. Closer to the lower figure.

[Misfire99]

Well first off I am keyholeing not tipping. It's so bad I could see it with my spotting scope. There is literally the outline of the side of the bullet, with flat base and rounded tip, in the target.

As for alloy. These are store bought Laser-Cast 500 grain FP. These are the hardest cast bullets I have ever seen. They are supposed to have silver in them. This tells me they come from a galena mine that, most likely, has to low a content of silver to make it profitable to extract the silver. When I setup the OAL for a round I drop a rod down the muzzle into an empty chamber and mark the rod with a file. I then drop the bullet I am going to use into the throat and hold it there with something. I then drop the rod on top of the bullet and mark the rod with a file right at the muzzle same as with no bullet. This gives me the OAL for that bullet engaged in the rifling. I used the same file I use on a steel rod to score one of these bullets. On the steel rod I get a very nice score that I have no problem finding with my finger nail. When I do this to one of the laser-cast bullet I can see the score line but can't feel it with my fingernail. These bullets are hard!!!

Soon I will pull the bullets and load them to 29 grains. This is the top end of the <28000 range. And also the top end of the pressure range for my Handi-Rifle. I probably won't get this done and tested until Monday or so.

[35remington]

As long as twist is in the region of 1-20, you should be okay for stability. Usually, I find severe keyholing a clue that your bullet is undersized.

My Microgroove Marlin .45-70 lever will throw .457-.458" bullets sideways through a target for the first several shots. Then, as the barrel leads and closes down a bit, accuracy becomes pretty decent, then goes to hell again as more shots are fired.

Which is why you see a lot of shooters here recommending .460-.461" if your chamber allows it. I haven't run into a .45 caliber rifle that won't chamber or shoot this diameter to date.

[mooman76]

Misfire 99

I don't know about the more modern 45-70's but my Trapdoor will keyhole with lead that isn't pretty soft. That could be the problem maybe but others that have your type gun could say better!

[ammohead]

Misfire,

How consistant are the bases of these boolits. Imperfections on the bases of bullets can cause all kinds of problems.

ammohead

[shotstring]

35Remington, I didn't even think about the black powder guys and the silhouette shooters shooting at 1000 yards. All the competitions around here are for a max of 600 yards in that arena. The 1000 yard competition I was referring to uses jacketed bullets out of 6mm and 30 cal guns. Just threw the figure out for a reference. I think it is interesting to see how the large cast bullets and jacketed bullets compare in terminal performance - what similarities and what differences.

I would be interested in when the ballistic coeffecient breaks down with large lead 45 cal slugs and when they become unstable and likely to keyhole. I haven't been able to do the testing I have wanted to do with 500 gr boolits out of my rifle as I have to drive a very long ways every time I wish to test a load. I thought this problem of low velocity short range keyholing an interesting problem and wonder what everyone's experience has been at super long range with similar caliber and boolit weight. With jacketed bullets at long range, as velocity decreases, eventually that bullet is going to destabilize and go sidways. I would think this would happen at some point with heavy cast boolits also, but I don't have enough experience shooting lead cast rifle boolits to know.

[Misfire99]

Well I'm all set to give it another test. I just loaded up twenty rounds. 10 of them are 500 grain laser-cast and ten are 500 grain solids. I got the solids from Midway in their blemished bullet sale. You never know when a herd of angry Cape Bufflao will charge down your street.:-D

But where I live there have been a lot of Grizzle bear attacks. One guy got his face torn off by one swipe from a grizzlies paw. I live near Yellowstone and a lot of the food sources for the grizzlies are in short supply. Yellowstone is an active volcano and in some parts of the park the ground has gotten to hot that it killed the pine trees. Pine nuts are a big part of the bears diet. So now the bears are coming out of the park to eat the nuts that live around hear. We have wolves also. One of my neighbors bought a calf to fatten on his land. He hadn't fenced the land yet so he stacked the calf. He got up in the morning and the wolves had eaten his calf. Veal for breakfast sounds good to me. We have sort of a habit to look out side before opening the door. You never know what will be out there.

I took a couple of picture of the bullets and rounds they make up:
Here are the bullets.
http://i212.photobucket.com/albums/cc138/misfire99/r22.jpg


And here are the rounds they make:
http://i212.photobucket.com/albums/cc138/misfire99/b1.jpg

I will take my crono with me next time and see how fast these thing fly. Hopefully it will be tomorrow.

[Misfire99]

Well I just slugged the bore. Actually I cast it with cerrosafe. And I found that On the lands I have .449 and in the groves I have .4545. This is a microgroove barrel I believe. This does not make me a happy camper. I found a guy on line that might be able to deepen the grooves out to at lest .458 but right now I think I found out why it is keyholing. I will still try the test with the 29 grains of powder behind the solid and cast 500 grain bullet.

[joeb33050]

The Curse Of The Store-Bought Boolit is alive and well........just kidding.

If the powder substitution of Unique is the only variable changed--and the boolits behaved without getting poetic using the 5744........the Pedersoli shooter may be correct. The ROOT CAUSE as to WHY Unique prompts this anomaly--and the pursuit of same--would make me nuts in short order.

Of course, driving me nuts is more of a chip putt than a long drive.......but I digress. My response to such a course of conduct would be to relegate the Unique to the mid-range magnum revolver cartridges from whence it came--and get me hence to the gunshop for more 5744.

I have shot about 1.46 zillion 45/70 shots with 14/15 Unique, bullets from 457191 to 457125 and not a single keyhole that I can remember. Also, never saw leading like that, and I can lead a barrel! I hope he just runs out of the bullets.
joe b.

[Scrounger]

I would think the under-sized barrel would tend to drive up pressure, so maybe lowering the powder charge would be the way to go. Actually, the way to go is to send that puppy back to HandiRifle, along with your targets prominently displaying the keyhole bullet holes, and maybe the pellet you slugged the barrel with. I'd tell them to replace the barrel or give my money back.

[Misfire99]

Well I just got back from the range. The 500 grain solids shot a one inch group. The 500 grain cast had an eleven inch group with two of the three keyholed. I am not happy. I doubt that H&R will give me another barrel. It does shoot one inch groups with jacketed but nowhere in there literature does it say that they have a micro groove barrel. I don't know what I'm going to do just yet but I will keep all posted. And thanks for your help with this.

[9.3X62AL]

Based on your latest results--I would say that your lands at .449" aren't tall enough to fully engage a lead boolit given the .4545" groove depth. FWIW, the Ruger #1 is an eight-groove pattern with near-equal land and groove width, .449" x .459". You are talking a .00275" land height here, which isn't a whole lot of grab-ability. Note the highly sophisticated ballistic terminology there. It works with the solids, and will likely do so with conventional jacketed bullets--but things seem shallow for shooting lead, to me.

H&R/NEF is now part of the Marlin corporate umbrella, so you make indeed have a Micro-Groove barrel there. Most MG's require fatter boolits to shoot well, so why this tight barrel is acting this way is really strange to me.

+1 to contacting the maker--nothing to lose at this point, and maybe they will listen and act.

[leftiye]

Misfire, I cast my chamber on my handi riffle and mine has an oversized chamber neck, no freebore, no leade. Did yours have any freebore or ballseat, or leade? When the rifling JUST STARTS, there's a lot of pressure, and the rifling CUTS grooves instead of swaging them, lots of deformation.

Try searching here about micro groove barrels, a lot of guys who have them say they will shoot cast well. The hardness of the lead should be a plus, you could try sizing them to about .456 (good luck finding that size of sizer!- maybe a tight .457 Lyman, or just size .457 or lap out a .454 die).

H&R seems to be using a lot of Marlin barrels lately (funny thing- Marlin owns H&R)- rejects? I had to buy a .444 barrel (1 in 10 twist) instead of a .44 Mag. barrel, the .44 Mag had 1 in 38" twist (who'd do that to a buyer?) can't even imagine that working. If ya go with H&R's rebarrel offer, CHECK THE TWISTS!

[Misfire99]

What I am looking into is having the rifling cut deeper. There are a couple of guys that do reboring. I am hoping, note crossed fingers and toes, that they are good enough with their machines to just cut the rifling deeper. This would solve the problem. I have emailed them and am waiting replies. One of them is Quality Barrel Works.http://www.cutrifle.com/index.html

I have seen his description of what he does and I suspect that it might be possible. If you know the twist rate and can index off of one of the grooves then you should be able to do it. If he can I will post back to the group. I think it's something lots of guys shooting Marlin rifles would like to do.

I think I have to take a long hard look at buying the Marlin 1895 Cowboy lever action I have been drooling over. I have never shot a micro groove bore before. I think they leave much to be desired.

[35remington]

The Marlin Cowboy rifles have standard rifling.

Can't speak for your barrel, but Microgroove rifling is not a problem with lead bullets as long as it is dimensionally correct - and this can be said of standard rifling, too.

Look at dimensions, throating, and chambering as being the most suspect area before you get involved in the rifling type debate. It's too far down the list to fixate on as a cause of inaccuracy. See if they did everything else right first, including cutting the Microgroove rifling adequately.

[Scrounger]

I'm pretty sure they won't touch your rifling. Look at the price of your gun, man, does it make any sense at all to put another $100 in it for something that probably won't help anyway. Send it back to H&R. tell them the undersize bore is a safety problem, it drastically increases chamber pressure and could blow with factory rounds. They will be glad to put another $87 barrel on it rather than risk a lawsuit.

[chuebner]

Hey Pumpguy where do you get .460 bullets?

If you can still find one, Rapine made a .460-500gr. mold that is a copy of the old Springfield 500gr. arsenal bullet. My mold drops them at .4615 and I shoot as cast in the trapdoor and size to .459 for my rolling block. One of my friends has the H&R Buffalo Classic that slugged out at .459 and he was having fits getting store bought bullets to shoot. He now shoots my 500 grainers on top of 70gr. 2F GOEX and is very happy with the accuracy.

Charlie

[jack19512]

One of my friends has the H&R Buffalo Classic that slugged out at .459 and he was having fits getting store bought bullets to shoot.
Charlie




I must have really lucked out. I haven't slugged the barrel of my H&R Buffalo Classic 45/70 but I think I will now, just curious. But, mine shoots jacketed bullets really well and after experimenting with powders and loads my cast is starting to come around very well.


In all of my testing with cast I have never had a keyhole with this rifle yet. I tried shooting my cast bullets as cast but they do better when sized to .459. Also I don't use gas checks. I cast using straight wheel weights and with the 340 gn. cast bullet velocity is around 1500 fps. at this time with no leading.

[leftiye]

Those $89 dollar barrels actually cost a bit more than that. There's a $15 fee for fitting them, and shipping on top of that. Scrounger is right- whole new barrel for the cost of recutting one. He's also right about H&R should replace that one because of the non-standard groove diameter. Standard .45 cal. bore is .450 (surprise) with .458 grooves (or .460).