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radkins
01-25-2010, 01:24 PM
A while back I mentioned a single shot rifle project I intend to build and I have finally gotten started. I intend to use an Adams&Bennett barrel from Midway USA, mixed reviews on these barrels but at 1/3 the cost I felt it OK for a first time project. The question is about rifling twist, this is to be a 45/90 shooting 400 and 500 grain bullets at mid velocities which according to all the data I can find should have a 1 in 18" twist for best accuracy. The problem is these barrel blanks are only offered in 1 in 14" or 1 in 22" twist rates for that 458 caliber so should I go with a faster or slower twist rate with these big fairly slow moving bullets? Maybe either extreme is too much and neither one will work? :confused:

Bob Ford
01-25-2010, 03:00 PM
Radkins

If you are using 400 gr and heavier bullets I would use the 1 in 14. My experience with other calibers is I have never had a bullet over stabilized, but have had barrels with too slow twist cause poor groups. Most grouping problems show up at longer ranges beyond 200 yds. I am about ready to start a .22 hornet with a 1 in 9 twist. My last had a 1 in 12 that works fine.

Bob

1367troy
01-25-2010, 07:13 PM
spend some time researching on the net for barrel mfrs many can produce a barrel at the twist rate that you request

radkins
01-25-2010, 07:26 PM
spend some time researching on the net for barrel mfrs many can produce a barrel at the twist rate that you request



I have found several barrels with the right twist (1 in18") and some makers that would supply about anything within reason but only at three times the cost, or more. This is my first building project and $80 for the Adams&Bennett vs $300 to $350 for a higher quality barrel is just not too attractive right now. I am sure that the extra money would be well spent but if I can make that cheaper barrel perform decent that is the way I want to go but I just didn't know which twist to choose.


Bob, my intentions were to shoot 500 grain cast bullets the most but 400 grain jacketed like I use for my factory 45/70 probably would be used also. Would the 1 in 14" work OK for 500 grain cast?

Bob Ford
01-25-2010, 10:00 PM
Radkins

I have not shot a lot of .45 cal in rifles. I do have a .458x2” on a FM2. It has a 1 in 18 twist, but I will be shooting 350gr and lighter mostly. These will be lighter loads, old age and arthritis. Most 45-70 pistols use 1 in 14 and silhouette rifles use mostly 1 in 16-18. If you are shooting heavy bullets I would go with the faster twist 1 in 14 as the 1 in 22 will fail at the longer ranges. The button rifling is shallow for black powder, but a paper patch bullet might over come this. These links show targets fired from my rifles. The 30-30 works well with a 173 gr flat point cast about 1-16 tin. Best group was 10 shots in 5/8 c to c at 100 yds.
http://bbs.homeshopmachinist.net/showthread.php?t=37641&page=3

http://bbs.homeshopmachinist.net/showthread.php?t=33676&page=2

Bob

Bob Ford
01-25-2010, 10:04 PM
Radkins

The .458 Winchester was rifled 1 in 14 and was designed for 500 and 510 grain bullets. It shot well with lead bullets.

Bob

radkins
01-25-2010, 10:40 PM
1 in 14" sounds like the only real option here so that's the way I will go with it, thanks!

38_Cal
01-25-2010, 10:47 PM
The original 45-70 Trapdoor Springfield rifles used a 1-22" twist, for the 500 gr. round nose bullet ahead of 70 gr. black powder. If you're going with 45-90 and bullets between 350 and 500 gr. is should be ok, but I think that the 14" twist would be a better choice for your cartridge. If you're going to be using smokeless powder loads, I would suggest chambering the rifle in 45-70...less case capacity, but still a lot of room. For black, the 45-90 might be a better choice if your wallet can stand the more expensive brass and more powder. :D

David

Angus in Wyoming
01-26-2010, 10:49 AM
You have more to think about. While true some of the older guns used slower twists like 1 in 22. Those guns were not designed to shoot more than a couple hundred yards.
Most 45 cal, long range, single shots use 1 in 18. I do know a couple of guys who shoot 1 in 16 but they have to shoot 560+ grain bullet to get the benifits of that twist.

Now something you need to look at is groove diameter. .458-.459 seems to be standard in these types of guns. These long rage shooters are shooting cast bullets. Most bullet moulds drop bullets in this range. Some 45 cal tubes that are designed for newer cartridges are .452. Now you could have a custom mould made to fit your barrel, but that is more money.

A+B barells can be good. I have never used one for cast bullets. I did however have to shoot lots of jacketed bullets to polish things up before I got any accuracy.

My advice is to decide if you are going to shoot cast or jacketed bullets, then pick a barrel to fit the available bullets. I'm not sure what size jacketed bullets come in nowl. Maybe they come in .452 and .458. I only shoot cast.

Green Mountain barrels are gaining some real respect in this type of shooting and I think they are about 2X as expensive as A+B. Much better quality and you won't have to spend $150 on a custom mould.
Just my two cents. BTW I shoot a 1874 Shiloh Sharps with a 1 in 18 twist with a 535gr bullet out to 1000 yards.

radkins
01-26-2010, 12:59 PM
The original 45-70 Trapdoor Springfield rifles used a 1-22" twist, for the 500 gr. round nose bullet ahead of 70 gr. black powder. If you're going with 45-90 and bullets between 350 and 500 gr. is should be ok, but I think that the 14" twist would be a better choice for your cartridge. If you're going to be using smokeless powder loads, I would suggest chambering the rifle in 45-70...less case capacity, but still a lot of room. For black, the 45-90 might be a better choice if your wallet can stand the more expensive brass and more powder. :D

David



For practical purposes there is no question that the 45/70 is a better choice than the 45/90 when using smokeless, which I plan to do, but there is the "just want to be different factor" :) , everybody and their uncle has a 45/70 (for a darn good reason!) and I just wanted something a bit different for this homebuilt project. A 45/110 or 45/120 would have been really nice but quite impractical both from a cost standpoint and powder choice options, all for no real gain so the 45/90 was chosen. I realize that neither the 1 in 22" or the 1 in 14" is the best choice but given the advice I have so far the 1 in 14" seems like the lesser of the two evils, since it was pointed out that the 458 magnum uses the 1 in 14" twist I think maybe I could nearly duplicate a low-end 458 load using 500 grain jacketed bullets and that should work.

Angus in Wyoming
01-26-2010, 01:13 PM
I think you can too. I have never loaded smokeless to velocities greater than black powder velocities. I'm sure it can be done. I also know you can use smokeless in 45-90. I don't know the size of the charge, but I know a couple of guys who use AA5744.
Sounds like a fun project. I was thinking of a project along the same lines but making a 405 Winchester/40-72. Angus

radkins
01-26-2010, 02:20 PM
When I said low-end 458 I mean I intend to keep pressures low since this is a homebuilt gun, probably well above blackpowder pressures but waaaay below a full-house 458 Mag load! I will try to get some pics up soon, as soon as I am sure all is well anyway. :)

Bob Ford
01-27-2010, 12:06 AM
Radkins

If you want a different looking cartridge and it does not have to be a old type. My .458x2” has the belt turned off. It is much easier to make a extractor work on a rimmed case. With the belt turned off you have a rimmed case. Best part is almost any magnum case that is at least 2” long can be used. It is close to 45-70 capacity and slightly less than .450 Marlin. I make my own reamers and dies also bullet molds and swage dies. I think you could probably use .450 Marlin dies.

Bob

radkins
01-27-2010, 09:54 AM
I make my own reamers


Now you went and done it! :D

I have been trying to do just that and what I have done so far is turn the basic body shape from drill rod, mill the flutes (4) and harden the thing BUT darned if I can figure out how to sharpen it properly. The last one I tried I lightly ground most of the relief in the flutes but when I tried to hone a finished sharp edge I lost a couple of thousandths off the OD. How do I do sharpen the thing and should it be tempered after hardening or used as is?

KDuffy
01-27-2010, 10:10 PM
The diameter should not reduce, you need a thin white line of full diameter on a reamer, it will be much thinner than on a cylindrical reamer (which will be .006", maybe), but it should still remain round in profile. May need to put more positive rake on the flutes, where are you at for rake on the ones you tried? It has been many years since I ground a reamer, but the setup was the hard part that I recall. It would be beneficial to look at one and then see what you need to do to make yours like it. I figured to use (already fluted and hardened) reamers to make the low taper or straight wall chamber reamers when I get to it.

radkins
01-28-2010, 11:56 AM
The diameter should not reduce, you need a thin white line of full diameter on a reamer, it will be much thinner than on a cylindrical reamer (which will be .006", maybe), but it should still remain round in profile. May need to put more positive rake on the flutes, where are you at for rake on the ones you tried? It has been many years since I ground a reamer, but the setup was the hard part that I recall. It would be beneficial to look at one and then see what you need to do to make yours like it. I figured to use (already fluted and hardened) reamers to make the low taper or straight wall chamber reamers when I get to it.


Since I posted that yesterday I have done some research and I think I have found my problem, I have been trying to relieve the flutes all the way to the edge. I lightly ground the relief leaving a slim edge then used a hone to try to cut a slight relief out to the edge but apparently this is not only unnecessary but it is actually a problem?

Bob Ford
01-28-2010, 02:12 PM
Radkins

I am not ignoring you. It is that I would take 10,000 words trying explain 50 years of practice. I need to take pictures and try to condense it down a little. Meantime look at Barrels and Actions by Harold Hoffman. http://hppublish.com/

Bob

radkins
01-28-2010, 03:01 PM
Thanks for the link I will definitely get that, it is exactly what I have been searching for! I understand completely what you are saying about answering the question about how to do that, I guess that is somewhat akin to to a newbie asking me "how do I weld" since apparently you and I have about the same amount of experience but in two different fields. :) I am starting out in a new field (hobby level) at a late stage in my life, a very late stage, so please bear with me if I ask what could be called some dumb questions. I greatly appreciate the response and the help you have offered, believe me I feel anything but ignored! Thanks

Bob Ford
01-28-2010, 07:13 PM
Radkins

Do not think you are getting a expert at gunsmithing. I built my first muzzle loader at age 10. First chambering reamer at about 15 and have been building various firearms for myself ever since. Will be 70 in spring.

I was a construction electrician and also certified structural welder for our trade. Been playing with machine tools since about age 15.
Bob

Bob Ford
01-29-2010, 04:37 PM
http://i717.photobucket.com/albums/ww174/metalworker/1-28002a.jpg

Top 30-30 8 flutes. .44 Mag 10 flutes. .458 x 2 10 flutes Throater for .458 cal 10 flutes.

All were cut with a new ¼” 4f carbide end mill. My experience more flutes less depth, but less distortion when hardened. Using O-1 these were turned on lathe, filed smooth, finished with emery paper. They were then set in mill for cutting flutes. Which are cut a few degrees past center to get positive rake. .After the flutes are cut, VERY carefully debur. Do not remove any on the diameter. Then file or stone relief leaving .005 - .020 margin at cutting edge. I warm the reamer and coat with borax. Then use a large propane torch in a fire brick lined furnace to bring up to hardening temperature. Then dip in oil straight down and ether move up and down or spin reverse of the flutes. After hardening Temper in oven at 400° for about 1 hour clean in water and mark the flutes with felt pen and stone on the face of the flutes to sharpen. I use magnifying glass for this work.
If you have a tool post grinder turn about .005 oversize harden and grind to size. I do not recall that Harry Pope had a tool post grinder in the early days.

These reamers are not for production work, but for hobby they work fine.
I run my reamers by hand. No power. Set your barrel accurately in lathe. I think you could bore the chamber undersize in straight wall cases then ream. If you drill the reamer follows the drill and then when the pilot of the reamer hit’s the bore it tears the rifling while pulling the reamer in line with the bore cutting a egg shape chamber. For this reason on bottle neck cases I use a ruffing reamer and cut with it all the way. No boring or drilling. Use the tailstock center and feed to guide the reamer and feed the reamer. Never turn the reamer backwards. When it starts to load up keep slowly turning the reamer while backing it out. Each time the reamer is removed be sure to clean all chips out of the barrel. I use lard oil or heavy cutting oil lots of it.

I have used 12L14 and casehardened it for one offs. There should be no problem using it for loading dies and case hardening or possibly Electroless nickle. Single shots are not high volume.

Bob

JCHannum
01-29-2010, 08:13 PM
Thanks for the photos and write up Bob. It is an inspiration for me to give it a try. I have a couple of projects that are lingering on the back burner for want of a reamer. The cost of purchase makes it very expensive for a one off, and rentals are not a great deal cheaper.

Do you index them when cutting the flutes, and if so do you vary the spacing to eliminate chatter?

radkins
01-29-2010, 09:03 PM
Yes thanks from me too, you have answered several questions there for me before I even had to ask! I now have a much better idea of what I need to do so tomorrow when I get back to the shop I will trash the reamer I have been working on and start anew.

Bob Ford
01-29-2010, 11:17 PM
Jim

I use my indexer and used to cut odd number flutes with odd spacing, a couple of holes more or less. Since I cut without power have not had chatter problems and now mostly cut even number flutes. I am more concerned with making the flutes close enough that I have little work on reliving the back side of the flute.
By the way the 30-30 reamer cut the chamber for the rifle that shot the group shown.

Bob

Bob Ford
01-29-2010, 11:26 PM
In making reamers without a toolpost grinder keep the pilot short as you can. This helps eliminate some warp problems.

Bob