f> .44 Magnum rifles and poor accuracy with super-slow twist? - Ruger Forum

Ruger Forum

.44 Magnum rifles and poor accuracy with super-slow twist?

This is a discussion on .44 Magnum rifles and poor accuracy with super-slow twist? within the Ruger Lever-Action forums, part of the Rifle & Shotgun Forum category; A recent article in the September 'RIFLE Sporting Firearms Journal' outlined potential poor accuracy with modern .44 Magnum leverguns and their outdated 1:38" rifling twist ...


Go Back   Ruger Forum > Rifle & Shotgun Forum > Ruger Lever-Action

Reply
 
LinkBack Thread Tools Display Modes

Old August 31st, 2016, 11:13 AM   #1
 
Join Date: Jan 2009
Location: N. Calif
Posts: 2,579
firescout will become famous soon enough
.44 Magnum rifles and poor accuracy with super-slow twist?

A recent article in the September 'RIFLE Sporting Firearms Journal' outlined potential poor accuracy with modern .44 Magnum leverguns and their outdated 1:38" rifling twist that comes from the old days when .44-40 caliber Winchesters and Marlins shot blackpowder-propelled 200 grain lead bullets. The author tests a variety of factory rounds and handloads and bullet weights at 100 yds in a peep-sighted Marlin 1894 with the factory barrel, and then rebarreled with a Shilen 1:16" twist. The before and after results are quite shocking. From 2 to 5+ inch groups to close to 1 inch, and a few sub-1 inch groups. My Ballard-rifled .44 Mag Marlin 1894 has been mainly a plinking gun, but I did work up a 270 gr JSP load at 50 yds for possible pig hunting use. I think I'll need to try out my loads at 100 yds from the bench to see how they do out of my rifle. 2 to 3 inch groups at 100 would be fine by me, but 5 to 6+ inch groups would disappoint me.



firescout is offline  
Advertisements
Old August 31st, 2016, 01:54 PM   #2
 
Join Date: Mar 2014
Location: Kansas
Posts: 3,167
Varminterror will become famous soon enoughVarminterror will become famous soon enough
I've owned a small collection of 20-25 44mag Marlin 1894's, only remain to have 5 of them currently, and I used to do a lot of re-work on them for CAS/SASS shooters.

Micro-groove or Ballard, I've handled a lot of them which disliked one load or another, but I have never handled one which honestly wouldn't shoot any better than 2", let alone not any better than 5". Like any factory rifle, I tend to be content with a 1" to 1.5" factory Marlin rifle, even a little looser than that since they're pistol cartridge carbines afterall. I have had a few argue with 300grn pills and heavier, but I've never had one argue with 240's or 250's. I'm planning to take meat-doe this season with one of my 1894 SS's, running the 300grn XTP - with a 3-9x40mm, it's a 1.25-1.75MOA rifle.

Not surprising the results with the Shilen barrel though. Regardless of the twist change, if you spend $500 to spin a custom barrel onto the front of a $500 rifle and it d@mned well better shoot better...
Varminterror is offline  
Old September 1st, 2016, 11:05 AM   #3
 
Join Date: Jan 2009
Location: N. Calif
Posts: 2,579
firescout will become famous soon enough
I was searching through the marlinowners.com 1894 Forum for info on this. I found a variety of experiences. Some rifles shoot 300 gr-and-heavier bullets just fine at 100 yds, and a few report keyholing. The general consensus seems to be that most 1:38" twist .44 Mag lever actions shoot 240-270 gr jacketed bullets with acceptable 100 yd accuracy. Cast bullets may take some work, though, with trying different styles, alloys, and weights.

Then there's the issues of the larger (.431-.432") groove diameter with typical .430" cast bullets, and the older MicroGroove barrels sometimes not working well with cast bullets.

It would be great to be able to get a Marlin 1894 out of the box with a 1:20" rifling twist!

Last edited by firescout; September 1st, 2016 at 11:08 AM.
firescout is offline  
 
Old September 1st, 2016, 11:18 AM   #4
In the Brig
 
Join Date: Sep 2013
Location: Flemington, NJ
Posts: 1,577
paulnlee is a glorious beacon of lightpaulnlee is a glorious beacon of lightpaulnlee is a glorious beacon of lightpaulnlee is a glorious beacon of lightpaulnlee is a glorious beacon of light
My Henry seems pretty accurate?
paulnlee is offline  
Old September 1st, 2016, 02:12 PM   #5
 
Join Date: Mar 2014
Location: Kansas
Posts: 3,167
Varminterror will become famous soon enoughVarminterror will become famous soon enough
The moral of my first post was INTENDED to be this:

Don't imagine a problem for yourself where none exists.

Sub-MOA with a bone stock factory, pistol cartridge levergun doesn't happen very often, whether it says Marlin, Winchester, Henry, Rossi, or Browning on the side. Doesn't happen very often with bolt action factory sporters either.

If your rifle doesn't shoot, work on different loads. If you can't find one which gets into that 1.5MOA ballpark, talk to Marlin, most likely they'll remedy it for you.

If you run through the Miller or Greenhill twist formulas, a 1:38" twist still marginally stable in a rifle barrel for a 300grn Hornady XTP at 1600fps (0.861" bullet length). Miller factor is about 1.2, with anything under 1.0 being unstable.

Picking a 1:10" twist in the article seems arbitrary - why so tight? A 240grn bullet in 44cal is under an inch long, and much more easily stabilized than a 150grn 30cal bullet which is over an inch and a quarter long... Stabilizing a 240grn XTP 44cal at 0.702" long is a lot easier than stabilizing a 338 cal 250grn pill that's over an inch and a half long (hornady 338 250grn BTHP = 1.567" long).

Shoot the rifle, if it doesn't shoot 1-2" groups at 100yrds from a rest with a scope with ANY ammo, then blame the rifle. But until then, don't let yourself get scared off by a magazine article.

Quote:
Originally Posted by paulnlee View Post
My Henry seems pretty accurate?
Another satisfied customer with a 1:38" twist rifle!
Varminterror is offline  
Old September 1st, 2016, 02:58 PM   #6
Retired Moderator & Gunsmith
 
Iowegan's Avatar
 
Join Date: Aug 2006
Location: CB, IA
Posts: 11,970
Iowegan is a splendid one to beholdIowegan is a splendid one to beholdIowegan is a splendid one to beholdIowegan is a splendid one to beholdIowegan is a splendid one to beholdIowegan is a splendid one to behold

Awards Showcase

firescout, As I think most people know .... what keeps a bullet stable down range is it's spin rate, which is based on the velocity of the bullet and the twist rate of the barrel.

For smaller high power rifle bullets (think 30 cal .... way smaller in diameter) a faster twist rate will keep a normal 30 cal bullet stable for several hundred yards, mainly because rifles chambered for these cartridges can maintain accuracy at phenomenal distances. When you get into larger diameter bullets such as those used in your 44 Mag rifle, weird things happen if the twist rate is too fast.

First, a 44 Mag rifle is not intended for long range shooting .... 100 yards would be considered optimum.

Second, the rifling will cause the bullet to go into a spiral that looks like a corkscrew (fat end of the corkscrew is at the muzzle when viewed from the shooter's position). This is caused by the centrifugal force generated by the rifling ... the heavier the bullet and/or the faster the bullet is spinning, the more centrifugal force, thus the larger the spiral will be. This actually spreads groups at distances less than 100 yards until the spiral dissipates. So .... your usable range is actually less accurate with a faster twist rate than with a slower twist rate.

Third, heavy 44 Mag bullets generate a lot of torque when spun by the rifling. This actually rolls the rifle barrel in the direction of the twist. As you know, recoil starts the moment the powder starts to ignite and continues until the bullet exits the muzzle. Torque does exactly the same thing so by the time the bullet exits the muzzle, if the spin rate is excessive the rifle will torque to the right and you will end up shooting way to the right (assuming a right hand twist).

Fourth, bullets for 44 Mags have terrible ballistic coefficients ... no where near that of a normal rifle bullet. As an example, a Hornady 240gr JHP has a BC of a mere .165. It is not unusual for rifle bullets to have BCs above .500 .... very low drag bullets can be well over .600. As such, poor BC 44 cal bullets slow down a lot due to air friction, making them a poor choice for long range shooting due to excessive bullet drop (more time to target allows gravity to have a greater affect). Spin rate also decays but at normal shooting distances the bullet will still be spinning plenty fast to maintain stability.

Fifth, A bullet must maintain enough spin to stay stable at the intended shooting distances, however a spin rate faster than needed for stability will NOT improve accuracy.
The optimum twist rate for a 44 Mag rifle is 1:38 .... no it's not outdated, it's the tried and true best compromise for a 44 cal rifle .....bullet spin versus barrel torque , especially when you consider the max practical shooting distance of 100 yards. 44 Mag Ruger Super Blackhawks have a 1:20 twist rate .... almost double that of a rifle but because of the velocity loss from a shorter barrel and pressure venting from the B/C gap, you actually need the faster twist rate to maintain stability out to 100 yards. If you never tried it .... take a good look at your shooting buddy's hand when shooting a 44 Mag revolver .... the whole gun torques but not nearly as much as a rifle would if it had the same twist rate.

Just a suggestion .... try some 180gr Hornady XTPs. These lighter bullets do not generate as much torque as heavier 44 cal bullets nor as large of a centrifugal force spiral. You can easily achieve 2000 ~ 2200 fps which means even with their horrible BC of .138, they will maintain a good spin for 150 yards (or more) from a 44 Mag rifle.
Iowegan is offline  
Old September 1st, 2016, 05:51 PM   #7
 
Join Date: Jan 2009
Location: N. Calif
Posts: 2,579
firescout will become famous soon enough
Quote:
Originally Posted by Iowegan View Post
...Just a suggestion .... try some 180gr Hornady XTPs. These lighter bullets do not generate as much torque as heavier 44 cal bullets nor as large of a centrifugal force spiral. You can easily achieve 2000 ~ 2200 fps which means even with their horrible BC of .138, they will maintain a good spin for 150 yards (or more) from a 44 Mag rifle.
Thanks for your input, gentlemen. The rifle is equipped with a Williams FP aperture sight, so no scope for 100 yd testing. My current bullet inventory is Speer 240 gr JSP and 270 gr Gold Dot/Deep Curl JSP. I'll look into trying the 180 gr bullets. Besides recreational plinking, I have also envisioned this rifle as a possible short-range pig hunting gun. The coastal wild pigs here in Calif can get pretty big, thus my initial selection of the 270 gr Gold Dot. Like I said, the 50 yd accuracy of the 270s was pretty good, after experimenting with the charge of W296 powder. 2 gr below max tightened up the groups. I don't expect sub 2" groups at 100 with this rifle; my scoped 7mm08 Remington Model Seven takes care of that...

I am puzzled as to why Ruger uses a 1:20 twist on the .44/77 rifle, when all the lever actions use the slower twist.

Another occasional complaint I've recently read about concerning the Marlin .44 Mag 1894, is bore imperfections in the area of the external rollmarks on the barrel. I'm going inspect mine for that.

Last edited by firescout; September 1st, 2016 at 05:55 PM. Reason: add more
firescout is offline  
Old September 1st, 2016, 08:18 PM   #8
 
Join Date: Mar 2014
Location: Kansas
Posts: 3,167
Varminterror will become famous soon enoughVarminterror will become famous soon enough
Worried about twist rate, now worried about roll marks - why not just go shoot it and see whether you have a problem?

Really seems like you're looking for a problem with your rifle?
Varminterror is offline  
Old September 1st, 2016, 10:27 PM   #9
 
Join Date: Jan 2009
Location: N. Calif
Posts: 2,579
firescout will become famous soon enough
Quote:
Originally Posted by Varminterror View Post
Worried about twist rate, now worried about roll marks - why not just go shoot it and see whether you have a problem?

Really seems like you're looking for a problem with your rifle?
'Worried'? No. But when I pay a decent amount of money for what is supposed to be a well-engineered, precision device, I don't like preexisting significant design or manufacturing flaws. There seems to be quite a bit of that in recent years with affordable production firearms.

I'd rather know about any potential issues BEFORE shooting it ('looking for a problem with my rifle'). That's one reason why I strip, clean, inspect, and properly lubricate any new firearm before shooting it for the first time.
firescout is offline  
Old September 2nd, 2016, 05:16 AM   #10
 
Join Date: Jun 2011
Location: wayne nj
Posts: 23,858
bwinters is a splendid one to beholdbwinters is a splendid one to beholdbwinters is a splendid one to beholdbwinters is a splendid one to beholdbwinters is a splendid one to beholdbwinters is a splendid one to behold
I find 300 grain to be long range accurate and 240 okaay.
bwinters is offline  
Reply

  Ruger Forum > Rifle & Shotgun Forum > Ruger Lever-Action


Search tags for this page
300 gr xtp 44 mag for ruger semi auto carbine
,
300 gr xtp ruger auto carbine loads
,
44 mag rifle twist rate accuracy
,
44 magnum in leverguns
,

44 magnum rifle accuracy

,
44 magnum rifle twist
,
bullet dia for modern marlin .44 mag rifles
,

marlin 1894 .44 magnum groove diameter

,
ruger 44 mag carbine accuracy
,
ruger carbine semi auto rifle loads for 300 gr xtp
,
troqueing a levergun barrel
,
why a slow twist on the .44-40
Click on a term to search for related topics.

Thread Tools
Display Modes


Similar Ruger Forum Discussions
Thread Thread Starter Forum Replies Last Post
What is the twist rate on Ruger .44 Magnum rifles? Virginian Ruger Semi-Auto 4 July 1st, 2016 12:11 AM
Poor Lonely Rifles ngashooter Gun Gallery 6 June 9th, 2016 04:48 AM
Twist rate of 223 and bullet accuracy moondog911 Ruger Bolt Action 25 March 30th, 2012 09:50 AM
Poor accuracy tudurgs Ruger Single-Shot 23 November 21st, 2011 11:00 AM

Top Gun Sites Top Sites List
Powered by vBulletin 3.8.7
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.1
Copyright © 2006 - 2017 Ruger Forum. All rights reserved.
Ruger Forum is a Ruger Firearms enthusiast's forum, but it is in no way affiliated with, nor does it represent Sturm Ruger & Company Inc. of Southport, CT.