barrel twist rate on a 44 carbine?

[mzimmers]

Hi, all –

I just got back from the range, where I was testing some Barnes Buster bullets in my 44 carbine. The results were spectacularly bad – at 50 yards, I was missing paper, and even at 25 yards, there was significant keyholing.

Is it possible the gun doesn't have enough twist for 300 grain bullets? The gun is good, the loads were fine, and I can't think of anything else. If someone knows the twist rate for this barrel, I'd appreciate it.

Thanks.

 

[wwb]

If I recall correctly, it's 1:20.

But if you have keyholing, you have some other issue. I sold my carbine several years back (Dumb move, I know), but it shot 300 grain bullets just fine, although the groups were tighter with 240s. 240 grain XTPs with a load 1/2 grain below max of 2400 would give 2-1/2" groups at 100 yards. Not too shabby for a "brush gun".

 

[Sig685]

Keyholing is a major indicator of lack of static stability, in other words the bullet is not spinning fast enough to overcome the upset induced by the atmosphere.

Your twist or your velocity is not fast enough.

The 300gr bullet is substantially longer than the more common 240gr bullet of the 44 Magnum, so you will either have to up the velocity, provided you are not at max already or use something else.

I should point out that even upping the velocity may not cure the problem because higher velocity, while providing faster spin rate also produces greater air resistance.

 

[mzimmers]

I found a couple references online that said the twist rate was 1:38"...given that the Busters call for 1:20", that would explain the problem.

I didn't mention in my post that I did try three loads. At the maximum load (per Hodgdon) accuracy was definitely better, but still not good enough to trust on a hunt. There weren't any signs of pressure problems with the max load, so I suppose I could experiment with going up a bit, but I'm not sure how strong the 44 carbine action is. I think I just need to go to lighter bullets. Which is a shame, because these would be excellent hog poppers.

 

[Sig685]

Why don't you just measure the twist and then you will know for sure.

 

[mzimmers]

How does one do that?

 

[Sig685]

You start with a cleaning rod to which you attach a patch so that everything is tight in the bore. Since you are going to go in from the muzzle and the twist rate is going to be very slow, you will only measure for 1/2 turn.

So CAREFULLY insert the patch in the bore and push in the rod a couple inches in. Then with a marker, make two marks; the first one right at where the rod enters the muzzle and the second one near the handle of the rod. Make that second mark at top dead center on the rod. Then carefully push in the rod until that second mark is now 180 degrees from where you started. This will be a half turn Make a third mark where the rod enters the muzzle; you may want to make that one 180 degrees from where you did the first one.

Now push the rod to the end, remove the patch in the chamber and pull out the rod. Measure the distance between the first and third mark and multiply it by 2. This will be the distance in which the rifling would do a full turn. The distance should be between 8 and 10 inches, which when multiplied will be 1:16 to 1:20.

Good luck and do this carefully, do not mess up the muzzle crown.

 

[MADISON]

Start a tight patch; being sure the jag is tight on the rod.
Mark the rod with a felt tip to indicate Top Dead Center and a starting point.
Advance the rod until it comes back to Top Dead Center.
Measure the distance traveled from the start mark. That is the rifling twist, one turn in xx inches.
A lot easier than trying to estimate the amount of twist in a foot.

 

[TDF]

I've had two 44 carbines and both handled the 300 gr hornady XTP just fine.

TDF

 

[mzimmers]

TDF: do you remember what loads you were using?

 

[captainkirk]

Start a tight patch; being sure the jag is tight on the rod.
Mark the rod with a felt tip to indicate Top Dead Center and a starting point.
Advance the rod until it comes back to Top Dead Center.
Measure the distance traveled from the start mark. That is the rifling twist, one turn in xx inches.
A lot easier than trying to estimate the amount of twist in a foot.

That works fine if the twist is fast enough so you can make the turn before you run out of barrel. My 1-38" winchester trapper didn't have enough barrel to make even 1/2 turn...

captainkirk

 

[TDF]

TDF: do you remember what loads you were using?

Yep, it was the 300 gr Hornady XTP-HP over 20.0 gr of H110 with a OAL of 1.600. The load comes from Hornady's reloading manual 4th edition and was supposed to be good for 1500 fps from their test gun which coincidentally happened to be a Ruger Carbine 44 mag. It functioned perfectly and although it wasn't a tack driving load it was plenty accurate enough for my uses. Don't remember exactly but seems like it was 1.5 inches at 50 yds.

Shot two deer with this load. Flattened them both.

TDF

 

[mzimmers]

20 grains, huh? Hodgdon says the load should be between 18.0 and 19.0...is this a case of the lawyers getting involved and making published loads too conservative? As I recall, my hotter loads were less terrible than the lower ones.

 

[TDF]

20 grains, huh? Hodgdon says the load should be between 18.0 and 19.0...is this a case of the lawyers getting involved and making published loads too conservative? As I recall, my hotter loads were less terrible than the lower ones.

I don't know man.........I guess that's what makes reloading so much fun. My Hodgdon manual from 1998 says 20.0 gr's is the max. My Lee manual from 2000 also says 20.0 is max for a 300 gr jacketed bullet. I worked my way up to the load and had no signs of excessive pressure or any problems so I guess all I can say is it's safe in my guns. Your mileage may vary.

Stay safe,
TDF

 

[cruzerlou]

I don't know but I was told here on the forum that the twist rate on the deer stalker was made for the 240 gr bullet given that that was the most common commercially bullet factory loaded bullet avalble at the time [the 60,s] I also try to stay with a mid range load Like the wincherster whitebox 240's to keep ware and tare down on my gun as parts are almost non existant and they do afine job on deer .I love that gun and the last thing I want to do is berak it shooting hot loads in it I have my SBH for those ,
Lou

 

[mzimmers]

Hey, guys –

I have to confess that I'm still a little nervous about shooting the full house loads that TDF mentioned above in my carbine. Does anyone want to comment on the strength of the action of these guns?

 

[mattsbox99]

The old carbines were 1-38" and the newer deerfields are 1-20". Even my 444 Marlin with its 1-38" twist has a tough time with bullets over 320 grains and it is much faster than the .44 Mag.

 

[Jimbo357mag]

My opinion would be if the gun shoots 240gr slugs well why try to make it shoot 300gr bullets? I don't think there would be a whole lot of difference in the outcome. Don't forget a 240gr bullet will be going faster. There are a whole lot of 240gr bullet and powder combinations that work well.

...Jimbo

 

[flatgate]

I'm no rifle guy but I distinctly recall an article, by Lane Simpson maybe, that reported the Hornady 265 gr. bullet was the heaviest projectile that the Ruger "Deerstalker" series Carbine would successfully shoot.

I have zero experience since I've NEVER fired a Ruger .44 cal. rifle.

.45-70 #3? Yowsuh! That got my attention.

flatgate

 

[SteveRuger]

flatgate !

I can not believe you jumped in a rifle thread! Is it a Blue Moon in Wyoming? :lol: