twist rate question

[45fan]

Well it is official, I have decided my next purchase is going to be a lever gun. From all I have read here on this thread I believe I have it narrowed down to a Marlin or Rossi. I do have a question though! Through my research and looking I have seen 18, 20, and even 24 inch barrels ranging from 1:10, 1:20, & 1:38 twist ratio's. What I get will be chambered in 44 mag. Can somebody enlighten me to the benefits or negatives of a 1:10 twist in relation to a 1:38? Also I have seen "micro groove" and "deep cut" as far as the rifling goes what is the reason for that? I will be using this for punching holes in paper as well as punching holes in piggies too. I know you guys will have answers for me thanks all!!!!

[herbert buckland]

Fast twist long bullet,slow twist short bullet.For the 44 mag out of the 3 twist rates mentioned the 1 in 20 would most likly work best with a long 300gr bullet even then velocitys wil have to be kept low for best acuracy ,for standard bullets I belive this twist rate is too quick , the 1 in 38 twist will work best for 200gr to 240gr bullets at around 1200FPS,the 1 in 10 is too fast even for longest bullet in a 444 marlin,if there was one with a twist rate of around 1in 28 to 1 in 30 I belive it would be a good choice

[45fan]

Fast twist long bullet,slow twist short bullet.For the 44 mag out of the 3 twist rates mentioned the 1 in 20 would most likly work best with a long 300gr bullet even then velocitys wil have to be kept low for best acuracy ,for standard bullets I belive this twist rate is too quick , the 1 in 38 twist will work best for 200gr to 240gr bullets at around 1200FPS,the 1 in 10 is too fast even for longest bullet in a 444 marlin,if there was one with a twist rate of around 1in 28 to 1 in 30 I belive it would be a good choice

Thanks, can you shed any light on the term "micro groove" and its possible advantage or disadvantage.

[herbert buckland]

Mircrow groove barrels have more lands and grooves and are also shalower than other types of rifling.The original idear was this would give less bullet deformation on it trip up the barrel,as for disadvantages I have found you need a hard bullet if you want to use cast .To me as a mainly cast shooter I do not use this type of rifling ,as I also use mainly black powder and it does not work well for me with BP, though this may be just my lack of experementing as Medforf rifling which is also a very shallow type of rifling gives me outstanding acuracy with BP and very hard bullets,that stated I have seen many Marlin mico-groove barreled rifles perform outstandinly with jacked and hard-cast with smokless powders,I would not buy a MG barrel as I belive the deeper types of rifling is more versitile,but this is only a personal thing and not based on any proven facts

[45fan]

Thanks Herbert, anybody else have experience with micro groove barrels? Do you like or dislike and why? Thoughts on twist rates and barrel length with cast boolits?

[singleshot]

I'll have to throw in my 2 cents on microgroove barrels. I find them to be excellent for cast boolits! No need to change alloy hardness. However, YOU MUST shoot larger boolits (generally speaking) in microgroove barrels. You should slug your barrel, but generally the boolits will need to be .001"-.002" larger. For a 44 mag anything from 1:20 to 1:30 should work fine.

[RobS]

I have 1:20" 45 cal Rossi lever action rifles and they work very well with 230, 260, 310 and to 340 grain boolits. One ragged holes from several different loads ranging from lower end velocities with the 230's to modest velocities with the heavies to 1800 fps with a 310 grain boolit powered by some H110 and pushed out of a 1:20" Rossi 454 Casull lever.

[knifemaker]

I would take a very hard look at the Rossi over the Marlin. I have had both and the Rossi 92 is heads above in accuracy over my Marlin 94. Marlin has a 1 in 38 twist and is not the best for stabilizing boolits over 265 gr. Marlin also has a reputation for oversize groove dia. I had to size my 44 cal boolits to .433 in order to get fair accuracy. The Rossi I have is a 92 in 357 mag. caliber and standard .358 dia. boolits are very accurate.
I replaced the Rossi semi buckhorn sights with a red fiber optic front sight and a Kiowa Jones peep sight that replaces the safety on the Rossi and it is a very good hunting sight combination. Even for these older eyes. My twist rate on the Rossi 92 in 357 mag is 1 in 30, and I am not sure what the twist rate is for the 44 mag. If it is the same as my rifle, it will be a better twist rate to stabilize the 300 gr, boolit that many hunters like to use in the 44 mag. over the twist rate of the Marlin.
If you check the Marlin site, you will see that there is a lot of complaints over the Marlin lever actions that are being made after Remington took them over. If it is justified, I do not know as my Marlin 94 was one made in the 70's . It had the micro groove barrel and I had to have Marlin replace that barrel as it had a .431 groove dia. at the breech end and .4325 groove dia. at the muzzle end and would not group at all with cast boolits. Marlin installed a barrel with their "Ballard rifling" and it was .432 in the groove dia. but consistant from breech to muzzle.

[Wuetastic]

I was also looking into this and found this article at castpics, very informative.

http://www.castpics.net/subsite2/ByC...um%20Rifle.pdf

[Duckiller]

I have a Marlin 1894 in 44 Mag. Have not shot boolits in it because of concerns about COL. No problem with Jacketed bullets up to 265gr. 270gr Gold Dots wandered off to the right. My gun is from early70's with a micro groove barrel.

[yeahbub]

Greetings, 45fan,

I have some commentary about .44 mag levers which may add to your repertoire before making a decision. My first experience was with two Marlin '94s, both with microgroove barrels. The first was a pre-lawyer-safety model which gave so-so accuracy with jacketed and dismal with cast. Much leading. An examination revealed the bore was tapered, tight at the breech and loose at the muzzle and lapping could never quite correct that one. It got better and shot cast more cleanly, but I finally had it re-barreled with 1:18 twist in conventional rifling. Even starting with a double stress relieved blank, it was apparent that some springing occurred when turning the contour and the new barrel needed just a few rounds of fire lapping. It is now the most accurate lever action I have with jacketed and cast. The other '94, a later "safety" model, had the same problem with the tapered bore, but has responded very well with some judicious lapping. It too is now a pleasure to shoot and one can spank stuff all over the opposite hillside, a 150 yards or so. It performs best with paper patched boolits of any conventional design with a hardness of 10 BHN or a bit harder and shows a particular affinity for a Lee 265gr RNFP tumble lube design, paper patched and sized .430, and the slow twist doesn't seem to be a disadvantage. It's accuracy with jacketed is also very good, but they seem an unnecessary expense when paper patched boolits are so easily made. Paper patching and micro-groove barrels get along very well. Were I to do it all over again, I'd go straight for the Marlin with the Ballard cut rifled barrel and consider myself well equipped.

The Rossi Model '92 action I find to be esthetically very pleasing in the feel of it as it is cycled, more so than the Marlin. I find the ejector springs that come in Rossi's to be fairly stiff, but they can be readily replaced with good ones from Steve's Gunz, aka Nate Kiowa Jones, http://stevesgunz.info/. Correct springs in the Rossi will make them smooth indeed. That said, there's a potential dark side to the Rossi in .44 mag caliber. If you find one used, there's a good chance the barrel will have been bored and rifled to SAAMI maximum dimensions. A friend's turned out to have a .426 bore and a .434 groove. This seems to have been a problem only on the .44 mag rifles, not in any other caliber. I examined one in .44-40 and the barrel was spot-on correct at .428 in the groove and the owner is very happy with it. I'm told that Rossi finally got the memo that their .44 mags had a problem and the barrel dimensions are now corrected on new rifles, but there are a goodly number of the older .44 mag M-92's gathering dust in closets due to their disappointing performance on target. The fellow with the oversize barrel partly fixed the problem by using boolits cast soft, depending on obturation to get them to fill the grooves, but the last I heard it's in the shop to be rebarreled. A pin gage could be used to determine bore diameter which shouldn't be more than .422 or .423 with conventional rifling. If a larger pin gage will slip into the barrel (light finger pressure only!), chances are the groove diameter is proportionally larger as well. Still, though, I consider the '92 design to be so attractive, I'd be inclined to buy even one of those just for experimentation to see what will make it work well and maybe a future rebarrel. In my opinion, the ultimate would be an M-92 with a Ballard cut-rifled barrel, but that's not yet on the horizon. Chiappa is also making '92's now and with a variety of twist rates, the last time I looked. They are fairly new at producing them, but I was told they're getting over their teething troubles and they are becoming worthy contenders. You might look into what the commentary is about them these days. Since you're looking specifically for a .44 mag, I figured you'd want to know. Good luck with whatever your decision turns out to be.