38-55: long starline VS short starline.

Well.. working harder on load development on 38-55 than i have on any other rifle i load for, even getting cast to shoot in a micro groove marlin 45-70.

After loading and shooting perhaps 250 rounds in the short brass, and about 125 rounds in the long brass, i can say that BOTH brass lengths can be loaded to an OAL that cycles in my lever rifle, and both shoot decent. The accuracy is not quite where id like to see it, as i often get two rounds close together, sometimes touching depending on how much i wiggle, with a third flyer that opens to group to 3-4", sometimes more. I'd like a single hole at 50 yards of course.
This may be me, as im shooting sitting, sometimes off sticks. The front sight is NOT real easy for me to shoot, and i'm looking for a beaded sight.

As far as i can tell, bullet fit and powder charge make more of a difference in accuracy than does that .045" of brass.

Ive ordered a lee bullet sizer, and im hoping that will take out some of the variation by making bullets more consistent.

I was forced to go with the short Starline cases for my two Marlin CBs, due to the infamous short chambers and the large bores. The short Starline cases allow me to shoot .380/.381 boolits in the 260 gr range +/- with not issue, and wicked good accuracy at 50 and 100 yds.

But not one hole at 50 yds. Close; the groups range usually from 0.75" to 1.0", and open up at 100 to about 1.25" to 1.5" as one would expect.

But I also inherited some long Starline cases when I bought second hand a Winchester/Miroku 1885 Highwall with 26" octagonal barrel. That rifle does shoot ORH accuracy at 50 yds, and slightly larger ORH groups at 100 yds. Out of curiosity, I fired my standard Marlin loads in short brass along and with high brass, and the groups maybe opened 1/8" to 3/16", splitting hairs with a caliper, but still ORH shooting off bags.

The difference? A single shot with a fairly stiff barrel and a tight locking action vs. a lever with rear locking bolt, a smaller across the flats octagonal barrel, and - IMO the biggest factor - a magazine tube of changing mass hanging under and off the barrel. Changing mass? It gets lighter with every shot. If I do my part, the groups in the Marlins are measurably tighter when single-loading them.

Which reminds me of accuracy problems I had with a Winchester 94 in .375 Winchester in the early 1980s. I could NOT get that to shoot despite several powders and several boxes of different J-projectiles and proper cast boolits. We're talking patterns, not groups; 5" to 8" were not unusual. The absolute best was 3.9".

A now-late friend suggested stripping off the fore end and magazine tube and shooting the 94 Big Bore off bags as a single shot to determine what the "absolute accuracy potential" was, without the magazine bits and front-end timber mucking about with the barrel vibrations. With certain loads, it was under an inch. Worst grouping was 2.375".

So I set about "tuning" the 94 Big Bore by relieving the top of the carbine band from contacting the barrel, and lining up the magazine directly under the barrel instead of where New Haven put it, at about 5:30 when viewed at the muzzle. Finally, I reworked the magazine cap screw and its recess in the bottom of the barrel so that the screw bottomed on the cap and not in the recess. Mind, the screw tip was up into the recess, but it did not make contact hard, bottoming contact. But it would still stop the magazine tube from sliding forward.

Using the two best loads from the stripped 94 Big Bore barrel-only trials, with a properly-dressed barrel the 94 delivered 1.375" to 1.75" groups at 100 yds using cast boolits properly sized to the bore, over 12.9 grains of Unique, no filler. Remarkable, consistent accuracy from that load (which is not far off what I use in short brass in the Marlins with .380/.381 boolits) that delivered five West Virginia whitetails.

The 94 Big Bore has found a new home, having transitioned to the 38-55 represented by the two Marlin CBs (one a previous owner cut to 18"), the Winchester 1885, a Winchester/Miroku deluxe Sporter Model 94, a 20" Cimarron 94 carbine, and the recent addition, an NEF/H&R Buffalo something single shot (I forget what they called it). The latter has chambering and rifling not that much different from that of the Marlins, no surprise, but I've not had time to fire it even once; I only slugged the bore and cast the chamber. The Cimarron delivers between 1.5" and 2.0" at 100 yds now that I've fired it more, but I've not had the time to do a proper tuning of the magazine bits and their alignment. Nearly every levergun I've so treated showed improved groupings.

Just some of the experience from my own 38-55 (and .375W) journey.

Noah

the Marlin CB is a grail rifle to me, in 45-70, 38-55 and 30-30. There are things l like about the winchester a little better, but i grew up with marlins.
Im going to have to try the rifle without the mag tube and forend and see how it does.
Great tips on the finer points of tuning the lever for accuracy, thanks!

Noah,
You're on the money, that full length magazine and it's attachment points are key. That is why the 2/3 magazine is my preferred configuration.Let the rest of the barrel float. And barrel bands are hopeless, you want that and the nosepiece dovetailed to the barrel, and then some very small o-rings, particularly under the
mag tube mount.
On the long vs short brass, with cast you want the boolit to be just touching the throat, no jump for the start of ignition. Take a case and start a boolit in the neck and then chamber. This will push the boolit back into the case. That is where you want the COAL. Crimp groove or not, that's where you'll get the best
accuracy from the load. Adjust case length to suit crimp cannelure, NOT the other way round. Won't feed you say? Then you have to start tweaking the action
so it will. Mic Mcpherson's book "Leverguns" has some great tips for that.

Spot on, Mr. Rrusse11 (Russell?). I believe we read the same book, and in addition a local gunsmith that put up with a kid hanging out in the 60s and doing odd jobs taught me a wealth of tricks on levergun tuning. What I didn't learn from him, my late friend in WV taught me.

'Preciate the comments, and Happy Thanksgiving.

Noah

Noah,
Leverguns are their own animal when it comes to accuracy. The nature of the beast is complicated, and each is an individual. Well worth it when you manage
to crack the code for a particular piece. But let's face it, not many of them are 300yd rifles. Yet to hear of any snipers using them, lol. But for minute of deer
in the woods, they're terrific. And the whole evolution of the repeating rifle for up close and personal with two legged game was their real forte, the historical
equivalent of the assault rifle. At least that's what all those western action movies use them for. Simple, reliable and effective, I love 'em!
Cheers!
Richard (no prizes for guessing my name, the double r and 1's have almost universally been unique across a multitude of forums over the years :) )