Hi folks, I posted this over at Leverguns, I thought I'd give it a shot here too. Thanks,
HRF

About two years ago, I bought a Marlin 336CB in .38-55 Cal. Since that time, I've had a lot of fun shooting this rifle, and loading the .38-55 cartridge. I've had such a good time shooting the 336CB, that it actually replaced a super-accurate Rem. 700 VS as my groundhog rifle. My usual load for this rifle is a .380" dia, 240 grain Oregon trail LRNFP bullet ahead of 18.5 grains of XMP5744. I load this in Winchester cases, and spark the whple thing with Remington large rifle primers. Over my chronograph, the bullets clock about 1200 fps, and they are deadly accurate to about 100 yds (one three shot group measured 3/4"). Recently I decided to try increasing the velocity of these loads to flatten out the trajectory for 100+ yard grounhogs. According to the Lyman #48 manual, the max load for 5744 is 25 grains. I theorized that as the cases were more completely filled with powder, the pressures would become more uniform. I expected that I would end up with a higher velocity load (i.e. flatter trajectory), with lower ES/SD numbers. All of which would maintain or increase my level of accuracy. Well, I was wrong. As increased the amount of 5744, my extreme spread, and standard deviation numbers increased dramatically. Worse still, my accuracy began to deteriorate. So now I'm back at square one. Does anyone have a load combination (preferably featuring a 240 grain LRNFP bullet) that has velocities in the 1500-1600 range (or better), that is accurate enough for intermediate to long range varminting ? I would be happy to hear any other words of wisdom you might have on loading the .38-55.
Thanks,
HRF

I have been using the Lee 250 grain plain base cast bullet in the .375 with good luck.

My most accurate load has been 2.8 grains of Alliant Bullseye which gives me 550fps from my 20" barrel.

In your speed range I have had good accuracy from Hodgdon 4895SC.
31.0 grains giving me 1611fps with an E of 26fps.
32.0 grains giving me 1657fps with an E of 61fps
Both of the above loads give good accuracy to 100 yards but I have not shot them beyond this distance. These low velocity loads will richochette on hard ground.

A maximum load of Accurate Arms No. 2 is 7.0 grains and it gives me 1019fps with an E of 17fps and bragging accuracy.

6.8 grains gives 994fps and less accuracy.
6,5 grains gives 978fps and still less accuracy.

24.0 grains of IMR 4227 gives me about 1700 fps. This
a particularly good load. I have shot it quite a bit for practice at the bench with this rifle.

I have shot quite a bit in this velocity range but these are the loads I would start with. I would not think there is a great deal of difference between our rifles at these pressures.Dont overlook forum member Greg Mushials Load data on his web site gmdr.com

I have a Marlin 38-55 CB also and my favorite load is a 269 gr Lyman cast bullet with 20gr of SR 4759 which gives me 1660fps with good accuracy and an ES of about 30fps. SR 4759 usually works well for me with cast bullets and is usually the first one I try - it always has a low velocity ES.

Hi folks, I posted this over at Leverguns, I thought I'd give it a shot here too. Thanks,
HRF

About two years ago, I bought a Marlin 336CB in .38-55 Cal. Since that time, I've had a lot of fun shooting this rifle, and loading the .38-55 cartridge. I've had such a good time shooting the 336CB, that it actually replaced a super-accurate Rem. 700 VS as my groundhog rifle. My usual load for this rifle is a .380" dia, 240 grain Oregon trail LRNFP bullet ahead of 18.5 grains of XMP5744. I load this in Winchester cases, and spark the whple thing with Remington large rifle primers. Over my chronograph, the bullets clock about 1200 fps, and they are deadly accurate to about 100 yds (one three shot group measured 3/4"). Recently I decided to try increasing the velocity of these loads to flatten out the trajectory for 100+ yard grounhogs. According to the Lyman #48 manual, the max load for 5744 is 25 grains. I theorized that as the cases were more completely filled with powder, the pressures would become more uniform. I expected that I would end up with a higher velocity load (i.e. flatter trajectory), with lower ES/SD numbers. All of which would maintain or increase my level of accuracy. Well, I was wrong. As increased the amount of 5744, my extreme spread, and standard deviation numbers increased dramatically. Worse still, my accuracy began to deteriorate. So now I'm back at square one. Does anyone have a load combination (preferably featuring a 240 grain LRNFP bullet) that has velocities in the 1500-1600 range (or better), that is accurate enough for intermediate to long range varminting ? I would be happy to hear any other words of wisdom you might have on loading the .38-55.
Thanks,
HRF


OPDRifleman,

Are you sure you want to use a .38/55 for varmint shooting? Roundhouse trajectory? Ricochets?

Anyway, here are some .38/55 reloading results using Oregon Trail's Laser Cast 240 grain RNFP .377" bullet. 18 1/2 grains of IMR-4198 in Winchester cases, sparked by CCI#200 primers gave an average velocity of 1312 fps, s=14.8 fps, es=41 fps. The 5-shot group at 50 yards measured 1 7/16 inches. Another 5-shot group with the same load measured 1" and gave an average velocity of 1316 fps, s=19.9 fps, and es=46fps.

You have discovered one of the truths associated with reloading the .38/55; if you try to increase muzzle velocity, accuracy will ususally deteriorate. Not alway, but usually.

However, the following would probably satisfy your requirement for a 1500 to 1600 fps load: Winchester cases, CCI#200 primers, 27 grains of IMR-3031, SAECO 373 250 grain gas-check bullet. Average muzzle velocity was 1574 fps, s=24.9, es=57 fps. One 5-shot group measured 13/16th inch at 50 yards, others ran over 2 inches.

The rifle used is a Winchester Model 94 with a 26 inch barrel.

I am going to experiment further with the Laser Cast bullet. I will let you know what results.

Carlino

OPD
I have the same rifle and shoot the same .380 bullet. my load is 20gr of H4198, WW brass and CCI 200 LR primer with a velocity of 1400 with an ES of 15.

My bore is .3803 but the neck is to tight to chamber a .380 bullet in this brass so I outside neck turned the brass till it just slipped in with just a hint of resistance. So I have what the bench shooters call a TNT (tight necked turkey).

I believe this is why this rifle will shoot one inch groups all day long at 100 yds off the bench. It also say's alot for the load, but thats in my rifle, who knows what it will do in yours till you try it.

Ken Waters Pet Loads shows 38-55 loads with H4198 starting at 21gr for 1286 fps, 23gr at 1485 fps and 26gr at 1618 fps using a Lyman cast 375248 bullet. Bottom line is your going to have to see what YOUR rifle likes the best.
Very interesting, shooting dirt pigs with a 38-55. You using a scope or receiver sights? My next trip back to the buckeyes, I may bring my 38-55 with me and give that a try.
Wascally Wabbit

No scope, I use a Williams FP receiver sight paired with a Lyman globe front. I like the cross-hair insert in the front. The main thing is it's FUN. I got almost bored with shooting the "ultra-accurate" bolt guns. The topography of the places I hunt dictacte that shots rarely surpass 250 yards in distance (most are considerably closer). The iron sighted 336CB puts some challenge back into the mix. It requires me to be better both in loading my ammo, and hunting/stalking/shooting. Some days the groundhogs win, that just provides motivation for me to get better for the next time ! Thanks for all the comments, I'd still be happy to read more.
HRF

Everyone is talking about loads but no one has mentioned anything about bullet alloys to get to these velocities ! JAGG

OPD,
Jag is right about the alloys. Anything above 1350 to 1400 is going to probably need a gas check.

If you don't cast your own (I dont) there arn't too many cast bullet makers that use gas checks. BTB does but their max dia for 38-55 is .378, that's two thousands under your bore dia. There is one here in Colorado that makes a .380 dia with a gas check. You can find them at www.bonusbullets.com. Their bullet is a 260gr RNFP GC and it say's (hard cast) what ever that means, guess you'll have to ask what their BHN is. I have 100 of them but haven't shot them yet, saving them for when I decide to go above 1400fps. There must be more bullet makers that will gas check, I just dont know who they are, maybe this will stir the pot, and you'll get some more names.
If you'd like some company on one of your outings let me know, I come back home( Medina Co) to visit late May/early June and again in early October. My sight is a Lyman 66rear and a Lyman 17A globe with a wide post.
Wascally Wabbit

Well, after a week or so of re-reading all the information on the .38-55 in my reloading manuals (which is surprisingly limited given the fact the cartridge has been around for over 120 years), I decided to try a couple of things. First, I went back to my 22.5 grain XMP5744 load, and increased the amount of crimp. This was to see if that alone would help to stabilize the velocity of the load. I have to say that it worked like a charm. When the weather was willing to cooperate, I went back to the range with my chronograph. I was very pleased to see my average velocity with this load had increased from 1433 to 1536, not bad for just screwing my factory crimp die a little further into the press. Equally impressive were the ES/SD numbers. ES settled down to 54.23, and SD was 17.57. The groups with this load were a little bit big coming in at about 2" @ 75 yards. I suspect I could do a bit better if I was shooting for pure accuracy, and not worrying about acidentally blasting my chrony. Along with this load, I also tested a completely new (for me) combination. Still using my Oregon Trail 240 gr. LRNFP, I loaded up 5 groups of 10 cartridges with IMR 3031. The begining load was 29 grains, each successive group of 10 increased in powder charge weight by .5 grains; the top load was 31.5 grains. There was a bit of a rocky beginning with these loads. As with my original attempt to increase velocity with 5744, my ES/SD numbers climbed noticably as the load/velocity increased. This remained a constant until my top end load of 31.5 grains (I should note here that this load is still below the Oregon Trail loading manual max load of 31.8 grains of 3031). With the 31.5 grain load, I had an average velocity of 1721 fps, ES:48 fps/SD:17.5. The only fly in the ointment was the fact that at 75 yards my groups were several inches high and slightly to the left. group size was still in the 2" range. I think for my next experiment I'll increase my powder charge from 31.5 to 31.8 by increments or .01 grain. I may also decrease from 31.5 to 31 by the same amount. As I do this, I'll simultaneously look for the absolute most consistent velocity and the tighest group size. Let me know if you guys are interested in seeing more of these results, or if I'm boring you to tears.
Bye for now,
HRF

“Let me know if you guys are interested in seeing more
of these results, or if I'm boring you to tears. “

I may not answer often but I think this is a very interesting thread.

“Well, after a week or so of re-reading all the information on the .38-55 in my
reloading manuals (which is surprisingly limited given the fact the cartridge
has been around for over 120 years), “

It is easy to find old writings but writing on the modern guns is not as easy. A search of findarticles.com will bring up several. The problem is they are fluff pieces and have little useful information. There are at least two article by John Taffin from Guns magazine and there may be one from Handgunner. There are a number of threads on Beartooth that discuss the difference in bore size between Marlin and Winchester rifles (mostly related to the .375 cartridge) and these give useful information. I have often thought that a board such as this should have a capability to search by caliber. I am just beginning to study the internet and don’t really understand how boards work – yet. For your searches on Beartooth be sure to go to the bottom of the page and change the search time to from the beginning.

“increased the amount ofcrimp. This was to see if that alone would help to stabilize the velocity of
the load. I have to say that it worked like a charm. “

“I was very pleased to see my average velocity with this load had increased from 1433 to
1536, not bad for just screwing my factory crimp die a little further into the
press. Equally impressive were the ES/SD numbers. ES settled down to 54.23,
and SD was 17.57. “

You are not the first person to discover an amazing improvement in results due to the Lee factory crimp.

“The groups with this load were a little bit big coming in at
about 2" @ 75 yards. I suspect I could do a bit better if I was shooting for
pure accuracy, and not worrying about acidentally blasting my chrony. “

I know what you mean! You will really become careful after you shoot one! I still chronograph and shoot for groups at the same time but it can be risky.

“Along with this load, I also tested a completely new (for me) combination. Still
using my Oregon Trail 240 gr. LRNFP, I loaded up 5 groups of 10 cartridges with
IMR 3031. “

I have good luck with IMR 3031 in straight wall cases but I do get the most uniform chronograph results from it. Goes to show, A load can be accurate even with a high extreme spread.

I think for my
next experiment I'll increase my powder charge from 31.5 to 31.8 by increments
or .01 grain.

If you have enough components try one of each on the same target at 100 yards to sewe if they climb the target relative to each other.
While waiting for my 25-35 (as in I cannot find one to buy) I brought out the Encore (.375 Winchester) and will work some with the Lee 250 grain bullet. This is a great bullet. I’ll shoot it with some IMR 3031 and we can compare notes between my small bore Winchester and your larger diameter Marlin.

William, do you size your Lee slug, or just shoot it as cast? My accuracy increased enough with lapping the bore, that I am impatiently awaiting some decent weather to see if my slightly higher vel. loads settle down from several weeks ago. These are all as cast. Don't have a Lee sizer in yet. I would need .377, and my bullets are larger than that. For very slow loads, the bullet unsized is probably adequate. Not sure about those loads over 1400fps yet.

I shoot them as cast - hand lubed. this goes very quickly. I'll have to measure one but i remember them as.379' or larger. Could be wrong on that though. these just chamber in my winchester.
Someone has posted on this board that there are a number of threads on other sites about this bullet but I have not found them yet.
I have driven these pretty fast with no trouble. i use 50/50 Alox, I bought a bunch of Javalina lube a few years ago. I am about to run out, I hope they are still buisness.

Thanks for the response, William. I'll post an update when I have time to actually carry out the experiment. I'd be very interested to see the results of your .375 loads with the Lee 250 grain bullet and 3031.
Thanks,
HRF

Lyman also made and so did other's , a mould for the 155grain 375 bullet for the 38/55 ! JAGG

I have been loading a 245 gr. plain base flat point sized to .379 with 8.5 grs. of Power Pistol and get excellent accuracy from my CB. The other day I loaded some Hornady .375 220gr. FP jacketed with 32gr. of 2015 and got better than expected accuracy (1/2" @ 50yd.). Don't know what velocity either load is going the jacketed round is published at 1886 fps.