JBledsoe, your post, while perhaps well intentioned, contains information that is potentially harmful for a novice reloader.:hmmmm: Bullet to land distance in the 38-55, which you dismiss as unimportant, happens to be controlled by case length. They go hand in hand so to speak. You can't have one without the other.

Furthermore, if you attempt to minimize bullet jump by using a case that is long enough to extend into the throat and impede bullet release you will have a lot more to worry about than a distorted bullet. How about a distorted rifle??:ahhhhh: That is what will happen when pressure spikes because a case can't release the bullet quickly enough. Under no circumstances should one ever use a case that intrudes into the throat of the chamber.:shot:

Two of the multiple prerequisites for accuracy as well as safety require that you know the proper case length for your rifle and that you select a bullet profile that fits the throat/leade of your rifle. Hope this helps.

 

I would like to add a few comments without using RUDE smilies that say a lot to someone with out typing the words.
"JBledsoe, your post, while perhaps well intentioned, contains information that is potentially harmful for a novice reloader.:hmmmm:" "Bullet to land distance in the 38-55, which you dismiss as unimportant, happens to be controlled by case length".


This is not always true. I have two particular .38-55 rifles that I shoot the RD cast bullet out of. One chamber requires that the RD bullet be seated to the first groove near the nose to be just off of the lands and the second rifle, with the same cases, allow the RD bullet to be seated out to the second groove to be just off of the lands. So the bullet to land distance is controlled by bullet seating depth. This is not law, it is just my two rifles.

"They go hand in hand so to speak. You can't have one without the other."

"Furthermore, if you attempt to minimize bullet jump by using a case that is long enough to extend into the throat and impede bullet release you will have a lot more to worry about than a distorted bullet. How about a distorted rifle??:ahhhhh: That is what will happen when pressure spikes because a case can't release the bullet quickly enough. Under no circumstances should one ever use a case that intrudes into the throat of the chamber.:shot:"

This statement of not letting the case extend into the throat is exactly what the OP stated. He even used bold type to make a point of this.

"Two of the multiple prerequisites for accuracy as well as safety require that you know the proper case length for your rifle and that you select a bullet profile that fits the throat/leade of your rifle. Hope this helps."

This sorta sound like exactly what the OP stated.

All of this was done without belittling anyones reading skills. This discussion can be a good one if we just add our experiences for all to learn from without bias one toward another.

 

I don't want to get in the middle of anything here, but JBledsoe's probably forgotten more about the 38-55 than the rest of us have time left to learn. Just sayin.

 

Thanks JBledsoe.
A practical and straight-forward way to make sure there's no interference. It catches either a case length interference, or a jamming the bullet against the lands interference.

As my chamber is about .07 inch longer than normal, I don't encounter length interference, and the bullets are a ways back from the lands when crimped in the crimp groove.
So far, limited experimentation confirms your thinking that there is not much effect on accuracy whether I have the bullets close to the lands or not.

 

Just buy the Starline 'long' length & call it good........

yes Starline makes two lengths in 38-55

 

That just doesn't always work. Ya gotta see what your chamber likes. It is nice to have a choice though. You can make the case shorter, but it is difficult to make them longer.

 

Well now boys and girls -- It seems we have some conflicting opinions on how a 38-55 cartridge case and bullet relate to a modern Marlin 336 Cowboy chamber. Let’s look at a few things. First a very fine chamber cast by JBledsoe. Note: there is no step in the chamber. Marlin chambered these rifles for the original 38-55 case length of 2.125”.

View attachment 58970




Modern chamber reamers also show no step. They taper just as the chamber cast shows.

View attachment 58971



Jamming a cartridge into the chamber with sufficient force to push the bullet past the driving band and into the rifling is not a good idea. Then prying it out, like a bent nail, with the bolt and extractor isn’t conducive to accurate measurements on the remains.

View attachment 58972



There are numerous factors in the cartridge to chamber/throat relationship. Commonly:

Brass thickness

Brass length

Bullet diameter

Bullet length

Crimp groove to nose – length

Barrel riding flat or drive band

And metplat/ogive

To name a few…

View attachment 58973 View attachment 58974

To be continued...

 

If the cartridge will initially chamber without engraving the bullet on the lands, you are good to go. In a tapered chamber, as in the 336 38-55 - .050” of bullet travel to the lands is of no consequence. It’s not half the width of the crimp groove. It will have no bearing on accuracy. Bullet diameter will be the key to that.

View attachment 58975

For you novice reloaders – Follow JBledsoe’s instructions. If your bullet lightly engraves the lands, measure that distance and shorten your brass accordingly.

View attachment 58976

This will leave the bullet diameter/shape and several other variations to consider. Welcome to the journey.

Best regards. Wind

 

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Excellent post, Wind, you said it better than I did, Thanks.

 

Hey Jim,

Thanks for sharing.

Later, Mark

 

Wind...what are those big honkin bullets in post #9?:biggrin:

 

Hey there Lou -- Just another step in the journey. Best regards. Wind

 

Hey there Lou -- Just another step in the journey. Best regards. Wind

Looks like a lot of material to grab the bore! I'm guessing 350 grainers? They look cool...like mini crater bullets.:biggrin:

 

"Jamming a cartridge into the chamber with sufficient force to push the bullet past the driving band and into the rifling is not a good idea. Then prying it out, like a bent nail, with the bolt and extractor isn’t conducive to accurate measurements on the remains.

Hey there Wind, I think you're referring to my pic of a bullet engraved with the rifling. The pic I think you referred to as a bent nail? I certainly agree with that statement. Obviously, my post wasn't clear enough. Let me try to clarify it. I made that bullet in a similar way to how I slug the bore. Pounded it in from the chamber end and then pounded it out from the muzzle.

It gave me a pic of my chamber throat; the ball seat, the leade, and the beginning of the rifling. By measuring that impression I determined that when that bullet is seated so that the crimp is fully located in the crimp groove, not above it nor below it, and when that bullet is loaded in Starline 'Long' brass, the drive band of that bullet is settled very nicely in the ball seat of my chamber. That means that the above mentioned long brass ends very, very close to where the ball seat begins. I'd like to suggest that the term 'ball seat' is the proper terminology for the otherwise 'mysterious' 6 degree taper in the Marlin chamber.

I confirmed this by loading that bullet into the brass case and then attempting to chamber it. That is the pic you referenced in your post with the 'bent nail' analogy.:biggrin: I kept pushing the bullet deeper, using a press, until it took just a slight bit of pressure to chamber the dummy round. When I reached that point, I made up a new cartridge and loaded it into the chamber and then extracted it. The ball seat of the chamber had slightly swaged the drive band making it shiny while the normal color was dull. The nose of the bullet does not contact the rifling but is not very far from it. If I wanted to contact the lands I'd have to use a bullet with a different ogive.

It's important to note that using any other length brass makes the measurement invalid. That's assuming that you crimp the bullet fully in the crimp groove of the bullet. So, if you're going to crimp the cartridge in the crimp groove, the only means you have of adjusting the fit of the bullet closer to or further from the barrel lands is to vary the length of the case.

What I was proving to myself was that my case did not intrude into the ball seat with potentially devastating results. In my opinion, this is much easier than making a chamber cast. It's amazing to me that Starline managed to make some brass that perfectly fits the Marlin 38-55CB chamber; at least my chamber, anyway:congrats: Kudos to Starline.

 

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Hey Mtnwind,

I am quite sure that Wind does not need a lesson in 38-55 bullet/chamber design. He has probably forgotten more than you or I know.... "Ball Seat"? Are we talking plumbing or what? I think you are mis-informed. There is nothing "mysterious" about the 38-55 chamber, it act like a forcing cone in a revolver barrel, and it's not a marlin only thing. The Marlin chamber is cut to SAAMI spec. just as those made by most rifle manufacturers.

" It's amazing to me that Starline managed to make some brass that perfectly fits the Marlin 38-55CB chamber." .......Marlin 38-55CB? What about Winchester 38-55....does the brass fit those rifles too? Starline makes excellent brass but they just copied what has been in use for over 125 years.

Maybe you should review your data on the 38-55, some of your revelations are common knowledge and others may be questionable.

My apologies if I misunderstood the tone of your post but it sounds as if you are presuming to be the expert and teaching the unwashed masses about the intricacies of the 38-55.

At any rate, I'm happy to see you experimenting and learning about our favorite rifle caliber. Next you will tell us that the 38-55 and the 375 Win. are two separate and distinctly different cartridges? :biggrin:

 

Wow! JBledsoe, I'm tempted to ask if you've missed taking your medication but that would be rude. I'll assume you're still on your medications and are simply being rude.

My post was not intended to teach anything to the 'unwashed masses' but rather to share my hobby with other like minded souls. Are you acting as some kind of self appointed censor assuring that any perceived slight to a friend of yours is soundly thrashed?

Something about your reaction to my post reminds me of Saul Alinsky. Ridicule, marginalize, isolate?

Its tiresome continually hearing the mantra about how much different people have forgotten about the 38-55, which of course is 'our' favorite cartridge. Who is the 'our' your referring to. I'm guessing that many of the folks who read this forum like the 38-55 as well as several other cartridges.

I'm not interested in carrying on a personal vendetta so I'm asking that you please refrain from attacking me personally in future posts. My goodness, if what I post offends you why do you waste time reading it?

 

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Good grief, Charley Brown, who has their shorts in a knot here. I was simply stating a rebuttal to your post. Now you have said that if I don't agree with you don't reply to your post.

 

Thank you.

 

That ended, sadly badly!

But... a great post with a lot of great info from everyone.

 

Yup ended with out an answer about those big boolits. If my chart is right, the top is maby Lyman Ideal 375-084 and the bottom 375-166. I have 375-166 it drops a .376 Dia. at 310 gr lubed. I have only shot it once and it key holed. I have a Kena 1893 and the slugs .3755. any hope for it. I cast 4# ww/ 1# no 2 and 4 oz. 67/33 bnh around 13. WW