.50 Cal Maynard tube specifications

[WBR10654]

Since there are few places to shoot Black Powder in Raleigh that I can go to with out an escort yet I have been looking at doing some long range shooting.

During the research on reloading I have learned a bit about Case Length, Chamfering, trimming and Annealing.

So it made me wonder if the reason some of my Maynard Tubes have been starting to budged is they have stretched and sitting in the chamber different.

So I measured the length of a bunch of them and found they are all very different.

So,

Who can tell me what the specs are for this case as so far I have not been able to find it on the internet.

I guess I might drop Larry
Romano to see what he has to suggest for his rifle but I thought this might also be of interest to the CREW.

DPB

[Ben Nevlezer]

Since there are few places to shoot Black Powder in Raleigh that I can go to with out an escort yet I have been looking at doing some long range shooting.

During the research on reloading I have learned a bit about Case Length, Chamfering, trimming and Annealing.

So it made me wonder if the reason some of my Maynard Tubes have been starting to budged is they have stretched and sitting in the chamber different.

So I measured the length of a bunch of them and found they are all very different.

So,

Who can tell me what the specs are for this case as so far I have not been able to find it on the internet.

I guess I might drop Larry
Romano to see what he has to suggest for his rifle but I thought this might also be of interest to the CREW.

DPB
I believe the guy you should contact would be Mr. John Bly. He is the modern day "Dr. Maynard ". He is on the b.b. here quite often.

[WBR10654]

Yep, that would be a good choice too but I will wait a few days and see if he sees it first.

DPB

[762x51]

In the book "A Guide to the Maynard Breechloader" by George J Layman he gives the following info:

Case Length: 1.24
Neck Diameter: .543
Rim Diameter: .770
Base Diameter: .54
Bullet Diameter: .520

Orin

[John Bly]

I can't tell you a lot about the cases but I can give you some dimensions of some chambers. I measured 3 original chambers. A 1st mod barrel measured 1.186" deep x .551" dia. at the breech end and .548" at the front. Two 2nd mod barrels measured 1.202" deep and 1.210" deep. They were both .552" dia. at the breech end and .548" dia. at the front.

The chambers on my barrels measured from 1.186" to 1.194" deep and my standard reamer cuts a straight chamber .547" diameter. If the groove diameter is .517" or larger then I ream the chamber to .550" diameter.

I've got a Romano in for work right now and the chamber measures 1.264" deep x .552" diameter. It's a very early one with hand engraved lettering and may not be indicative of what he is producing now.

I've got a Hoyt chambered one in now for work also and the chamber length is 1.169" x .550" diameter.

I measured a bunch of cases and the lengths varied from 1.159" to 1.173" long in front of the rim. I measured this way to compare to the chamber depths. The diameters ran about .542"-.543" average with some being as small as .538"

I had one plastic case and it measured 1.159" long.

The longest case was .013" shorter than the shortest chamber so there should not be a problem with cases being too long except in the Hoyt chamber. I've dealt with some of his in the past and I know his lengths vary quite a bit. When he lines a Maynard barrel for me I have him leave it long at both ends and I chamber and crown them.

The worst case scenario seems to be the very small diameter reduced capacity cases in a large chamber. The front expands to fill the chamber but the heavy back section can't expand and the brass stretches all in a very tiny area right at the junction of the two diameters. Sometime they crack in this area.

I don't recommend sizing the cases every firing but only if they get too tight to chamber easily. The grain direction in the brass rod the cases are machined from is opposite from the ideal direction for continuous expansion and contraction and I'm surprised they last as long as they do.

[Kevin Tinny]

Hello:

As a suppliment to John Bly's 50 Romano Maynard chamber dimensions,
my unfired 50 Romano, frame number 199 measures:

Depth to rifling: 1.18"
Neck OD: .546"
Chamber mouth OD: .548"
Larry confirmed these to me after I measured and he said the .002" taper is correct.

For what it may be worth, I have seen "altered" 50 Maynard chambers with .038" of taper!

Regards,

Kevin Tinny

[WBR10654]

Thanks,

Now off to measure 400 cases...

BUT my first measurements indicate mine are much SHORTER (an edit from later) than that...

I mine are coming in in the 1.19ish range.

DPB


In the book "A Guide to the Maynard Breechloader" by George J Layman he gives the following info:

Case Length: 1.24
Neck Diameter: .543
Rim Diameter: .770
Base Diameter: .54
Bullet Diameter: .520

Orin

[WBR10654]

I missed you post until later,,,,

So are coming in a bit larger at the 1.19+ range.

Could be be cause I have been shooting them for 16 years and they have gotten longer.

Now the question is, should I care?

I know this makes a big difference in Long Range Shooting but at 50 and 100 yards? one wonders if it makes any difference.

I have yet to hear of anyone trimming Maynard Cases.

DPB







Hello:

As a suppliment to John Bly's 50 Romano Maynard chamber dimensions,
my unfired 50 Romano, frame number 199 measures:

Depth to rifling: 1.18"
Neck OD: .546"
Chamber mouth OD: .548"
Larry confirmed these to me after I measured and he said the .002" taper is correct.

For what it may be worth, I have seen "altered" 50 Maynard chambers with .038" of taper!

Regards,

Kevin Tinny

[Kevin Tinny]

Hello, again:

My new turned brass 50 Maynard cases from both Romano and Lodgewood
measure:

OAL, incl. rim: 1.200" - 1.202"
Rim thickness: .027" - .030"
Rim OD: .749"
Case BODY length: 1.170 - 1.173"
OD of body at rim: .544"
OD of mouth at rim: .544"

So these new cases are:
Nominally .010" shorter than the Romano chamber.
Nominally .002" to .004" smaller than the Romano chamber.

Larry told me that he is still shooting his original batch of brass Maynard cases after years, using Rem #11 pistol caps, and at least a hundred shots, EACH, with no flash hole erosion, no sizing, no trimming, no annealing and no accuracy issues.

If the bullet is NOT firmly gripped because of either or both case expansion or thin mouth walls, that is ok as long as the bullet does not fall out in one's cartridge box and the bullet is at least lightly pressed into the rifling.

He does not use reduced capacity cases. These are in short supply and Charley Hahn said a thin poly tube inside the powder section of full capacity cases will easily create a reduced capacity one from the " internal dunnage" of the poly.

Regards,
Kevin Tinny

[John Bly]

I shoot long range Black Powder Cartridge Silhouette and target matches and you are correct, great pains are take to ensure the brass is very consistent for each cartridge. Consistency is the name of the game as far as accuracy is concerned. For 50 and 100 yard offhand matches we generally do not need to be as picky as if we were trying to hit a basketball sized target at over 400 yards. You certainly don't want any cartridges longer than the chamber in which they are shot. I've never heard of anyone trimming Maynard cases either. The pressure is low enough that I would doubt they would stretch with each shot.