|
|
Post by twomoons on Mar 9, 2011 17:21:03 GMT -5
After hearing a lot of guff about hw inferior the micro groove barrels are with casr i decided to do a serious test. I had a 50 cal M/L barrel for my Encore and it was sitting unused. I also had a new Marlin micro groove barrel from a 336. I utrned down the 336 barrel and used it to line up a bull barrel 20" single shot for the Encore. The new barrel has a minimum chamber and is headspaced for the brass I will use for the test. The muzzle has a recessed 11 degree target crown and i have a 3x9 scpoe mounted on the barrel. Without any variables from magazine tube or bedding of the foreend this should show just how accurate a Marlin barrel can really be. I will be assembling loads and shooting the rifle with different cast bullets and different loads and we will see what we will see.
My first job was to empty some brass for loading so I shot up 25 rounds of 30-30 I had loaded with a 310 bullet and straight w/w for a Winchester 94. Now this was just emptying brass at 25 yards with a 3X settng on the scope and a piece of tape for a target. Lo and behold the toos soft too small bullets all went into 1" at 25 yards with NO leading. This may be interesting.
|
|
|
|
Post by deputydon on Mar 9, 2011 17:31:16 GMT -5
I'm curious how the 7MM-08 barrel will shoot.......
|
|
|
|
Post by jmarriott on Mar 9, 2011 18:26:24 GMT -5
It is all going to come down to how soft a lead you are using and how fast you are going to push them.
Twomoons lately I have been seeing some barrels with a little deveation on bore size where the dovetails for either the rear sight or the tube hanger bar is. Have you happened to see any of thisalmost like they were squeezed a little when they cut them. +++++++++
.
|
|
|
|
Post by Jack on Mar 9, 2011 20:21:57 GMT -5
This will be an interesting test! All the stuff that typical leverguns have - barrel bands, a magazine hanging off the barrel bands that changes weight every time another cartridge goes in or out of the magazine, etc. I have always been surprised at how well some levers shoot, with all that stuff affecting the barrel.
I'm not an expert on cast bullet shooting, but, I have always wondered. . . in Thee Olden Days, lead bullets were, by today's standards, dead soft. Elmer Keith used to talk about using a mix of 1-20 tin/lead. By today's standards, that is really, really soft.
Today, you always hear about how cast bullets have to be hard. I'm sure for some applications, hard bullets are better, but I wonder if we really need to shoot such hard bullets for a lot of applications.
|
|
|
|
Post by twomoons on Mar 9, 2011 21:56:20 GMT -5
This barrel deformation is common in Eyetie guns especially lever guns with big bores. They push in the dovetail sights with a press and it actually dents or wrinkles the barrel. I have had to cut back several barrels and put in a properly fitted dovetail to get the guns shooting as when a cast bullet is deformed by the barrel accuracy is gone.
By the time I am done we will know just how hard a bullet has to be to shoot well in a microgroove barrel. A cut rifles barrel will shoot cast well soft as pure lead IF the bullet fits and the lube will hold up. I will be posting on this as I go along and I will have some pictures coming. DD has already seen the gun and my next job will be sorting brass and making up test loads.
|
|
|
|
Post by jmarriott on Mar 10, 2011 8:28:43 GMT -5
To get a proper fitting cast bullet you should slug your bbl.
The micro-groove rifling needs a bullet that is .002-.003" over bore diameter. If you are going over 2000 FPS you should go with a gas check bullet. I would like to see gas checked verse regular bullets is you have the molds for each.
According to Brophy there have been three different types of .30-30 micro-groove rifling. We’ll call them a., b., & c. These are Marlin specifications but individual rifles may vary slightly due to tolerances:
a.) 1955 to 1957 - 16 grooves - .304” bore diameter / .308” groove diameter
b.) 1958 to 1968 - 22 grooves - .304” bore diameter / .308” groove diameter
c.) 1969 to present-12 grooves -.302” bore diameter / .308” groove diameter
30.0gr of IMR-4064 under a 165gr bullet should pretty much duplicate the original 30-30 factory loads. "water quenched" and "gas checked" using wheel weights would be a nice place to start and I believe you will get no leading until you get past 2000 FPS. Unless you have a 1958 to 1968 barrel with the 22 grooves. These whould have a tremendous amount of bearing surface and I would think the lead would need to be hard enough to act like a FMJ bullet and not expand well in deer size game.
As you can tell you hit the sweet spot for me taking a lever gun barrel and placing in on a T/C frame. 2 of my all time favorites. To bad you are so distant from me as I would come and help out in the testing and casting process.
I have a guy who is redoing a small medical office and I believe it has a X-ray room. I hope to help him out removing the lead sheet walls of the room. Should get me 8 sheets of pure lead a little over 1/4 inch thick. A casters dream.
|
|
bounce
Royal Member
Posts: 5,727
|
Post by bounce on Mar 10, 2011 9:05:35 GMT -5
I do know they don't work at all with black powder. lol.
|
|
|
|
Post by jimiowa on Mar 10, 2011 9:24:15 GMT -5
I really think the "Micro Groove won't shoot lead" theory is an overblown myth. Propogated by armchair gun experts(GOD I HOPE I"M NOT ONE). there seems to be about an even split on both sides of the arguement.
TwoMoons, I know you spend time on Cast BOOLITS and Beartooth sites, so you know all the theories on the Marlin/cast bullet thing.
I have no doubt you can make this shoot.
|
|
|
|
Post by jimiowa on Mar 10, 2011 9:30:08 GMT -5
It is all going to come down to how soft a lead you are using and how fast you are going to push them. Twomoons lately I have been seeing some barrels with a little deveation on bore size where the dovetails for either the rear sight or the tube hanger bar is. Have you happened to see any of thisalmost like they were squeezed a little when they cut them. +++++++++ . Scuttlebutt on the Beartooth Bullets site is the bore needs to be lapped in to make them shoot. I have yet to shoot my 444 enough to load up cast bullets for it? Not likely to happen this year either. I have a house to tear down and 5 acres of cornstalks to reseed and put in order. |
|
|
|
Post by twomoons on Mar 10, 2011 23:00:01 GMT -5
The object is not to make it shoot as that is fairly simple. What I want to do is explore the myths and misconceptions. For example MIcrogroove needs hard bullets, well my first test was shooting up a batch of loads to get brass. The straight w/w bullets I was shooting in a W94 shot just fine in the micro groove at 25 yards and no leading. I can't wait to get out to the range and see what is true and what isn't.
Bounce way back in 86 or so I had a M95 Marlin and got it to shoot B/P fairly well by using the right lube and a W/W bullet. Right now the hang up is distance to shoot as all my ranges are either drifted or mudded in.
|
|
|
|
Post by Bill on Mar 11, 2011 8:07:20 GMT -5
You must be bored Two Moons. Must be all that extra time you have on your hands now days. ;D I had plans on having that much time this year also but it does not look like its going to happen this year.  What I should do is send you my .38-55 336CB that is still unfired in the box and have you get it to shooting for me. ;D I have too many to shoot again. Wife says I should get rid of those I don't shoot. Thats getting harder and harder to do as their all ones I want.  |
|
|
|
Post by deputydon on Mar 11, 2011 8:16:18 GMT -5
You must be bored Two Moons. Must be all that extra time you have on your hands now days. ;D I had plans on having that much time this year also but it does not look like its going to happen this year. What I should do is send you my .38-55 336CB that is still unfired in the box and have you get it to shooting for me. ;D I have too many to shoot again. Wife says I should get rid of those I don't shoot. Thats getting harder and harder to do as their all ones I want. There's a lot worst problems that you could have there Willy !!! ;D ;D ;D |
|
|
|
Post by jimiowa on Mar 11, 2011 20:57:45 GMT -5
My suspicion has always been that people were pushing the velocity in the microgroove barrel and stripping the bullet, so had to go to harder bullets or the ballard rifled barrel.
I believe if they hold the velocity in a reasonable range the mictogroove barrel will work just fine.
|
|
|
|
Post by twomoons on Mar 16, 2011 21:20:01 GMT -5
At 25 yards I will learn nothing as all the left over loads I have shot up so far are all in about 1" and no bulet tipping and no leading with any load so far. All the loads I am shooting up to get brass are bullets sized to 311 and as bullet size is most important I am not surprised so far.
|
|
What I should do is send you my .38-55 336CB that is still unfired in the box and have you get it to shooting for me. ;D I have too many to shoot again. Wife says I should get rid of those I don't shoot. Thats getting harder and harder to do as their all ones I want. 