This is driving me CRAZY!

[crabo]

I have a Marlin 357 CB. I can shoot great groups at 50 yards with several different powders and boolit combinations. I cannot shoot a good group at 100 to save my life. Every group blows up between 50 and 100 yards.

I am resting my reciever on a bag right in front of the lever. I am using a Bunny bag in the rear. I have a good trigger. I have used 2 different Luepold scopes and know the base and rings are good. I put a couple of washers under my mainspring to make it hit a little harder. I am using new and once fired Starline brass.

The first target is at 50 yards, the second at 100 yards. It went from 1 1/4 to 8". Same batch of loads, just shot from 50 then at 100.

The third target was from the last time out and I could not repeat it. Same components, same boolits, same everything.

The only think I can think of is to recrown it. The crown looks good, but something has to be causing it. I know how to shoot. I am sure it is not bad technique. I can shoot sub MOA groups with several of my rifles.

I have tried sizing at 358, 359, 360. I have aircooled, waterdropped, gas checked and plain based. I can get lots of 1-1 3/4" groups at 50, but they all blow up at 100. I even tried some jacketed, same results.

What am I missing?

[tuckerdog]

I dont know about the rest of the crowd but I have to play with different combos powder, lube, primers,bullet weights & styles till I get the combo that works for me,but then I'm a tinkerer at heart and it is what I do.Marlin makes good firearms and you just have to find what works best for you

[Johnch]

Have you tryed to up the powder charge ?

As my Marlin ( from memory , load notes are not handy ) shot 158 gr GC cast , either 15.5 or 15 gr of H4227 best

I believe somewhere around 16 gr is max

Also try changing lubes

John

[GP100man]

have ya chronoed em? , If there super sonic at fifty then drop out to sub sonic theres a pressure wave that disrupts true flight especially with short pistol type boolits from a rifle.

I sold a 44 lever gun for the same thing!! Wish I had it back !

[crabo]

I dont know about the rest of the crowd but I have to play with different combos powder, lube, primers,bullet weights & styles till I get the combo that works for me,but then I'm a tinkerer at heart and it is what I do.Marlin makes good firearms and you just have to find what works best for you

This is why I am crazy, I have done this alot.

[HangFireW8]

I have a Marlin 357 CB. I can shoot great groups at 50 yards with several different powders and boolit combinations. I cannot shoot a good group at 100 to save my life. Every group blows up between 50 and 100 yards.

If your groups are good at 50 and blow up at 100, the rifle and the shooting are good. The issue is either gale-force winds or bullet stability.

Using too much lube will help destabilize a boolit. Fill only the rear groove or enough to prevent leading. If you are using a very soft lube, trying moving to a hard lube. It is the random and uneven departure of lube that throws off stability, helped along by the spinning of the boolit.

Not enough velocity and rifling twist will lower stability. Try upping the velocity in small increments, and/or going to a shorter length boolit. (The other alternative, upping the rifling rate, is not much of an option). I say small increments, because at some point all cast boolit groups blow up due to too-high velocity.

The final idea is to try to change the pressure curve of the load. If you are using primarily very fast powders, try something relatively show, or vice-versa. I'm not sure what you are using but there are several theories as to why this might help (or hurt).

Hopefully this will give you some ideas to try before giving up!

-HF

[sagacious]

I have tried sizing at 358, 359, 360. I have aircooled, waterdropped, gas checked and plain based. I can get lots of 1-1 3/4" groups at 50, but they all blow up at 100. I even tried some jacketed, same results.

What am I missing?

Every bullet of every possible description, of every hardness, at every practical size, and presumably using every appropriate powder you have, at varying powder levels... simply does not shoot at 100yds? I don't mean to add to the craziness factor, but something seems wrong here.

Please do not take this as anything but an intention to assist, but your recipe of 4227 is almost exactly in the middle of the range for Lyman data for your components, which is often where folks begin. Not saying that's the case here, but middle-of-the-road recipes are not usually the point folks return to right before they give up. Crown damage should be visible with a good magnifying glass and strong light. If you cannot find any damage, it might be better to keep looking for a solution.

I'd be interested in seeing the results of a H110 or WW296 recipe with an air-cooled ww-alloy gc wax-lubed bullet. If a carefully assembled WW296 handload doesn't get it at 100yds, then I would say the craziness was hard-earned indeed!

Keep us posted, and best of luck.

[Matt_G]

You say it's doing this with jacketed as well?
Maybe it does need a recrown...

Have you checked the twist in the barrel and made SURE it is what they say it is?

[1Shirt]

Have a 94 Win in 357, that with 158 Kieth (cast hard), Lar's lube, over 12 gr.of 2400 shoots well at 100. Aroung 3" or so, probably better if it had a shooter with younger eyes.
1Shirt!

[Blammer]

I'd check the velocity of your boolits first. I suspect that the drop in velocity is causing you grief at 100 yds.

Up the powder charge or change powders. I'd recommend Lil'gun for powder.

[crabo]

Have a 94 Win in 357, that with 158 Kieth (cast hard), Lar's lube, over 12 gr.of 2400 shoots well at 100. Aroung 3" or so, probably better if it had a shooter with younger eyes.
1Shirt!

I tried 12, 12.5, and 13 of 2400, same results

[Fly]

You know it's stuff like this that makes me wonder if casting boolit's is really worth it.Don't
take this the wrong way.I just got into this a few weeks ago & I really do enjoy playing
with it.

But I'm now playing with paper jackets because I don't like slowing the boolits down that
much & taking away that much knock down energy.It seems the paper jacket may be
less subject to problems the guy above is having.

I don't know for I'm just trying that out.But it sure seems the lubed boolit's are a lot
of trouble just to save a few bucks.

[canyon-ghost]

How about bullet weight? I've seen light bullets do that, just lack the sectional density to carry 100 yards well.

[Turk]

Try resting on the front of your forend or 12' from the muzzle on the mag tube.

[MtGun44]

I have excellent accy with 16.3 gr H110/W296 under several different boolits shootes
extremely well in several different pistols and the velocity is well up into the magnum
range. Give that a try. I think you need to move faster (stay supersonic) or spin
the boolit faster (more velocity) to keep it stable at 100 yds.

Bill

[waksupi]

You know it's stuff like this that makes me wonder if casting boolit's is really worth it.Don't
take this the wrong way.I just got into this a few weeks ago & I really do enjoy playing
with it.

But I'm now playing with paper jackets because I don't like slowing the boolits down that
much & taking away that much knock down energy.It seems the paper jacket may be
less subject to problems the guy above is having.

I don't know for I'm just trying that out.But it sure seems the lubed boolit's are a lot
of trouble just to save a few bucks.

Problem is, if you push a cast boolit too fast, you will not like the destruction of the game being hunted.

[SCIBUL]

I already had this kind of problem with several hunting rifles before...
And I learned from an old shooter (older than me) that some kind of rifles needed to be kept in hands to shoot OK. Hunting rifles are (generaly) light rifles. If you shoot them from a bench they will not recoil perfectly in line and your results won't be regulars from shoot to shoot !
You want to shoot it from a bench ? OK, but just keet your hand under the forend and hold it firmly. Keep it rested on your shoulder and... God that rifle really shoots well
If it don't works, throw away your rifle but just tell me where you did it
Hope this helps...

[mag44uk]

FWIW.
I organised,for our club here in the UK,what will be our annual gallery rifle long range championship. Course of fire: Bullseye target at 200 yards:2 convertable sighters,10 shots to count fired twice. Rifles used,any conventional pistol calibre underlever with any sights.
There was also a sporting semi 22 class. Bag allowed under the fore end.Size of the black is 15 inches.
We mostly shoot Marlins with the 44 being most popular. I am the boolit caster amongst us. The other guys use commercially cast boolits (made in the UK)
I have a 41 and a 44 Marlin and mainly use saeco moulds.
I used my 41 and really struggled to even hit the black. Same with my 44
The guy who won the Underlever event although owning a 44 marlin used his 357 winchester trapper. W296 under a Hornady silhouette bullet @1650 fps.
We shoot alot of Marlins over here in competition. Some of the top shooters are cleaning the 1500. We have alot of experience in manufacturing "soft" target loads.
I have come to the conclusion that these underlevers just cant shoot long range.
I have fired many different loads and boolits thru my two Marlins at 100yds and the very best I can get is about 6 inch groups with 5 shots.
At the 200 yard comp most people were shooting about a 2 foot group. I think this is the best you will ever get.
Incidentally,the 22`s did much better even using standard ammo at 1000fps. Most folk got all rounds in the black even allowing for 6 feet of holdover!
I am going to try using one marlin with the fore end and mag tube taken off.
HTH
Tony

[Bret4207]

You know it's stuff like this that makes me wonder if casting boolit's is really worth it.Don't
take this the wrong way.I just got into this a few weeks ago & I really do enjoy playing
with it.

But I'm now playing with paper jackets because I don't like slowing the boolits down that
much & taking away that much knock down energy.It seems the paper jacket may be
less subject to problems the guy above is having.

I don't know for I'm just trying that out.But it sure seems the lubed boolit's are a lot
of trouble just to save a few bucks.

Castings not for everyone. And it's more than saving a few bucks, some people just don't like cast.

[Bass Ackward]

Seems that you are questioning the gun .... or the bullets. I probably would too as it shouldn't be THAT bad with a 35, even with a wadcutter.

See if you can get access to another 357. Can be a handgun, preferably scoped. Load those same everything in it with 14 gr of 4227 and shoot it at both ranges. The group size isn't important, only that accuracy is linear. (twice the size of 50)

If it is, then it isn't the bullets. An a handgun should have a lower muzzle velocity to rule that out too if that isn't a problem. If it is, then at least you are pointed in the right direction.

The next thing I would do is to slug dirty. I would get someone to send you a few Pure lead slugs that are olgivals like Hornady's for this purpose so they should allow the throat to align them and start off just like you fired them.

Remove the bolt from the action and feel what the slug feels. Size as close to bore as possible and coat it with some of the lube you are using so you aren't beating uncontrollably to get it started. With moderate pressure, it should .... glide smooth as silk from the throat to the muzzle and you should feel the resistance lighten up as the bullet (bearing length) is clearing the muzzle.

Observe the slug. I mean under magnification for any irregularities. See if the slug is establishing bore center. If it isn't, then the base will always be out of square (same effect as a bad crown) and why only a little velocity loss shows up wildly. Look for deeper rifling or shaved lead, anything out of the ordinary. Try to use a set of verniers and measure your rifling height as well. Measure ALL parts of the slug. (front and back for every land combination)

Now as to crown. Many people believe that you can see your crown. Sometimes you do, sometimes you don't. If your bore is enlarged some at the muzzle for any reason, then the last place that it was bore diameter is the "real" crown. That could be two or three inches or more back from the muzzle. You need to remove the bolt and do this from the rear so that everything is copacetic.

Take what ever you are going to push with and run it into the bore stopping at the muzzle MINUS the bullets bearing length you are going to use. Mark the rod at that point on the rod at the back of the action so that you know when you are approaching that point. Then mark it a second time when you ARE at the muzzle with the rod tip.

If the bullet jumps free before you get to that second mark on the rod, then you have an enlarged bore or lowered rifling height from the point it pushed free and that is where your "real" crown (broke seal) currently is. To be able to cut a "true" crown, that is how far the barrel will need to be cut off to allow that to happen.

WARNING: It is best to support the gun so that you can have two hands free. This may take one individual to assist if you don't have a shooting vise or such. Then have a second set of eyes that that person doesn't move once the marks are in place so his optical point of reference remains the same using the marks on the rod. He must not move from the time the rod is marked. Your job is to apply constant pressure which may take your undivided attention. Two inches is going to look like a mile but anything less than 1/2" is hard to see from the pushers perspective. The pusher is living through the slug. As an old TV series once said, "become one with the slug, Grasshopper."

A lot of work, and the answer may not be to your liking. But at least you will have a better idea.