300 gn TSX 45-70 Distance from lands?

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CourtenayBoy

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Trying to start load development for my new Marlin 1895 SBL using a 300 gn Barnes TSX. I have loaded for my 7mm rem mag were best about 0.050" off the lands. I cut the neck of my 7 mag cases so I could chamber a bullet held loosely and eject it and measure. It worked great to find the distance to lands.

My Marlin however using the same method, will chamber and seat but I can't eject it as the tip of the bullet doesnt clear. If I tap it in a bit with a cleaning rod I can get it to eject but then my measurement is no good. If I tap the bullet in manually on the bench to what I believe is the exact same spot, it measures out at 2.630" which is 0.080" over S.A.M.M.I. spec of 2.550"

If I look at COAL from the Barnes manual for the 300 TSX, it states 2.515" which is 0.115" shorter than my lands.

So here is my dilemma, I have to back up how far do I go? 0.050" brings me to 2.580" which does eject but is over S.A.M.M.I

If I back up to S.A.M.M.I. I'll be off 0.80" and if I go with Barnes manual I'm waaaay back at 0.115"

Confused on where to start and appreciate any advice


Cheers

Mike
 
Looking for 1/4 moa at 100 with a 45-70? I can't comment on your specific combination but when loading for my marlin 45-70 I went with the manual coal and accuracy is more than acceptable and cycling isn't an issue
 
laker415 said:
Looking for 1/4 moa at 100 with a 45-70? I can't comment on your specific combination but when loading for my marlin 45-70 I went with the manual coal and accuracy is more than acceptable and cycling isn't an issue
Click to expand...

Just wanting the best, nothing less. Thanks for your input

Mike
 
CourtenayBoy said:
Just wanting the best, nothing less. Thanks for your input

Mike
Click to expand...

Best what?
The last thing to worry about with the Marlin 45-70 is the distance the bullet is from the lands.
Best operation of the Marlin is when the cartridges cycle easily in and out and the action locks up without undue pressure on the lever.
If you are going for bench rest accuracy you picked the wrong calibre and the wrong rifle.
 
H4831 said:
Best what?
The last thing to worry about with the Marlin 45-70 is the distance the bullet is from the lands.
Best operation of the Marlin is when the cartridges cycle easily in and out and the action locks up without undue pressure on the lever.
If you are going for bench rest accuracy you picked the wrong calibre and the wrong rifle.
Click to expand...

Best combo of accuracy with adequate velocity. I realize I'm loading for a mortar but still feel attention to detail is necessary
 
so worst case scenario , your group size opens up a bit .

unless your building a target rifle , the primary function of a hunting rifle is it must function flawlessly , even if it means being less accurate than it is potentially possible .

something else to think about , is the 45-70 going to push that bullet fast enough to make it expand ?

years ago I got a bunch of x bullets for my 45-120 and did some testing with them and some of them failed to open up properly . they penetrated really deeply .
found out later that the bullets in question where designed with the 460 weatherby in mind .


a more rounded bullet will have the edge of the bullet that touches the lands , closer to the lands , with a overall length that will function properly in your action .

another option if you really like the bullets your using , is to modify the action to function with the longer overall length .
 
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laker415 said:
Are you shooting with a scope and in a lead sled? Probably best to spend your time on charge weights as opposed to coal variations in a 45-70 lever gun.
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Not sure yet. I have a 3 power fixed I might use for load development but I'll probably stick to ghost ring. No lead sled, just bags. Thanks for your input
 
burnt_servo said:
so worst case scenario , your group size opens up a bit .

unless your building a target rifle , the primary function of a hunting rifle is it must function flawlessly , even if it means being less accurate than it is potentially possible .

something else to think about , is the 45-70 going to push that bullet fast enough to make it expand ?

years ago I got a bunch of x bullets for my 45-120 and did some testing with them and some of them failed to open up properly . they penetrated really deeply .
found out later that the bullets in question where designed for the 460 weatherby in mind .


a more rounded bullet will had the edge of the bullet that touches the lands , closer to the lands , with a overall length that will function properly in your action .

another option if you really like the bullets your using , is to modify the action to function with the longer overall length .
Click to expand...

I hear you, but I figure worst case with this caliber, even if it doesn't open, that is a big hole. As far as accuracy goes, at the end of the day you are right, it is a hunting rifle.

I got the guide gun for hunting BC's interior where them big damn grizzlies hang out. I may just use the TSX for black bear on Vancouver Island and load some 405 grain lead from the bullet barn for the interior. Not sure the 300 TSX is up to the task of stopping 1000lbs plus of angry bear at full charge.

I just love those Barnes though!
 
CourtenayBoy said:
Not sure yet. I have a 3 power fixed I might use for load development but I'll probably stick to ghost ring. No lead sled, just bags. Thanks for your input
Click to expand...


OK, I see what you want. I have loaded for two different Marlin 45-70s and did a good deal of experimenting.
As we have pointed out, forget about changing the distance to the lands, in looking for accuracy. As far as I could determine distance to lands has virtually no effect on accuracy and as you have discovered, there is not much you can vary it, anyway. So move on.
There is a whole shelf full of medium burning rifle powder that will work very well in that outfit in hunting class loads. Experiment with various weights.
Bullets that weigh 400 to 420 seem to work the best.
In order to know what you are doing for accuracy you should mount that fixed power scope. But stay away from a lead sled. I wrecked two good scopes from using my 45-70 on a lead sled.
The recoil will likely be too rough to bear, before there is any danger of over loading the rifle.
 
I agree that max loads in a Marlin are too much. I've broken down some loads to recover the components. Being able to shoot enough of them to determine accuracy would be difficult...
 
Load for function and suitability for purpose first, then see what you get for accuracy. Besides, my experience with TSXs in Weatherby cartridges makes me think that they are one of the better bullets to jump 3/8" or in the case of my .375 Weatherby 3/4" to the lands.

I'd be more concerned about using those bullets in a tube magazine than the distance to lands.
 
Dogleg said:
Load for function and suitability for purpose first, then see what you get for accuracy. Besides, my experience with TSXs in Weatherby cartridges makes me think that they are one of the better bullets to jump 3/8" or in the case of my .375 Weatherby 3/4" to the lands.

I'd be more concerned about using those bullets in a tube magazine than the distance to lands.
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I just searched these bullets and I agree with your concern on using in a tube magazine. These tsx seem pretty pointed. Not sure how I would feel forcing these into my marlin.
 
laker415 said:
I just searched these bullets and I agree with your concern on using in a tube magazine. These tsx seem pretty pointed. Not sure how I would feel forcing these into my marlin.
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They have an enormous hollow point that more than covers the primer pocket of the shell on front......not sure what bullet you folks are seeing
 
H4831 said:
OK, I see what you want. I have loaded for two different Marlin 45-70s and did a good deal of experimenting.
As we have pointed out, forget about changing the distance to the lands, in looking for accuracy. As far as I could determine distance to lands has virtually no effect on accuracy and as you have discovered, there is not much you can vary it, anyway. So move on.
There is a whole shelf full of medium burning rifle powder that will work very well in that outfit in hunting class loads. Experiment with various weights.
Bullets that weigh 400 to 420 seem to work the best.
In order to know what you are doing for accuracy you should mount that fixed power scope. But stay away from a lead sled. I wrecked two good scopes from using my 45-70 on a lead sled.
The recoil will likely be too rough to bear, before there is any danger of over loading the rifle.
Click to expand...

Sound, clear advice. Thank you kindly

Mike
 
I don t load for a marlin but in my sxs overall length meant nothing. I realize its a different action but I played around with seating depth and the only difference was a few fps in SD. Accuracy was not effected in either barrel
Load so that you get flawless function fast and slow
The 45/70 is a grand old round. You don't need a barns bullet to kill a bear. I played with the expensive stuff. Wasted a few pay checks. Went back to the standard Remington bulk 405 gr bullet. I haven't recovered one from the bear yet when fired from my 45/70.
I did get one back when I used my 458 wm.
Went in the back hip and was on the hide in the front shoulder. It expanded to larger than a twoonie and retained weight was 369.5 gr. Muzzle velocity was just over 2400 fps and impact was at 160 yards

Even at 1000 fps they open as well
 
brybenn said:
I don t load for a marlin but in my sxs overall length meant nothing. I realize its a different action but I played around with seating depth and the only difference was a few fps in SD. Accuracy was not effected in either barrel
Load so that you get flawless function fast and slow
The 45/70 is a grand old round. You don't need a barns bullet to kill a bear. I played with the expensive stuff. Wasted a few pay checks. Went back to the standard Remington bulk 405 gr bullet. I haven't recovered one from the bear yet when fired from my 45/70.
I did get one back when I used my 458 wm.
Went in the back hip and was on the hide in the front shoulder. It expanded to larger than a twoonie and retained weight was 369.5 gr. Muzzle velocity was just over 2400 fps and impact was at 160 yards

Even at 1000 fps they open as well
Click to expand...


Thanks for the input, it is appreciated. I clocked the Barnes at just over 2000 fps and will use that bullet on Vancouver Island. I'll be moving up in weight in a hard cast bullet in Grizzly country. I'm thinking the 390 grain from the bullet barn might be the ticket

Mike
 
99% of the reloading I did for my 45/70 was with 405gr hard cast lumps. IIRC I used Varget for those but would have to check my log book to verify, they were good for about two inches at 100yds with a scope and sandbags. I loaded to the cannelure with a good crimp. I found that keeping them under 1800fps was best for accuracy and for my shoulder (1600-1700 was best).
I wouldn't worry much about if one of your loads will stop a bear and another won't. A 45 cal slug at over 1600fps is going to make anything think twice about continuing it's course of action. The difference in terminal performance won't make as much difference as your shot placement will.
Just for reference my Marlin would shoot those Hornady 325gr FTX factory loads into around one inch at 100 yards but I could never duplicate them with handloads. I should have tried harder.
As most have already stated loading for reliable cycling is your primary concern with the Marlin. Getting a 1/4 moa increase in accuracy changing the seating depth at the expense of reliability isn't going to help you in a bear defense situation at 15 yards.

One thing to watch for is leading if you are using cast. My barrel ended up severely leaded and accuracy went down the crapper until I bought some different solvent to take care of the lead which my old product was missing.

Good luck
 
Yes, cast bullets in the 400 grain class is sure the way to go in 45-70, with the Marlin rifle.
I find hunting accuracy in many different powders, from the velocity of factory loads and up.
I have 420 grain bullets, some gas check and some flat base (non gas check.) I wanted to see if there was any difference in how they shot, so I fired five gas check at a target, circled the hits, then fired five flat base on the target.
Here is the target, but the circle around each of the first five can't be seen. The white inside the black is a 2 inch white square.
I forget the load, but it was medium power. A good medium power load of around the speed of factory loads is 42 grains of 3031, which give a little over 1400 fps.
 
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