Range Report - 45-70

[tonygrz]

Finally got the correct scope base from Brownnell's and it worked just great.  Mounted my 2.5X scope on my 45-70 and then started to load some shells.  I ordered Starline brass and 405gr lead bullets.  After priming them with large rifle primers, I began to weight some powder.  I used Trail Boss.  The load sheet says 12 to 13.5 grains.  I started at the low end and loaded 12 grs.  Speed should be around 950 fps.  One problem I had reloading was that some of the bullets ran farther into the brass than others.  I think I might have open the mouths too much.  I'll fix that next time. 

So off I go to my range.  I started at 25 yards using a paper plate for a target.  The scope on the rifle is the european cross hairs with a circle in the middle.  The circle was the same size of the paper plant so I could hold fairly steady.

After some shots to see where the scope was hitting, I started working the scope knobs to try to get the circle (and the bullets) hitting the plate.  Once I had everything were I wanted, I put up a new plate and fired a five shot group.  This is where I was rather disappointed.  The group measured close to 2 inches at 25 yards.  I don't know if the load was too weak or was it because some of the bullets were seated too far into the case.  I was shooting off a Caldwell gun rest so I was not shooting free hand.

Questions - Do I need to jack up the bullet speed with a little more powder??  Are the 405 gr bullets to big for a reduced cowboy load??  Any other ideas you may have ?  Any help or suggestions would be appreciated.

thanks,

Tony Garza

[quickdtoo]

What's the bullet diameter and what does your barrel slug at? See bore slugging in the FAQs. Cast bullets need to be sized .001"-.002"  larger than the groove diameter to be accurate. Most H&R 45-70 bores shoot .459"-.460" cast bullets best.

Tim

[stimpylu32]

Tony

Your seating depth will make a big diffrence as will the powder charge and the amount of crimp , I have shot some TB in my 45/70 and was not at all impressed with how it did .

Switch over to Unique at 12 grains , will give you 1125 FPS from a 22" barrel , also control the seating depth and crimp , then you should be able to do the same 2" only at 100 yards with no problen .

stimpy

[Fat NDN]

Finally got mine worked out.  350gr Oregon Trail Lasercast bullet with 31grs H4198 Velocity 1368fps.
3 shot group all touching like a colverleaf at 100 yds.

[tonygrz]

Quickdtoo, the bore mics out at approx .454 as best I can tell with my calipers.  The bullit diameter is 458 or 459.  Can this disparity cause the larger groups???

[cwlongshot]

Quickdtoo, the bore mics out at approx .454 as best I can tell with my calipers.  The bullit diameter is 458 or 459.  Can this disparity cause the larger groups???

 To answer for Tim, yes it would make a difference but more importantly, I do not think you have measured correctly.
 The .454 dia is the old dia for the 45COLT round it was reduced to .452 and standardized many years back, You say you have a 45-70, this uses a .458 dia bullet. (Jacketed) As Tim suggested, generally a couple thousands up when using lead for a dia of .459 - .460.

 Also 960fps is a mighty slow velocity, step it up a bit to the 11-1200 range. I have never used trail Boss my self, my favorite for light 45-70 loads 5744. Its also a bulky powder then better fills large cases for light loads.

 Back to you seating problem, Only open /flair the case mouth enough to keep the bullets from shaving lead when seating. Back that stem out a bunch!! You may need to sacrifice a couple cases to get this correct. But it is IMPORTANT!!

CW

[LaOtto222]

Seating depth is important. I seriously doubt if a flair is is causing your different seating depths. It is only the first part of the bullet length that the case is not in contact with the bullet. In any case the flair should be uniform from case to case. If the cases are not of uniform length they will flair differently. Measure a few to see if they are the same length. If not then trim them so they are. Your flairs should be the same from one case to the next. Adjust your die so that the press ram bottoms out on them before you reach the top of the stroke. Do this by running the ram all the way up, then turn the die down until it touches. Back off the ram and give the die another full turn. Then adjust for just enough flair to seat the bullets with out shaving lead. Adjust your bullet seating dies so you get the desired amount of crimp. While adjusting for crimp, you will need to work on the bullet seating depth at the same time. You will have to experiment a little to find the correct amount of bullet seating to match up with a crimp. With experience you will know about how much to seat the bullet just before the crimp. I use a separate crimping die, it makes this a little easier and I feel I get more uniform crimps. But that is another die you would have to buy, that is not needed if you adjust every thing correctly. Better check your die inside to make sure there is no crud built up on the seating die. After you get the dies adjusted, always run your press up to a uniform height or the same amount of crimp, do this by feel. You should get uniform seating depths, with in a few thousands of COAL. Good Luck and Good Shooting

[tonygrz]

Thanks for all the great suggestions.  I have some Unique that I may try next time.  I really think the problem is with the seating/crimping die.  I really have to get that one adjusted correctly.  This is the first I've reloaded in about 25 years.  I thought it would come back to me but it hasn't.  I guess back to the books. 

Tony G.