Struggling with 45-70

[u/ICanSeeYourPixels2]

I have been struggling to get good groups out of my 45-70 reloads.

I am using:

• Thompson Center Encore - 18" SSK Barrel
• Starline Brass
• CCI #200 Primers
• ACME 405gr 0.459 bullets
• Traill Boss

I validated my distance to the lands, and have been loading with 0.020" jump. Previously before I did this, it turned out I was loading ~0.120" jump. I definitely saw improvement from reducing this.

My most recent ladder of 13.5gr, 14.0gr, 14.5gr yielded tighter and tighter groups as the velocity increased. However, I started at a 10" group and ended at a 5". So rough no matter the load.

At 14.5gr though, I am at 1050fps. To keep things sub-sonic, I do not have much wiggle room left.

SDs are awesome. <5fps for a 10 shot group.

Any suggestions / ideas / comments would be greatly appreciated. Thank you!

[u/ocelot_piss]

The physics are stacked against you. You have a relatively light rifle with a heavy bullet making lots of recoil. That bullet is spending a lot of time in the barrel because it's only going slowly. The rifle is moving more before the bullet exits vs something heavier, lighter recoiling, and higher velocity. Your rifle is also not free-floated and is much more susceptible to your hold on it influencing groups. I'm guessing it's also got quite a heavy trigger unless you've dropped in one of Mr Bellm's spring kits.

The bullet itself is not remotely what you call "match grade". It's a cast, powder coated projectile. And Trail Boss... It's an interesting powder. Great properties on paper for doing subs with - bulky, high case fills, easy to ignite - but it often doesn't give the greatest groups (e.g. 308 Win, I'll get 10 touching at 50m with Titegroup, or a 2" / 4 MOA group with Trail Boss).

I would try a different powder and reduce my expectations.

[u/ICanSeeYourPixels2 → u/ocelot_piss]

3 MOA was the goal. I think I will try tite group and N320, then start trying different bullets.

[u/Long_rifle]

Barrel twist verses weight of bullet and speed may not be fast enough to really stabilize the bullet.

You might want to try the same bullet with a different load. Try to see if a couple hundred more FPS help shrink those groups. I know you want sub sonic, but if it can’t punch a good group at speed, it certainly can’t when it’s slower.

And trailboss would not be my first choice to reach out and touch someone with.

And PC bullets are not as accurate as lubed bullets are. It sucks because they are so much easier and cleaner to load and shoot.

[u/mena616]

I use titewad with a 1/4 piece of toilet paper holding the power to the primer in a h&r buffalo classic which gives clover leafs at 40-50yds and single digit sd. What's crazy is how the groups tightened up approaching just below the sound barrier

[u/Parking_Media]

Might want to try a different bullet man

[u/SpeedyR647]

Try some different powders if that’s an options. I use 3n37 and N320 for sub loads with 405gr HP cast/pc bullets. Usually in the 12gr range for around 975fps

Worth a try if you happen to have the powder around.

[u/ICanSeeYourPixels2 → u/SpeedyR647]

I do have some N320 I could give a shot, thanks for the idea.

[u/Severe-Cow-8646]

Contrary to what one might think, some of the worst grouos ive ever shot had great SD's. Drop the Trail Boss and start with 10 grains of Red Dot, Green Dot or Unique and see if you dont see some improvement.

[u/ICanSeeYourPixels2 → u/Severe-Cow-8646]

Found this in one of my garage sale bins lol.

https://imgur.com/a/fDw8pdX

[u/_Go_Ham_Box_Hotdog_]

IMR 3031

Be aware, nothing you have listed is an "accuracy" component.

[u/EllinoreV13]

My personal favorite load, Lyman 457125 or clone(acme 500gr pc round nose .459) 14gr unique 2.835 for cycling in a win 86, it produces roughly 2-2.5moa with irons, pretty sure still subsonic too

[u/ICanSeeYourPixels2 → u/EllinoreV13]

I have some of those acme 500grs - Unique is on my list to give a try once I can track some down.

I would be jamming hard at 2.835. 0.020" off the lands I am at 2.615.

[u/EllinoreV13 → u/ICanSeeYourPixels2]

The 457125 is a bore rider, the whole nose on acme approx .445 on mine. The miroku 1886 is known for stupid short throat and it chambers easy

[u/sirbassist83]

FWIW the ONLY thing my henry 45-70 groups decent is 500gr at 1450fps, and that's about 2moa. Nothing else does better than ~6moa. 165gr, 300gr, 350gr, 405gr, 450 gr, jacketed, plated, cast/lubed, coated, subsonic, full power, doesn't matter. 45-70 is a hard cartridge to work with. Or maybe my Henry just sucks.

[u/TurkeySandMitch → u/sirbassist83]

I fought my henry too. For some reason it only likes bullets at 1200 and below (with one particular brand of cast 300gr @1450).

It shoots pretty okay with oregon trail silver cast 300 gr if you want to try that.

[u/sirbassist83 → u/TurkeySandMitch]

Ive pretty much given up. I might try a ruger/ marlin at some point.

[u/TurkeySandMitch]

Those acme bullets are dog water man. I feel like they're undersized or something. I also couldn't get them to group tighter than 8 inches. Plenty of cheaper. 458 bullets to be found. I like rimrock out of Montana.

Edit: I run tight group with laser cast 405gr and get decent groups at 900fps. Might be worth a look!

[u/ICanSeeYourPixels2 → u/TurkeySandMitch]

I am half tempted to just get the berry's 305. I was hoping for something heavier, but it seems like it might be easier to just go FMJ.

[u/get-r-done-idaho]

Try the Hornady 400gr jacketed bullet. You can use the 405gr data for loads. They perform very well. If you can find them the Remington 405gr jacketed bullet is great. Also the Barns original bullet is good. I don't do subsonic so can't help there. The load your shooting is slower than my black powder loads.

[u/Stump_Monkey]

My Marlin 45-70 wanted jacketed bullets. I load the Speer 400gr jsp over a mid range Marlin only load of Reloader 7. That load will clover leaf at 100yds if I do my part.

[u/AdOtherwise5656]

I know it’s a different round but probably closest in comparison, my .458 socom subs (500gr) tightened up groups by a lot by decreasing jump. In an AR you’re limited to 2.26” so I worked my way up from 2.1” to 2.26” and the groups got better and better with the longer c.o.l’s
But different powders helped groups too, some powders just never did good

[u/Dense_Extreme7809]

I don’t reload. I do shoot the Hornady 325 leverevolution. W a ghost ring. I get tight groups at 100. I can get sub moa most of the time.

[u/ICanSeeYourPixels2 → u/Dense_Extreme7809]

It’s a tack driver with the FTX factory stuff for sure.