45-70 cast bullet keyholes.

[Howard31]

I have been shooting my 1886 Springfield (Trapdoor) for years using 300gr JHP's and IMR 4895 without a hitch. I decided to try a BP sub, Pyrodex P,and a 405 gr Moyer cast bullet .459 dia and loaded with 70gr by volume with milk carton wad. The 1st three shots touched, range was 100 yds so I was really impressed with a sub MOA group from a 125 year old gun. Tried a few more shots and they started to spread with shots 8,9 and 10 keyholing through the target. Am I going to have to clean the bore every three shots or is there other problems ?

 

[B.L.E.]

Yes, with black powder you have to frequently clean the bore, and Pyrodex only fouls the bore slightly less than real black powder.
What kind of bullet lube are you using?
You may also be experiencing bore leading.

Pyrodex P = 3fg black powder, usually 2fg is used in a .45-70.

 

[NoSecondBest]

I purchased some Moyer's cast bullets for my 45-70 and got mixed results. The 300 grain were marginally OK but the 405 grain were horrible! I got my micrometers out and did some measuring. Unbelievable...they varied by 20 thousandths at the base. They shot so bad that some of them wouldn't hit the backboard, a 4x4 sheet of plywood. I sent Moyer's an email and needless to say, they didn't respond. No more money wasted there. Get some mics out and measure them and then weigh some. They were total garbage to shoot. I ordered some Oregon Lasar Cast and some Montana Bullets and got pretty good results. Actually some outstanding results with the Montana but the downside is that I can shoot factory jacketed for the same price.

 

[Hawg]

I shot 405 grain homecasts out of my original trapdoor carbine and I never had to clean that often.

 

[Hellgate]

With the first 3 touching it sure sounds like barrel fouling to me. If you have PLENTY of the right lube it should shoot longer than that.

 

[savagelover]

Just a word of caution...Some of the factory ammo is way too
hot for your old trapdoor rifle...And you should be using only
a soft lead cast bullet in it...But it's your rifle and your face..

 

[Jim Watson]

A .459" bullet is undersize for most Trapdoors.
Moyers says their .45-70s are BHN 13 but I suspect it is still antimonial lead.
You had been shooting jacketed bullets and probably still had some copper deposits.
All that and a rapid loss of accuracy adds up to a badly leaded bore. It is going to take a lot of cleaning and then proper loading.

There is a book on loading for the trapdoor by Pat and Spence Wolf. It would pay to read it.

 

[savagelover]

Jim is correct as usuall...The book he speaks of is full of good information...You probably should not have run the jacket bullets through it...I use 1 in 30 in mind....And he is right about the bigger bullet diameter as well...Is that rifle an 1886 by any chance? Good luck with it...Be careful man...

 

[Hawg]

I ran a lot of Winchester factory loads with 300 grain JHP's thru my 1884 carbine. It was a little more accurate with lead 405's but not by a lot.

 

[Fairshake]

45-70 loads

Howard 31, The very first thing that should be done with any rifle that goes from the jacketed round to firing any lead bullet is a good cleaning to remove any and all copper fouling.
The next thing is that your trapdoor will do better with bullets that are in the 20-1 alloy range which have a BHN of 10.
All commerical lead bullets are way too hard for firing with BP and they also contain the wrong lube. I did see where you stated that you used Pyrodex which I don't care for but that is your choice.
If you really want to see that trapdoor perform do the following things
(1) Use real BP by KIK, Swiss, Schutezen, Goex Express
(2) Anneal all your brass case necks
(3) Slug your bore with a egg shaped fishing sinker with lots of oil
(4) Buy your bullets from a BP dealer such as Sagebrush and use the heaver offerings not the lighter ones.
(5) Use Ballistol and water in a 7-1 mix (Moosemilk) or Windex/Vingear for all your cleaning and a good oil like EEZOX
(6) Have fun like you have never seen

 

[Howard31]

45-70

I would like to thank everyone for their input. I think the culprit is the bullets . I did a thorough cleaning and tried it again using mild smokeless load. I still had bullets keyholing. I cleaned the rifle again and retried the pyrodex loads and the results were the same.
The rifle is an 1886 with the rod bayonet. Read somewhere for better results remove the rod when shooting.
I use the subs because it is hard to get real BP here in NY. Looking at the price of BP bullets at Montana bullets I think I will stick with jacketed bullets for the time being.

 

[DPris]

Seriously, you'll wear the bore much quicker with jacketed loads on that old relatively soft barrel steel.
If you want to keep shooting it, I'd STRONGLY recommend you find a lead bullet. Smokeless or BP, don't care, but LEAD is the best way to keep your antique shootable.

I think you're the first I've ever heard of anybody shooting jacketed on a regular basis through an original Trapdoor.
Denis

 

[radom]

I sure would not shoot jacketed stuff tru a old soft barrel like that.