45-70 Contender Load ?

[rescue_171]

Hey guys I just got a new to me 45-70 super 14 barrel with a muzzle break.

I am getting ready to reload for it and have a good bit of IMR 3031 so that is what I will be using since I read this is a good powder for this round. I have chose to use the 300gr HP from Seirra.

My question is do you guys have any pet loads for the loading at contender pressures?

Also I read on the IMR site on there loading data and they list:

300 GR. SIE HP  IMR  IMR 3031  .458"  2.525"  56.0gr  1884fps  21,100 CUP  max --- 59.5grC  2021fps  22,000 CUP 

Isn't 59.5 grains of 3031 a heafty charge? And could that pressure be right? But it says that this is a loading for the trapdoor rifles.

Also what is there to look for as signs of excess pressure in this cartridge as the gun will come apart before it show signs of normal over pressure such as flat primers spit cases...etc?                                                                                                                                       
Thanks

[qwikrick]

IMO yes 56.0 gr is a good size load with 3031.

My Lymans 49th edition shows starting load for the contender with a 300gr JHP at 38.0gr / 1206 fps up to 43.0gr / 1410 fps

hope this helps. 

[Slowpoke Slim]

I've fired a bunch of smokeless loads off of that Hodgdon/IMR website. I tried IMR 4198, Varget, and Benchmark.

All I can say is I think their pressure values are off on that website. Most of those loads seemed WAY over pressure for "Trapdoor" loads. Except for the IMR 4198 loads. I did not have any trouble with them in the Contender platform, but there's NO WAY I'd shoot most of those loads in an original, or a replica Trapdoor. I had a fellow over on AR forum run some of those loads through the Quickload program, and the results were higher than recommended pressures for Trapdoor rifles. Now, they say in the Quickload program that estimating pressures in straightwall cartridges can be a little off. But my "seat of the pants" experience tells me that the Quickload pressure values were pretty much spot on.

I would go with caution if I were you.

According to the Lyman 49th edition, you will be way, way over pressured with that 3031 load you quoted.

Lyman lists 45.5 grs to start, and 48.0 grs as MAX for a 300 gr jacketed bullet and IMR 3031.

That is listed from the "Trapdoor pressure" tables.

The "Contender" tables are even milder, as qwikrick says, they list 43 grs as max!

Please be careful. Personally, with IMR 3031, I would stay around 46 to 47 grs MAX in a Contender. That's still going to be pretty healthy, and you may want to work up to that one.

In my opinion, 59.5 grs is going to lead you to a KABOOM in your Contender. That is very close to a MAX charge in the "Ruger #1" pressure tables.

Picture yourself pulling the pin on a hand grenade and holding it out and arms length...

You are going to get hurt. Maybe BADLY hurt.

[rescue_171]

I thought those pressure values was off a good bit....I know the Contender will go up to 28,000 but i believe 59.5 grains as listed on that sight like you said would make a mess to say the least.

[blpenn66502]

Sierra's 5th edition shows 49.5 grain starting and 51.9 grains max for IMR-3031 in the single shot pistol section for their 300 gr HP/FN.  It also indicates the IMR 3031 max load was the accuracy load for the contender they tested with (also the lowest max velocity by 100 to 150 fps of the 8 powders they tested).

[qwikrick]

Sierra's 5th edition shows 49.5 grain starting and 51.9 grains max for IMR-3031 in the single shot pistol section for their 300 gr HP/FN.  It also indicates the IMR 3031 max load was the accuracy load for the contender they tested with (also the lowest max velocity by 100 to 150 fps of the 8 powders they tested).

  I have that same book and in the remarks section it says ( at no place within the data section is recoil not objectionable ) ouch !!! 

[quickdtoo]

The SAAMI MAP for the 45-70 is 28kpsi which is the same as 28kcup according to an Alliant booklet, Hodgdon's warmest trapdoor load is 28kcup. Maybe a better question is, Who's trapdoor data to use in the Contender? http://www.gboreloaded.com/forums/index.php/topic,192786.msg1098974129.html#msg1098974129


Tim


http://www.leverguns.com/articles/saami_pressures.htm

http://www.handloads.com/misc/saami.htm

http://www.lasc.us/SAAMIMaxPressure.htm