Reloading question

Joined
Oct 22, 2020
Messages
11
Location
Ohio
I have been Reloading for some 40 plus years both pistol and rifle and I have not had this ever happen before.
A few years ago I finally bought a 45-70 a marlin 1895 classic and for the last few years I have been buying Federal power shok 300gr cartridges just building my brass collection.
Now that I have a few rounds I have started loading them up. I have loading manuals for the last again 40 years and just recently bought the lyman 50th anniversary and the cast bullet manuals.
The powder that I have chosen is IMR4198 it seems to be in all three categories springfield to ruger no.1. The starting out charge is 31.5gr. for about 1310fps and goes to 35gr. for 1450fps. I am loading a 405 rnfp hard cast.
At 34.5gr I am only getting about 890fps and something seems off. I have tested with the chronograph with federal ammo and it is right on at 1874fps the box states 1850fps.
Just wondering why I am not getting what the manuals say I should be getting. Also chro is about 15ft from muzzle.
 
I looked in the Nosler #8 and Hornady 9th Edition and at first glance I would say you're not putting enough powder in the case.
You said you're loading a 405gn bullet. Nosler doesn't have that heavy of a bullet but list a 300gn with 47.5-51.5gn of IMR-4198 at 2022-2228fps, respectively.
Hornady list a 350gn; 42.2gn (1700fps) to a max of 53.3gn (2200fps). They list a 500gn slug with a starting load of 39.1gn of IMR-4198 @ 1500fps, all the way to 47.6gn @ 1800fps (ouch!).
I would look at your load data again. Hope this helps.
 
Take a look at the springfield data that is where I am starting at and that is where you should see the 405 bullets. This is where I am getting my data. And yes I am using a roll chrimp.
Also jonnyk ouch is right that is why I would like to stay around the 1300 to 1400 fps range.
 
I load my own, cast from a Lee 400gr mold. Cast from pistol range scrap. Bullets come out at 398 grs before lubing. . Test out a 15 BN on my LBT unit. Loaded with 33grs of IMR-4198 chrono's at about 1350 fps out of the 24" Bbl of my Marlin XLR. So, don't understand the low reading you are getting. This is a load I have used for 40+ years. Wish I were there to work with you. Is there anything else you notice that looks even a little out of place??
 
No everything looks good, but I think I have figured it out. The trapdoor loads are for a 30in barrel my marlin is a 22in barrel. I did go back and look at a 1970s manual and it did say for a marlin with a 22in barrel the starting load was 37gr. I will ease up and see what I get.
Everything that I have loaded for in the past has had a 24in barrel (for rifle) anyways and I forgot that the 45-70 has barrels from 18 to 36 inch's. And that can make a big difference in muzzle velocity.
Thanks all for rattleing the dust out of my raffers.
 
Are you sure you are getting a reading on the bullet speed and not the gas, etc. coming out behind the bullet? I've had that happen a few times on an optical chrono. My Oehler clocks twice so it will usually see issues like that. On the flip side, if you ARE actually getting tame velocity like that you are going to need a bit more cowbell to get her up to speed. Chamber variances, barrel length, case volume, priming, actual bore diameter, twist rate... So many variables in pressure creation. We had a similar situation happen on a 30-06 load many years back. It shot well and we never chrono'd it for years. It was only really used for short rang to mid range so drop was never an issue; we found out when we put it over a chrono that we were 400 fps short on book vel...
 
I am 15ft away from chronograph and I also fired a factory round as well and the factory was spot on. I think it is the barrel length. In any case I will ease up and keep checking.
And again thanks.
 
At 34.5gr I am only getting about 890fps and something seems off. I have tested with the chronograph with federal ammo and it is right on at 1874fps the box states 1850fps.
Just wondering why I am not getting what the manuals say I should be getting. Also chro is about 15ft from muzzle.
I am 15ft away from chronograph and I also fired a factory round as well and the factory was spot on. I think it is the barrel length. In any case I will ease up and keep checking.
And again thanks.

First of all, welcome to LRH and enjoy it. Unless I misconstrued what you are trying to convey, it cannot be your barrel length since your chronograph is reading near factory ammo's claim.
 
First of all, welcome to LRH and enjoy it. Unless I misconstrued what you are trying to convey, it cannot be your barrel length since your chronograph is reading near factory ammo's claim.

That's what I thought about at first glance.
If the factory load is showing speeds across the Chronograph, then it needs to be determined if the factory load data is for the barrel length being used by the OP, which is what I suspect is the case.
Good luck and keep us posted as to your results.
 
Just checking in as I want to work up a load for my 1985 CBA this winter and I am curious what you come up with. I hope everything works out
 
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