H335 loads for 55gr .223

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JonMorganHill

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I'm just starting to load .223. Using RMR 55gr FMJBT
Hornady says 20.8 - 23.2
Lyman 50th has a starting load of 24.3
Hodgdon has 23.0 - 25.3

Cases are Win, primers are CCI #450. Loading for a new Mini-14
I'd typically start at or close to the starting range, but these numbers seem all over the place. Looking for suggestions from those with experience.

Thanks,
Jon
 
I found that 25.2 is what works for me and is now my standard load. The Hornady did seem a little low also when I was working up my loads.
 
I would probably start about 23grn and work your way up. If memory serves the Mini is over gassed, so I would just look for an accuracy node and stop there.
The Mini being over gassed is probably an understatement. I haven't had a chance to shoot mine yet thanks to the fires around here, but I see lots of reports of 20-30 throws on brass
 
I'm at 25.3 grains. The Hodgdon data is weak, but my lyman 49th (too hot) shows somewhere above 27grains, while I was finding the best results at 26.2. I had a few head separations, and found a new best results (25.3). I know someone who had 2 flashovers using 19 grains, so the hodgdon starting load makes me nervous. the first blew out the casehead, ballooned the magazine. Thinking it was an out of battery, he shot more and eventually did the same on another rifle. Thanks to the powder shortage, we know he was using rifle powder, its the only kind he had. It was not an overcharge either, you can't accidentally fit enough H335 in a case to KB a bolt gun in one shot. In addition, I can't imagine any pistol powder that would not have blown out far more than the bolthead with 19 grains in a .223.

I know the validity of flashover is debated and I won't argue on another persons behalf, but going too low does cause squibs, and I have recently experienced 2 squibs using published data, for a less than ideal powder, in a caliber I don't load enough to justify buying its own. Again, published loads.

The most common universal load I have seen is 25 grain, which will run reliable in everything, and needs only slight adjustment for accuracy. My favorite source for load data is Lyman 49th, and for unusual combos, Speer has some good info, published on the internet, including Alliant 2400 for .300 AAC. If thats somethig anytone heres looking for .

. https://reloading-data.speer-ammo.c...Rifle/22_caliber_224_dia/223_Remington_55.pdf
 
In this case trust Hodgdon's max data. Lyman's is dangerously high and Hornady's is unrealistically low. Hornady has listed the same data in the last several manuals and hasn't tested the most popular 55 gr. bullet in the most popular rifle, the AR.
 
With H335, I have always throw a 25grn load with 55 grn bullets. These make for a fairly accurate and clean plinking load. Anything less seemed to be to soft shooting in my guns. I experimented with higher charges too, even going to max, but saw no benefits in doing so.
 
Yes 25.0 gr of H335 seems to be the sweet spot, but I agree with the above posts to start lower and work your way up checking for pressure signs.
 
I have come around to the 25 grains of H335. Using less powder will still toss the carts 5 feet but I do not see enough Feet Per Seconds out of the barrel.

What FPS do you guys get with that load?
 
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I use 3 different bullets in 55gr for .223 and H335. I load between 23.5 and 25. I have not run any of them across the chronograph, but they are accurate enough for me. I'd start around 22.5-23.

-Jeff
 
I agree with starting 23.0 grains and working your way up. You might actually find a load that functions and shoot accurately out of your rifle before you get to 25 grains. The usual caution: start low and work your way up. 24.3 grains of H335 under a 55Gr FMJ works quite well for most of my rifles.
 
I guess I'm loading on the low end of most here with H335 and 55 Gr FMJBT in my AR. I've been using 23.7 grs which chronos a little over 2700 fps. I'm just plinking not looking for high precision and haven't had any problems with that load through a couple thousand rounds.
 
Use the manual that the bullet manufacturer suggests. I avoid confusion like that by sticking to bullet manufacturers recommended loads. If you are using hornady bullets use the hornady reloading manual and so on. It works for me.
 
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Use the manual that the bullet manufacturer suggest. I avoid confusion like that by stick to bullet manufacturers recommended loads. If you are using hornady bullets use the hornady reloading manual and so on. It works for me.

MS-

Certainly not trying to be argumentative but the Hornady Manual was not helpful to me. It read that their range for H 335 was 20.8 grains to their MAX of 23.2. I found those numbers to be very conservative and/or they used a 25 or 26 inch test barrel.
 
MS-

Certainly not trying to be argumentative but the Hornady Manual was not helpful to me. It read that their range for H 335 was 20.8 grains to their MAX of 23.2. I found those numbers to be very conservative and/or they used a 25 or 26 inch test barrel.

There is some merit to Hornady's data... they are testing their bullets... and not all bullets are equal. Barrel length matters not, except if you are chasing velocity predictions. You can always start low and work your way up into other data, but starting with... using your example... Lyman's notably high starting charge, seems like a fool's errand.
 
I agree on Lyman's load data being on the warm side. Start with either Hornady or Hodgdon data. I would reload 5 with the start load and work my way up to just below max to find the sweet spot for my rifle if it was me. I have several AR rifles in 5.56 and the charge weight I use is not the best for any one single rifle but does work the best in all of my rifles. I have used Winchester 55Gr GMJ (junk and very inconsistent) in the past and switched to Hornady 55Gr FMJ haven't looked back. I did start over with my powder charge when I switched from Winchester to Hornady but ended up at the same charge working best for all rifles.
 
I’ve emailed RMR to see who’s bullet the suggest using as a reference. I see that Lyman data for that weight is soft point, not fmj, I don’t know if that makes a difference in loads though
 
I load 24.0g for my run of the mill AR. It’s just over MOA with 55g FMJ and runs great. I figure going a bit lighter on charge gives me a bit more safety when the temperature is high.
 
MS-

Certainly not trying to be argumentative but the Hornady Manual was not helpful to me. It read that their range for H 335 was 20.8 grains to their MAX of 23.2. I found those numbers to be very conservative and/or they used a 25 or 26 inch test barrel.

Never thought you were argumentative and I do agree with you when it comes to reloading the variables encountered are as many as the stars in the heavens . Even if you follow loads that fall within the parameters of your gear it still not a guarantee that your particular firearm will perform well. The only peace of mind here for me is that there is a starting and ending recommendations on loads that will keep me from getting blown up and the manufacturers for each of the components have been tested by them.
 
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