.223 H335 question

[jvpark]

I got back from the range today and wanted to share my results and have a question.

Weather:
60-65 with 2-4mph cross breeze

Rifle:
Mossberg MVP Patrol (an absolute blast to shoot)
16" barrel
1/9 twist

Bullet:
55 grain V-Max

Powder:
H335

Primer:
CCI Small Rifle

Load Date/ Average Velocity (multiple 5 shot averages)
23.5/ 2,600fps
24.5/ 2677fps
25.0/ 2744fps (best results under1" @ 100yards)

C.O.L 2.238

PMC Bronze .223
2579fps

PMC X-Tac (xm193)
2,905fps


Question...

At 25gn of H335, there was no signs of over pressure.

Has anyone experimented with 25.5 or 26 grains (or more)?

If is switch to a 55 grain HPBT will the max load data change versus a V-max?



My reloading books give conflicting data with maximum load data...

Lyman 49th says... Max load is 27 grains (55gn Jacketed SPT)
One Book/ One Caliber says... 23.2 (specifically names 55gn V-Max)

What am I missing and what experience do you folks have?

[damon1272]

I run 26.5 grns of h335 with a V max bullet, winchester cases, and a wolf primer. No issues of over pressure out of my bolt gun or AR's

[bigedp51]

jvpark

The throat is longer in my Savage .223 bolt action than my two AR15 rifles, meaning load data for a .223 with a SAAMI chamber and throat will max out on pressure MUCH sooner than a longer throated rifle.

25 grains of H335 is my low pressure practice ammunition for my AR15s and my bolt action with a long throat. This is 50,000 psi and the max rated pressure is 62,000 psi (European CIP and NATO standard pressure) 26.5 grains of H335 would be the max estimated load using quickload software.



Now comes the fun part, your case capacity also controls chamber pressure. Below are the same exact loads using cases with the max and minimum case capacity. The case capacity can change your chamber pressure approximately 7,000 psi so "NO" load data is written in stone.





Learn to read your primers for signs of over pressure and measure the base of the case for expansion. Below is a exaggerated example of extremely high chamber pressure and the brass starting to flow.

[bsumoba]

most load data, especially from the mfg, will be on the low side as far as max charge weights go.

The one thing you are missing in the specs of your round is what brass you're using. if you're using military 5.56 brass (LC, FC, etc) for your reloads, these will have less case capacity and you will ultimately experience pressure signs at a lower charge weight relative to regular .223 brass. With that said, you can keep going higher in charge weight so long as pressure signs are not there. Switching from V-max to HPBT should not be a problem either. However, your OAL may change based on the bullet. Always do workups, and dont necessarily trust other people's load data. every gun is an individual.

Remember, in a bolt, you will experience pressure signs at higher charge weights than a semi-auto gas gun. If the 2744 fps was chrono'd by you, that is a little low for a 55gr'er. Out of my 18" larue, im using 25gr of H335 w/ 55gr Blitz and getting a 3,084 fps average.

I say you can do a work up. Do a few rounds at 25.3, 25.6, 25.9 and 26.2 grains and shoot each one and after each shot, look for pressure signs. Its good to know where your gun will show signs of pressure anyway so you can back off and be in a good safe zone (usually around 1 grain below the point where you started to see pressure). This is usually recommended, especially with H335, which is a ball powder and if you decide to shoot this in a high temp condition, where you will experience higher pressures due to your atmospheric conditions.

My one big question to you is...do you want/need the higher velocity? Youre only using more powder and causing shorter barrel life. If you're getting sub-MOA with 25 gr, isnt that good enough, especially with a 55gr V-max round and factory barrel? If you are going to do long range shooting (up to say 600 yds for a .223), or varmint hunting or any kind of hunting, then yes, find the higher velocity/accuracy combo for your gun.

[bigedp51]

The one thing you are missing in the specs of your round is what brass you're using. if you're using military 5.56 brass (LC, FC, etc) for your reloads, these will have less case capacity and you will ultimately experience pressure signs at a lower charge weight relative to regular .223 brass.

Military Lake City 5.56 cases have the "MOST" case capacity and develop the lowest chamber pressures.





223 Rem + 223 AI Cartridge Guide

http://www.accurateshooter.com/cartridge-guides/223rem/

In my Quickload charts above the high pressure was with the cases with 28 grains of water capacity. And the "LOWEST" pressures were with the Lake City cases with 30.6 grains of water capacity.

Lake City and Contract 5.56 ammunition made for the military must meet higher cartridge case standards than civilian .223 cases. The reason for these higher standards is because the cases will be fired in larger diameter chambers with longer chamber headspace settings. (the cases are built Ford truck tough)





Below, milspec 5.56 cartridge specifications.



In the past military 30-06 and 7.62 NATO cases were made thicker and had less case capacity. But because of the longer throat on the 5.56 the case needs to hold more powder to obtain the same chamber pressures and velocity with the M855.

[FLIGHT762]

For over 30 years, my go to load for my AR-15's, Remington 700 V and Sako L461 in .223 Remington using 55 grain bullets has been 26.0 grains of H-335. No pressure issues with any of the rifles. You do need to work up to that though.

[CK_32]

25gr seems to be the GO TO load for 55gr and H335. I did load work up and found the same thing as well as MANY other people running 55 w/25gr have had great results.

As for the pressure yea as long as your not seeing pressures I'm sure you can go well over.

Hell book max on 308 is 45 gr of varget. I went to 47 with 0 pressure signs. But YMMV. Always be safer than sorry. Even with that I went with the node around 44.2 gr. Longer brass life with enough FPS to do what I needed.

[Witch Hunter]

try it in your rifle, each one is different. When you see pressure signs. Stop and pull the rest, no loss.

[POINTMANDDT]

Tag

[ireload]

25 grs H335 is my practice load. I load 26.5 for my max SHTF load. Never had any pressure sign.

I fire it from a Colt Hbar with 1/7 twist 5.56 chamber.

I'd load like 5 rounds per .2 or .3 grain increment till you get to max load

[wild_weasel]

I used a pound of H335 recently with the Hornady 55gr FMJ-BT. Hornady recommends 23gr with their bullets which cycled fine in my mid-length upper. From there I worked up to 25gr of H335, close to the Hodgdon max, under the same bullet which is supposed to be a factory duplication load for Federal American Eagle 223 with 55gr bullet, note not the Federal XM-193 which runs 200 fps faster. All loads were accurate but what I do not like about H335 is the horrendous muzzle flash at the indoor range I use. Comparable loads using WW748 and CFE223 at the same indoor range have very little muzzle flash. I have used TULA 223, CCI#41, and WSR primers all with good results with all three powders.

[mskochinski]

Sounds like it is still burning.

What length barrel and twist you have?

[Sticky]

I run a 55gr Vmax with 25.3gr of H335 out of a wylde chambered 20" AR varmint barrel (1:8) with great success.. no pressure signs and about a half MOA accuracy. Lethal on whistle pigs too... LOL

[Arcaporale]

H335 is my go to .223 powder. My load is Hornady 55gr FMJ-BT's or SP's over 25.2gr H335 with mixed brass including LC. I get about 1.5 MOA accuracy outta my 1-7 16" barrel. Never bothered to chrono them as they are just practice/plinking rounds.

Never had any pressure signs, I've even loaded 62gr ss109's with that charge of H335, also no pressure signs.

I've loaded em down to 20 grs of powder just to see what would happen and had with no issues cycling my carbine length system.