I finally got my reloads through a chronograph, and to my surprise they were printing 3350fps on average. I am using 25.1gr WC844 under a 55gr fmjbt. Max load is 25.3gr. This is a little hotter than I expected and slightly over spec, especially since I have a 16" barrel.

Is this too hot? Will I have excessive throat erosion?

Rifle is a Rock River M4

Thanks

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Never teach a pig to sing.
It wastes your time and annoys the pig

I'm surprised you aren't losing primers. That sounds more tha a little hot to me. What's air temp where your at? The load will only get hotter as the weather does too.

Thanks for the reply, the primers look ok.
Current temp is about 80 degrees F.

This sounds a little hot to me also, but the Hogdon website lists the max load for this projectile as 25.3 gr H335.

The cases do not show any sign of pressure, and the rifle is milspec.

This parallels another post I made moments ago, how closely does velocity correlate for chamber pressure for a given powder?
It would seem the other variables would more than mask this!

Where was that post, I could not find it.

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Never teach a pig to sing.
It wastes your time and annoys the pig

El Viejo
The other similar thread is
http://www.serveroptions.com/ubb/Forum6/HTML/004384.html
My thoughts are that the barrel diameter will influence velocity in ways the we can't tell about overpressure conditions by velocity alone. I think that if you are not seeing classic signs of overpressure then you are probably safe, but I don't have enough experience to say this with any authority.
It seems there is quite a bit if guessing with maximum loads since few of us have test barrels with sensors, and even then they can only report pressure for that and only that test barrel. What happens with a smoother or rougher bore? More or less lead/throat?
I think that if we could see some uncertainty figures associated with published loads then we would feel better about what get from chonograph data.
Just guessing so far.

The lack of pressure data prevents me from saying "Use it". But, as long as you don't get any pressure signs, why not? You might try the loads in new cases and measure web expansion. Compare that to a factory load.
Thing is, we really can only guess. It does sound hot to me. I'm frankly surprised you aren't getting pressure signs.
How does that velocity compare to Hodgdon's?

Throat wear? Of course, more than a lower velocity load. Will you notice??? Barrels are cheap enough that I'm willing to shoot 22-250 class cartridges.

TomJ
I am using load data for H335. According to their data, 25.3gr H335 with a 55gr bullet should give a velocity of 3203fps. I am using 25.1 gr and getting a velocity of 3300fps

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Never teach a pig to sing.
It wastes your time and annoys the pig

Your pressure situation doesn't sound alarming to me El V. with the signs, or lack of signs, you mention. What is hot in one rifle may not be hot in another due to several variables. However, boattail bullets, by their very design, are harder on your barrel. This tapered base on a boattail promotes barrel erosion over time. So, it depends on how much you intend to shoot the rifle and what it's purpose is. But we should be talking over 1,000 rds before measurable effects.

[This message has been edited by Pecos45 (edited 04-13-2002).]

3350fps sounds way high from a 16" barrel, why don't you chrono a factory M193 round and see what that does.

Pecos45,
Thank you for the reply. I am curious, why does a boat tail bullet cause more erosion?
I have no doubt that you are correct, but I have never heard this before and would like to learn some more about.
Txs.

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Never teach a pig to sing.
It wastes your time and annoys the pig