Is This Excessive Pressure??

[Pdvdh]

Now those pics are in the interesting pressure levels...

 

[jasonco]

This is simply not true. If this were the case NO ONE would be using large overbore cartridges. We would most likely be using a 6BR case in our favorite caliber, stuffing it with with roughly 30-33 grains of the appropriate powder, seating our favorite bullet, and calling it done. Powder charge, burn rate, and barrel length play a large role in the equation. As others have said from the pics it appears as if you are at or near max pressure. I find it better to judge with the extraction effort(click at the top of bolt lift). RL33, as reported by roughly half or more users, is temp sensitive. My little experience with it was not good as far as stability goes. H1000 will get 180s between 2900 and 3000 fps in all most any 26" 7 rem mag and is one of the most temp stable powders available and will require far less charge weight to do it.

Excuse me?! I never said it was at any pressure?! What's propels the bullet down the barrel, magical fairy dust? Pressure is relative and or specific.

 

[Pdvdh]

Never seen a large rifle primer that didn't flatten before it fell out of the fired casing on it's own. But there are more and better ways to monitor pressure.
Anyhow..., the velocity is being tracked, and seems reasonable for that bullet weight in the 7mm RM.

 

[Ingwe]

What do you guys think of RL33 anyway?

 

[Pdvdh]

I don't have excessive temperature sensitivity from ~35-74F. Drop down to <23F and it's a problem in my 30/375 S.I.
I don't get an opportunity to test it above 80F in AK. But the rumor is it's more temp sensitive at elevated temps also. Works well in Alaska.

 

[Ingwe]

I don't have excessive temperature sensitivity from ~35-74F. Drop down to <23F and it's a problem in my 30/375 S.I.
I don't get an opportunity to test it above 80F in AK. But the rumor is it's more temp sensitive at elevated temps also. Works well in Alaska.

What would probably happen if you use it at high temps...90 in sun etc??

 

[Pdvdh]

MV and pressure would increase at a greater rate.
For example, between ~23-75F, MV increases about 0.6fps per degree increase in ambient temperature.
In 80-95F MV might change more like 1fps per degree increase in temperature.
Below 23F, my MV dropped with decreasing temps more like 1.2fps per degree F.

 

[Tidus56]

Oh shoot, you arent pushing it yet. Add four more grains or so...jk. From the pics the second one is approaching pressure but not over. JMO

 

[Pdvdh]

Yeah... No worries

 

[MagnumManiac]

I have a Model 70 that I re-chambered the stock barrel from 375H&H to 375 Weatherby that will crater primers just as max is surpassed, next step is ejector marks and loose pockets.
I always look for craters, it often tells me my load is getting on the hot side.

RE33 is working well for me in 264WM, 338Edge, 338-416 Rigby Improved and 270 Weatherby is looking promising too. I will try it in my 300WM at some point too.
I found if I work up loads in the warmer months, I don't get pressure surprises as I once did in my 25-06 and summer temps. Gas cut bolt faces aren't pretty.

Cheers.

 

[okie man]

When you start flowing metal, ejector marks, flattening primers, case head growing its time too back off or find another load

 

[imyourhuckleberry]

The first one looks good. Will 33 react to temp extremes negatively?

Here is a link to an old thread, where some one did some testing on rl33 and temperatures.
https://www.longrangehunting.com/threads/rl33-temperature-regression-thread.130521/

 

[Ingwe]

Here is a link to an old thread, where some one did some testing on rl33 and temperatures.
https://www.longrangehunting.com/threads/rl33-temperature-regression-thread.130521/

I just read though the whole thread...thanks for that!

It does leave me wondering about the temp changes though for RL33.
It seems as though temperature does effect velocity and pressure with RL33 but shouldn't that be true with ANY powder?

IS RL33 temp overly sensitive or are all powders?

Going by this thought, If I load at 70 at home and then my gun is sitting in the sun at 95 in Africa, then hasn't my load "changed" ?

Almost like we have to develop a load at 95 to shoot at 95, and 32 to shoot at 32...

Am I reading too much into this LOL?

 

[FURMAN]

I just read though the whole thread...thanks for that!

It does leave me wondering about the temp changes though for RL33.
It seems as though temperature does effect velocity and pressure with RL33 but shouldn't that be true with ANY powder?

IS RL33 temp overly sensitive or are all powders?

Going by this thought, If I load at 70 at home and then my gun is sitting in the sun at 95 in Africa, then hasn't my load "changed" ?

Almost like we have to develop a load at 95 to shoot at 95, and 32 to shoot at 32...

Am I reading too much into this LOL?

Most Alliant powders are temp sensitive. RL26 seems to be better and RL16 is supposed to be as well. I have no experience with RL16. As I stated before you are getting speeds that are easily obtainable with H1000 which is arguably the best powder for many of the magnums including the 7mm rem mag. To answer your question, yes all powders are temp sensitive. When we say they are not we are really saying not near as much. most of the hogdgon extreme powders are .5fps per degree or less. Some of the Alliant powders are well over 1fps per degree. I have never noticed my poi changing with H1000 or H4831 outside of what my ballistic calculator predicts due to weather/atmospheric conditions.