Loading over max powder charge

[Kramerica]

RPR 6.5cm. 140 Berger VLDH- H4350- 2.780 COAL- LabRadar chronograph- Nosler brass- CCI200primer. 26*F-29.98 Hg- today. chronoed my load at the max powder charge according to the Berger manual (40.7grains) got an average of 2564FPS, SD=12.1 (5shots). Berger manual says they are getting 2634fps at max powder charge (they also have a 2.800 COAL). I wanted to get up around 2650 FPS in this cool temperature, so in the summer I’d maybe be around 2700fps? How much above max should I go before it’s unsafe? A friend said to work it up slow 0.3 grains at a time over max and check for pressure signs like sticky bolt, flattened/dented primer etc. but in general how much above max can you go? Just from the other numbers I got running different loads I’m guessing I’ll need to be around 41.6 grains to hit 2650 at 25*F.

 

[stacy]

JALEN THOSE BERGER MANUALS ARE LOW ON POWDER CHARGES WITH SEVERAL CARTRIDGES THAT I HAVE DEALT WITH WORK SLOW UR RIFLE WILL LET YOU KNOW WHAT IT LIKES JUST WATCH FOR PRESURE SIGNS

 

[timeout]

First of all I don't have a CM. Secondly, I do often find suggested max loads in my Berger manual to be conservative. Thirdly, listen to your friend, he is spot on.

 

[LA50SHOOTER]

Jalen,

Reloading data from different sources varies. - What I recommend is that you consult some other available sources, possibly the Hodgdon on-line reloading site could be of help. - Also depending on who & how the data was formulated and the individual components - i.e. pressure barrel(s) there is some latitude at what the top "published" load will be. - The thing to keep in mind is Your Rifle is an "individual & unique" firearm unto itself. - As was recommended " work up slow & concise" - keep good records of what you did as well as the conditions that the ammo was tested under. - And be observant of pressure signs during the course of working up.

 

[Kramerica]

Jalen,

Reloading data from different sources varies. - What I recommend is that you consult some other available sources, possibly the Hodgdon on-line reloading site could be of help. - Also depending on who & how the data was formulated and the individual components - i.e. pressure barrel(s) there is some latitude at what the top "published" load will be. - The thing to keep in mind is Your Rifle is an "individual & unique" firearm unto itself. - As was recommended " work up slow & concise" - keep good records of what you did as well as the conditions that the ammo was tested under. - And be observant of pressure signs during the course of working up.

Hodgdon says 40.9 max for a 140 Hornady amax is 2736fps. Different bullet but similar max powder charge. I’ll work it up 0.3gn at a time. Really was just curious as to how much is “normal” to go past max. Thanks for the replies everyone

 

[Milo 2.0]

Hodgdon says 40.9 max for a 140 Hornady amax is 2736fps. Different bullet but similar max powder charge. I’ll work it up 0.3gn at a time. Really was just curious as to how much is “normal” to go past max. Thanks for the replies everyone

Most data you see for H4350 with 140gr bullets in a 6.5 creed is in the 42gr range, just work up to it.
Both the Berger manual and Hodgdon's page are conservative.

 

[Shrek]

All sorts of things bear on what your rifles actual max charge is. The books are really just conservative guides to get you in the ballpark. Type of brass , OAL , jump , firing pin/firing pin hole size , chamber size , and your barrel all come into play. I’ve owned rifles that were destroying brass at less than book max and others I couldn’t stuff enough powder into to find max. Work your loads up and find out where max is then work back to your best accuracy node. I’ve gotten over cutting brass life in half for the last 50fps.

 

[jds holler]

When you get up to listed max and above, there is no "in general" or "normal" amount to go to. You are in territory where only your rifle, and no one else, can suggest how far to go.

And remember that when you are in the Max Zone for your rifle, ANYTHING done differently with future loads can put you over the line where you don't want to be. jd

 

[Hydenseek]

Dont put any more than their lawyers would

 

[ebb]

Read up on what pressure signs are some of them are small and easy to miss. Temperature is a big one. What is a safe load in December is not in June and when pushing the limit even more so.

 

[Kramerica]

So here are my results from working up the load, today it is 19* F:

41.0gn: 2598; 2591; 2595; Avg:2595

41.3gn: 2613; 2634; 2611; Avg:2617

41.6gn: 2633; 2632; 2645; 2669; Avg:2645

41.9: Chrono didnt pick the velocity up but the bolt was sticky so i stopped there, primer and brass looked fine to me but then again im no expert. I guess the next step would be to test them for grouping? Im also assuming that if the 41.6gn load is the best for grouping that I would have to test it again in the spring and summer to make sure it's still good to go...

 

[Zero333]

So here are my results from working up the load, today it is 19* F:

41.0gn: 2598; 2591; 2595; Avg:2595

41.3gn: 2613; 2634; 2611; Avg:2617

41.6gn: 2633; 2632; 2645; 2669; Avg:2645

41.9: Chrono didnt pick the velocity up but the bolt was sticky so i stopped there, primer and brass looked fine to me but then again im no expert. I guess the next step would be to test them for grouping? Im also assuming that if the 41.6gn load is the best for grouping that I would have to test it again in the spring and summer to make sure it's still good to go...

If you felt the bolt was tougher to open at 41.9gr I'd suggest not going above 41.5gr.

 

[rammac]

What is your barrel length?

Berger and Hodgdon did their load development using a 24" barrel, a 22" inch barrel will produce muzzle velocities of about 50 FPS slower.

 

[rammac]

Cut back to about 41.8 grains and you'll be right around 2650 FPS.

 

[HTSmith]

With my 260 Rem I worked up to 43.0 Gr of H4350 behind a 140 Gr Berger VLD. I could have gone a bit higher, but 42.0 Gr shot very well and seemed to be in the middle of my node. No signs of pressure and primer pockets stayed tight. Then.....I got the Berger manual. It said 41.1 Gr was max! I've just kept shooting my load. My throat is kinda long. YMMV

 

[Kramerica]

24” barrel length. 41.8 seems a bit to close for comfort, bolt was sticky at 41.9.

 

[Falfan2017]

I don’t know how temp sensitive that powder is but if it’s only 19 degrees I’d be real careful loading anything close to a sticky bolt. I loaded some rl17 in a 284 and was getting great groups and no pressure signs around 65 degrees. Fired a couple at 95 degrees and the second one blew the primer straight out of the brass and the bolt was very hard to open. This was just slightly above max.

 

[Flouncer]

There are powder burn rate charts . .. and discussion about them.. Is there a temp sensitivity chart or some collection of knowledge on this ? - thanks. (Building beyond max with RL-17_

 

[Kramerica]

I don’t know how temp sensitive that powder is but if it’s only 19 degrees I’d be real careful loading anything close to a sticky bolt. I loaded some rl17 in a 284 and was getting great groups and no pressure signs around 65 degrees. Fired a couple at 95 degrees and the second one blew the primer straight out of the brass and the bolt was very hard to open. This was just slightly above max.

Good to know, I am a bit curious about how it’ll preform in warmer temps. I think I’ll stick with my light 39.0 load until summer then run the test again and see how the velocity compares just to be safe

 

[Capt. Oblivious]

Look at max speed and not max load. There are to many things that changes with every rifle/bullet/powder lot/load combo. Start low and work up and obviously stop whe you hit any preassure signs. With the labradar you will know exactly whats going on with every load.