Is This Excessive Pressure??

combatcurt

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washington
my .02 cents. I have been working up loads for a 270-4831sc and 300-H1000. in the 300. 3 different brass, and 2 different bullets (copper and lead). In all caliber and bullet combinations. My accurate load is usually .5-1 gn. less than when pressure starts appearing. And have had similar velocity losses as you. Most of my testing has been at 70-80F. One thing I haven't tested which I know may happen in the field is cooking the second round and the bullet shift after firing. I have however seen significant velocity changes end up at the same POI when using a chrono in my testing.
Please post your recipe!!!!!
 

Stiletto150

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Jul 25, 2013
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**All loads are over Sammi COAL and probably book max***Work up your stuff.
Didn't find the max load on this one because I was patterning near the node of 2860-2890 fps. Went up 76.8 and may go to 77.
300WM-Berger 210VLD's
ADG Brass-new brass
CCI 250
H1000 76.8 gns 2846 fps average
CBO: 2.820" .040 off lands(long throat Rem)
ES 25 SD 13
300WM Berger 210VLD's over:
R-P Brass-1x fired and annealed
CCI 250
H1000 77.7 2892 fps-2x fired brass
CBO 2.820 .040 off lands
ES 31 SD 16
300WM-Nosler 182 gn copper
Win Brass- 2x fired and annealed
Fed 215M
H1000 81 grains 3001 avg
.040 off the lands ES 20 SD 8
 

Nevmavrick

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Reno,Nevada
Fed 215s are a hard primer, like the CCI 250s, just a little hotter, in my experience.
Of course, keep using the same primers as you change the load for accuracy.
I always keep at least an extra K of each around to compare.
Have fun,
Gene
 

PBR driver

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Afton, Wyoming
I would appreciate hearing your comments on these pic's.

Fired from a 7mm Rem Mag loaded with 78.0gr of RL33 pushing a 175gr Nosler Accubond LR at 2,922fps.

I am seeing some cratering on the primer but it doesn't look flattened-out and hasn't spread out. I don't see any marks on the case either.

What do you guys think...does it look safe or excessive?

The second pic (lighter-shiny brass) is loaded with 79.0gr of RL33. The cratering is a bit more pronounced but not by much.

The extra grain of powder is only giving me an extra 13fps so I would go with the 78.0gr if you guys think it's OK.

Whatdaya Think?;)
The one sure way to know if you are having high pressure in your chamber with your components is measuring the case expansion compared to a factory load.
Factory ammo with a few exceptions are loaded to max pressures so going past those pressures is not prudent.
Measure your factory cases at the expansion ring (diameter) with a 0.0001" micrometer.
Once you have the same expansion as the factory ammo you have reached the maximum in your chamber with your components...period.
Looking at primers may give you a false reading unless it is a known primer in your rifle.
Some primers are softer than others so a soft primer will flatten out and flow sooner than a hard cupped primer.
One of Exceptions to this rule is 30-06 where the factories reduce the pressures that are in weaker actions such as the 1895 Winchester Lever Action or other weaker actions were you may go approx 0.00015 past factory loads.
Always remember every chamber/bore of the same calibers are different, your components are different Lot Numbers are different so pressures will most likely vary from loading manuals.
Get a good 0.0001" and learn to use it properly and it will keep you safer than looking at primers.
 

Nevmavrick

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Actually, Rhovee, I do believe that the factory, SAAMI, is the practical max. For instance, some are loaded so that the highest round of a series is, ie, 65k. Others are loaded so the highest of a series is, ie, 45k.
All of this would depend heavily on the actions that are built for that particular cartridge.
Some calibers are produced in very strong actions, such as .300WSM, or .300 Roy, so the factories would load to higher pressures, but they are practical maximums. There is very little reason to try to exceed their ballistics. To do so would only shoten barrel and case life. To increase by any usable amount, only increases the likelihood of popping a primer and sending gasses back through the bolt. Few would use those pressures in an auto, or lever-action.
We return to the low-pressured calibers....30/30 cases aren't as strong as Magnum, because the actions they are used in don't have the lockup strength.
The "Max" that many handloaders refer to is the most that a case will hold before it fails most of the time. Cases fail looong before actions do.
Ingwe has reached a point that with quite a bit of powder (1gr) will give a bare minimum (13fps) of return, therefor, he has passed the practical max.
I would expect 30-50fps to be gained with .4-.5gr of powder with 175gr bullet in a short-magnum (2.5" case) Any less, and I would start looking in a different direction, probably looking for my best accuracy.
He asked if his effects were excessive, and, mostly, has been told he is looking at the wrong things, but already has found his answer through his chronograph.
Have fun, Gene
 

PBR driver

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First time I have ever heard that factory ammo is max pressure.
Most are loaded to max pressures with some xception such as .30-06, 6.5X55, 7X57 and several others.
It is normally base on the action used such as the .30-06 in the 1895 Winchester, which is not as strong as a Bolt Action, 93-96 Mausers which have a pressure rating of 45,000 and many others.
There is SAMMI in the America and CIP in Europe that set pressure standards.
I have had a lot of firearms in my shop that have been ruined or other problems due to improper hand loads, most would have been OK if they used the .0001" micrometer test.
Guns will last longer, shell casings last longer, you get to keep your fingers and eyesight and save money in the long run, what is not to love?
 

Rhovee

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I have loaded for a few factory rifles and ended up being over 2.5 grains above book max with 8 reloads on Hornady brass and all is good. I seriously doubt that factory 300 win mag ammo shooting 2900 is anywhere near max. Quickload and SAAmI have psi requirements for specific chambering. 65000 is seen often for large magnums as max. There is no way factory ammo is loaded to 65000. Looking at Hogdon website there book max is aroun 61000 psi
 

okie man

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I’ve never been able too get 2.5 grains over max loads in a manual. I skipped starting loads in a hornady manual and went right too max once in my 243 and blew primers! Never again
 

PBR driver

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I have loaded for a few factory rifles and ended up being over 2.5 grains above book max with 8 reloads on Hornady brass and all is good. I seriously doubt that factory 300 win mag ammo shooting 2900 is anywhere near max. Quickload and SAAmI have psi requirements for specific chambering. 65000 is seen often for large magnums as max. There is no way factory ammo is loaded to 65000. Looking at Hogdon website there book max is aroun 61000 psi
If the powder, prime, case, and bullet combo reach max pressure at 2900fps with the acceptable accuracy then yes the factory ammo is max.
You do what ever you must do but as a Gunsmith and someone that not only had an ammo business and a reloading instructor I know where My maximum load is.
The few FPS extra you may gain always comes at a cost, be it the case life, wear and tear on a firearm such as the throat and bore erosion and worse case your hand or eyes.
Your gun your choice.
 

BLK

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If the powder, prime, case, and bullet combo reach max pressure at 2900fps with the acceptable accuracy then yes the factory ammo is max.
You do what ever you must do but as a Gunsmith and someone that not only had an ammo business and a reloading instructor I know where My maximum load is.
The few FPS extra you may gain always comes at a cost, be it the case life, wear and tear on a firearm such as the throat and bore erosion and worse case your hand or eyes.
Your gun your choice.
 

BLK

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Oct 1, 2010
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NY
This is an excellent answer and a very good piece of advice. Everyone should heed this.
 
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