How often do you see pressure signs at minimum powder charge? I'm loading for my 223 rem with varget after referring to several different manuals I ended up with flattened primers. Ended up going 1 gr under minimum second day out and the primers look fine and it grouped 3 shots within 0.45'' (very happy with that). Only primers I've ever flattened so was a bit of a surprise. Are some lots of powder just hotter or what other factors come into play? Going to test the loads long range next trip out, see if they will group out there a bit further.
Pressure at minimum load?
- Thread starter TikkaWSM
- Start date
I could try finding them tomorrow for a picture but they are flat according to photo's I could find on google (rims aren't bent though). Winchester once fired brass, shot from the same rifle. The primers look normal after firing the factory ammo, sized to OAL according to manual if that matters.
ultimate_monkey
CGN Ultra frequent flyer
- Location
- victoria BC
as mentioned what primers??
some brands are very soft compared to others.. federal for example will flatten at almost any load. where as CCI have a much harder cup
some brands are very soft compared to others.. federal for example will flatten at almost any load. where as CCI have a much harder cup
duncansuds
CGN frequent flyer
- Location
- Weyburn, SK
Just out of curiosity... I have had the experience that it seems when my primer pocket was less then perfect ie build up of misc carbon the tumbler and brush missed or out of perfect shape , I experienced pressure in far from max loads. Also, is it and aftermarket barrel/chamber that might be cut to match type spec and sensitive to seating depths? Just throwing out some ideas I have experienced.
I tried 49 gr of reloader 22 ( which is the starting load in the Berger manual) in my 6.5-284. Using new Lapua brass I had .002 CH expansion and velocities about 200fps faster than they should be. I then tried 47 and 48 gr of reloader 22 and still getting almost .002 CH expansion and velocities around the 2950 fps. I checked my charge master and 10-10 scale against my buddies 10-10 scale. They where both bang on. I had cleaned the barrel with wipeout and I thought I had it copper free until I tried using Montana copper extreme in it. After about an hour I finally got rid of the blue. I haven't been back to the range yet to see if my pressures have dropped. But I'm thinking I have a loose chamber or tight bore or maybe a combination of both.
I've got a few rifles that use the minimum loads as max. Some of them are custom barrels with tight chambers, and others are more a matter of what manual you want to believe. Some exceed the velocity of the max load while using the starting load. One thing that I've noticed is the barrels that pressure up early with one load tend to do it with all loads. That makes me believe that it is more barrel/chamber variation than lot to lot variation of powder.
hometownhero
CGN Ultra frequent flyer
- Location
- Toon Town, Sk
And your load is??
Right or wrong I've always been careful about minimum loads because of detonation. The best argument for why detonation occurs rather than the simple burning and slow burning rate of smokeless propellant (deflagration) is that very light loads expose a larger surface to the primer jet. These loads can be unpredictable because of how the powder is sitting when the primer ignites?
This is another example of why many "Pressure Signs" are useless to determine safe pressure. The only signs the common reloader can really rely on are: muzzle velocity; expanded primer pockets; and casehead expansion, and even then they have to be interpreted.
Okay, some great things mentioned there guys, thanks. I am using winchester brass and winchester small rifle primers, 50 gr v-max bullet, and I'm down to 26 grains of varget. Rifle is a factory issued model 200 stevens. I have a richard lee reloading manual but also looked up data on several of the manufacturers websites. Really wish i had a chrony as I'm not sure where my velocities stand. Now, i know if i suspected pressure signs i was supposed to stop shooting but i fired the rounds with 27 and 27.5 gr of powder anyways, they also grouped well (under 0.7'') and the brass have flat primers but nothing else looks amiss. I am trying to find the brass here, not sure where the heck they got to after they made it home. Would it be dangerous to shoot that load? It's only 0.5 gr below the minimum from my lee book, it does seem to group really well. I'm going to try different brass I have on hand as well, started with the winchester simply because it was the most plentiful. Also have good piles of remington and IVI so maybe that will make a difference. First reloading issue I have encountered so thanks for bearing with me, loads for the 270's and 25-06 went easy and have hunted great for a few seasons already.
hometownhero
CGN Ultra frequent flyer
- Location
- Toon Town, Sk
That is really odd. I have loaded stuff were the case is full as it can be (27.5+ of varget in a winchester case) and crammed a 60gr bullet into it and no pressure signs.
Hodgdon lists the start load at 26.5 for that bullet and powder also with win brass and win primers.
Hodgdon lists the start load at 26.5 for that bullet and powder also with win brass and win primers.
- Location
- Banana Republik of Kebekistan
If you are observing pressure signs (pictures pls?), investigate pressure.
I would suggest to halt the guessing work and to chronograph your loads.
If you read velocities significantly higher than expected, then a pressure issue is confirmed, then you can look at load data, primers, bullets, seating depth, COAL, etc.
I would suggest to halt the guessing work and to chronograph your loads.
If you read velocities significantly higher than expected, then a pressure issue is confirmed, then you can look at load data, primers, bullets, seating depth, COAL, etc.
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Update to this load. Bought a chrony after reading through this thread and averaging 3200 ft/sec with the below minimum load in the 223. Brass looks fine now, averaging just under 0.5'' groups at 100 yards which is simply fantastic. Think I'm sticking with this load, works for what i need to accomplish. Great tool this chrony is, happy with my new loads for the 270WSM and I think it will help in getting the 338 WM to shoot in time, having trouble with consistency there still (first experience with ball powder, H414 may not be worth the struggle but not giving up yet).
TikkaWSM
Nothing is written in stone but I have a Stevens 200 in .223 also, it has a 1 in 9 twist and has a longer throat than either of my AR15 rifles. Meaning it can be loaded hotter than my AR15 rifles, BUT we live in a plus and minus manufacturing world and your rifle may be tighter.
Below at Accurate Shooter the long range competitive shooters will keep increasing the load until brass starts to flow into the extractor. This means they have reached the elastic limits of the brass and then they back off one or two grains of powder and then look for the best node/accuracy at the upper end of pressure.
Also if you are bumping the case shoulder back too far this creates "head clearance" between the bolt face and the rear of the case. This allows the primer to back out of the primer pocket further before being reseated by the bolt face. Meaning this "extra room" can let the primer "mushroom" and give the false impression of high pressures.
The first .223 die I purchased was a Lee full length die and it was on the "small" side of manufacturing tolerances. And if the bottom of the die was making hard contact with the shell holder with press cam over this would create .011 shoulder bump and over resize the case.
SIMPLE TRICK FOR MONITORING PRESSURE OF YOUR RIFLE RELOADS
http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads
"One of the first rules of handloading is to always follow the approved reload data. The cautious reloader gradually works up to approved maximum loads to ensure his particular gun does not show pressure signs. Generally this is visual observation of the fired shell case head and primer. There is another slick way to check for pressure signs if you are interested.
Using a blade micrometer that measures in ten thousandths (.0001"), new, unfired cases can be gauged before and after firing to determine reasonably accurate maximum loads. Micrometers measuring in thousandths (.001") are insufficiently accurate to perform these measurements, and should not be used. Previously fired cases cannot be used accurately due to various levels of brass hardening. Measurement is taken just ahead of the extractor groove on the case head and must be taken at the same place on the case before and after firing. By placing a small mark on the case head – entering the cartridge in the chamber with mark at 12 o’clock – a consistently accurate measurement can be taken with each firing.
Lower pressure rounds, like the .30-30 Winchester, usually yield maximum pressures at .0003"-.0004" expansion. Modern cartridges, like the .223 Remington, will show maximum pressure at .0004"-.0005", while .308 Winchester, .270 Winchester, etc., typically yield .0005"-.0006" expansion at max pressure. Magnums, like the .300 Winchester Magnum, show maximums at .0006”-.0007” expansion, and should be measured on the belt.
In conjunction with these measurements, case head signs of pressure should be monitored as well. These signs include very flat primers, slightly cratered primers, ejector marks on the case head, and stiff extraction. All these case head signs indicate high pressure, and loads should be reduced until these signs disappear.
As always, start with the beginning load listed, and cautiously work up to the maximum shown for that set of components, using the methods listed herein".
Nothing is written in stone but I have a Stevens 200 in .223 also, it has a 1 in 9 twist and has a longer throat than either of my AR15 rifles. Meaning it can be loaded hotter than my AR15 rifles, BUT we live in a plus and minus manufacturing world and your rifle may be tighter.
Below at Accurate Shooter the long range competitive shooters will keep increasing the load until brass starts to flow into the extractor. This means they have reached the elastic limits of the brass and then they back off one or two grains of powder and then look for the best node/accuracy at the upper end of pressure.
Also if you are bumping the case shoulder back too far this creates "head clearance" between the bolt face and the rear of the case. This allows the primer to back out of the primer pocket further before being reseated by the bolt face. Meaning this "extra room" can let the primer "mushroom" and give the false impression of high pressures.
The first .223 die I purchased was a Lee full length die and it was on the "small" side of manufacturing tolerances. And if the bottom of the die was making hard contact with the shell holder with press cam over this would create .011 shoulder bump and over resize the case.
SIMPLE TRICK FOR MONITORING PRESSURE OF YOUR RIFLE RELOADS
http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads
"One of the first rules of handloading is to always follow the approved reload data. The cautious reloader gradually works up to approved maximum loads to ensure his particular gun does not show pressure signs. Generally this is visual observation of the fired shell case head and primer. There is another slick way to check for pressure signs if you are interested.
Using a blade micrometer that measures in ten thousandths (.0001"), new, unfired cases can be gauged before and after firing to determine reasonably accurate maximum loads. Micrometers measuring in thousandths (.001") are insufficiently accurate to perform these measurements, and should not be used. Previously fired cases cannot be used accurately due to various levels of brass hardening. Measurement is taken just ahead of the extractor groove on the case head and must be taken at the same place on the case before and after firing. By placing a small mark on the case head – entering the cartridge in the chamber with mark at 12 o’clock – a consistently accurate measurement can be taken with each firing.
Lower pressure rounds, like the .30-30 Winchester, usually yield maximum pressures at .0003"-.0004" expansion. Modern cartridges, like the .223 Remington, will show maximum pressure at .0004"-.0005", while .308 Winchester, .270 Winchester, etc., typically yield .0005"-.0006" expansion at max pressure. Magnums, like the .300 Winchester Magnum, show maximums at .0006”-.0007” expansion, and should be measured on the belt.
In conjunction with these measurements, case head signs of pressure should be monitored as well. These signs include very flat primers, slightly cratered primers, ejector marks on the case head, and stiff extraction. All these case head signs indicate high pressure, and loads should be reduced until these signs disappear.
As always, start with the beginning load listed, and cautiously work up to the maximum shown for that set of components, using the methods listed herein".
That's interesting (thanks) but if the brass looks fine at and we are getting 3200 ft/sec at 26 gr of varget I would say it's probably not related to shoulder bump no? That velocity seems adequate by the data i have and I don't think I need to push for anything extra out of it. Reading online it seems as though there is lots of gun to gun variation, learning lots through this reloading trial ha ha.
Below a Savage button rifled barrel, one inch from the muzzle and the throat.
Before and after fire lapping.
Below a custom hand lapped barrel.
I'm not sure but maybe one of the more experienced shooters that have done pressure testing might know if these type button rifled bores can effect chamber pressure.
Before and after fire lapping.
Below a custom hand lapped barrel.
I'm not sure but maybe one of the more experienced shooters that have done pressure testing might know if these type button rifled bores can effect chamber pressure.
