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Pressure Issues

I've notice several post recently regarding serious pressure issues and I thought it might be worthwhile to share some of my experiences for those new to reloading. I would also recommend other experienced reloaders add in their experiences and thoughts. All my experience is with bolt rifles. This is not a substitute for reading your reloading manual. Instead, it is just to re-enforce some of the issues based on my experience.

1. Whenever possible, I use the bullet manufacturer's published and tested load data when developing loads. The reason is that I have often seen different pressure results with different bullets, especially those with secant ogives versus tangential ogives even with the same powder and same charge.

2. Any time you change components in a previously proven load you should treat it as a new load and work up accordingly.

3. Elements like changes in seating depth and neck tension can affect pressure. I always measure the maximum base to ogive in each rifle when I change bullets, so I know how far I am from the lands. I have had bullet movement in the case in the magazine / revolver cylinder on light weight heavy recoiling rifles and pistols due to insufficient neck tension or in the case of revolvers, insufficient crimp.

4. Learn to read pressure signs such a hard bolt lift, ejector marks engraving on the case head, and loose primer pockets. Primer appearance can be tricky to interpret but when combined with any of the above, it's a sign of pressure. Excessive case head expansion is one of the sure signs of over pressure, but this requires some expertise and special equipment to measure correctly. However, this usually manifest itself in loose primer pockets.

5. Another issue that can be confusing is powder charge. For example, the Hodgdon label on Varget shows a maximum charge of 27.5 for 223 Rem for 55 Speer Soft Points. Whereas the Nosler Manual for 55 grain BT shows a maximum charge of 25.0 grain. In my rifles, even 26.0 grains with any 55-grain bullet I have tested produces significant pressure signs. It's another reason why I prefer the bullet manufacturer's load data.

This should be obvious, but it may be worth mentioning, never start at the maximum powder charge when developing a new load. Also, do not push the limits of a cartridge trying to make into a higher velocity or higher energy cartridge. If you need that then get another rifle with a suitable cartridge to meet your needs. I often found that the medium published powder charge produces the best accuracy.

6. Ball powders, in my experience, can be more sensitive to temperature changes and create pressure surges. I had pressure surges with H380 in a 22 250 in the field in 90+ degree weather that never exhibited pressure signs at the range under a cover in the same temperatures. In my experience ball powders are also more sensitive to small changes in powder charges versus extruded powders.

7. Reloading mistakes such as using the wrong powder / bullets / etc. while less common, does happen. That is why it is always best to only have the powder and bullets you are using on the table while you are reloading. Also, make sure you always empty the powder measure after a reloading session.

8. I always check each case to make sure the case is charged before I seat a bullet. This is especially critical for pistol reloads since it can be easy to double charge a case. This is why I turn primed pistol cases upside down in the loading block before I start charging them then double check by visual inspection after charging.

9. Even less common but I have seen it at the range is using the incorrect ammunition in the firearm. Any time you experience any unusual recoil, sound, or other out of ordinary firearm reaction, STOP, and investigate.

I hope this helpful and look for to others offering their contributions to safe reloading experiences to promote safe reloading.
 
4. Learn to read pressure signs such a hard bolt lift, ejector marks engraving on the case head, and loose primer pockets. Primer appearance can be tricky to interpret but when combined with any of the above, it's a sign of pressure. Excessive case head expansion is one of the sure signs of over pressure, but this requires some expertise and special equipment to measure correctly. However, this usually manifest itself in loose primer pockets
This is the real deal. I have always felt that a starting load is more important than a max load in a manual because each rifle is different. If you learn to read pressure you will be able to determine your own max and stay safe.. JMO
 
That's a well-written summary of handloading do's and don'ts. It covers issues any handloader should be aware of. I think it's likely that all handloaders will see excessive pressure at some time, if they haven't already. Hitting that threshold gradually while keeping a lookout on the way is likely to save body parts and avoid broken guns. Nicely done K22!
 
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The problem with bullet maker data is they seldom update it these days and who knows how many different lots of powder have come and gone since their last update. So it seems each new lot of powder should include a load redevelopment.

Another issue is it seems these days speed is the most important thing and becoming more so. This leads to increased pressures and then summer temps come and the load is far over pressure.

Keep in mind that by the time you are seeing pressure signs such as brass flow at the ejector or bolt swipe that you are already over pressure to the tune of about 74,000 psi depending on brass hardness. Measuring case head expansion is the best way to determine max load if you don't have a pressure trace system.
IF you powder maker has your bullet listed in their data, I tend to go with that since they constantly test new lots of powder.
Loading for a target cartridge designed for accuracy while trying to drive it to magnum speeds for hunting or long range is just plain stupid and a bad habit. Use a magnum cartridge to start with. Cant count the number of people doing this with the creedmoors. The CM was designed for 600 yd max, the PRC was designed for beyond that.

Be quick to mentor new reloaders. The internet is NOT the place to learn reloading and it IS being watched and mistakes put here are the fastest way to get this enjoyable hobby regulated. Think safe and be safe.
Never be afraid to pick up a phone and talk to powder and bullet makers. They pay people to talk to you and share facts
 
The problem with bullet maker data is they seldom update it these days and who knows how many different lots of powder have come and gone since their last update. So it seems each new lot of powder should include a load redevelopment.

Another issue is it seems these days speed is the most important thing and becoming more so. This leads to increased pressures and then summer temps come and the load is far over pressure.

Keep in mind that by the time you are seeing pressure signs such as brass flow at the ejector or bolt swipe that you are already over pressure to the tune of about 74,000 psi depending on brass hardness. Measuring case head expansion is the best way to determine max load if you don't have a pressure trace system.
IF you powder maker has your bullet listed in their data, I tend to go with that since they constantly test new lots of powder.
Loading for a target cartridge designed for accuracy while trying to drive it to magnum speeds for hunting or long range is just plain stupid and a bad habit. Use a magnum cartridge to start with. Cant count the number of people doing this with the creedmoors. The CM was designed for 600 yd max, the PRC was designed for beyond that.

Be quick to mentor new reloaders. The internet is NOT the place to learn reloading and it IS being watched and mistakes put here are the fastest way to get this enjoyable hobby regulated. Think safe and be safe.
Never be afraid to pick up a phone and talk to powder and bullet makers. They pay people to talk to you and share facts
Wow, couldn't have said it better. To the point on which load source to use it can really be confusing. IN most cases I agree that the powder manufactures like will have the best data but what needs to be understood is most sources give Maximum Safe Load or something similar. We as hand loaders don't know the true meaning of those terms. They may or may not be at maximum SAAMI pressure. Also there is still data out there where loads were not pressure tested to any standard but merely didn't show pressure signs.
 
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