General Reloading Advice - Pressure and Velocity

[Packmansion]

The load I am developing has a different max charge across multiple loading manuals by as much as 3.5 grains. It is H4350 with 168 TTSX. I have a Chrono and a 22" tikka 30-06 superlite. I loaded some up using the highest max from Hogdon

24" barrel data:
Hogdon 2897 fps and 59 grains
Hornady 2900 and 58.9
Nosler 2872 and 57.5
barnes 2825 and 55.5

I am curious why Barnes is so far off the rest of the pack, at 55.5 I got 2799 not to far off.

I hit 2910 fps with 57.5 grains. I got very mild ejector mark but its Federal Brass... I got an ejector mark on the first low charge shot as well. I am not getting any hard bolt lift. I plan to dial the load back to somewhere between 56.5 and 57 where I was getting right around 2850 which correcting for barrel length would match the load data velocity. I just wanted to share this and get people to chime in on what they would do and what they have seen.

 

[Castle Rock]

Supposedly the solid copper bullets offer more resistance so the data is more conservative

 

[ORhunter74]

Is all that data for solid copper/mono’s? Copper bullets produce higher pressure which is why the typical starting and max loads tend to be lower than lead core bullets. Each bullet manufacturer will have slightly different charge weights for similar bullet weights due to the slight differences in bullet specs. As in, how many pressure relief grooves are cut into the bullet, the geometry of said groves and other differences like ogive shape, bullet length, etc.

If it were me, I would confirm whether those other loads were for similar weight monos rather than lead core. If they are mono loads, I would load up at the higher charges you described. If they are not, I would stay around max for the Barnes load data and mess with seating depth a bit. They tend to like big jumps to the lands. If you’re getting good accuracy and speeds are where you want them, I wouldn’t push higher unnecessarily.

If you’re chasing speed, maybe look at going down in bullet weight to 150’s or even 130’s. Not a bad idea to shoot lower weights at higher velocities in the monos. I shoot 130 TTSX’s in my .308 and 165 CX’s in my .300 wsm. Just my personal experiences over the past 13 years, as I am no expert.

 

[Packmansion]

Is all that data for solid copper/mono’s? Copper bullets produce higher pressure which is why the typical starting and max loads tend to be lower than lead core bullets. Each bullet manufacturer will have slightly different charge weights for similar bullet weights due to the slight differences in bullet specs. As in, how many pressure relief grooves are cut into the bullet, the geometry of said groves and other differences like ogive shape, bullet length, etc.

If it were me, I would confirm whether those other loads were for similar weight monos rather than lead core. If they are mono loads, I would load up at the higher charges you described. If they are not, I would stay around max for the Barnes load data and mess with seating depth a bit. They tend to like big jumps to the lands. If you’re getting good accuracy and speeds are where you want them, I wouldn’t push higher unnecessarily.

If you’re chasing speed, maybe look at going down in bullet weight to 150’s or even 130’s. Not a bad idea to shoot lower weights at higher velocities in the monos. I shoot 130 TTSX’s in my .308 and 165 CX’s in my .300 wsm. Just my personal experiences over the past 13 years, as I am no expert.

Hornady and Nosler load data includes copper monos

 

[35WhelenAI]

Thus the caveat to start at the lowest published by a component manufacturer and work up from there. Looks like you've done a good job of following that and checking signs along the way.

I believe Nosler uses a harder gilding metal in their copper bullets compared to Barnes. Which could allow slightly higher powder charge

As well, what bullets do Hornady and Hodgdon show for their data? Does Hornady show their copper bullet, does Hodgdon have copper bullet data?

I found the newer Barnes aren't as critical on pressure as the ones I started using 30 years ago with the solid shank. I don't see a problem using data from all the sources to extrapolate and continue development cautiously.

You are shooting a 2 inch shorter barrel, makes sense your velocity for the barnes is what it is. Keep in mind the '06 is a lower SAAMI PSI rating even though it's shot from the same guns as cartridges that have a higher rating.

As was said copper bullets do behave differently. I shoot the 130 ttsx from my '06, it's taken Pronghorn deer and elk without flinching.

 

[A382DWDZQ]

I get about 2800fps with the 168TTSX out of my 30-06 T3X Lite with IMR4064. O have generally found Barnes max charge is fairly hot as far as published load data goes.

With the publishers you listed, if the load data was not for the 168TTSX specifically, then expect some variation because the other bullets, mono or not, will have a different profile and composition. They will have more/less bearing surface in the barrel, more/less seating depth, affecting the case volume, etc.

With the ejector mark, I would not take that alone as pressure. When you start feeling g stiff bolt you will probably see an ejector swipe with that which is noticeably different.

 

[TaperPin]

Case head expansion measured with a micrometer in .0001”, or the number of times a case can be fired before a partial head separation starts to form or primer pocket is loose, are reliable means of comparing loads and determining max. If a case only lasts less than 5 firings the load is too hot, if the case lasts 8 to 10 firings that’s a safe max, regardless if velocity matches something printed in a book.

Sticky bolt lift may be pressure, or may be straight walled case in a rough chamber.

The more pieces of evidence a person can get on the load the better.

 

[35WhelenAI]

Agree. I did case head measurements developing loads for a newer powder that didn't have published loads for the bullet I was using. It takes some time and patience however I was able to push a bullet for my favorite hunting gun almost a hundred feet per second faster than my old standby load. Also did case head measurements for my old standby load and it turned out to be a safe maximum load.

 

[Packmansion]

Case head expansion measured with a micrometer in .0001”, or the number of times a case can be fired before a partial head separation starts to form or primer pocket is loose, are reliable means of comparing loads and determining max. If a case only lasts less than 5 firings the load is too hot, if the case lasts 8 to 10 firings that’s a safe max, regardless if velocity matches something printed in a book.

Sticky bolt lift may be pressure, or may be straight walled case in a rough chamber.

The more pieces of evidence a person can get on the load the better.

So if you measure case head expansion with a micrometer what change in dimension are you looking for? Alternatively do you just take a piece of brass and shoot it 8 times and if it survives you're good?

 

[35WhelenAI]

In essence your are correct on both counts.

I fireformed brass for my 35 Whelen Ackley Improved, taking virgin 35 Whelen brass measurement and after a light fireforming load. No change in case head dimension (diameter). Then took known loads I had developed years ago using traditional signs and fired them in the fire formed cases that had no expansion. I got .0002"-.0004" which is traditionally considered to be on the low to middle range of case head expansion for a safe load. I used that same measurement criteria as well as traditional signs working up loads with a newer powder that gained the velocity mentioned in my previous post.

As far as a round count method, I don't keep track of things that closely. After numerous firings if the primer pockets start opening up they go in the scrap pile. With that said, the loads I have developed don't show primer pocket expansion after multiple reloads over the years with the ones I have dedicated to hunting use.

 

[Packmansion]

In essence your are correct on both counts.

I fireformed brass for my 35 Whelen Ackley Improved, taking virgin 35 Whelen brass measurement and after a light formfing load. No change in case head dimension( diameter). Then took known loads I had developed years ago using traditional signs and fired them in the fire formed cases that had no expansion. I got .0002"-.0004" which is traditionally considered to be on the low to middle range of case head expansion for a safe load. I used that same measurement criteria as well as traditional signs working up loads with a newer powder that gained the velocity mentioned in my previous post.

As far as a round count method, I don't keep track of things that closely. After numerous firings if the primer pockets start opening up they go in the scrap pile. With that said, the loads I have developed don't show any primer pocket expansion after multiple reloads over the years with the ones I have dedicated to hunting use.

Do I need to measure the virgin brass as a baseline? Do I need multiple samples at a given load to measure?

 

[35WhelenAI]

I used five cases. Measured the virgin brass, then measured after the load I wanted check. A good way to give it a try is get some Factory loads. Measure them unfired, and after firing. See what you get.

When you are working up your loads check velocity with the chronograph as you go, as well as watch for traditional signs. It's all part of the process. I believe case head measurement is very useful and a period at the end of the sentence kind of thing with respect to being safe.

I couldn't use Factory loads being an Ackley improved version, so measuring virgin brass and being sure there was no expansion after fire forming was the route I took.

You can do a lot of good research on the internet with processes people have used, they're all going to be similar but it's really helpful information. I had a guy on another forum walk me through it after he had done it on his Whelen AI testing different bullets with new powders as well.

 

[Packmansion]

I used five cases. Measured the virgin brass, then measured after the load I wanted check. A good way to give it a try is get some Factory loads. Measure them unfired, and after firing. See what you get. Check velocity with the chronograph as you go, as well as watch for traditional signs. It's all part of the process. I believe case head measurement is a very useful and a period at the end of the sentence kind of thing with respect to being safe.

I couldn't use Factory loads being an Ackley improved version, so measuring virgin brass and being sure there was no expansion after fire forming was the route I took.

You can do a lot of good research on the internet with processes people have used, they're all going to be similar but it's really helpful information. I had a guy on another forum walk me through it after he had done it on his Whelen AI testing different bullets with new powders as well.

Very helpful I will test this out.

 

[35WhelenAI]

As you were quoting me I edited my post a little bit. Not much difference in information, just some general editing.

 

[35WhelenAI]

Once I reached that level of expansion, I used the same cases to fire repeated loadings of the same recipe. And didn't get any additional expansion. That's something to look for as well.

 

[wyosam]

Hornady and Nosler load data includes copper monos

Yeah, but they also lump a bunch of different bullets together by weight. Lousy way to present data. Using that system, it’s a ballpark at best. Otherwise you’ll have anemic loads for some bullets in the list, and be over pressure on others. Drives me nuts that they publish that way.


Sent from my iPhone using Tapatalk

 

[danhuntingmi]

IMO I would consider drop charge to next lower accuracy node and see what you get. Notice your velocities are (slightly) higher than any provided and yet you're using mono bullets.


Assuming you don't have pressure due to not sticky bolt lift is inaccurate, imo. Pressure limits are like speed limits and sticky bolt lift is like fish tailing around the curves as you greatly exceed the limit.

I wouldn't be surprised if dropping <50 fps leads to higher brass life and, to be honest, no practical difference in external and terminal ballistics. At least it's worked that way for me

 

[Packmansion]

IMO I would consider drop charge to next lower accuracy node and see what you get. Notice your velocities are (slightly) higher than any provided and yet you're using mono bullets.


Assuming you don't have pressure due to not sticky bolt lift is inaccurate, imo. Pressure limits are like speed limits and sticky bolt lift is like fish tailing around the curves as you greatly exceed the limit.

I wouldn't be surprised if dropping <50 fps leads to higher brass life and, to be honest, no practical difference in external and terminal ballistics. At least it's worked that way for me

2850 would match the velocity for hogdon and Hornady but it's probably about 75 over Barnes and 50 over Nosler. I have a feeling Barnes data is reasonable it being an 06 I'm not worried about being slightly over Barnes. That's my thought. You're probably right though if I run it at say 2800 it's not the end of the world.

 

[OMF]

Interesting discussion. I think much of the difference has to do with different testing equipment, different test barrels, different lots of powder, and different conditions when the testing was done.

I load monos differently than I do traditional cup & core or partition style bullets. With monos I find that I usually end up somewhere between 50% to 75% of max load for the given bullet before I start to see pressure signs I MY rifles. The first monos I loaded were Barnes 7mm 140 gr flat base way back when. Those were for a pawn shop Ruger Mark II. I didn't get to 50% of max before I was pounding the bolt open.
Aweful-->

Those things were awful. These days I tend to start right in the middle of a min - max load and go from there.

For load data on monos I like to/prefer to use the data from the bullet manufacturer if I can. I also like to see if the powder manufacturer has data for the exact bullet. As others have mentioned, it is good/interesting to look at multiple sources and extrapolate from there.

 

[35WhelenAI]

Barnes lumps bullets together as well with LRX, TSX, TTSX of slightly different weights within a category.

That picture of the old school Barnes X is a blast from the past! I still have many boxes of those that I stocked up on back in the day. The TTSX is so much better I will never use them. They did the job fine out of a number of rifles though starting 30 years ago. First bull, first cow, first muley buck, first whitetail.

Ty at Barnes and I talked a good bit years ago. The 200 TSX was coming in .358. He sent me some before they were introduced to work with in my 35 Whelen AI, asked for feedback and how loads compared to the original X in the same weight. I got about 50 fps more all else equal with the same components, but an extra grain or two of powder from the same lot.