to chrony or not to chrony? That's my question

1Cor15:19

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Well maybe. I know this is a extreme example but if I overload my 30-06 with, say 4198 to the point where the brass is flowing into the bolt face will I see high FPS? Never tried it but I think not.
Your velocity will be high compared to what 4198 should produce in your rifle. The velocity will not be as high as you might reach with other powders, but that's not the concern either. The question is what is the pressure with the load in hand. For that question, known velocity is indispensable to normal handloaders.
 

tccak71

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Suppose it doesn't really matter, as you'll eventually shoot it anyway!! May not be worth it...
 

Amigo Will

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I've found an under loaded bullet will flaten a primmer just like a over loaded case.I've also found speed mostly just kills when talking motorcycles not bullets.
 

Smokey

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For me a chrony just helps add to the enjoyment of reloading. One thing I find interesting is how extreme and how narrow the FPS spreads can be by using different powders. If I am getting good groups and can keep the spread tighter it makes me more confident in my chosen load...
I bought a chrony in the mid 80s when I was getting competitive in outdoor archery and we were pushing the limits of the equipment. First time I shot a rifle over mine I blew the 2 sun blocker cover strips to pieces! A little close I reckon. After that I used it without any and found I had better readings on cloudy days as the sun can interfere. Must be a reason they came with those antenna looking thingy's? :)
I now use a custom made wooden box that I painted the bottom of the top board with gloss enamel white paint. Now I have great readings, a good window to shoot through, and it keeps my chrony protected if it is a bit rainy out. Its to heavy to lug around much but I am fortunate to have my own place to shoot and can leave this contraption under my bench..
I say buy the chrony if just for the fun factor alone!
 

Smitty of the North

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Well maybe. I know this is a extreme example but if I overload my 30-06 with, say 4198 to the point where the brass is flowing into the bolt face will I see high FPS? Never tried it but I think not.

I've not "tried it" either because I don't deliberately try to produce excessive pressures, BUT from what I've run across, IME, howbeit limited, YES.

However, it is to be remembered that there is a point where the increase in velocity will not increase as fast as the pressure does.

How you gonna know your pressure is excessive if you have none of the case pressure signs? The velocity helps. If it's HIGH, instead of claiming a Fast Barrel, or thinking you have some kinda MAGIC load, recognize it as a PRESURE SIGN.

I'm sure that there are many hand loads in use that produce unsafe pressures, but folks get away with it, but the least little thing can cause them to skyrocket.

The thing about handloading also to be remembered, is that you can't POSITIVELY assume anything. Excessive Pressure can happen for reasons that are unclear.

Hand Loading is largely an experimental process.

Smitty of the North
 

Smitty of the North

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For me a chrony just helps add to the enjoyment of reloading. One thing I find interesting is how extreme and how narrow the FPS spreads can be by using different powders. If I am getting good groups and can keep the spread tighter it makes me more confident in my chosen load...
I bought a chrony in the mid 80s when I was getting competitive in outdoor archery and we were pushing the limits of the equipment. First time I shot a rifle over mine I blew the 2 sun blocker cover strips to pieces! A little close I reckon. After that I used it without any and found I had better readings on cloudy days as the sun can interfere. Must be a reason they came with those antenna looking thingy's? :)
I now use a custom made wooden box that I painted the bottom of the top board with gloss enamel white paint. Now I have great readings, a good window to shoot through, and it keeps my chrony protected if it is a bit rainy out. Its to heavy to lug around much but I am fortunate to have my own place to shoot and can leave this contraption under my bench..
I say buy the chrony if just for the fun factor alone!

Send Picture.

Smitty of the North
 

jim in anchorage

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I've not "tried it" either because I don't deliberately try to produce excessive pressures, BUT from what I've run across, IME, howbeit limited, YES.

However, it is to be remembered that there is a point where the increase in velocity will not increase as fast as the pressure does.

How you gonna know your pressure is excessive if you have none of the case pressure signs? The velocity helps. If it's HIGH, instead of claiming a Fast Barrel, or thinking you have some kinda MAGIC load, recognize it as a PRESURE SIGN.

I'm sure that there are many hand loads in use that produce unsafe pressures, but folks get away with it, but the least little thing can cause them to skyrocket.

The thing about handloading also to be remembered, is that you can't POSITIVELY assume anything. Excessive Pressure can happen for reasons that are unclear.

Hand Loading is largely an experimental process.

Smitty of the North
I don't know why so many are afraid of gauging pressure by examining the case. Even Phil Sharpe didn't like it [using the case to read pressure] claiming flat primers where because powder grains had worked their way into the primer pocket trough the flash hole. In a bolt action only the case is the weak link. If it looks good you're ok. Picture a brass case as a CUP piston. the more it deforms the higher the pressure. Is the solid head of the case taking on machine marks from the bolt? Pressure too high, the brass is flowing. MV means nothing.
 

ADfields

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I don't know why so many are afraid of gauging pressure by examining the case. Even Phil Sharpe didn't like it [using the case to read pressure] claiming flat primers where because powder grains had worked their way into the primer pocket trough the flash hole. In a bolt action only the case is the weak link. If it looks good you're ok. Picture a brass case as a CUP piston. the more it deforms the higher the pressure. Is the solid head of the case taking on machine marks from the bolt? Pressure too high, the brass is flowing. MV means nothing.
You are correct that CUP (copper units of pressure) are measured by how much the pressure deforms copper. And correct that if you are seeing pressure signs on your case they are indicative of a pressure. However the tricky thing is that not seeing pressure signs on your case is not indicative of lower pressure, in other words you can have excessive pressure and no signs at all on the spent case.

For CUP testing a known alloy of a known hardness is used then the deformation measured . . . then its thrown away and a new one used for the next test. Rifle brass comes it a thousand alloys and all react differently under pressure. Brass also becomes work hardened from forming, sizing, firing and so on so even the very same piece of brass may react very differently to pressure shot to shot. I’ve seen flattened primers in 357 brass after popping 3g of Bullseye so flat primers means absolutely nothing to me in terms of pressure. Then the reading of all this stuff is very subjective and varies reader to reader. This means reading pressure signs on brass is better than nothing but acutely doesn’t tell you very much at all about the real pressure in there.
 

jim in anchorage

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Your velocity will be high compared to what 4198 should produce in your rifle. The velocity will not be as high as you might reach with other powders, but that's not the concern either. The question is what is the pressure with the load in hand. For that question, known velocity is indispensable to normal handloaders.
I'm not a "normal" reloader? Just looked at my purchased new[by me] 1973 shooters bible and there is no listing of chronographs in there. And I remember the days when chronographs required replacing the strips of paper on both screens after every shot and no one but gun writers had one. Well we got by. Am I saying a chronograph is useless? Absolutely not . I think it would be a lot of fun and add to the enjoyment us handloaders have. Required? No.
 

OldRgr

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Chrony

Chrony

I have one and use it frequently. It is not a necessity but sure helps understand what is going on. When you do not get a tight group the extreme spread will tell you if its the powder. If ES is good, 30 fps/5 rds; look to the bullet. For me, it is worth it. Best wishes. J.
 

GD Yankee

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As to the OPs original question, I would buy a chronograph for fun, not to determine pressure.

If you are shooting a .375 JDJ, eeking out extra FPS above and beyond what the load books list isn't worth it. If you want more velocity, shoot a different caliber. If you want to save powder, shoot a smaller cartridge. At 150 yards with a big bullet doing the rainbow arc trajectory, I would work up loads for accuracy rather than velocity. Move your charge weights up or down a couple of grains, not to exceed the book and stick with the best grouping. If still not satisfied, go to a different bullet.

Also, use a current reloading manual, avoid an old (like my 25 year old Speer) manuals. Be careful switching bullets. All can contribute to excessive pressures. Once I used my Nosler Ballistic Tip load for a Nosler Partition load. I'm a little slow and after THREE rounds, which all felt stout and the bolt was a little sticky, I checked the brass. Totally flat primers and bolt face engraving on the case head. Nice group. I bought a Nosler manual and I was several grains over max for the partition. Backed off the load and no more pressure signs. It actually became my best grouping bullet in that gun, even better than the old Ballistic Tip.

Some guys try to make the 45-70 a 458 WM, or the 30-06 a 300 WM. I have only one set of eyes, hands, and face, and I prefer to keep them OEM.

:topjob:
 

1Cor15:19

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I don't know why so many are afraid of gauging pressure by examining the case. Even Phil Sharpe didn't like it [using the case to read pressure] claiming flat primers where because powder grains had worked their way into the primer pocket trough the flash hole. In a bolt action only the case is the weak link. If it looks good you're ok. Picture a brass case as a CUP piston. the more it deforms the higher the pressure. Is the solid head of the case taking on machine marks from the bolt? Pressure too high, the brass is flowing. MV means nothing.
Hard to know where to start, but this approach is at best naive. Measuring pressure with copper or lead crushers is an exacting work that requires many controlled components to determine breech pressure. Cartridge cases are of such inconsistency that trying to base pressure readings on their signs is at best tricky and are no way comparable to copper crusher methods because of these many inconsistencies. I've used a strain gauge enough to know that the makeup of the brass is more significant to the characteristics touted as proof of pressure than the actual pressures generated in many instances. However, MV is directly proportional to generated pressures irrespective to the composition of the brass.

FWIW, I've a 300 WM (24 inch barrel) that will fire 165 SPBT at 3450+ fps without the brass flowing, with an unaltered bolt lift, and perfect looking primers. A properly cut chamber that is square to the bolt fired in a strong rifle simply won't tell me (or anyone else) that the pressure is overloaded by 15-20,000 psi by inspecting the brass. The MV does tell me that, as has a previously attached strain gauge. It is really a very simple concept. Under normal combustion conditions with any given powder, higher velocity indicates higher pressures. I've seen soft brass that leave various "pressure signs" at 85-90% of SAAMI listed maximum average pressure though the "pressure signs" would have had some "experts" foolishly running for cover expecting that the rifle was a bomb with those loads. Handloading is rocket science; trying to take pressure measurements using a divining rod (brass flow, bolt lift, etc.) seems a hopeless method to me, but suum cuique.
 

jim in anchorage

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You are correct that CUP (copper units of pressure) are measured by how much the pressure deforms copper. And correct that if you are seeing pressure signs on your case they are indicative of a pressure. However the tricky thing is that not seeing pressure signs on your case is not indicative of lower pressure, in other words you can have excessive pressure and no signs at all on the spent case.

For CUP testing a known alloy of a known hardness is used then the deformation measured . . . then its thrown away and a new one used for the next test. Rifle brass comes it a thousand alloys and all react differently under pressure. Brass also becomes work hardened from forming, sizing, firing and so on so even the very same piece of brass may react very differently to pressure shot to shot. I’ve seen flattened primers in 357 brass after popping 3g of Bullseye so flat primers means absolutely nothing to me in terms of pressure. Then the reading of all this stuff is very subjective and varies reader to reader. This means reading pressure signs on brass is better than nothing but acutely doesn’t tell you very much at all about the real pressure in there.
No and I thought about the fact that not all brass cases are the same metallurgy and will not give you absolute pressure readings but can tell you that with this case, with this load, in this gun you are pushing the envelope of pressure. If I have, say 500 Federal .223 cases and load to book max and beyond till the spent primers are falling out, then thats max for that lot of brass.
But thats all I care about in a modern bolt. Some lots of brass will take more pressure then others, no doubt. Thats why I do not mix brass in my loads. All the same lot, or I weigh them.
 

jim in anchorage

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Hard to know where to start, but this approach is at best naive. Measuring pressure with copper or lead crushers is an exacting work that requires many controlled components to determine breech pressure. Cartridge cases are of such inconsistency that trying to base pressure readings on their signs is at best tricky and are no way comparable to copper crusher methods because of these many inconsistencies. I've used a strain gauge enough to know that the makeup of the brass is more significant to the characteristics touted as proof of pressure than the actual pressures generated in many instances. However, MV is directly proportional to generated pressures irrespective to the composition of the brass.

FWIW, I've a 300 WM (24 inch barrel) that will fire 165 SPBT at 3450+ fps without the brass flowing, with an unaltered bolt lift, and perfect looking primers. A properly cut chamber that is square to the bolt fired in a strong rifle simply won't tell me (or anyone else) that the pressure is overloaded by 15-20,000 psi by inspecting the brass. The MV does tell me that, as has a previously attached strain gauge. It is really a very simple concept. Under normal combustion conditions with any given powder, higher velocity indicates higher pressures. I've seen soft brass that leave various "pressure signs" at 85-90% of SAAMI listed maximum average pressure though the "pressure signs" would have had some "experts" foolishly running for cover expecting that the rifle was a bomb with those loads. Handloading is rocket science; trying to take pressure measurements using a divining rod (brass flow, bolt lift, etc.) seems a hopeless method to me, but suum cuique.
Thats why I said one lot of brass.
 

iofthetaiga

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No and I thought about the fact that not all brass cases are the same metallurgy and will not give you absolute pressure readings but can tell you that with this case, with this load, in this gun you are pushing the envelope of pressure. If I have, say 500 Federal .223 cases and load to book max and beyond till the spent primers are falling out, then thats max for that lot of brass.
But thats all I care about in a modern bolt. Some lots of brass will take more pressure then others, no doubt.
^^This is why I don't like to shoot at public ranges. You never know when this guy might be at the bench next to you.
 

ADfields

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No and I thought about the fact that not all brass cases are the same metallurgy and will not give you absolute pressure readings but can tell you that with this case, with this load, in this gun you are pushing the envelope of pressure. If I have, say 500 Federal .223 cases and load to book max and beyond till the spent primers are falling out, then thats max for that lot of brass.
But thats all I care about in a modern bolt. Some lots of brass will take more pressure then others, no doubt. Thats why I do not mix brass in my loads. All the same lot, or I weigh them.
So because its brass from the same lot hardness case to case will be consistent? Well it isn’t at all consistent, these lots are treated in a huge basket thousands of cases at a time. The ones in the center get a far different heat cycle than those outside, top varies greatly from bottom and so on.


Loads can be safely made without a chronograph; I did it for many years myself. But When you get tools you quickly see just how mislead you were.

And for the record never EVER exceed max data!!!!!!!
 

1Cor15:19

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Loads can be safely made without a chronograph; I did it for many years myself. But When you get tools you quickly see just how mislead you were.

And for the record never EVER exceed max data!!!!!!!
I agree Andy. I loaded tens of thousands of rounds before I had a chronograph with very few issues and due to the inherent safety element built into modern firearms I did so unscathed. However I'd be very reluctant to go back without one and for the amount of ammo and variety of firearms for which I load, my ammo would suffer greatly.
 
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