Factory ammo muzzle velocities - data collection project

[Aaron-in-CO]

I have recently been facing a problem that I think we can collectively solve. I cannot find a centralized, reliable source of REAL WORLD data for muzzle velocity of factory ammo.

The sources that are out there (numbers printed on the ammo boxes, youtubers, writers, forums) are either not accurate, lacking details, or don’t have much variety of data.

I’m planning on buying a new big game rifle soon and am having a harder time than expected deciding which cartridge, barrel length, and ammo I want. It would be a huge help if I could see the actual muzzle velocities people are getting from various factory loads in various configurations. I would plug that MV and bullet specs into my ballistics calculator with my typical environmentals to determine if a particular barrel/ammo combo will be sufficient at my max range given the downrange velocity.

I’m envisioning a separate thread for each cartridge so that things are better organized and easier to find. Here’s is what a post might look like in a 6.5cm thread:

===========================

Ammo (brand and name): Hornady Match
Bullet (type and weight): 147 eldm
Bullet G1 BC: .646
Avg. Muzzle Velocity: 2580

Ammo (brand and name): Barnes Vor-tx
Bullet (type and weight): 120 ttsx
Bullet G1 BC: .412
Avg. Muzzle Velocity: 2775

Rifle: Tikka T3X lite
Barrel (if aftermarket): Proof prefit carbon fiber
Barrel length: 18”
Suppressor: AB A10 7.62
Suppressor length (past muzzle): ~6”

===========================

My questions to the Rok:

• Would you also find this interesting/useful?
• Is there anything about the template of the example post above that you would suggest changing?
• Any other thoughts to ensure the success/usefulness of this if I go forward with it?

And if you like the idea but don’t feel like commenting, feel free to give this post a thumbs up so I can better gauge interest.

 

[bnewt3]

You might want people to include environmentals(temp, elev, humidity)

 

[nm.otter]

Useful, yes.

Might be worth setting up a Google Form that feeds a Google Sheet.

 

[The Harbor Master]

I could see it being useful. At least will give a better starting point than box velocity, then mental subtraction of FPS based on barrel length etc. Obviously there can be some changes between lots, environmentals, etc. More info out there is never a bad thing IMO, consolidating it in a useful way will be key. The data is out there, but scattered in different posts, in different threads, on different subforums, across different websites.

Most guys won't browse through tens of thousands of posts (like the .223 for hunting thread) to find very specific data.

 

[Aaron-in-CO]

Yeah, from what I understand, environmentals will have a very small impact on MV. I’m thinking the biggest exception to this is if someone is letting their ammo bake in the sun on a hot day.
But maybe I’m underestimating the importance of ambient temp. Anybody have a better idea on MV differences affected by ambient temp?

I’m fairly certain that other environmental factors have practically no effect at the muzzle, but obviously a lot of effect downrange. But please let me know if I’m wrong here. I just didn’t want to clutter things with unnecessary data.

 

[The Harbor Master]

Yeah, from what I understand, environmentals will have a very small impact on MV. I’m thinking the biggest exception to this is if someone is letting their ammo bake in the sun on a hot day.
But maybe I’m underestimating the importance of ambient temp. Anybody have a better idea on MV differences affected by ambient temp?

I’m fairly certain that other environmental factors have practically no effect at the muzzle, but obviously a lot of effect downrange. But please let me know if I’m wrong here. I just didn’t want to clutter things with unnecessary data.

I doubt environmentals would have enough effect to drastically change MV, but if you don't include it, you'll probably get a lot of "yeah, but..." type questions... I'm that kind of person who will wonder/ask about that sort of minutae anyway

 

[Chris in TN]

At the end of the day there's going to be lot to lot variation and I don't think publishing exact figures from a lot of ammo you can't buy anymore, fired in some other guy's rifle, is really giving you anything better than just taking nominal published specs and adjusting them a bit up/down to match what you expect from your barrel/throat length.

I'm not saying your idea has no value. I'm just saying I fear the value would be pretty marginal above what we can already get by using nominal chart values.

YMMV, and I'm not against you trying anyway, certainly.

 

[bnewt3]

Yeah, from what I understand, environmentals will have a very small impact on MV. I’m thinking the biggest exception to this is if someone is letting their ammo bake in the sun on a hot day.
But maybe I’m underestimating the importance of ambient temp. Anybody have a better idea on MV differences affected by ambient temp?

I’m fairly certain that other environmental factors have practically no effect at the muzzle, but obviously a lot of effect downrange. But please let me know if I’m wrong here. I just didn’t want to clutter things with unnecessary data.

Fair

number of shots in the string?

 

[Q_Sertorius]

Useful, yes.

Might be worth setting up a Google Form that feeds a Google Sheet.

I agree that if you have a Google form that feeds a Google sheet, with broad options, this could be useful.

 

[Q_Sertorius]

Ammo (brand and name): Hornady Match
Bullet (type and weight): 147 eldm
Bullet G1 BC: .646
Avg. Muzzle Velocity: 2580

Ammo (brand and name): Barnes Vor-tx
Bullet (type and weight): 120 ttsx
Bullet G1 BC: .412
Avg. Muzzle Velocity: 2775

Rifle: Tikka T3X lite
Barrel (if aftermarket): Proof prefit carbon fiber
Barrel length: 18”
Suppressor: AB A10 7.62
Suppressor length (past muzzle): ~6”

===========================

If something like this is going to be useful, it has to be capable of aggregation and averaging. Or, at the very least, easy searching.

A Google form that has brands, barrel lengths, lot numbers, MV, ES, SD, etc. in it can be useful. But it will only ever be as useful as the data put into it.

Posting a new thread for each load is not going to work. Heck, posting a new thread for each caliber or brand is not going to work. A stickied thread that a moderator was willing to keep clean, which people were willing to follow a standard format, could work. Still only as good as the data put into it though.

 

[streamerfish]

At the end of the day there's going to be lot to lot variation and I don't think publishing exact figures from a lot of ammo you can't buy anymore, fired in some other guy's rifle, is really giving you anything better than just taking nominal published specs and adjusting them a bit up/down to match what you expect from your barrel/throat length.

I'm not saying your idea has no value. I'm just saying I fear the value would be pretty marginal above what we can already get by using nominal chart values.

YMMV, and I'm not against you trying anyway, certainly.

Yeah, kinda this.....

I get the point of what you want to do completely.

But their are way too many variables to even begin to make it meaningful. I don't think your going to get anything more conclusive then just saying...(Hornady says their 143 eldx 6.5 creed ammo is 2700fps in a 24" barrel). "I am probably going to get somewhere between2650 and 2750fps shooting the Hornady 143 eldx ammo out of my 24" 6.5 creedmoor, most likely around 2700."

Environmental conditions can have a pretty big impact on velocity. Especially depending on temperature, and what powder is used(which you don't know). Elevation has an impact as well, can be fairly noticeable.

And of course, you have to get into, well every single barrel is different, the amount of freebore is different company to company, the friction coefficient is different in every barrel.

The powder charge in every case is potentially different, the lot to lot variations in powder can make it different. bullet seating variations. Etc, etc, etc.

Only way to know beyond assuming what's on the box is a decent general guess with realistically probably a +- a couple percent swing either way is to just buy them, shoot them, and find out what they do in your system.

 

[bnewt3]

I would say its interesting, but ultimately a decent bit of work without really anything very meaningful out of it.

The other side of this, IMO, is that you are overthinking your rifle/cartridge choice. I agonized for months over the cartridge choice for my Tikka......it didnt really matter. I went with 308, but 270, 6.5, 7RM, .30-06, 243, etc, etc, etc would have been fine too. Unless you have some seriously lofty goals(ie: hitting a pronghorn @1000), just about all big game cartridges work on just about all big game. Pick a known performer and enjoy.

And even if you do have some lofty goal, there are known performers there too.

 

[MuleyFever]

It would be useful in the aspect that you may get a general idea of what a cartridge is likely to give you. However, velocity spreads between rifles and ammo lots would keep you from getting any definitive data.

 

[flyfisher117]

Meh, a running forum thread style would results in pages of data that doesn’t really tell me anything. Some sort of tool or survey that could take taken and the data compiled would potentially be useful.

Example being if I could quickly filter that data to see what average muzzle velocity guys are getting with 20” barrels shooting 140 eldm. Someone may find use in that.

Then again without a large sample it’s not worth much.

 

[bnewt3]

Meh, a running forum thread style would results in pages of data that doesn’t really tell me anything. Some sort of tool or survey that could take taken and the data compiled would potentially be useful.

Example being if I could quickly filter that data to see what average muzzle velocity guys are getting with 20” barrels shooting 140 eldm. Someone may find use in that.

Then again without a large sample it’s not worth much.

to add to that sample size point, It would likely take many weeks or months to gather enough useful data. On top of that, clearly around here you are likely to get data heavily weighted toward Tikka which does nothing if you have a savage or winchester, etc.

Meanwhile OP is waiting to make the cartridge choice when he could have been shooting his new rifle that whole time.

 

[Aaron-in-CO]

This is good feedback. I appreciate it! Will do some more thinking on this and reply later.