Velocity Loss With Shorter Barrels

[Viral_SIGness]

Again, the Ruger cartridges were designed for shorter barrels so that minimal velocity loss isn’t surprising. I was surprised that in the barrel test report you provided, the velocity loss wasn’t more significant with the .300WM? ALTHOUGH, if one could extrapolate from that test, the velocity loss from a 26” to a 22” at around 200fps loss, that would be somewhat significant and now in the realm of .30-06 velocities?

You just aren't going to see 50 fps/inch losses every cut. This .338 Lapua with a 250 grain bullet was 2868 at 26" and 2751 at 22". Losses just are not as big as everyone used to claim. I haven't found a single test on their site (yet anyway) that 4 inches has added up to 200 fps. The 7mm Rem Mag which I thought would be effected badly, barely lost more than 200 fps in 8 inches!

Here is the 338 Lapua from 30" to 17" it lost 395 fps, with the biggest drop from 18 to 17.

338 Lapua Magnum: Barrel Length Versus Muzzle Velocity (30-17 inches)

338 Lapua Magnum: Barrel Length Versus Muzzle Velocity One of the decisions we make when we build or buy a rifle is how long the barrel should be. Like everything else in life, barrel length is a …

rifleshooter.com

Full list of tests

Barrel length – rifleshooter.com

rifleshooter.com

 

[Rule 303]

Calling FACTS bullshit and rubbish and Not beeing able to know the difference between austria and australia is a good start. ‍
most of the powder will burn in the barrel - only some flakes or kernels leave the barrel. Most of the time this happens on low pressure reloads.

Powder is a chemical compound that does not need ambient air to burn - muzzle flash is a re-ignition of hot gases. There are enough high speed vids of bullets leaving the barrel - so proof your own bullshit.

The Steyr Factory is near my place - they did tests with FIVE piezo sensors over the whole barrel length. Pressure is WAY higher in the chamber and drops very fast the farer you are from chamber - doestn matter if bullet still in barrel or not. Also calculated will show same results.

GRT calculated velocity loss is the same as measured with a Mehl BMC 19 to single digit differences.

I know the difference between our countries. You introduced suppressors that may be fine where you are but not where I am, sorry that went over your head.

I stand by the facts as proven in real life. Do the test I outlined and you will see real world facts exist and disprove the facts obtained by drawing conclusions from experiments. I do understand every thing you have said and have for many years, but you seem to fail to see the difference between real physical evidence and conclusions drawn from experiments. Also how do you explain the unburnt powder grains on bench tops next to those with to short a barrel. Yes some does hit you in the face. So no bullshit from me only you.

OK the experiment with the 308 was around 1995. Using AR2208 powder burnt marks on the sheets and a few individual grains of powder were present. Using AR2206 powder non were present. AR2206 is a faster powder so to me this was to be expected. In an 18" barrel there were burn marks on the sheet but no unburnt powder from AR2206.

Calculated velocity loss is just that calculated, not proven by fact. My question still stands. What is your ACTUAL measured velocity loss in your rifles? I ask out of curiosity, not interested in calculated or suppositions.

 

[Rule 303]

Good points! I’m just curious as to why it seems the fatter cased cartridges seem to achieve the same velocities in shorter barrels as compared to their contemporaries which need longer barrels to achieve the same velocities. I.e the .375 or .416 Ruger cartridges with 20” barrels vs. a .375 h and h or .416 RM, which SEEM to need longer barrels to achieve the same velocities? The velocity difference may be moot, but you don’t see many/any of the latter cartridges with 20” barrels. I’m surmising the powder burn is more efficient in the shorter/fatter cased cartridges? I still prefer longer barrels, so it’s a moot point for me personally.

As I understand the factory rounds for the Ruger 375 and 416 are loaded with a powder developed just for those rounds to make velocity in a 20" barrel. Or so the original brochures claimed. Like you am curious as well.

The only reason I have not chopped the barrel on my CZ550 in 416 Rigby is, with my eyes, I now need the longer sight radius. Other wise I would take 3" off and bring it back to 22".

I think as powders develop we get better burn rates for same or very similar velocity in shorter barrels.

 

[CoElkHunter]

You just aren't going to see 50 fps/inch losses every cut. This .338 Lapua with a 250 grain bullet was 2868 at 26" and 2751 at 22". Losses just are not as big as everyone used to claim. I haven't found a single test on their site (yet anyway) that 4 inches has added up to 200 fps. The 7mm Rem Mag which I thought would be effected badly, barely lost more than 200 fps in 8 inches!

Here is the 338 Lapua from 30" to 17" it lost 395 fps, with the biggest drop from 18 to 17.

338 Lapua Magnum: Barrel Length Versus Muzzle Velocity (30-17 inches)

338 Lapua Magnum: Barrel Length Versus Muzzle Velocity One of the decisions we make when we build or buy a rifle is how long the barrel should be. Like everything else in life, barrel length is a …

rifleshooter.com

Full list of tests

Barrel length – rifleshooter.com

rifleshooter.com

Very eye opening on barrel lengths and velocity. I did notice the velocity loss with the .243 going from a 24” to an 18” barrel was 224fps. That’s a huge loss! Even the loss of 162fps from the standard 22” to an 18” is a lot for a cartridge that doesn’t have a lot of umph to begin with? A lot of newer inexpensive rifles, Savage, Mossberg, etc. have these shorter barrels from the factory. I can see a real problem with using these rifles with cartridges like the .243 on at least elk sized game with that kind of velocity loss?

 

[CoElkHunter]

But wait there’s more....... for many years, both the Browning A and now X Bolts and Remington 700s and to a lesser extent the Winchester M70 put 26” barrels on their belted mags from .264 to 7mm to .300 through to .338. I wonder why? Chronographs have been around for years so you’d think these companies could have put 24” or even 22” barrels on these magnums and saved a lot on the cost of barrels after figuring out the velocity loss wasn’t that great? Maybe during all those years, none of their ballistic experts ever checked this barrel length/velocity loss thing out? I find that difficult to believe, but.....?

 

[CoElkHunter]

As I understand the factory rounds for the Ruger 375 and 416 are loaded with a powder developed just for those rounds to make velocity in a 20" barrel. Or so the original brochures claimed. Like you am curious as well.

The only reason I have not chopped the barrel on my CZ550 in 416 Rigby is, with my eyes, I now need the longer sight radius. Other wise I would take 3" off and bring it back to 22".

I think as powders develop we get better burn rates for same or very similar velocity in shorter barrels.

With a large voluminous case like the Rigby, one would think it would require a longer barrel so all the powder would burn before the bullet exits the barrel? Or loaded with a faster powder? I don’t know, this thread has really made me think conversely to what I believed about longer barrels and velocity?

 

[Rule 303]

But wait there’s more....... for many years, both the Browning A and now X Bolts and Remington 700s and to a lesser extent the Winchester M70 put 26” barrels on their belted mags from .264 to 7mm to .300 through to .338. I wonder why? Chronographs have been around for years so you’d think these companies could have put 24” or even 22” barrels on these magnums and saved a lot on the cost of barrels after figuring out the velocity loss wasn’t that great? Maybe during all those years, none of their ballistic experts ever checked this barrel length/velocity loss thing out? I find that difficult to believe, but.....?

I can't help but wonder if it is due to one of three possibilities. 1) The modern powders burn more efficiently so require less barrel length. 2) Back then they were aware of the minimal loss but wanted to wring every last foot of velocity out of the cartridge for sales purposes. 3) They wanted to keep the blast and sound down as much as possible.

Re the Rigby. I use AR2209 (IMR4530, H4350) with 96 grains. AR2213SC (H4831) use 10 grains more powder to get same velocity. I figure the AR2209, the faster of the two, should burn all in the 22" or hope it would. However I'll live with the longer barrel for resale purposes. Figure I have about 5 more years with it.

 

[CoElkHunter]

I can't help but wonder if it is due to one of three possibilities. 1) The modern powders burn more efficiently so require less barrel length. 2) Back then they were aware of the minimal loss but wanted to wring every last foot of velocity out of the cartridge for sales purposes. 3) They wanted to keep the blast and sound down as much as possible.

Re the Rigby. I use AR2209 (IMR4530, H4350) with 96 grains. AR2213SC (H4831) use 10 grains more powder to get same velocity. I figure the AR2209, the faster of the two, should burn all in the 22" or hope it would. However I'll live with the longer barrel for resale purposes. Figure I have about 5 more years with it.

Could be a combination of all of the above? I recently acquired a CZ .416 Rigby. I haven’t shot it yet, but I like the 25” inch barrels. I have a couple of other CZs and they handle and shoot real well for me. As soon as I find reloading dies, I’ll try H4831 and 400gr bullets.

 

[Viral_SIGness]

Very eye opening on barrel lengths and velocity. I did notice the velocity loss with the .243 going from a 24” to an 18” barrel was 224fps. That’s a huge loss! Even the loss of 162fps from the standard 22” to an 18” is a lot for a cartridge that doesn’t have a lot of umph to begin with? A lot of newer inexpensive rifles, Savage, Mossberg, etc. have these shorter barrels from the factory. I can see a real problem with using these rifles with cartridges like the .243 on at least elk sized game with that kind of velocity loss?

I am not a proponent for short barrels at all. I was expecting to gain 150 fps by going from 20" to 23". Thats what led to my own testing and research on others tests.

I don't think the .375 Ruger case was designed for shorter barrels. All they did was basically use the belt from a 300 Win Mag as a "foundation" and built the case walls on it. As far as factory ammo, the numbers on the boxes are from a 24" barrel. The 20" comes up 80-85 fps shy of the box. Having these two .375 Rugers and a chronograph on hand has opened my eyes to a lot.

 

[IvW]

I am not so pos on 338 lapua stats....

 

[Viral_SIGness]

I am not so pos on 338 lapua stats....

Ok, so this "magazine" that's known for being neutral in everything, suddenly told lies to hurt the feelings of those who think 50-75 fps per inch is the set rule.

 

[Wyatt Smith]

I bet the type of powder used has a lot to do with the velocity loss. I bet a 30-06 loaded with 4831 would lose a lot more speed than one loaded with 4895.

 

[Viral_SIGness]

I bet the type of powder used has a lot to do with the velocity loss. Bet a 30-06 loaded with 4831 would lose a lot more speed than one loaded with 4895.

I've got more tests planned for my 20 vs 23 tests in 375 Ruger, but so far the losses have remained the same with RL15, Varget, and IMR4350. RL17 is the ideal powder for the .375 Ruger, so I think it being a little slower, it will favor the 23" barrel a little more. Trust me, I'm hoping it does !

 

[IvW]

My own 338 Lapua recorded higher velocities with 300gr bullets than what was published on the box with 300gr bullets....sporting a 30 1/2 inch match barrel...some calibers require a certain barrel length to achieve optimum performance....I cannot see mine doing what it was designed to do with a short barrel.....may of course be different for different calibers....

 

[Viral_SIGness]

My own 338 Lapua recorded higher velocities with 300gr bullets than what was published on the box with 300gr bullets....sporting a 30 1/2 inch match barrel...some calibers require a certain barrel length to achieve optimum performance....I cannot see mine doing what it was designed to do with a short barrel.....may of course be different for different calibers....

There seems to be no set in stone rules. Those tests definitely show this, when one cut takes 8 fps and the next takes 60. Barrel harmonics have got to be involved some how. Like the 300 WM gaining speed from 22 to 21. I understand there are certain margins of error, but there is more at play than powder speed.

 

[Rule 303]

Could be a combination of all of the above? I recently acquired a CZ .416 Rigby. I haven’t shot it yet, but I like the 25” inch barrels. I have a couple of other CZs and they handle and shoot real well for me. As soon as I find reloading dies, I’ll try H4831 and 400gr bullets.

May I suggest you use H4350 instead. This is AR2209. H4831 is AR2213sc and it kicks like a mule compared tot he 4350.

Re velocity loss, I think for most the rule of thumb works. However I believe individual barrels are different. You can have a barrel of a given calibre that will give you a MV say 100fps above the quoted velocities and another give 100fps less. fast and slow barrels. I suspect this also plays a part.

I envy Austrianhunter living close to the Steyr factory. They make a very good rifle and their barrels are top notch. My 270Win in their Prohunter drives a 140 grain projectile at 3200fps, with no pressure signs-I load to 3100fps as there is no difference in accuracy. Not many 270 barrels will give you 270WSM performance. I sure as hell am not going to cut that barrel down or play with it.

 

[Rule 303]

Ok, so this "magazine" that's known for being neutral in everything, suddenly told lies to hurt the feelings of those who think 50-75 fps per inch is the set rule.

Probably not, but as we all seem to agree, different rifles can give different data.

Please keep posting results when you get them as, to me, this is a fascinating subject.

I have a 308 with a 20" barrel and can not get withing 200fps of published data from 22' barreled 308's so is this velocity loss of 100fps per inch or do I have a slow barrel?

 

[CoElkHunter]

May I suggest you use H4350 instead. This is AR2209. H4831 is AR2213sc and it kicks like a mule compared tot he 4350.

Re velocity loss, I think for most the rule of thumb works. However I believe individual barrels are different. You can have a barrel of a given calibre that will give you a MV say 100fps above the quoted velocities and another give 100fps less. fast and slow barrels. I suspect this also plays a part.

I envy Austrianhunter living close to the Steyr factory. They make a very good rifle and their barrels are top notch. My 270Win in their Prohunter drives a 140 grain projectile at 3200fps, with no pressure signs-I load to 3100fps as there is no difference in accuracy. Not many 270 barrels will give you 270WSM performance. I sure as hell am not going to cut that barrel down or play with it.

I don’t have any 4350, but I’ll have to buy some eventually. Everything else I have (W748, RL 15, H335) I use in my .416 Taylor, .458WM and Lott and I guess it’s too fast for the Rigby?

 

[Viral_SIGness]

Probably not, but as we all seem to agree, different rifles can give different data.

Please keep posting results when you get them as, to me, this is a fascinating subject.

I have a 308 with a 20" barrel and can not get withing 200fps of published data from 22' barreled 308's so is this velocity loss of 100fps per inch or do I have a slow barrel?

.308 from 28" to 16.5"

 

[CoElkHunter]

.308 from 28" to 16.5"

View attachment 391151

That’s not much of a velocity loss even if it was a 22 to an 18? Wonder why with the .243 going from a 22” to an 18” the velocity loss is so much greater?