Shotgun barrel length - how much does it matter?
- Thread starter Brobee
- Start date
If you feel like spending some more money on research, it looks like Reliable Gun has, in stock, 36 packs of Federal Premium Truball Deep Penetrators and 34 packs of Rottweil Brenneke Classic Magnum 3".
Keep up the great work and I'm loving the numbers coming out of the Dlask 12.5" barrel.
Yup, reinventing the wheel for the most part. Dlask already posted a few velocity charts on their forum as struff55 mentions.
I'm no gun expert but I've read that forcing cone can play a role in velocity too, but not sure how much. What is interesting, imo, is that the Dlask 12.5" appears (from the graphs) to have better velocity numbers versus the 14" barrel in regards to all the Federal slugs Brobee tested. Also, the huge drop in velocity from the Challenger Magnum slugs in the 12.5" barrel versus the 10" barrel. I wouldn't be surprised if the 14.5" barrel used in the tests was also a Remington barrel.
This is probably one of the articles you're talking about: https://smallarmsreview.com/energy-by-the-inch-the-great-shotgun-chop-of-2007/
ENERGY BY THE INCH THE GREAT SHOTGUN CHOP OF 2007
Really??? I've never seen any of the tests Brobee is doing with specific ammo like the Challenger Magnum along with specific barrels such as the Dlask 12.5".
Can you please post the velocity charts that "Dlask already posted" - would love to see them??? Shouldn't be a problem for you considering I think you might be a former employee
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There was a chart from a guy in the US that did every barrel from the Serbu 6.5" right up to a 34" barrel. The really surprising thing was that the difference between the 14" length and 26" length averaged right around 150 fps iirc. Made a really good point to the people that use the gun for legitimate bear defence and have to crawl through thick bush that it's just 100% more convenient to use a 14" vs. a 20"+ barrel. Even the 18.5" just seems sooo much longer than a 12.5" or 14" when you have to carry the thing.
The chart I'm quoting is for velocities, not spread or accuracy since if you are using it to defend yourself you won't be making 50 yard shots, more like 10-15 at best.
The chart I'm quoting is for velocities, not spread or accuracy since if you are using it to defend yourself you won't be making 50 yard shots, more like 10-15 at best.
The link I posted above also talks about velocities going all the way down to 6.875" but for some reason it's not displaying the velocity chart.
I've edited to add the missing Velocity chart for the "Great Shotgun Chop" article above:
"All muzzle velocity figures were measured using a PACT MKIV XP Chronograph and Timer from a distance of 8-feetfrom the muzzle. As we watched the flex of the screens with each round fired, it quickly became obvious that this day would be a serious endurance test of the Chronograph at the same time. We are happy to report that it survived just fine and is still used regularly."
"The first readings with the 2.75-inch Remington Slugger, 1-ounce rifled slugs in the stock shotgun averaged 1,555 feet per second (fps). The generator was fired up and it was time to start chopping. The barrel was carefully squared off and the abrasive wheel easily sliced through the barrel. The barrel was de-burred after each cut and the inside diameter was measured every time. Much to our surprise, the inside diameter of the barrel was completely consistent throughout the entire test."...
"The final muzzle numbers for the tests conducted during The Great Shotgun Chop are included in the accompanying chart but the summary is as follows: the starting muzzle velocity with a 30-inch barrel was 1,555 fps. The highest muzzle velocity measured was at the 26-inch point at 1,605 fps. The shortest barrel length tested was 6.875 inches and the muzzle velocity at that point was 1,117 fps. The spread from fastest to slowest recorded average was 488 fps. As indicated in the included data there is no consistently reliable formula to determine decrease or increase in muzzle velocity based on initial barrel length vs. inches cut. This is mentioned because the most popular question asked during the research phase of the testing was, 'What was the drop in muzzle velocity per inch cut?' From 12 inches down to 6.875 inches it could be established that the average drop in muzzle velocity per inch of barrel reduction was 48.2 fps, but it would not be reliable as the sharpest decline was in the last few cuts..."
"...Aside from the unexpected results in the 20-inch muzzle velocity testing, it is a safe assumption that for maximum performance at a minimal size for shooting slugs, a 12-inch barrel seems to be the optimum length..."
"...After conducting these tests it is our opinion that a 12-inch barreled shotgun with proper sights gives the owner/ operator the best performance in the smallest practical package without any major sacrifices in size or performance."
The chart you might be talking about is from a video:
I've edited to add the missing Velocity chart for the "Great Shotgun Chop" article above:
"All muzzle velocity figures were measured using a PACT MKIV XP Chronograph and Timer from a distance of 8-feetfrom the muzzle. As we watched the flex of the screens with each round fired, it quickly became obvious that this day would be a serious endurance test of the Chronograph at the same time. We are happy to report that it survived just fine and is still used regularly."
"The first readings with the 2.75-inch Remington Slugger, 1-ounce rifled slugs in the stock shotgun averaged 1,555 feet per second (fps). The generator was fired up and it was time to start chopping. The barrel was carefully squared off and the abrasive wheel easily sliced through the barrel. The barrel was de-burred after each cut and the inside diameter was measured every time. Much to our surprise, the inside diameter of the barrel was completely consistent throughout the entire test."...
"The final muzzle numbers for the tests conducted during The Great Shotgun Chop are included in the accompanying chart but the summary is as follows: the starting muzzle velocity with a 30-inch barrel was 1,555 fps. The highest muzzle velocity measured was at the 26-inch point at 1,605 fps. The shortest barrel length tested was 6.875 inches and the muzzle velocity at that point was 1,117 fps. The spread from fastest to slowest recorded average was 488 fps. As indicated in the included data there is no consistently reliable formula to determine decrease or increase in muzzle velocity based on initial barrel length vs. inches cut. This is mentioned because the most popular question asked during the research phase of the testing was, 'What was the drop in muzzle velocity per inch cut?' From 12 inches down to 6.875 inches it could be established that the average drop in muzzle velocity per inch of barrel reduction was 48.2 fps, but it would not be reliable as the sharpest decline was in the last few cuts..."
"...Aside from the unexpected results in the 20-inch muzzle velocity testing, it is a safe assumption that for maximum performance at a minimal size for shooting slugs, a 12-inch barrel seems to be the optimum length..."
"...After conducting these tests it is our opinion that a 12-inch barreled shotgun with proper sights gives the owner/ operator the best performance in the smallest practical package without any major sacrifices in size or performance."
The chart you might be talking about is from a video:
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Re my 14” barrel - it is from a factory 870 police and has a fixed mod choke, whereas everything else I’m using is choked cylinder or improved cylinder. I hypothesize that the off-trend 14” barrel velocities are attributable to choke, however forcing cone geometry is another plausible dimension I have not considered. I would expect that all the factory remington barrels have the same forcing cone geometry, something I’ll look at later on.
Re re-inventing the wheel - I am aware of the great 2007 barrel chop adventure and findings (which I LOVE!), but unaware of other meaningful efforts. The barrel chop only considered 1 type of slug, whereas I am interested in a larger dataset that spans multiple manufacturers and a variety of different loadings, like managed or reduced recoil offerings - something I have not seen.
Also, work-thus-far is only an overture to get to what I’m actually interested in, which is expansion characteristics of slugs in terminal media across a variety of different impact velocities. My starting point is to explore muzzle velocities, then to move on to external ballistic characteristics (how fast do they bleed speed en route to target?), then, how fast are they going when they hit their target? I’m mostly there in my data collection with one or two more range sessions to complete these first two stages.
Once the snow is gone and the weather is a bit better, I’ll be prepared to properly explore slug terminal performance at different impact velocities, and know how those impact velocities relate to barrel length and distance-to-target. I have not seen any prior work in this department.
Re re-inventing the wheel - I am aware of the great 2007 barrel chop adventure and findings (which I LOVE!), but unaware of other meaningful efforts. The barrel chop only considered 1 type of slug, whereas I am interested in a larger dataset that spans multiple manufacturers and a variety of different loadings, like managed or reduced recoil offerings - something I have not seen.
Also, work-thus-far is only an overture to get to what I’m actually interested in, which is expansion characteristics of slugs in terminal media across a variety of different impact velocities. My starting point is to explore muzzle velocities, then to move on to external ballistic characteristics (how fast do they bleed speed en route to target?), then, how fast are they going when they hit their target? I’m mostly there in my data collection with one or two more range sessions to complete these first two stages.
Once the snow is gone and the weather is a bit better, I’ll be prepared to properly explore slug terminal performance at different impact velocities, and know how those impact velocities relate to barrel length and distance-to-target. I have not seen any prior work in this department.
And produce an enormous amount of foot/pounds kilo joules.. in a very short period of time when your mortality is in question.
Where does it matter. As a fumbly old guy the short barrel makes a big difference trying to get out of the truck while the chicken is thinking about a hasty stage left exit. But longer is probably better to swing on duck and geese. As for speed nothing I shoot is going to notice.
If you can source the new USA Brenneke, both your American and Canadian audience will go crazy
On paper, it looks like the 2 3/4" - 602 grs - "Bear Protection Magnum" @ 1650 ft/s is the granddaddy of ALL brenneke slugs. That slug coupled with the Dlask 12" barrel will give you the same punch as a full length barrel shooting the 3" Black Magic. I imagine the 12" Dlask will get around 1500 ft/sec muzzle velocity.
Checked with my
Checked with my LGS, no availability yet, but will pounce if I can find any. Received a good quantity of Rio ounce-and-an-eighth Brenneke's yesterday, am good to finish off my velocity testing protocol and do a thorough terminal ballistics discovery session once the snow is gone, woohoo!If you can source the new USA Brenneke, both your American and Canadian audience will go crazy
On paper, it looks like the 2 3/4" - 602 grs - "Bear Protection Magnum" @ 1650 ft/s is the granddaddy of ALL brenneke slugs. That slug coupled with the Dlask 12" barrel will give you the same punch as a full length barrel shooting the 3" Black Magic. I imagine the 12" Dlask will get around 1500 ft/sec muzzle velocity.
Oh this is just a friggin treat. Hilarious to see some of my old chronograph results pop up too. I'm so happy to see you doing more testing Brobee and very excited about the scope of your testing. Regarding the Challenger slugs, they're loaded with Gualandi slugs. Ballistics Products sells them as components, calling the 1 1/8 oz flavor the DGS or dangerous game slug. Jason Wimbiscus did a pile of testing back in the day and I've spent some time loading them. My current load has them at 1530fps avg with 34 grs of Longshot, very similar to the factory Challengers. Jason saw stellar penetration with minimal deformation in his testing. I really like this slug and keep them loaded for my M2 tactical. As for the RIO Royal Brenneke 1 1/8 oz, my Garmin says they left the M2's 18.5" bbl at a paultry 1290fps avg. It was a little below freezing which may have played a role in the low mv. At any rate, I'm excited to watch the testing progress. You're a wealth of knowledge on shotgun ballistics Brobee.
Re score magnum slug (bpi thug slug loaded by prairie shot) - was out this past weekend in the cold and drifting snow working on down range vcity data collection. When testing the thug slugs at 75 and 100 meters, I could see something that looked like it was peeling off the back of the slug about a third of the way there and then getting blown/substantially deflected by the wind. Went down range to investigate before they got drifted in:
looks to me like air resistance/turbulence is pulling the wad out of the back end of the slug and the two are separating.
looks to me like air resistance/turbulence is pulling the wad out of the back end of the slug and the two are separating.
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Brobee, can you post a closeup picture of the wad and slugs?
From your picture it looks as if Challenger is using a different wad now with the Gualandi slug ... but I would need to see a close up to be sure.
Anyhow .... I never got any accuracy with the Challenger Gualandi slugs ... and I always attributed it to Challenger's quality control.
At one point I found this in one of the Challenger boxes together with loose powder in that box. That round dit not even chamber ...
From your picture it looks as if Challenger is using a different wad now with the Gualandi slug ... but I would need to see a close up to be sure.
Anyhow .... I never got any accuracy with the Challenger Gualandi slugs ... and I always attributed it to Challenger's quality control.
At one point I found this in one of the Challenger boxes together with loose powder in that box. That round dit not even chamber ...
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