Shotgun barrel length - how much does it matter?

257hunter said:
Might be easier to buy an entire 12.5” grizzly. Be more expensive but you can actually find them. Could sell after your testing and recoup costs.
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This was my thought, simple, you could also buy a 8 1/2" in the grizzly, I sold some, but no longer being imported as far as I know.
CanAmmo was the importer for Dominion Arms grizzly shot guns, 870 Chinese norinco knockoff.
I liked the 12 in, but the 8" is cute, but more noise then action, and you really need to watch where you off hand fingers are.
Put a ad in the EE or shot gun section, someone local could bring one over., the 8 1/2 " will not fit a reg 870 because the front ring is too far back on the barrel. at the time ,I think they cost just under 4 bills.
 
Brobee said:
Hey CGN!!

I am working on concepts for my Brobee223 2025 youtube hunting video...am thinking about "returning to my roots" and doing a proper episode on 12 gauge rifled slugs, stuff like:

  • distance/velocity curves of a bunch of commonly available rifled slugs
  • slug expansion characteristics at a variety of different impact velocities
  • effect of barrel length on muzzle velocity
  • maybe a deer or bear hunt to round it all out
I have a good selection of 870 barrels from 14" through 28", but missing from my collection is a 12". Reaching out to Dlask to pursue one of their factory offerings seems like I'm on the wrong side of a black hole event horizon (phone and email unanswered), am wondering if they are still in business?

And as an alternative, if there is anyone out here that has a factory Dlask 12" they aren't really using, please reach out as I would love to buy it from you!

Hope you're all having a great start to 2025!

Best,

Brobee
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How short are you going to go for the test? Dlask sold a bunch of 870 Super Shorty's in 8.5 and 10.
 
m1008 said:
I realize that but why use a foster slug over a Brenneke or Italian hard cast
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Well, from my experience .... some Foster slug designs like the Federal Truball are more accurate than the Brenneke or the Gualandi slugs.
I trust the Federal Truball High Velocity slug out to 100 meters .... I can't say that I trust the Brennekes that I tested (Rio and RWS Rottweil Brennekes) or the Gualandi for that distance.

(tested out of several shotguns)
 
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Brobee said:
...and just because it's interesting, here's some (still incomplete) downrange velocity data.
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Not that I'm trying to take away your excuse to go shooting more, but is there a reason you aren't using a ballistic calculator to look at longer range performance once you have all the muzzle velocity data?


Mark
 
mmattockx said:
Not that I'm trying to take away your excuse to go shooting more, but is there a reason you aren't using a ballistic calculator to look at longer range performance once you have all the muzzle velocity data?


Mark
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Not many shotgun ammo manufacturers publish G1 ballistic coefficients for their slugs, but some do. Here’s a sampling of the few I was able to find, and super interesting is that for the same slug, they suggest different BCs based on their muzzle velocity:

0.110 - federal hydrashok tactical 1oz (I really don’t believe this one)
0.075 - federal powershok 1oz foster slug
0.070 - federal 1600fps true-ball 1oz foster slug
0.063 - federal 1300fps true-ball 1oz foster slug
0.075 - Remington slugger 1600fps 1oz foster slug
0.068 - Remington slugger 1200fps 1oz foster slug

The Sierra Bullets guys have a decent write up on this:

When the bullet velocity falls below 1600 fps, radical changes in ballistic coefficient begin to occur. In the next subsection, we will show some examples of this phenomenon for both rifle and handgun bullets.

When the bullet velocity is greater than 1600 fps, the G1 drag function is a reasonable model from which to compute the aerodynamic drag on a bullet. The gradual changes in BC value with velocity can be handled in trajectory calculations by adjusting the BC values used in those calculations by changing the BC stepwise as the bullet traverses four or five velocity regions. The trajectory will start with the bullet velocity in one of those velocity regions. As the bullet velocity decreases and crosses the boundary between that initial velocity region and the next lower region, the BC is changed to the value corresponding to the next lower region. This process is repeated as the bullet velocity falls through successively lower velocity regions.

When the bullet velocity is less than 1600 fps, the G1 drag function just does not characterize the aerodynamic drag on the bullet. This causes the BC values to vary widely as the bullet velocity falls through the speed of sound (about 1120 fps) and to lower subsonic velocities. The step change method of adjusting BC values is, at best, a crude approximation. This situation is mitigated somewhat by the fact that aerodynamic drag on a bullet diminishes dramatically in the lower transonic and subsonic velocity regions. Consequently, the effect of large ballistic coefficient errors on bullet trajectories is much less than when the bullet velocities are above 1600 fps. For handgun bullet trajectories, the effect is also lessened by the fact that ranges to the targets or the game animals are considerably shorter than for rifles. But at the present time, accurate long-range trajectories simply cannot be calculated for bullets that travel at lower transonic and subsonic velocities. This affects the ballistics of rifle cartridges such as the 30-30 Winchester, 35 Remington, 444 Marlin, 45-70, and the “Whisper” class of cartridges, as well as all handgun cartridges chambered in rifles.

This is an area of continuing research for these authors. Ballistic coefficient data have been gathered for a variety of rifle and handgun bullets at transonic and subsonic velocities. Investigations are under way to find modifications to the G1 drag function at velocities below 1600 fps that will enable ballistic coefficients to remain reasonably constant in this velocity region. We hope to be able to report successfully on this research effort at a later date.

If you have a spare hour sometime, the “Head Ballistician” at Hornady has an excellent missive at
that also looks into this.

Also, some of the slugs I’m interested in (like the Brenneke and whatever you call the one the Challenger guys are using) I could not find recommended BCs for.

Anyway, there’s the long-form reason I decided to experimentally generate my own data.

Best,

Brobee
 
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i have shot the 8. 5 dlask guns . my unscientific assessment shooting at a barrel with a short dlask gun versus a twenty inch gun is the barrel rocked like crazy from the long gun versus little movement from the short gun. i know it is a red neck test . looking foreword to brobees tests. from what i have read guns with barrels shorter than twelve inches suffer from a large velocity loss.
 
farmer47 said:
from what i have read guns with barrels shorter than twelve inches suffer from a large velocity loss.
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That is my understanding as well. And according to supernova and Brobee, their results seem to verify that:

supernova said:
I don't feel like digging the pics up but here's the MVs of 3 slugs I chrono'd out of my 8.5" Grizzly.
Remington Managed Recoil 1 oz advertised 1200 fps, 8.5" hit 950 fps
Royal Brenneke 1 1/8 oz advertised 1410 fps, 8.5" hit 1080 fps
Federal 1 1/4 oz slug advertised 1560 fps, 8.5" hit over 1100 fps
I can't remember the exact numbers but there you have it. At 10 yds those slugs are moving just as fast as a longer barrel drives them out at 50-75 yds. Do your part and that's a dead bear. You don't need a longer barrel unless you want one. A short barrel works just as well and in some cases better (reduced chance of fragmentation) Carry an short shotgun in the bush when you're actually doing something and you'll have a whole new appreciation for them.
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The above quote is from '8.5" 12 ga vs Bear' thread: https://www.canadiangunnutz.com/forum/threads/8-5-12ga-vs-bear.1153872/page-2#post-10710031

8.5" barrel - Royal Brenneke = 1080 fps - supernova results

12.5" barrel - Royal Brenneke = 1310 fps (approx) - Brobee results
 
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257hunter said:
If you feel like going shorter send me a message, I have a 8.5” I might be willing to lend out for testing.
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That is a generous offer! Much appreciated.

I think I have found a 10” barreled gun to use, will get it done in the next few days and see what my remaining ammo stores are looking like. I still have to have enough left over to do some terminal ballistic /expansion experiments this summer and I think I’m tapped out a bit on incremental $$ in my already ridiculous ammo budget…;)

Will take stock in the days to come and see if the plan could accommodate this.

Best,

Brobee
 
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Brobee said:
That is a generous offer! Much appreciated.

I think I have found a 10” barreled gun to use, will get it done in the next few days and see what my remaining ammo stores are looking like. I still have to have enough left over to do some terminal ballistic /expansion experiments this summer and I think I’m tapped out a bit on incremental $$ in my already ridiculous ammo budget…;)

Will take stock in the days to come and see if the plan could accommodate this.

Best,

Brobee
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It’s crazy how much some 12g ammo has gone up in price the last couple of years, I would love to start reloading slugs and buckshot at some point. Both for cost and fun, I have some of the needed equipment but haven’t jumped in the pool yet.
 
Found a 10" barrelled cylinder bore gun that I borrowed this aft and shot to collect another dataset, also added the two data points provided by other CGNners above re super-shorties. I think it would be interesting to complete the 8.5" barrel data gathering - will investigate borrowing one or perhaps there's a CGNner out there with a shorty, a garmin, and a massive ammo stash?


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Brobee said:
Found a 10" barrelled cylinder bore gun that I borrowed this aft and shot to collect another dataset, also added the two data points provided by other CGNners above re super-shorties. I think it would be interesting to complete the 8.5" barrel data gathering - will investigate borrowing one or perhaps there's a CGNner out there with a shorty, a garmin, and a massive ammo stash?
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Just curious if both the 12.5" and 10" barrels were made by Dlask?
 
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