SHORTENED BBL

[4xforfun]

Components being what they are......scarce and expensive....I will ask before I waste time and $ testing. I shortened up a bunch of tubes for use with a suppressor. Various chamberings. Some, like my hunting 300 WBY, I seemed to loose very little FPS when chopping off 4 1./2 inches.....about 40 FPS loss. I am good with that. Others, like my 6-47L I took them way down from 29 down to 17 inches. It was getting a little long in the tooth and I figured, why not? I went from 3100 down to 2750 with the 108 BT. Still shoots OK.

Wondering if I tried a little faster powder than the H4350 I am using now if I could pick up a few FPS. My thoughts are that even though the FPS is down, the PSI is the same. Just don't know how much unburnt powder is getting spit out the business end and if faster powder might help.

Side note........GOD I LOVE SHOOTING SUPPRESSED!!!!!!
I am going to put that shit on everything!!

HAPPY NEW YEAR!!!!

TOD

 

[ClayM]

Quickload...

 

[Paul's Black Rifles]

Components being what they are......scarce and expensive....I will ask before I waste time and $ testing. I shortened up a bunch of tubes for use with a suppressor. Various chamberings. Some, like my hunting 300 WBY, I seemed to loose very little FPS when chopping off 4 1./2 inches.....about 40 FPS loss. I am good with that. Others, like my 6-47L I took them way down from 29 down to 17 inches. It was getting a little long in the tooth and I figured, why not? I went from 3100 down to 2750 with the 108 BT. Still shoots OK.

Wondering if I tried a little faster powder than the H4350 I am using now if I could pick up a few FPS. My thoughts are that even though the FPS is down, the PSI is the same. Just don't know how much unburnt powder is getting spit out the business end and if faster powder might help.

Side note........GOD I LOVE SHOOTING SUPPRESSED!!!!!!
I am going to put that shit on everything!!

HAPPY NEW YEAR!!!!

TOD

Has the accuracy changed?
Unless you are shooting long range fps wouldn't be my concern.

Paul

 

[alf]

I just finished up testing my 6x47 Lapua for velocity loss.

Back when the barrel was 25", I had a shoot off of several groups each between 39 grains and 40.5 of H-4350 with 108 ELD-M's. Temperature that day was 75 degrees.

Four groups of three, 39 grains averaged 3073
Four groups of three, 40.5 grains averaged 3173

I had the barrel cut and crowned at 18", & shot the same loads again. Temperature was 32 degrees.

Five groups of three, 39 grains averaged 2868, a loss of 205 FPS, or 29.3 FPS of loss per inch.
Five groups of three, 40.5 grains averaged 2992, a loss of 181 FPS, or 25.9 FPS loss per inch.

The X factor would be how much of the loss was due to the difference in temperatures.

 

[4xforfun]

Has the accuracy changed?
Unless you are shooting long range fps wouldn't be my concern.

Paul

Just got my can 3 months ago and got the tubes shortened since. I also had quadrupal bypass and haven't fired a shot since early November. Fired my first shots yesterday to re zero. I know that on my 300 Wby I banged center steel at 100, 300, 600, and 1000. Really haven't shot any groups with it. Just zero and verify new FPS data at the above distance. did this B-4 deer season in early Nov. One shot at each distance.

I had 7 different tubes threaded......some were also shortened......that will give me something to do this winter.

Tod

 

[Loudenboomer]

I shortened a Push feed Mod 70 .308 to 18". Suits the rifle, Banish 30 suppressor, and my hunting stile well.
Before shortening I had the suppressor on a 26" Sendero. The length got a little long and awkward for my tastes. Accuracy with my old load seemed to open up with the abbreviated barrel a little but the deer didn't seem to notice.

 

[wedgy]

The specialty pistol guys like Ernie have said that the same powder that gives the best velocity in the longer barrel will still yield the most velocity in the shorter tube. The powder is burnt but the gas is still expanding creating more velocity in the longer barrel.

 

[alf]

The specialty pistol guys like Ernie have said that the same powder that gives the best velocity in the longer barrel will still yield the most velocity in the shorter tube. The powder is burnt but the gas is still expanding creating more velocity in the longer barrel.

I shot multiple barrel lengths in 6.5-284 from 30" down to 18" in an XP-100, and from an accuracy standpoint, the right powder is the right powder no matter barrel length.

 

[Ray123]

I shoot a variety of barrel lengths in 308, from 18, 22, 24, 27, 30. You lose velocity and there is no way to recover it ... from any powder. You live with the velocity loss as the trade off. The lighter the bullet the more velocity you lose ...like over 300 fps going long to short, like 340 to 350 fps. Heavy bullet loads will lose a lot less velocity...a big difference from 110 to 200 grs
So ya want to keep up velocity and energy...use the heavy for caliber bullets...it will do more than a different powder burn rate... and usually the fastest velocity powder in your long barrel will be the fastest velocity powder in your short...in the 308 with 18" to 30 " which I suspect is true physics for any caliber. I haven't tested pistols in rifles calibers, with super short barrels.