Short Barrel accuracy impact?

[dan belisle]

So, do the barrel start whipping before or after the bullet exits?
If we’re talking 3000 FPS , how long do it take to travel 26 inches.. lol

Starts moving as soon as the gas starts expanding is how i had it explained to me. - dan

 

[saitek11]

I have a 783 with 12" carbon six barrel.
It's sub moa rifle. The it Remington parts on it are the actual action, they are cheap enough that it leaves lots of budget for trigger/barrel and chassis. I went with an mdt chassis as well.
Optics I went Athlon with a mag range of 2-12.
It's extremely handy and weighs about 7pd with optic.
.308 is very stable in short barrels, if you want to go that short I would definitely use .308. the wheels start to fall off the creedmore when things are shorter then 16.

 

[5.45]

Rem 783 16.5" 6.5CM in MDT chassis
Hornady ELD-M 120 grain, 38.8 grain Varget, 2655 fps
shoots alright mostly

 

[Joel]

Starts moving as soon as the gas starts expanding is how i had it explained to me. - dan

If this weren't the case, follow through wouldn't matter either, just buy a 22-250 or such and your bullet would be faster than your poor technique

 

[coleman1495]

Another thing to consider is where your accuracy nodes are. I’ve had 2 22” 7/08 barrels and 2 24” 7/08 barrels. In both instances the 24” had more practical accuracy nodes. The 22” barrels had accuracy nodes that were a little on the spicy side. Obviously that’s going to vary with cartridge choice.

It would be interesting to see where the accuracy nodes are for barrels shorter than 22”.

 

[Joel]

That is really interesting!

Reminds me of what the Colt Canada rep said about their accuracy node in their barrels being 15.7" for the British SAS contract guns. I had wondered why it was such an odd length.

Were your two barrels of the same contour?

 

[Grizzlypeg]

Another thing to consider is where your accuracy nodes are. I’ve had 2 22” 7/08 barrels and 2 24” 7/08 barrels. In both instances the 24” had more practical accuracy nodes. The 22” barrels had accuracy nodes that were a little on the spicy side. Obviously that’s going to vary with cartridge choice.

It would be interesting to see where the accuracy nodes are for barrels shorter than 22”.

Handloaders try to tune the load to produce the highest accuracy with given barrel length. More or less powder may change this.

 

[Jmcc]

I have a 783 with 12" carbon six barrel.
It's sub moa rifle. The it Remington parts on it are the actual action, they are cheap enough that it leaves lots of budget for trigger/barrel and chassis. I went with an mdt chassis as well.
Optics I went Athlon with a mag range of 2-12.
It's extremely handy and weighs about 7pd with optic.
.308 is very stable in short barrels, if you want to go that short I would definitely use .308. the wheels start to fall off the creedmore when things are shorter then 16.

if you don't mind me asking, what's the ballpark you have into that?

Im not looking to build a unicorn but im ok saving a bit longer to "Buy once"

 

[coleman1495]

Handloaders try to tune the load to produce the highest accuracy with given barrel length. More or less powder may change this.

Yes thats what I’m saying. My point is that longer barrels often require a little less powder to hit the accuracy node.

For example: The OCW for a 22” 6.5 Creedmoor was 42.0gn and the OCW for a 26” barrel was 41.7gn. The accuracy node for the longer barrel was in a more reasonable pressure spot.

 

[Joel]

0.3 grain being more reasonable pressure wise sure is dancin with the devil

EDIT: Sorry, I don't know if that was just a made up example, I took it literally on first reading.

 

[Hunter7]

Actually shorter barrels are stiffer leading to more constancy because of less barrel vibration. There is no accuracy loss from barrel length only velocity loss. I have multiple 16" barreled rifles and my Renegade 10.5" 300 blackout is awesome!

Also theoretically the shorter barrel should increase accuracy due to faster lock time. Shorter time from the time the trigger is pulled to the time the bullet exits the muzzle.

 

[jparent]

Another thing to consider is where your accuracy nodes are. I’ve had 2 22” 7/08 barrels and 2 24” 7/08 barrels. In both instances the 24” had more practical accuracy nodes. The 22” barrels had accuracy nodes that were a little on the spicy side. Obviously that’s going to vary with cartridge choice.

It would be interesting to see where the accuracy nodes are for barrels shorter than 22”.

Interesting that you brought that up. I had a .243 shortened from 22" to 20". Prior to the cut, I had tested it with factory 80 grain and 100 grain loads and the 80 grain shot markedly better. After the shortening, the opposite was true. Same ammo, same lot numbers both times. It baffled me as to why, but i suppose as good an explanation as any would be the accuracy node for the 80 grain was removed... ok that made more sense in my head than when i wrote it.

 

[coleman1495]

0.3 grain being more reasonable pressure wise sure is dancin with the devil

EDIT: Sorry, I don't know if that was just a made up example, I took it literally on first reading.

Not a made up number, it’s something I found through experiment. Its pretty well whatever velocity you gain from the longer barrel you reduce the charge accordingly. Its a pretty small difference but its noticeable.
Barrel contour is irrelevant in this case.

 

[Joel]

Ah, yeah I get ya.

In that case, yeah...dancing with the devil, pressure wise if .3 grains is noticably on the "too hot" end but 6.5 CM kinda does that