Stability and barrel length

[eastern_hunter]

Guys,

I have a 16.5" pistol gassed 300 blk upper. Is a bit awkward w a can.

Been thinkin' abt doing a Form 1 SBR with it. Plenty of meat on it for shortening and rethreading. Would send the barrel back to the maker when approval received.

Rifle currently shoots better than 1 MOA subsonic. How short can one go with the length of a 1:8 bbl using 220 or 225 gr projectiles and still achieve good stabilization and accuracy? Is 8" OK? Is 10" OK?

Thanks,

Mike

[marsh-vol]

I'd at least consider selling it and buying the new length you want. It may cost less that way. Also, a factory short barrel shouldn't have any concentricity problems. A good gunsmith (or the manufacturer) could do it, but it will probably cost $100 or more with shipping, etc. You could run into problems with gas port size on a long barrel cut down. The gas port should be right on a factory short barrel.

It should work down to 8" or so (AAC sells a 9"). I have seen a 12.5" AAC barrel and a 10.2" or so that both run (both were factory). The AAC barrel runs with anything and everything, with or without a suppressor. The 10.2" ran with supersonics--the owner didn't try subs.

[Dolomite_Supafly]

You can go as short as you want. It only takes a few inches to stabilize a bullet. If it required 8" to stabilize a bullet a lot of pistols would have a lot longer barrels.

Dolomite

[marsh-vol]

You can go as short as you want. It only takes a few inches to stabilize a bullet. If it required 8" to stabilize a bullet a lot of pistols would have a lot longer barrels.

Dolomite

It might stabilize the bullet, but an AR won't cycle without a gas system or with a barrel too short to develop adequate dwell time.

[eastern_hunter]

Fella who will shorten and rethread it is the guy who made it ... and his work is reasonable, rapid, and superb. Not at all concerned abt that!!! is Paladin Machine services.

Am also sure he knows the appropriate diameter for the port under his switch block.

The question of stability and accuracy is of concern ... would like to retain decent 100-150 yard accuracy and not risk dinging the can.

[300Blk]

It is more of a function of velocity. Shoot them at 1000 fps and they will be more stable than 900 fps.

1/7 gives more of a margin.

[JohnInNH]

It is more of a function of velocity. Shoot them at 1000 fps and they will be more stable than 900 fps.

1/7 gives more of a margin.

Exactly.. this is why i load to fps and target as a minimum 950. It is very quiet, 1040 is my sub power load and is louder due to bullet flight. The 1:7 is safer with the longer heavy bullets at 950. If your ES is 50+ fps keep that in mind! You do not want an Average of 900-950 with a 150 ES! You may have a strike. 800- 850 fps with a 229 smk or 247 lead in a 1:8 is asking for trouble.

If you have a 16" and a 8" barrel you may want to keep two different loads, each set to the target fps for each length. Luckily the 300 BLK is SBR friendly and not a huge difference like the 223.

[eastern_hunter]

Getting 1050 fps and a SD of 13.6 w 220 SMKs with the current 16" tube which is made from Douglas barrel stock. I see no value in having a 16" tube if the rifle is SBR'd ... so I may have it cut to 10" and rethreaded. Will cost me $40 including shipping.

The 16" tube is giving me better than 1 MOA.

Obviously will need to redo the loads for the shorter tube.

[300Blk]

You can get someone to cut a barrel, thread the barrel and two-way shipping for $40?

I am kinda surprised it would be under $150.

[Dolomite_Supafly]

You can get someone to cut a barrel, thread the barrel and two-way shipping for $40?

I am kinda surprised it would be under $150.

"My guy", that is local to me, charges me between $75-$100 to chop and thread a barrel. The difference comes in whether he has to remove the barrel from the action or if I come in with just the barrel. That same smith charges me $150 to thread, contour and chamber a blank for my bolt guns. He has done no less than 10 barrels for me in as many years.

If I were going to send a barrel off I would send it to ADCO. He is probably the best out there because of the sheer numbers he has done. I have NEVER heard of anything being screwed up from ADCO. And even if something did get screwed up he is a stand up guy who would make sure his customers were happy.

Dolomite