SBR barrel question

[pyplynr]

I'm in the process of putting together a sbr with 7" barrel. Does the twist matter in this short of a barrel? Does the quality of the barrel even matter when your not looking for precision accuracy? I've been looking at the Noveske Diplomat barrel with a 1/7 twist. But I could get a DPMS or RRA barrel for half the price of the Noveske. I know in my 22-250AI with a 1/8 twist if I shoot the lightweight varmint bullets that they overspin and won't hold together to even a target at 100 yards (of course they're going about 4800fps). I'll mainly be shooting regular 55 grain ammo for plinking. Also might take it out coyote hunting for the hell of it with some varmint rounds. Would there be an upside going with the 1/7 twist over the 1/9? My main interest has always been in long range precision bolt guns, where twist and barrel length have input on performance. Does it really matter on short distances and short barrels?

Thanks

 

[Jwryan84]

Usually the reason most go with the 1/7 barrel in SBR is they use the heavier bullets due to less muzzle velocity in the short barrel.

But if your just shooting 55 grainers then the 1/9 would be good to go.

Another thought is if you plan on getting a can on it you might look at the Noveske switchblock. If not go with the RRA.

 

[pyplynr]

I was thinking about the switchblock but it may be a headache. I would have to remove the handguard to switch it. Here's the mock up sans barrel, BCG and the infamous tax stamp.

 

[Jwryan84]

Well you officially suck. Didn't know you were that far into it.

You can sell me that upper cheap and start all over. Hell its worth a try. Just go with a 1/9 or 1/8 cheaper barrel and blast away.


Have you already made your trust and sent you paperwork in?? I'm going to meet with a CPA on Monday, wander if he can help me make a trust while I'm there forming and LLC.

 

[Spiff]

If you want to stabilize the heavier stuff, you definitely need a 1/7 or 1/8. 1/9 is marginal for 75gr in a standard length, and with the shorter barrel you're getting less RPM due to decreased muzzle velocity. If I was putting an SBR together, I'd go with 1/7. I like 1/8 for 18"+.

 

[pyplynr]

Well you officially suck. Didn't know you were that far into it.

You can sell me that upper cheap and start all over. Hell its worth a try. Just go with a 1/9 or 1/8 cheaper barrel and blast away.


Have you already made your trust and sent you paperwork in?? I'm going to meet with a CPA on Monday, wander if he can help me make a trust while I'm there forming and LLC.

The upper is a spikes blem for $60 and I can't find anything wrong with it. The handguard is a Spikes 9" BAR made by Seekins Precision. I Made a trust on Quicken Willmaker but I need to get off my ass and fill out the form and send it in.

If you want to stabilize the heavier stuff, you definitely need a 1/7 or 1/8. 1/9 is marginal for 75gr in a standard length, and with the shorter barrel you're getting less RPM due to decreased muzzle velocity. If I was putting an SBR together, I'd go with 1/7. I like 1/8 for 18"+.

This is my biggest concern with stability

 

[pyplynr]

Just found this. I'm thinking I may go with this barrel http://www.rainierarms.com/?page=shop/detail&product_id=1026 It starts as a Shilen blank and it's 1/8 twist. A little faster twist and $100 cheaper than the Noveske.

 

[Spiff]

That's a slower twist than the 1/7 Noveske you were talking about, not faster.

7.5" is awfully short for a 5.56 sbr. 11.5 is the most common length, I think. Most suppressor companies won't warranty anything that gets put on something shorter than that.

 

[Wall]

Just found this. I'm thinking I may go with this barrel http://www.rainierarms.com/?page=shop/detail&product_id=1026 It starts as a Shilen blank and it's 1/8 twist. A little faster twist and $100 cheaper than the Noveske.

Just an FYI.
If you decide to suppress it, Most all manufactures will not warrantee a suppressor used on anything less than a 10 1/2" barrel.

 

[Jwryan84]

Just found this. I'm thinking I may go with this barrel http://www.rainierarms.com/?page=shop/detail&product_id=1026 It starts as a Shilen blank and it's 1/8 twist. A little faster twist and $100 cheaper than the Noveske.

Looks good, has 1/8 twist and the Wylde chamber. Buy it up.

 

[pyplynr]

That's a slower twist than the 1/7 Noveske you were talking about, not faster. 7.5" is awfully short for a 5.56 sbr. 11.5 is the most common length, I think. Most suppressor companies won't warranty anything that gets put on something shorter than that.

Just an FYI.If you decide to suppress it, Most all manufactures will not warrantee a suppressor used on anything less than a 10 1/2" barrel.

I should have typed what I was thinking. Faster than the DPMS and RRA barrels I was looking at. This one would be in between those and the Noveske. I understand that if I suppress it that it wouldn't have warranty. That's a whole different bridge to cross for my AR's. If I do end up getting a suppressor I will probably build another upper that will be with the 10.5"/11.5" barrel. The first suppressor I will be getting will be for my .308 bolt gun.

 

[Wall]

I should have typed what I was thinking. Faster than the DPMS and RRA barrels I was looking at. This one would be in between those and the Noveske. I understand that if I suppress it that it wouldn't have warranty. That's a whole different bridge to cross for my AR's. If I do end up getting a suppressor I will probably build another upper that will be with the 10.5"/11.5" barrel. The first suppressor I will be getting will be for my .308 bolt gun.

That same suppressor would work great on your .223 SBR as well. All of my suppressors pull dbl./trip./quad./etc duty.

 

[Wall]

Just an FYI.
If you decide to suppress it, Most all manufactures will not warrantee a suppressor used on anything less than a 10 1/2" barrel.

The above is for CF rifle cal. only.

 

[pyplynr]

That same suppressor would work great on your .223 SBR as well. All of my suppressors pull dbl./trip./quad./etc duty.

Very very interesting!

The above is for CF rifle cal. only.

What is the difference in the cf and rf suppressors?

 

[Wall]

What is the difference in the cf and rf suppressors?

RF suppressors see very little pressure compared to CF. With the SBR's the shorter the barrel the more pressure. So, most manuf. limit CF to 10.5". I'm not aware of a limit on RF suppressors, since the same suppressor could be be used on a rifle or a pistol.

 

[pyplynr]

All my bolt guns are or will be threaded at 5/8"x24. If I got the suppressor at that thread pitch do they make a adapter to go down to 1/2"x28 for the AR or would I have to use a QD mount on all of them?

 

[Wall]

All my bolt guns are or will be threaded at 5/8"x24. If I got the suppressor at that thread pitch do they make a adapter to go down to 1/2"x28 for the AR or would I have to use a QD mount on all of them?

you can get a thread adapter but my preference would be the QD mounts. The Suppressor Manuf. should have them in all sizes you need. My QD's have built in muzzle brakes or comps for when I'm not using the suppressor.

For thread adapters, IMHO TROS is the best you can get. Don't skimp. A cheap adapter may not line up the suppressor correctly. I've seen people ask about threading their own barrel or making their own adapter. Many seem to think you can just throw a set of threads on & go, or to just line the threads up with the barrel & it's good. The threads for a suppressor have to be concentric with the bore, not the barrel.
Thread Adapter