Any input as to what would be the best thread size for a 1.25" straight taper barrel? 5/8'-24 or 3/4"-24? This would be for a muzzle brake. Thank you.
Gunsmithing Best Muzzle thread Size straight taper barrel
- Thread starter axarob44
- Start date
5/8x24 will have more options.
Some argue that you should get the biggest thread possible to mitigate the possibility of the crown belling out.
On a quality barrel I'm not sure the latter is really much of an issue. Personally I think the argument is more of an academic one than anything else.
Flip a coin.
Some argue that you should get the biggest thread possible to mitigate the possibility of the crown belling out.
On a quality barrel I'm not sure the latter is really much of an issue. Personally I think the argument is more of an academic one than anything else.
Flip a coin.
Relevant video. Muzzle device torque also comes into play later.
It's the general consensus that less material removed is better. So 3/4x24 would be preferred. However, I have seen no data that proves a precision advantage. It's more just theory. Muzzle brakes are easier to come by and more common in 5/8x24 so I have always stuck to that even on barrels that are plenty big for 3/4 threads. I have experienced incredible precision with 5/8x24 and haven't ever had a reason to suspect it causing a problem.
By the way, it's just a "straight 1.25" barrel" not a "straight taper". There is no taper on a straight 1.25" barrel. Straight taper is usually used to denote a barrel like heavy varmint or MTU that doesn't have a compound taper like a Palma contour.
By the way, it's just a "straight 1.25" barrel" not a "straight taper". There is no taper on a straight 1.25" barrel. Straight taper is usually used to denote a barrel like heavy varmint or MTU that doesn't have a compound taper like a Palma contour.
What cal ? Thats a determining factor.
As for barrels doing a bell-mouth, thats been disproven time and time again, and that video still gets passed around.
Ask @Frank Green . A properly drilled and cut rifled barrel, and stress relieved, it wont bell mouth. Not in my experience of chambering barrels. Factory barrels YES, because of the manuf process, but many brands of after market barrels WONT be a problem.
As for barrels doing a bell-mouth, thats been disproven time and time again, and that video still gets passed around.
Ask @Frank Green . A properly drilled and cut rifled barrel, and stress relieved, it wont bell mouth. Not in my experience of chambering barrels. Factory barrels YES, because of the manuf process, but many brands of after market barrels WONT be a problem.
I run 3/4 on my straight profile barrels coz 5/8 looks dumb 
Sorry, should have added it's a Krieger 7mm
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This is my understanding as well.
That with a high quality barrel, there's very little risk of this belling phenomena to occur. More so an issue with lesser quality barrels.
And it should also be pointed out that the bigger the thread, the less shoulder you have. Whether that will matter is dependent on your specific circumstances and what you are using that shoulder for.
There will always be residual stress in the barrel. Even after stress relief. Machining will induce stress. The more material that is taken off, the higher likelihood the dimensions will change.
Anybody that Machines parts to somewhat tight tolerances knows this. Stress relief of a billet before machining or after roughing will have much different results. We will rough a part, send it out for stress relief, then finish turn a minimum amount of material off the part. They will still distort.
Does it matter for a barrel? Maybe.
Like @Mordamer I use 5/8-24 just because I already have muzzle brakes around. They shoot well.
Anybody that Machines parts to somewhat tight tolerances knows this. Stress relief of a billet before machining or after roughing will have much different results. We will rough a part, send it out for stress relief, then finish turn a minimum amount of material off the part. They will still distort.
Does it matter for a barrel? Maybe.
Like @Mordamer I use 5/8-24 just because I already have muzzle brakes around. They shoot well.
I'd say if you are going to be making the brake then thread it whatever you want. If you're going to buy the brake then find one you like and thread the barrel for what is available for the brake.
This.
Ain't many brakes full 1-1/4" diameter. Having a brake with a diameter smaller than the shoulder looks fucked up.
I like Holland's QD for bull barrels.
