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Post by mikeyanxu on Aug 29, 2016 15:45:24 GMT -8
Looking forward to build a spr kind upper with a custom 18” inch barrel, rifle gas system. I will shoot with a suppressor and that is why I prefer a naturally short gassed rifle gas. I want the barrel to be stiff for both accuracy and suppressor POI shift reasons. I am not happy with my current 20" FN made barrel. Its government profile is not stiff enough. I am deciding among the three profiles but can’t make my mind:
SPR profile; 2.35 lbs
National match profile (Ø.97” under handguard and Ø.750 gas block); 3.1 lbs
Semi bull profile (taper from Ø.97-.93” under hand guard and Ø.875 gas block, Ø.860 to muzzle); 3.3 lbs
I know the heavier one is also stiffer, but, decisions are difficult to make. Someone help me to get the semi-bull profile out of my mind. I'm afraid it is too heavy. Which one to pick for mostly bench shooting and occasion hike in the woods ?
Thank you for your time.
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Post by GLSHOOTER on Aug 29, 2016 18:35:28 GMT -8
Based on how they shoot I'd pick a standard weight. The others will be a tad better for long strings but I've used my standard at 500 with no problems in timed fire.
Greg
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Post by mikeyanxu on Aug 29, 2016 20:05:40 GMT -8
Based on how they shoot I'd pick a standard weight. The others will be a tad better for long strings but I've used my standard at 500 with no problems in timed fire. Greg Thanks Greg,
Can you please tell me the three diameters of the standard profile? Or compare it to SPR profile? It seems that it doesn't have the SPR collar but I don't really need it.
Found one of your barrel on surplusammo.com. It is a h-bar profile but I never see it on your website. What is the difference compare to the other two? www.surplusammo.com/black-hole-weaponry-ar-15-18-rifle-length-stainless-steel-5-56-1-8-poly-barrel-free-shipping/ Sorry for so many questions. Thanks for your time.
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Post by GLSHOOTER on Aug 29, 2016 20:51:44 GMT -8
I'll get some numbers in the AM. The H-bar they sell is the standard profile.
Greg
STANDARD 18"
Weight 2.55 lb 0.895 nominal under the HG 0.750 gas block and out front.
Greg
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Post by mikeyanxu on Aug 30, 2016 8:08:17 GMT -8
I'll get some numbers in the AM. The H-bar they sell is the standard profile. Greg STANDARD 18" Weight 2.55 lb 0.895 nominal under the HG 0.750 gas block and out front. Greg Roger roger. So it is very similar to the SPR (Ø.840 vs Ø.895 under hand guard) except the cutout for collar. From the picture on your website, it seems that the chamber area larger diameter (maybe Ø.9xx?) is slightly longer on the standard barrel and it is shorter on the SPR. Can you please confirm this? Also, based on a semi-bull profile, if I want you folks to add a thread (between 3/4 and 7/8 pitch diameter) and shoulder between the gas block journal and the muzzle. Near the gas block journal. I will finalize the cad file. I figure since you guys cut the barrel profile on the lathe, why not just let you folks do it other than I buy the bull barrel and have someone else spend twice the time in setup. Please let me know if that is something you are interested? Thank you for your time sir.
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Post by GLSHOOTER on Aug 30, 2016 8:27:03 GMT -8
I'll get some numbers in the AM. The H-bar they sell is the standard profile. Greg STANDARD 18" Weight 2.55 lb 0.895 nominal under the HG 0.750 gas block and out front. Greg Roger roger. So it is very similar to the SPR (Ø.840 vs Ø.895 under hand guard) except the cutout for collar. From the picture on your website, it seems that the chamber area larger diameter (maybe Ø.9xx?) is slightly longer on the standard barrel and it is shorter on the SPR. Can you please confirm this? Also, based on a semi-bull profile, if I want you folks to add a thread (between 3/4 and 7/8 pitch diameter) and shoulder between the gas block journal and the muzzle. Near the gas block journal. I will finalize the cad file. I figure since you guys cut the barrel profile on the lathe, why not just let you folks do it other than I buy the bull barrel and have someone else spend twice the time in setup. Please let me know if that is something you are interested? Thank you for your time sir. I have no idea on the length you want. Send a note to JP in sales for that. They will not do a custom profile in most cases as it is all CNC driven and programming is not economical for one offs. Greg
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Post by mikeyanxu on Aug 30, 2016 8:32:34 GMT -8
Roger roger. So it is very similar to the SPR (Ø.840 vs Ø.895 under hand guard) except the cutout for collar. From the picture on your website, it seems that the chamber area larger diameter (maybe Ø.9xx?) is slightly longer on the standard barrel and it is shorter on the SPR. Can you please confirm this? Also, based on a semi-bull profile, if I want you folks to add a thread (between 3/4 and 7/8 pitch diameter) and shoulder between the gas block journal and the muzzle. Near the gas block journal. I will finalize the cad file. I figure since you guys cut the barrel profile on the lathe, why not just let you folks do it other than I buy the bull barrel and have someone else spend twice the time in setup. Please let me know if that is something you are interested? Thank you for your time sir. I have no idea on the length you want. Send a note to JP in sales for that. They will not do a custom profile in most cases as it is all CNC driven and programming is not economical for one offs. Greg Got you. That makes sense. The thread will only be .600" long. I will do. Thanks.
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