fiftyohm Posted February 8, 2021 Author Report Share Posted February 8, 2021 Perfect. Quote Link to comment Share on other sites More sharing options...
fiftyohm Posted February 9, 2021 Author Report Share Posted February 9, 2021 Hey '98 - Don't mean to bother you, but have you any more words of wisdom on my gas port? Quote Link to comment Share on other sites More sharing options...
Armed Eye Doc Posted February 10, 2021 Report Share Posted February 10, 2021 2 hours ago, fiftyohm said: Hey '98 - Don't mean to bother you, but have you any more words of wisdom on my gas port? @98Z5V, you are being called if you are around. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted February 10, 2021 Report Share Posted February 10, 2021 5 hours ago, fiftyohm said: Hey '98 - Don't mean to bother you, but have you any more words of wisdom on my gas port? Based on the gas port location, barrel length, and the (ASSUMING HERE!!!) 0.750 gas block journal diameter - because you never stated the gas block journal diameter - what I told you before should work. 0.080"~0.083" range on your gas port will have you running, zero issues. If that's wrong, and it has to go up from there - then we will BOTH learn from this... Both the barrels I could find, matching what you state, are both 1:11.25" twist. https://shopwilsoncombat.com/Match-Grade-Barrel-308-WIN-Recon-Tactical-16-1-1125-Twist-Stainless-Fluted/productinfo/TR-308RCIG16FT11.25/ https://shopwilsoncombat.com/Match-Grade-Barrel-308-WIN-Ranger-16-1-1125-Twist-Stainless/productinfo/TR-308RAIG16RT11.25/ That's real cool for 168gr projectiles, and it's the minimum twist rate to run (determined to be the "optimum" twist rate to run) for Sierra MatchKing 175gr projectiles. You run anything heavier, and you're out of twist. Most modern .308 Win twist rates are the faster 1:10" twist. I run that for the 178s that I load, and the 195s that I try... I'll perfect those bastards, one day, and they'll slay dragons. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted February 10, 2021 Report Share Posted February 10, 2021 3 hours ago, Armed Eye Doc said: @98Z5V, you are being called if you are around. Good push, brother. Side note for Doc, here - Berger 185gr Juggernauts - you better be running the 1:10" twist rate, and they're fuckin' MAGIC!... I still have these for you, brother. No way could I just hog them all up - I saw what they did, and decided to STOP until YOU get here. They're safely stored, until we can meet again, and sling lead. ❤️ Quote Link to comment Share on other sites More sharing options...
fiftyohm Posted February 10, 2021 Author Report Share Posted February 10, 2021 16 hours ago, 98Z5V said: Based on the gas port location, barrel length, and the (ASSUMING HERE!!!) 0.750 gas block journal diameter - because you never stated the gas block journal diameter - what I told you before should work. 0.080"~0.083" range on your gas port will have you running, zero issues. If that's wrong, and it has to go up from there - then we will BOTH learn from this... Both the barrels I could find, matching what you state, are both 1:11.25" twist. https://shopwilsoncombat.com/Match-Grade-Barrel-308-WIN-Recon-Tactical-16-1-1125-Twist-Stainless-Fluted/productinfo/TR-308RCIG16FT11.25/ https://shopwilsoncombat.com/Match-Grade-Barrel-308-WIN-Ranger-16-1-1125-Twist-Stainless/productinfo/TR-308RAIG16RT11.25/ That's real cool for 168gr projectiles, and it's the minimum twist rate to run (determined to be the "optimum" twist rate to run) for Sierra MatchKing 175gr projectiles. You run anything heavier, and you're out of twist. Most modern .308 Win twist rates are the faster 1:10" twist. I run that for the 178s that I load, and the 195s that I try... I'll perfect those bastards, one day, and they'll slay dragons. Thank you, sir! I'll open it up, and let you know. It is a WC "Hunter" profile that's been discontinued. All the other specs are identical, (twist, etc.) to those you posted above. And I won't be using my bargain basement NATO ammo much any more, either. My hog and boar hunt that's coming up next month will be with actual 308s with 175gr SMK BTHPs. I suspect though, the gun will run just fine even with M80 ball after this surgery. Thanks again, pard! Quote Link to comment Share on other sites More sharing options...
billymagg Posted February 11, 2021 Report Share Posted February 11, 2021 2 hours ago, fiftyohm said: Thank you, sir! I'll open it up, and let you know. It is a WC "Hunter" profile that's been discontinued. All the other specs are identical, (twist, etc.) to those you posted above. And I won't be using my bargain basement NATO ammo much any more, either. My hog and boar hunt that's coming up next month will be with actual 308s with 175gr SMK BTHPs. I suspect though, the gun will run just fine even with M80 ball after this surgery. Thanks again, pard! Yes it should, my 18" fluted, Tactical Hunter was under gassed as well, and I found that out with M80 ball... Quote Link to comment Share on other sites More sharing options...
fiftyohm Posted March 9, 2021 Author Report Share Posted March 9, 2021 (edited) So - to 98Z5V and all the rest, I'd like to report that opening up the gas port to 0.082" completely solved the issue. Function is now perfect - even with (crappy) M80 ball. Thank you all for your help! The next build is a 300 BLK, but the 308 is now in rotation! Edited March 9, 2021 by fiftyohm Clarity Quote Link to comment Share on other sites More sharing options...
Rsquared Posted March 9, 2021 Report Share Posted March 9, 2021 And another happy ending. It's always good to hear a success story. Now get on up with the 300 black. I built a 10" SBR years ago. One fun rifle, and "Hollywood" quiet. Quote Link to comment Share on other sites More sharing options...
fiftyohm Posted March 9, 2021 Author Report Share Posted March 9, 2021 That's the plan, man. 10.5" BA barrel's sitting here on my desk, and the receiver is in the safe. Trigger is in the mail. My can's in jail, but the pistol will be done when it's paroled. Done some conjugal visits with the 308, though. This is the beginning of a very looong and quiet relationship! Thoop, thoop... Hollywood, indeed! Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 9, 2021 Report Share Posted March 9, 2021 On 2/9/2021 at 10:26 PM, 98Z5V said: 0.080"~0.083" range on your gas port will have you running, zero issues. 4 hours ago, fiftyohm said: So - to 98Z5V and all the rest, I'd like to report that opening up the gas port to 0.082" completely solved the issue. Function is now perfect - even with (crappy) M80 ball. Thank you all for your help! Well sonofabitch... The math works. Quote Link to comment Share on other sites More sharing options...
DNP Posted March 9, 2021 Report Share Posted March 9, 2021 Hey...everyone gets lucky once in a while.... Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 10, 2021 Report Share Posted March 10, 2021 14 hours ago, DNP said: Hey...everyone gets lucky once in a while.... Even a Blind Monkey finds a Banana once in awhile, right?... Quote Link to comment Share on other sites More sharing options...
DNP Posted March 10, 2021 Report Share Posted March 10, 2021 Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 10, 2021 Report Share Posted March 10, 2021 I'm just glad the math works... Quote Link to comment Share on other sites More sharing options...
DNP Posted March 10, 2021 Report Share Posted March 10, 2021 Math always works. I’m just glad someone knows the math. Quote Link to comment Share on other sites More sharing options...
billymagg Posted March 13, 2021 Report Share Posted March 13, 2021 On 3/8/2021 at 6:22 PM, fiftyohm said: So - to 98Z5V and all the rest, I'd like to report that opening up the gas port to 0.082" completely solved the issue. Function is now perfect - even with (crappy) M80 ball. Thank you all for your help! The next build is a 300 BLK, but the 308 is now in rotation! Glad to hear your rifle is fully functional now, my 18" barrel with rifle gas, started out where you finished at around .082, it functioned fine, but ejection was disappointing. I went with a 5.3 oz 2.5" KAK heavy buffer, ejector and spring and briefly ran the Sprinco orange spring, I ended up at .095 to run that combination, gas block wide open, and it functioned fine with M80 ball, and ejection was much improved. (my 300 Ham'r flings them out about 8 ft in a nice neat little pile) The one issue that I found objectionable with that combination was the effort required to pull it out of battery with the charging handle, it was very stiff, so I replaced the Sprinco with the Wilson 40 coil flat wire... all good now, and that heavy buffer makes my rifle much more pleasant to shoot. Quote Link to comment Share on other sites More sharing options...
fiftyohm Posted March 13, 2021 Author Report Share Posted March 13, 2021 18 minutes ago, billymagg said: Glad to hear your rifle is fully functional now, my 18" barrel with rifle gas, started out where you finished at around .082, it functioned fine, but ejection was disappointing. I went with a 5.3 oz 2.5" KAK heavy buffer, ejector and spring and briefly ran the Sprinco orange spring, I ended up at .095 to run that combination, gas block wide open, and it functioned fine with M80 ball, and ejection was much improved. (my 300 Ham'r flings them out about 8 ft in a nice neat little pile) The one issue that I found objectionable with that combination was the effort required to pull it out of battery with the charging handle, it was very stiff, so I replaced the Sprinco with the Wilson 40 coil flat wire... all good now, and that heavy buffer makes my rifle much more pleasant to shoot. Yup. While function is now fine, even with low pressure stuff, but there is no doubt upping the mass would make it more pleasant to shoot. You had even less dwell than I did at the start, so your final port size makes perfect sense. I guess I could rent a Ditch Witch and bore a honkin' huge hole like you at some point, too! (The can will be no help as it's an OSS with little to no back-pressure.) The way you mitigated the charging force is very interesting. Good stuff - thanks for that! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.