Resjudicata Posted November 30, 2014 Share Posted November 30, 2014 I fit an STI trubor barrel to one of my 9mm 1911's. I'm using this for Bianchi Cup. So, the 9mm ammo is running minor PF. I haven't been able to get the barrel to group very well. Shooting at 25 yards from a rest I'm getting 2.5-3.0 inch groups. My old barrel (6" Schumann AET 1:24 gain twist) got around 2" but I had to run the loads hot around 145 PF to get it to group. The ammo I've been using is made from Starline brass, Zero 115 and 125 gr JHP and Titegroup. I've tried both weights and from 4.0 to 4.7 gr of Titegroup. I've tried OAL from 1.09" out to 1.170". All group about the same. Today I tried some 125 gr. Zero JHP .357" revolver bullets. The group dropped down to 1.5" at 25 yards. I then shot a couple of the old loads and some more of the new just to see if I was having a "good day". Same results. The old loads with the .355" bullets are 2.5-3.0" groups and a bit wild, but the .357 bullets are 1/2 the group size. I tried some coated lead in 115 gr. .357" diameter and some 135 gr. .356" diameter. These groups were better than my old loads, but not quite as good as the .357" JHP. Before trying the above I slugged the barrel and got a diameter of .3555". Anybody else found that they need to run oversize bullets in the STI trubor barrels to get best accuracy? Chris Link to comment Share on other sites More sharing options...
toothguy Posted December 1, 2014 Share Posted December 1, 2014 Chris, I found that my 9mm Target Master was much more accurate with .357 sized bullets. I was able to get the best accuracy using Hornady .357 110 grain XTP's. The Zero .357 125 JHP's work well also. I asked Tim Theno, who also shoots the Zero .357 125's. Tim said he slugged his Trubor .38 super and Trubor 9mm barrels and found them to both be .356. Link to comment Share on other sites More sharing options...
Resjudicata Posted December 1, 2014 Author Share Posted December 1, 2014 Chris, I found that my 9mm Target Master was much more accurate with .357 sized bullets. I was able to get the best accuracy using Hornady .357 110 grain XTP's. The Zero .357 125 JHP's work well also. I asked Tim Theno, who also shoots the Zero .357 125's. Tim said he slugged his Trubor .38 super and Trubor 9mm barrels and found them to both be .356. Thanks, that's good to know. How do you like the 110 grain bullets? What powder are you loading with? Chris Link to comment Share on other sites More sharing options...
DWFAN Posted December 1, 2014 Share Posted December 1, 2014 I'd blame the gunsmith Link to comment Share on other sites More sharing options...
Resjudicata Posted December 1, 2014 Author Share Posted December 1, 2014 I'd blame the gunsmith My wife would too. She blames me for everything. BTW, I need to get your tools back to you. Let me know what day is good for you and we can meet for lunch. Chris Link to comment Share on other sites More sharing options...
toothguy Posted December 1, 2014 Share Posted December 1, 2014 Chris, I found that my 9mm Target Master was much more accurate with .357 sized bullets. I was able to get the best accuracy using Hornady .357 110 grain XTP's. The Zero .357 125 JHP's work well also. I asked Tim Theno, who also shoots the Zero .357 125's. Tim said he slugged his Trubor .38 super and Trubor 9mm barrels and found them to both be .356. Thanks, that's good to know. How do you like the 110 grain bullets? What powder are you loading with? Chris The 110 XTP's cost about twice as much as the Zero 125's but always seem to be available. I had some left over from my Bianchi revolver load and at the time it was all I could find. The 110 XTP's shoot pretty well using 5.6 grains of Power Pistol. Link to comment Share on other sites More sharing options...
reptoid Posted December 1, 2014 Share Posted December 1, 2014 (edited) Zero #161 (.356") 125's always shot better for me than the Zero #162 (.355") 125's. Their #136 (.355") 125 conical was a close second. For absolute best groups in my 9's and Supers it is Hornady 125 HAP's and they are .356". The #161 Zeros would consistently group under 1" @ 25yds from a rest in my STI with Nowlin match barrel loaded to minor or major. Edited December 1, 2014 by reptoid Link to comment Share on other sites More sharing options...
Resjudicata Posted December 1, 2014 Author Share Posted December 1, 2014 Zero #161 (.356") 125's always shot better for me than the Zero #162 (.355") 125's. Their #136 (.355") 125 conical was a close second. For absolute best groups in my 9's and Supers it is Hornady 125 HAP's and they are .356". The #161 Zeros would consistently group under 1" @ 25yds from a rest in my STI with Nowlin match barrel loaded to minor or major. Thanks. Good to know about the .356" bullets. Unfortunately, the .356 Zero's never seem to be in stock. I have had better luck finding the .357 revolver bullets in stock. I have 3k of them coming. Chris Link to comment Share on other sites More sharing options...
DWFAN Posted December 2, 2014 Share Posted December 2, 2014 (edited) The Zero .356 121gr bullets are what I had to shoot through my Schuemann. HAP has a .356 as well. I think I still have a box and if I can find them ( the .356 Zeros) I'll give you some to try. Edited December 2, 2014 by DWFAN Link to comment Share on other sites More sharing options...
Service Desk Posted December 2, 2014 Share Posted December 2, 2014 For some reason best known to Zero and Hornady, the 115's are always .355" - I can't recall the last time I saw .356" !!! Link to comment Share on other sites More sharing options...
Resjudicata Posted December 2, 2014 Author Share Posted December 2, 2014 (edited) The Zero .356 121gr bullets are what I had to shoot through my Schuemann. HAP has a .356 as well. I think I still have a box and if I can find them ( the .356 Zeros) I'll give you some to try. Thanks, Jeremy. Let me know what you are doing later this week. I'm going to try some different powder amounts and OAL with the .357 bullets to see if I can find the sweet spot. Maybe even do a batch with weighed powder charges to see if I can tighten the group even more. Here is a 25 yard group with the 357 bullet with 4.4 gr of WST. I think the one flier shot was me twitching. Chris Edited December 2, 2014 by Resjudicata Link to comment Share on other sites More sharing options...
jim v Posted December 3, 2014 Share Posted December 3, 2014 I can confirm your results. I have 4 trubor barrels which all slug at 0.356". Two have a Brazos design compensator and two have the T2 design. I cast my own bullets and always battled to find a good accurate load using the 0.356" bullets from the unmodified moulds. When I polished out the cavities in my Lee 6 cavity 123gr moulds, I found that bullets of 0.357-0.358 gave a slightly more accurate group. The cast bullets were hardly touched when using a 0.358" sizing die. The problem with this approach is that aluminum is not a good material to grind or polish out to a larger size. The resulting cavities looks horrible and scoured. They are also not very round. Recently I decided to go the whole hog. I ground a new cherry from an existing end mill and using a diameter of 0.365 I got consistent 0.362 diameter bullets at 124 gr. These were then sized down to 0.358". The resulting groups were significantly more accurate and consistent. There is a lot less smoke coming out of the barrel and much less lead buildup on the CMore blast shield. All of my loads are major using 9x23 brass and local powder. Link to comment Share on other sites More sharing options...
jcc7x7 Posted December 6, 2014 Share Posted December 6, 2014 Montana gold 356 125grs run great in mine BUT If your barrel shoots with 357 use them. Not a big deal lots of makers sell both dia. Good fortune with a load Link to comment Share on other sites More sharing options...
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