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racer-x

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    Tulsa, OK
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    Jay Mackey

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  1. The corncob was 'pre-installed' from Montana Gold
  2. Agreed. I'm not saying the MG CMJ's aren't capable of being accurate. MG knows how to make a high quality and consistent bullet. I expect that I could work up an accurate load with these in a gun with a more conventional throat profile (i.e. a barrel that wasn't throat reamed to chamber long 9 major loads) I am saying that they are not an option for me with any of 9 major open guns (barrels throated). Also, I did experiment with crimp on these CMJ's with no difference in performance. I seat & crimp a bullet and then measure the crimp ring left on the bullet. My experience is that this crimp ring measuring .001-003" less than the bullet diameter is optimal and accompanies a completely straight case mouth (no bell or crimp). I first tested with my normal .002" crimp ring and then backed off to no measurable/visible crimp ring (very slight case mouth belling). No difference in accuracy, but not what I would load either since the slight bell on case is problematic.
  3. I repeated my previous baseline & tests with a different gun today. My standard load (MG 115 JHP's loaded to 1.165 with 10.8 AA7 & CCI500) shot ragged hole groups at 25 yards over and over. MG 115 JHP @ 1.165 OAL - 1/4" groups MG 115 CMJ @ 1.165 OAL - 3/5 in 10" target MG 124 CMJ @ 1.165 OAL - 3/5 in 10" target MG 124 CMJ @ 1.200 OAL - 8" -10" groups MG 121 IFP @ 1.165 OAL - 2.5-3" groups and again: MG 115 JHP @ 1.165 OAL - 1/4" group JHP plunks & spins out to 1.205 OAL (1.205 - 1.165OAL=.04) CMJ plunks & spins out to 1.270 OAL (1.270 - 1.165OAL=.105) Since the longer 1.200 124's were more accurate than the 1.165 loads, my freebore theory seems like a big factor. Problem is I can't load the CMJ's in a 9MM out to 1.230 in this barrel to have the same freebore as the JHP's. Lots of testing and I'm right back where I started - JHP's rule in my 9 major open guns.
  4. I have not tried AA5, but looking at it's relative placement on several burn rate charts is enough to keep me from messing with it in a 9 major load - not worth it to me. I'd use the AA5 for minor loads. AA7 is my favorite powder for 9major. Slow burn, (relatively) low case pressures with lots of gas to work comp & popples. If it's too dirty for your gun to run reliably, that's definitely a problem. How do you lubricate your gun (what & how much) ? Might try some variations with lube to see if you can get reliable operation with AA7. Maybe go lighter weight oil (i.e. try 0W-20 if you are currently running 5W-30).
  5. +1 Speaking of cracks, I used to find a cracked case every month or so when I was shooting faster powders like True Blue due to the higher case pressures. Since switching to slower powders like AA7, I haven't found a split case from my gun in 2 years now. That's with a healthy 10.6-10.8 grain charge under a 115 as well. I thought I had loose primer pockets once last year, but it turned out my 1050 needed the primer depth increased .002" to work with all the mixed head stamp brass I put through it.
  6. Yes, the MG CMJ, IFP and JHP's all measure the same exact diameter.
  7. I recently got a thousand of each - 115 and 124 CMJ's, and also 121 IFP's to test out. Haven't done accuracy testing on the 121 IFP's but like you said, they are just filled 115's - I expect they will be just as accurate. Now that my loads are confirmed, I need to use & evaluate each in practice. Have always come back to 115's though - just like how dot tracks & returns faster with them. Experimenting with different combinations and building my understanding is part of the fun for me.
  8. Yes sir, I do and that's exactly how I remove the corn cob. Still have to inspect and use a tooth pick once and a while on the few that resist the air. Think I picked that trick up from you on another post last year - thanks!
  9. Thanks Jason - I cant make match on Sunday. What JHP's are you using now? No corn cob in them from manufacturer? This is a new situation with MG. I've used tons of them over the years, and this last purchase of 16K is the only time I've ever seen this. Hopefully it was a fluke. So on another tangent, since I've been picking out corn cob anyway, I started using a DIY lanolin case lube and then tumbling for 15 minutes. Figured since I was already picking corn cob, why not ? Love how much easier this makes loading so much, I loaded up 5 gallons of 9 major the next day and wasn't sore at all. Funny though... looking to reduce steps and I added one instead
  10. My last 4 cases of MG JHP's were full of corn cob straight from MG. Tiny little pieces that hide in the HP and have made it into my gun if I don't pick it out. Worst case was when it got into trigger and blocked trigger from moving enough to break shot. I pick it out now. I'm going to try some of the longer 124 CMJ's out to 1.200 to test the freebore theory, but there isn't room to increase OAL significantly on the 115's and maintain reliability (i.e. bullet staying in case). I like how 115's feel with AA7 best and also like knowing I can hit a 10" plate at 25 yards 10 out of 10 times. Might end up just picking corn cob.
  11. I've used MG JHP's for years and they have proven exceptional accuracy. Would like to eliminate the task of picking corn cob out of the JHP's, so I'm evaluating the accuracy of Montana Gold 115 & 124 CMJ's in my 9 major open guns. First round testing with MG CMJ's is disappointing. Shooting fully supported on bench, 4 out of 10 in a 10" circle at 25 yards disappointing. Same load with a MG JHP, (170PF, AA#7, 115, 1.165OAL), all shots in same ragged hole. Repeated multiple times with same results. Got to thinking about possible differences in freebore between the round node and JHP and setup a plunk test for each profile in my barrel. JHP plunks & spins out to 1.205 OAL (1.205 - 1.165OAL=.04) CMJ plunks & spins out to 1.270 OAL (1.270 - 1.165OAL=.105) Wondering if this big difference in freebore is responsible for the lack of accuracy? I would need to load the CMJ's out to 1.230 in this barrel to have the same freebore as the JHP's and that's not gonna work with 9.
  12. Did a hot - cold test with same batch of ammo today (MGJHP115-CCI500-10.7 AA7- 1.165 OAL). 20 rounds heated in truck from hot gun vs. 20 rounds at air temp (29F). Average for hot was 11fps faster than cold. SD & ES were nearly identical between the two.
  13. Agreed. The prep to the wall is important for control and reset - a 50/50 distinction feels right. I set my triggers to be 50% pull force (3/4#) to the wall and another 50% (1.5#) to break the shot. The 50/50 part is more important to me than the force to pull (within reason ). Slack out to the wall and bang! Perfectly safe setup with some dry-fire to get used to it. I still prep the trigger (slack out) in the last 10% of a draw - after the gun is on target - so I can break the shot the instant I see what I need to see.
  14. Is the Xtreme case have a step inside it like these? The swage / backer station on my 1050 catches stepped brass & I toss them. No worries - that case is not too full to load. I'm running 10.8 under 115's. AA7 is slow & forgiving. Might be slightly compressed, but not a problem. After using 3N38, that still looks like a partial drop
  15. The zero was off a hair on my caliper. Here are the updated results: CCI 500 - .175" (+/-.0005) CCI 550 - .178" (+/-.001) CCI 400 - .178" (+/-.001) New (unfired) primers (CCI500, 550 and 400) all measured precisely .1745" - no variations found All primer pockets measured .172" - no variations found over mixed head stamp brass. All of these primers started out as the same .1745" diameter pressed into a .1720" primer pocket. These results indicate the 550 (SPM) and 400 (SR) primers expanded more than the CCI 500 SPP's. I expected the opposite result since SPP's are generally expected to be softer than SPM or SR. Only explanation I can think of is that these 500's I have (purchased in 2008) are from a batch when CCI built the reputation of having the hardest & most difficult to ignite SPP. Will be interesting to test again with a current batch of CCI 500's...
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