Friend and I picked up 2 new ss mz - by all reports excellent BH209 shooters.
Cleaned mine thoroughly. Started with Bore Scrubber, then choke cleaner, and alcohol - still getting gunk after 15 patches. Did a hot water/soap bath with bore mop and got it squeeky clean. Same with the Bp. Buddy did similar.
Yesterday (20 deg - 5 mph wind at back) started shooting - 100gr BH (new can), 260 Nosler w/short black sabot, ccim primers (new box). 5 shots at 25 yds to get scope adjusted - holes nearly touching. Out to 100 and 1st 2 grouped at 3/8" - little high and right. Next shot (8th total) was a hangfire. Pulled the BP and cleaned - did not swab barrel. Next shot 6" low. Next 3" high and left. Checked mounts and bases - fine and tight. Next another hangfire!
Cleaned bp again without swabbing - all reports of BH say not needed and never have in my other BH shooter (non stainless). Switched to 300 gr xtp w/100 gr. 4 shots - 8 inch "group". Quit for day to clean gun to see if that might be a problem.
Cleaning - 25 patches of Montana Cboy then 5 Hoppes and a couple alcohol and dry to get clean. My other BH mz cleans with 8 to 10. Thought this very strange with a SS.
My buddy used BH 100 gr, ccim primers and 240 xtps - shot 20 times with no swabbing and no hangfires/perfect ignition. Settled with 2" at 100 - which is great for him.
Looking for thoughts on why the hangfires and cleaning.
I know I need to switch scopes or try open sites to rule out those accuracy issues, but feel at this point its not scope, rings, or bases. Too windy and rainy to try again today.
I had similar results in my inlines. Ignition isn't consistent. I was using W209 primers. I'm not sure how cold but there was alot of snow the day I first tried BH209. You got off more shots before hangfiring than I did. I started with a cleaned BP but it wasn't new.
Your friend got them all off without a hitch, Hmmm. I don't know.
I've got alot of different powders here pyrodex, T7, blackpowder ... etc. The next thing I tried was duplexing pyro p and blackpowder with the BH209. On the first trip to the range with BH209 I attempted 8 shots with BH209. By the 4th shot, I was getting irregular burn. Without cleaning the BP and without swabbing the rifle, I went back home and measured out 3 vials of 20 gV pyrop and 60 gV BH209. And 3 vials of 20gV 3f Goex and 60gV BH209. Then went back to the range without cleaning and with the rifle in a condition which couldn't shoot BH209 reliably I shot all of those vials under a fiber wad and Buffalo 270 ballet.
First I shot the pyro-p duplex. Good ignition everytime and made less than 1" group at 50 yards with two touching. The recoil seemed similar to straight BH209. Then I tried the blackpowder duplex. Again boomed every time. A similar grouping 3/4 above the pyro-p duplex' grouping. The recoil was definitely sharper than the pyro-p duplex and the straight BH209. I think the blackpowder accelerates the burn of the BH209.
I went back and measured 8 more vials of the blackpowder duplex and bought a battery for my chrony. I set up the chrony at 10 yards. The velocities averaged 1602 which equates to a mv of 1660. All shots went off without a hitch and the velocity range was tight and consistent with well measured by volume loads. Subsequent testing on a newly cleaned barrel and BP got mv's of 1648 for BH209.
I've not chronied the pyro-duplex but intend to when I get more time. It is possible with lighter projectiles that it will outperform the blackpowder duplex on velocity even with the milder recoil. It definitely has a more progressive build to velocity than the blackpowder duplex. I think it would have lower peak pressures than the blackpowder duplex also.
The yields of each powder are fixed but the duplexing can affect the rates of burn ... particularly the rate of burn of the slower powder (BH209). Because of that, I think the max loads of BH209 should most definitly be avoided with duplex loads ... (except ... perhaps ... in cases where duplexing may reduce the muzzle yields). Blackpowder at 25% by volume yields more as the duplex than straight BH209. So pressures are higher than straight BH209 (although I think less than the peak of an equivalent volume of 100% blackpowder). Of the the two, probably pyro p is the safest for duplexing (though it has a higher ignition temp).
Duplexing ensures ignition by reducing the temp required for ignition. One of the things which concerns me is that if W209 (standard shotgun primers) will not consistently ignite BH209 in my ML then just how reliable are the W209A's (or other stronger primers) going to be in the field even if I should find them reliable at the range. I don't want an opportunity afforded while hunting to be lost due to inadequate ignition. Of course one can modify the BP's but I prefer to have a powder with a lower ignition temp.
Regarding the way the duplex fouls the barrel. It is quite similar to BH209. I've shot 20 straight shots without swabbing and I think I could do it indefinitely when using the fiber wad and full bore conical. I am using Hoppes elite to clean it and everything comes out with 2 wet patches and a 2 dry ones alternating. I do swab 2 dry patches before any wet patchs and that takes the vast majority of the fouling out.
If you have ever run a dry patch into blackpowder or pyrodex fouling ... you will recall how difficult it can be to pull the patch and rod back out. It isn't that way with the duplex. The fouling is pliable and can be removed from the barrel easily with dry patches.
I am probably mixing more of the lower temp powder than required. I would next like to begin testing lower volume concentrations than the 25% by volume have tested. At some point I am going to settle on something but I intend to test it by leaving it outside on a sub-zero night (or in my deep freeze) trying it on a target and through a chrony the following morning. If it passes that test, then I think I have something I can trust to take to the field hunting.
Pglasgow - good info - thanks. Got 8 more days of mz with nonfriendly weather.
Will probably just use my 451 White and my Triumph. Play with this one more when I can stand in the yard. The duplexing sounds interesting - I have some Swiss here I could try.
New rifle w/BH209
