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Post by Alabama on Nov 19, 2014 20:16:13 GMT -5
Went ml hunting yesterday let my buddy use my CVA Accura v2 50 cal. 250 gr Barnes tez. Make a long story short nice buck presented himself around 415. Temp in high 30's. approx 100 yrd shot on a good rest not rushed. no blood no deer, so we assumed it was a miss. This morning we skipped hunting to go to range and check poi. The CVA was 6 inches high. Not sure what the problem was buts its adjusted back to 2 inches high at 100 and 2.5 at 50 yds
I get my 45 rempac out 275 mh 70 gt imr4198. Gun has shot consistent 2 inches high in warmer weather yet this morning with temps in mid to upper 30's 2 inches low. Even tried a duplex 10 4759 60 4108. Same poi.
One thin I noticed was I loaded the gun Monday first day of ml season with the duplex. It shot 2"high. Right where it should have. The other loads which were left in truck shot low whether duplex or single. Kinda confused me. Next hunt is in the morning now I don't know if I'm gonna shoot 2 " high or 2 " low. Shot 6 times other that the one that been in gun (2" high""). All the rest were low. I bring gun inside but powder has been left in truck. I figure I am dead deer either way.
Anyone else have any type of similar situation? Or thoughts?
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Post by bigm00se on Nov 19, 2014 20:59:25 GMT -5
6" high of aiming point is still a hit. Same with 2" difference
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Post by deertroy1 on Nov 19, 2014 21:12:06 GMT -5
Yes. I had this problem with a light load in a Savage 10 ML-II shooting 250gr Hornady XTP's in a Harvester Smooth Black Sabot, 40.5gr AA5744 and a W209 primer. Velocities were very erratic when temp got down in the low 30's causing shifts in POA!
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Post by Alabama on Nov 19, 2014 21:15:46 GMT -5
The CVA was scope adjustment. But a high shoulder shot not knowing you are 6" high is a miss all day
The rem/pac. Yea the couple inches at 100 deer won't notice but what about at 200? 300? He will scamper off to live another day.
The only other diffence I can consider is the shots today were off a bag. I normally shoot road off sled. Has to be some reason for the sudden loss of 2".
Since there is no 275mh available and I'm down to maybe 10 left was not able to test much.
Hard to believe a custom bullet manufactor would not have his best selling bullet available for hunting season. Something up with that. Wish I had another choice!
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Post by 1coyotemaster on Nov 19, 2014 21:29:21 GMT -5
In my experience with cold weather shooting it is always prudent to check zero in cold temps. Nearly all my rifles shoot lower in cold(10-20F) than they will in 60-70F. I settled on a duplex load for my SML hunting to insure reliable ignition and I have it sighted in for 20F temps. A pretty good idea to sight in and then at least check zero with whatever implement you will shot off of ie. bipods, sticks or a shooting bag.
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Post by jsthntn247 on Nov 19, 2014 21:37:08 GMT -5
Your 100 yard zero should not be shifting that much at 100 yards. At longer distances it definitely makes a difference. I be thinking about bedding the rifle. Stocks heating and cooling could definitely move poi that much.
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Post by Deleted on Nov 19, 2014 22:13:44 GMT -5
his gun is bedded so that's not it, I would suspect the sled/ bag rest is the difference. I would shoot it with the bag again and adj to that poi. the sled will make the muzzle rise more than shooting off the bag.
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Post by lwh723 on Nov 19, 2014 22:44:12 GMT -5
his gun is bedded so that's not it, I would suspect the sled/ bag rest is the difference. I would shoot it with the bag again and adj to that poi. the sled will make the muzzle rise more than shooting off the bag. I agree. Different rests can make a world of difference. I can make my shots go up and down just by how I hold the rifle.
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Post by madcityhoosier on Nov 19, 2014 22:50:36 GMT -5
his gun is bedded so that's not it, I would suspect the sled/ bag rest is the difference. I would shoot it with the bag again and adj to that poi. the sled will make the muzzle rise more than shooting off the bag. Yep, I suspect Bill's right (and 1coyotemaster). The biggest difference, or the thing that causing the majority of your POI shift is the change in shooting rest. If you're not gonna hunt with the leadsled, then do your final sight-in from something that closely or exactly replicates your hunting set-up.
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Post by rambler on Nov 19, 2014 23:14:55 GMT -5
If your scope is aligned properly with what you're shooting at what difference does the type of rest make? I mean if you've got the bulls eye in your crosshairs and holding steady and everything else is static you should be good right?.
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Post by rangeball on Nov 19, 2014 23:29:36 GMT -5
If your scope is aligned properly with what you're shooting at what difference does the type of rest make? I mean if you've got the bulls eye in your crosshairs and holding steady and everything else is static you should be good right?. Different rests/holds affect the recoil impulse. In a sled type rest rearward movement is restricted so the gun reacts upwards. Since the bullet is still in the bore the shot impacts higher. On bags the gun can more easily react rearward minimizing muzzle rise and resulting in a relatively lower shot. I always try to match my bench technique as close as possible to how I shoot in the field.
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Post by Mid_Tn_Plowboy on Nov 19, 2014 23:33:09 GMT -5
If your scope is aligned properly with what you're shooting at what difference does the type of rest make? I mean if you've got the bulls eye in your crosshairs and holding steady and everything else is static you should be good right?. Shooting off my rest and a rear bag my POI changes if I hold the forearm or not. On the temperature note I've noticed if I sight in 3" high @100 at 40º and when I shoot it in the 20's my POI is around 2" lower. I never bring my pacnor in after a hunt. I leave it in my shop's gun safe. (Closer to outside temps) if I leave it loaded over a couple days then shoot it around sight in temperature it still drops a bit oven an inch. Makes me want to fire it after every hunt :/
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Post by jsthntn247 on Nov 20, 2014 7:10:57 GMT -5
If your scope is aligned properly with what you're shooting at what difference does the type of rest make? I mean if you've got the bulls eye in your crosshairs and holding steady and everything else is static you should be good right?. I shot a 600 yard f/tr match this past Saturday with my 223. I had a horrible first 2 relays 191 and 192 out of a possible 200 and dropped most shots to verticle. It had been 2 months since I shot this gun and I forgot that this rifle has a flat but stock on it like a benchrest gun and meant that I needed to shoot with my rear bag backwards so I wasn't putting uneven pressure on the but of the gun while shooting. I turned the bag around and shot a 199 on the last string in worse wind than the first 2 strings. Hold and bag placement makes a world of difference on a gun with no recoil, imagine the difference on a heavy recoiling muzzleloader.
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Post by bestill on Nov 20, 2014 7:23:38 GMT -5
Cold weather also brings another issue that seems many muzzleloading hunters neglect. They load there gun in a warm house then head out into extreme cold weather which seems to work but when return home they bring gun back into warm house which causes gun to sweat and then head back out for evening hunt with a damp powder charge and may repeat this cycle for several days. This is a recipe for a bad day hunting. I always keep gun outside during season and allow to stay at ambient temp changing at a slow rate if concerned pull plug dump load and reload
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Post by deadeye on Nov 20, 2014 8:34:40 GMT -5
fwiw- just conducted a short test w/ 327mh tested from 73 deg to 13 deg which resulted in a approx. 100 fps total loss @ 200yds. at that distance with the same rest my poi was largest @ approx. 1.25" now if I were to take a shot 350yds or farther I would have to make an adjustment(dialing) to connect in which I have those figures just in case.
73 deg.....2741,34,20 70 deg.....2700,04,23 31 deg.....2717 27 deg.....2666 13 deg.....2645
the 31 -13 deg test were all fresh loaded in am. with the barrel out for at least an hour to reach ambient temp.
bullets all seem to load consistently for the above results_ notice the fps swing with this particular load from 31 to 27 degrees.
hope this helps!
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Post by rangeball on Nov 20, 2014 9:33:21 GMT -5
Deadeye, what powder and amount? What size vent/bushing and flame channel? LRMP or 209?
Thanks.
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Post by deadeye on Nov 20, 2014 10:37:57 GMT -5
Deadeye, what powder and amount? What size vent/bushing and flame channel? LRMP or 209? Thanks. i4198//73.0 hankins ignition lrmp////fwiw- there are a lot of factors with good poi impacting & even my test are not absolute science. I think some prior post hit Alabama's poi on the head-the rest... get your shoulder hard into a very accurate rifle & you will see difference's or just a rest change that does not give like another rest that used prior. muzzle jump comes into play-that's why I like heavy barrels/ime
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Post by rangeball on Nov 20, 2014 10:49:40 GMT -5
Thanks.
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Post by rambler on Nov 20, 2014 10:58:07 GMT -5
So if everything else is equal we still have the one constant variable of temperature. How can one account for that??
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Post by 1coyotemaster on Nov 20, 2014 11:08:55 GMT -5
Deadeye, what powder and amount? What size vent/bushing and flame channel? LRMP or 209? Thanks. i4198//73.0 hankins ignition lrmp////fwiw- there are a lot of factors with good poi impacting & even my test are not absolute science. I think some prior post hit Alabama's poi on the head-the rest... get your shoulder hard into a very accurate rifle & you will see difference's or just a rest change that does not give like another rest that used prior. muzzle jump comes into play-that's why I like heavy barrels/ime Most all of us shoot extruded powders in our guns and as a rule they are less sensitive to temp swings than ball powders. In a slow twist .223 with AA2230 I have had swings as high as 300fps (over a shooting chrony--which may or may not be accurate) It is a very accurate warm weather load but I prefer Varget when it gets cold as it seems to be relatively unaffected by temps. This may be one area where H4198 trumps IMR4198 because of the coating that Hodgdon puts on their extreme series of powders. No experience with this just a speculation with the 4198's.
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Post by rangeball on Nov 20, 2014 11:12:38 GMT -5
So if everything else is equal we still have the one constant variable of temperature. How can one account for that?? Some have done extensive work to develop duplex loads that do so.
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Post by rambler on Nov 20, 2014 11:12:45 GMT -5
I wonder if duplex loads help with any temp. sensitive issues? I know from other posts it helps with ignition.
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Post by 1coyotemaster on Nov 20, 2014 11:38:23 GMT -5
I wonder if duplex loads help with any temp. sensitive issues? I know from other posts it helps with ignition. I am shooting AA5744(10 gr) for a starter powder which supposedly has a pretty high nitro content(easily ignitable) under 50 gr.H4198 under a 250 FTX with an .060 veggie--the test will be tomorrow but so far I am not seeing a big deviation in impact with this duplex combination. Both powders are relatively?? insensitive to cold.
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Post by deadeye on Nov 20, 2014 11:45:39 GMT -5
So if everything else is equal we still have the one constant variable of temperature. How can one account for that?? until a great duplex is created for the 327mh,one can hold up or dial in the variables from what your gun is doing in temps. if we could only get savageshooter & some other great powder/pressure men launchings these 327's
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Post by rangeball on Nov 20, 2014 11:49:15 GMT -5
I wonder if duplex loads help with any temp. sensitive issues? I know from other posts it helps with ignition. Absolutely. Dave W and Savage Shooter among others are a great resource as they have done extensive testing.
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Post by Dave W on Nov 20, 2014 13:36:35 GMT -5
i4198//73.0 hankins ignition lrmp////fwiw- there are a lot of factors with good poi impacting & even my test are not absolute science. I think some prior post hit Alabama's poi on the head-the rest... get your shoulder hard into a very accurate rifle & you will see difference's or just a rest change that does not give like another rest that used prior. muzzle jump comes into play-that's why I like heavy barrels/ime Most all of us shoot extruded powders in our guns and as a rule they are less sensitive to temp swings than ball powders. In a slow twist .223 with AA2230 I have had swings as high as 300fps (over a shooting chrony--which may or may not be accurate) It is a very accurate warm weather load but I prefer Varget when it gets cold as it seems to be relatively unaffected by temps. This may be one area where H4198 trumps IMR4198 because of the coating that Hodgdon puts on their extreme series of powders. No experience with this just a speculation with the 4198's. In my experience H4198 looses speed just like Deadeye mentioned with the I version. Tested it in all types of temps,charge weights, bullet weights. Loads have windows where they perform their best, as Coyote has pointed out. If you shoot enough, you find where the window closes. Duplex gives me a bigger window, that is why I prefer it to singles. I also agree with the others. Different rest/hold, different POI.
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Post by Dave W on Nov 20, 2014 13:56:26 GMT -5
I wonder if duplex loads help with any temp. sensitive issues? I know from other posts it helps with ignition. Here is a link to a post I did some time ago regarding the duplex I use and its lack of temp sensitivity. All shots were at ambient according to my barrel thermometer, including the first shot that had been in the gun for more than a month and in and out of the house numerous times. There is H4198 data in that link also. Later that summer I shot that same load of H4198 and velocity jumped to approx. 2800fps. dougsmessageboards.proboards.com/thread/12865/somewhat-cold-weather-shooting-cal
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Post by Deleted on Nov 20, 2014 14:01:24 GMT -5
My $.02 and no harm intended here by any means, but this is why I shoot solely duplex loads, they work for me and I don't mind using two powders. This was shot last night with my .45 McRem at 100 yards, the first two were shot as foulers (250 SST's) then I went back to the load it was sighted in with last year. (Scope has not been touched since then). Load was 12/58, N110/H322, 275 MH, .060 Veg wad, Fed primer. Last year this gun was sighted in in a t-shirt so I believe IIRC it was pretty warm out, yesterday was in the low 30's with a stiff wind. MY POI is exactly where it was last year when I sighted it in. These shots were fired back to back with no cool down time. JMO but duplex is worth it and takes out the worries of ignition problems and temp instability. Thanks again Dave for turning me onto this for the .45
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Post by TGinPA on Nov 20, 2014 14:56:07 GMT -5
RE: Temp sensitivity of different loads is something on which I too have burned some powder, and spent time thinking about and testing. Without going too much into factors affecting temperature insensitivity of different bullets and powder loads, FWIW, here are some of a few limited traces from the TG pressure trace archive pertaining to some tests of temp sensitivity of selected loads: 26F, 28F 40F, 44F, 12I, 15I, 25I, 26I, 28I, 29I, 32I, 44I, 45I, 46I). Traces 15I and 46I were done with 327mh bullets. A few loads were tested as single powder loads. As one example, 28F maybe is instructive as to why have some may have difficulty maintaining POI shooting the same load of H4198 as a single powder with 195gr sabotted bullets in wide temperature swings. Others were tested as duplex loads. The traces cited above suggest that, one doesn’t necessarily need to shoot duplex loads to minimize temperature sensitivity. As others on this board who know a lot more about this than I ever will have previously stated, constructing a bullet/powder load combination that develops pressures for which a powder is designed to efficiently perform is tremendously helpful in limiting load temperature sensitivity. Light bullets in large bores need faster powders to maintain pressure to burn consistently and efficiently. Conversely, slower powders require some combination of heavier bullets/smaller bores and longer barrels to keep the pressure high enough and allow enough time to create a temperature insensitive, efficient and consistent powder burn. In my testing, some single powder loads tested above were relatively temperature insensitive (which for the purposes of this post, might be arbitrarily defined as less than 1fps/degF temperature change).
Though I can’t remember exactly where, either RB and/or Savage Shooter (possibly others?), have stated that to minimize temperature insensitivity, for many powders, the peak pressure generated by a load must exceed 500psi/gr? Though that cutoff seems reasonable, maybe a spectrum of increasing pressure per grain (600psi/gr may be better and 700psi/gr even better than that) might also be true with the effect diminishing or even being eliminated as higher pressures are reached? (JMO).
Something else to note from these traces: With some of these loads, velocity was relatively unaffected or even increased as temperature dropped over the range. tested. Duplexes utilizing some of the faster boosters such as BlueDot or RedDot seemed exceptionally temperature resistant in the pressure ranges tested. From this, I believe in sml, that it is probably possible to create bullet/bore/powder combinations which eliminate temperature sensitivity altogether? To many, none of the above is new. But it seems worth repeating in that the issue of temperature sensitivity always shows up at this time of the year. Please accept my apologies for any typos I may have missed. TG
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Post by rangeball on Nov 20, 2014 14:58:08 GMT -5
My less that $.02, for what it's worth.
Last year I sighted in the 310 APB FF with 70gr of H4198, .030 veggie and fed 209A. Savage plug had the standard .030 ventliner in it. 3" high at 100 yds. Temps in the upper 50s.
This year I have the .040 bushing and 7/32 flame channel in the same plug. Same load as last year, same sizing, after 5 foulers on a clear bore first shot was 3" high at 100 yds. 22*.
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