Hi Guys, grateful for the opportunity to post here, as I'm going nuts setting up a brand new 1895G (New Haven Address, but REP proof). Installed XS ghost ring and took it out today for initial sight-in. Took a buddy along and also borrowed his laser bore sighter. Set the sights to the laser and then fired at paper at 25 yards. Handed the rifle to the buddy and his shot touched mine, both High and Left. Ammo was Winchester cowboy load 405 grains [email protected] 1150 fps. Made slight sight adjustment, and we each fired again. Again, 2 shots touching, windage fixed, but elevation was still high. Switched ammo to 300 grain Federal jacketed at 1800 FPS. Suddenly, elevation moved a good 6" LOWER! Moved out to 50 yards and took turns working our way through the 300 grainers and then some 325 gr Hornady FTX at a stout 2050 FPS or so, and finally back to the 405 grain Winchester. 2 shooters taking turns, each putting shots right on top of the other shooter's result, it's plenty accurate. Here's where it got crazy. The faster stuff ALWAYS hits about 6" LOWER than the barely supersonic, 405 grain lead! Any clues what's going on here? I understand the trajectory, with line of sight intersecting line of bore and the bore being aimed slightly upward in order to get the bullet to intersect line of sight at a chosen distance, then cross above it. I cannot understand how faster loads drop 6" more than a load with barely 1/2 the velocity. Sights are tight, nothing obviously moving around on the rifle. It seemed like the rifle would be happy to do this little trick all day long, as we were able to swap back and forth between the 'real' loads and the cowboy stuff and it kept repeating the bizzare behavior. HELP! before I bald myself pulling hairs in frustration! Any theories?`Thanks
Bizarro Ballistics - HELP!
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Think of recoil, the longer it takes the bullet to exit the bore, the more time the bore has to rise. So generaly speaking a faster load will shot lower, on a rifle with sights set for slower loads. Somebody is bound to get real technical, cuz there are exceptions, or situations that can be set up, but this is likely what your experiencing.
Its not really dropping more. The effect your seeing is the differences of the barrel angels when the shot exits the bore.
Even if the recoil of the faster light bullet load seems less, the same or greater, remeber the light bullet at faster speed exited the barrel much sooner than the slower heavy bullet load, and recoil effect (continued muzzle rise) continued long after the light bullet exited the barrel relative to the heavy bullet.
Hope I made sense.
Its not really dropping more. The effect your seeing is the differences of the barrel angels when the shot exits the bore.
Even if the recoil of the faster light bullet load seems less, the same or greater, remeber the light bullet at faster speed exited the barrel much sooner than the slower heavy bullet load, and recoil effect (continued muzzle rise) continued long after the light bullet exited the barrel relative to the heavy bullet.
Hope I made sense.
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Hello and Welcome to Marlin Owners from the State of South Dakota
Welcome Aboard, Enjoy the Journey
444GS2
Welcome Aboard, Enjoy the Journey
444GS2
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Welcome from Goldthwaite, TX! Glad you're here! John
Thanks Fellas,
Yes, I do believe Gray Mustang has a viable explanation. Since my other rifles are primarily varmint calibers, I never would have believed the muzzle could rise enough during the travel of the bullet through the bore to change POI like that, but it does seem plausible given that the 45-70 is firing 8 to 10x the bullet mass at 1/3 to 1/2 the velocity. Those of you familiar with the older ported version of the guide gun, I know they are derided for being loud, but is the porting effective to help negate the weird behavior I'm seeing? Given that I intended this gun for use inside of 75 yards, I expected to be able to swap ammo without much worry of need to re-zero. Do most of you treat your 45-70 as a 1-load gun where you choose your favorite, sight in, and never change loads?
Yes, I do believe Gray Mustang has a viable explanation. Since my other rifles are primarily varmint calibers, I never would have believed the muzzle could rise enough during the travel of the bullet through the bore to change POI like that, but it does seem plausible given that the 45-70 is firing 8 to 10x the bullet mass at 1/3 to 1/2 the velocity. Those of you familiar with the older ported version of the guide gun, I know they are derided for being loud, but is the porting effective to help negate the weird behavior I'm seeing? Given that I intended this gun for use inside of 75 yards, I expected to be able to swap ammo without much worry of need to re-zero. Do most of you treat your 45-70 as a 1-load gun where you choose your favorite, sight in, and never change loads?
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Welcome to the forums from the Great Smoky Mountains of East Tennessee! Just keep in mind that every gun has its own particular characteristics and it will have its own point of impacts with different loads. Just find the one that works best and stick with it.
Ron
Ron
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2,319 Posts
Howdy and welcome from Kansas!
GreyMustang has the root of it.
Faster bullets exit the muzzle faster and earlier in the recoil cycle. They shoot straight.
Slower bullets exit the muzzle much later in the recoil cycle leading to higher shots.
It seems counter intuitive until you think it through.
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I've seen the same thing with 45-70 and .300 win mag. Just swapping from 180 to 200 grain bullets.
If it were me czfan I'd stick with the 405 grn bullets.
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Welcome aboard! Just for info, there are some videos I've seen before on YouTube showing the difference in muzzle jump/recoil on the ported vs. non-ported guide rifles; in slow motion etc. There is quite a difference between them, more than I thought myself, and interesting to watch if you can find them online. Good luck to you.
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Enjoy the forum........................
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Its scary the knowledge that is on this forum, Welcome.
Thanks again guys! I will indeed be sticking with the 405's, just got a box of 1K "Lasercast" from Oregon Trail. Gonna start with some trailboss loads until I can figure what I want to do for powder. I have H335 on hand, but other options merit consideration..... Looking forward to laying a serious god-smack on some silhouettes with the big-boy version of the Red Ryder!
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