Problem with accuracy when using less than 150 grains - The Firearms Forum

wpshooter · 08-05-2012, 06:06 PM

I was talking to my nieces' husband this evening about various firearm and hunting topics and he related to me that on his muzzleloader (which I believe he said was a Thompson Omega) he could just not seem to get it to sight in correctly unless he used 150 grains of propellent.

He said that he is using the preformed pellets and that when he first tried to get the gun sighted in, that no matter how much he adjusted the elevation on his scope, the impact of his shots were always EXTREMELY low on the target, i.e. below the point of aim. This was when he was using only 2 pellets, i.e. 100 grains.

He said that subsequently he attempted shooting at the same target at the same distance BUT with 3 pellets, i.e. 150 grains and after adjusting the scope to the proper setting, the gun placed the shots at the correct vertical position on target.

So my question is, is it mandatory on some of the newer 150 grain rated muzzleloaders to use 150 grains of propellent in order for them to get correct shot placement ?

Thanks.

hunter29180 · 08-05-2012, 06:20 PM

what distance was he shooting at? 100 gn will not shoot as far as 150 gn, as the propellant charge drops, so does the distance the bullet can travel and remain accurate.

wpshooter · 08-05-2012, 06:47 PM

Quote:

Originally Posted by hunter29180

what distance was he shooting at? 100 gn will not shoot as far as 150 gn, as the propellant charge drops, so does the distance the bullet can travel and remain accurate.

He was shooting at fairly short distance (50 yards or under) just for sight-in purposes.

With 100 grains he could not get rifle to hit point of aim even after adjusting scope as high as it would go. But as soon as he switched to 150 grains, he could then adjust the scope to proper vertical setting and have bullet hit at point of aim.

Thanks.

old semperfi · 08-05-2012, 09:58 PM

first off,what grain bullet is he shooting.i have seen some scopes that may need to shim the frount mount.i use the plastic from a anti freeze jug but any thin material will work.as i said before he may want to use a different bullet or different weight.the other end of the stick is if you weigh the pellets you will find they are not real consistant.i now use only loose powder 777.i get better accuracy that way. old semperfi

gvw3 · 08-08-2012, 06:54 PM

I think 150 grain is pretty hot. I know it would be in my gun.

kempnerkaos · 09-09-2012, 06:32 AM

When shooting for sighting and target purposes,A lower grain count will give you better accuracy...More is not always better.. I use 80 grains for sighting on my Thompson .50 cal Grey hawk Percussion Rifle at 100 feet and hit dead on consistantly.I get A pattern with round balls of about 2.5 to 3 inches with 6 shots,most will be touching the red on the bullseye.Lower Grain count will give you the accuracy you need with round balls other than increasing the load.

08-05-2012, 06:06 PM	#1
wpshooter V.I.P. Member Join Date: Jul 2009 Posts: 249	Problem with accuracy when using less than 150 grains I was talking to my nieces' husband this evening about various firearm and hunting topics and he related to me that on his muzzleloader (which I believe he said was a Thompson Omega) he could just not seem to get it to sight in correctly unless he used 150 grains of propellent. He said that he is using the preformed pellets and that when he first tried to get the gun sighted in, that no matter how much he adjusted the elevation on his scope, the impact of his shots were always EXTREMELY low on the target, i.e. below the point of aim. This was when he was using only 2 pellets, i.e. 100 grains. He said that subsequently he attempted shooting at the same target at the same distance BUT with 3 pellets, i.e. 150 grains and after adjusting the scope to the proper setting, the gun placed the shots at the correct vertical position on target. So my question is, is it mandatory on some of the newer 150 grain rated muzzleloaders to use 150 grains of propellent in order for them to get correct shot placement ? Thanks. --> Last edited by wpshooter; 08-05-2012 at 06:16 PM..

08-05-2012, 06:20 PM	#2
hunter29180 Advanced Senior Member Join Date: Jan 2011 Location: in a motorhome where ever we park! Contributor Posts: 1,627	Re: Problem with accuracy when using less than 150 grains what distance was he shooting at? 100 gn will not shoot as far as 150 gn, as the propellant charge drops, so does the distance the bullet can travel and remain accurate. __________________ As I get Older, I have come to understand why our Founding Fathers chose our countrys motto to be "IN GOD WE TRUST", somehow they knew in the future WE would come to the point that WE COULD NO LONGER TRUST THE ONES WHO RUN IT!

08-05-2012, 09:58 PM	#4
old semperfi Advanced Senior Member Join Date: Aug 2009 Location: i live in southern indiana,old country boy at heart Posts: 1,506	Re: Problem with accuracy when using less than 150 grains first off,what grain bullet is he shooting.i have seen some scopes that may need to shim the frount mount.i use the plastic from a anti freeze jug but any thin material will work.as i said before he may want to use a different bullet or different weight.the other end of the stick is if you weigh the pellets you will find they are not real consistant.i now use only loose powder 777.i get better accuracy that way. old semperfi

08-08-2012, 06:54 PM	#5
gvw3 Advanced Senior Member Join Date: Oct 2011 Location: Chicago IL Area Contributor Posts: 3,316	Re: Problem with accuracy when using less than 150 grains I think 150 grain is pretty hot. I know it would be in my gun. __________________ Criminals advocate stronger gun laws to foster a safer work environment. This limits their exposure to risk.

09-09-2012, 06:32 AM	#6
kempnerkaos Member Join Date: Sep 2012 Posts: 5	Re: Problem with accuracy when using less than 150 grains When shooting for sighting and target purposes,A lower grain count will give you better accuracy...More is not always better.. I use 80 grains for sighting on my Thompson .50 cal Grey hawk Percussion Rifle at 100 feet and hit dead on consistantly.I get A pattern with round balls of about 2.5 to 3 inches with 6 shots,most will be touching the red on the bullseye.Lower Grain count will give you the accuracy you need with round balls other than increasing the load.