Mossberg 500 patterning very high -- why?

Hueco · March 17, 2000, 11:47 AM

I have been shooting my dad's Mossy 500 for the past few months. We both shoot trap on the weekends, and so far we have put about 1000 rounds through it. We patterned it a few weeks after we got it. During patterning, we used Winchester AA Light Target 8 shot, and full, modified, and imp. cyl chokes. In all three, it shot a pattern of about 60% on top, 40% on bottom -- they only varied in core density. But now, it patters extremely high. We shot 35 yards (with the mid bead centered on the front bead, same as the first time we patterned), and the beads both centered on the target. But this time, it patterned very close to 90% on top, and 10% on bottom!! Ah! The only thing that was different from the first time we patterned was we used AA *heavy* target loads. What is going on?! You can imagine how frustrating this is... We do reload by the way. Can you recommend a way to somehow get the pattern lower?

Hueco

Al Thompson · March 17, 2000, 01:33 PM

The reason is pretty simple - the heavier load is slower and dwells in the barrel longer. The longer dwell time has the shot exiting the barrel when it is higher in it's recoil arc.

The same thing happens with rifles and pistols. Faster projectiles strike lower than heavy projos, relative to the point of aim.

I am under the impresion that trap shooters like higher patterns.. The guys in my club have their guns with the center of the pattern a foot above point of aim at 30 yards.

Giz

Hueco · March 17, 2000, 02:07 PM

I thought it could be the same thing that you mentioned. And yes, high is good -- but this is absurdly high! I'll load some lights and get them patterned -- that will fix it most likely. Thanks!!

Hueco

Art Eatman · March 17, 2000, 04:13 PM

Is the change affecting your hitting the clays? If so, you might consider a slip-on butt-pad.

Remember all our discussions about length of pull, and the effect on where you hit? A longer stock would make you shoot a bit lower, and thus lower the center of your pattern, would it not?

Something to consider...

Regards, Art

Hueco · March 17, 2000, 11:22 PM

Goodness yes it is affecting it! Otherwise I wouldn't mind much at all. Your solution is a good one Mr. Eatman -- in theory. Problem is, Dad is smaller than me. I actually do need a longer butt-stock. But he needs a shorter one. I will try tailering a few rounds up to shoot low. After that, I guess I might have to shim the butt-stock/reciever joint. Thanks!

Hueco

Dave McC · March 19, 2000, 11:55 AM

I'd suggest getting another shotgun,Hueco, instead of switching over the stock constantly.

FWIW, I'm a big guy,and I can shoot Daughter's 870 Youth model with its 12 1/2" pull OK, tho not quite as good as a standard stock.

On shimming, I've done it with folded aluminum foil. Remember, dropping the stock takes the recoil further from straight line, so you'll feel it a little more.

BTW, have you tried shooting trap with those high hitting loads to see if they break clays? Might be what you need.

Also, switching to larger beads will lower impact a bit, that may work better for you than shimming the stock.

Hueco · March 24, 2000, 08:47 PM

Dave...it is already shooting high -- why would I try high-hitting loads?

Anyway, I am not simply shooting under the bird about a barrel width -- works great. It's come out nicley in fact, I can see the target and where it is going. In high wind this is great because I can see the minor coarse variations! Today, I shot my best ever, I just held low. I see no reason now to get it to shoot a pattern lower.

Hueco

Also, we did get another one!

An 835...we both love it!!

[This message has been edited by Hueco (edited March 24, 2000).]

Dave McC · March 25, 2000, 07:55 AM

I'm glad you're now happy with it, Hueco. Sometimes what seems to be a problem isn't.

Hueco · March 25, 2000, 05:10 PM

Well, yes! Dad and I went back again today to shoot some more. We believe (have yet to pattern it though), the 835 might be shooting too high also -- shots that were held under do well. WE were joking that we wre most likely the ONLY two trap shooters who hold *under* the bird.

But hey, just as long as they are breaking, I don't care where I have to hold!!

Hueco

Dave McC · March 26, 2000, 01:11 PM

Hueco,if you're busting an appropriate number of birds,patterning holds few surprises. patterning will enable a fine tune to be done tho.

Good luck and good shoooting...

March 17, 2000, 11:47 AM	#1
Hueco Senior Member Join Date: December 7, 1999 Posts: 561	I have been shooting my dad's Mossy 500 for the past few months. We both shoot trap on the weekends, and so far we have put about 1000 rounds through it. We patterned it a few weeks after we got it. During patterning, we used Winchester AA Light Target 8 shot, and full, modified, and imp. cyl chokes. In all three, it shot a pattern of about 60% on top, 40% on bottom -- they only varied in core density. But now, it patters extremely high. We shot 35 yards (with the mid bead centered on the front bead, same as the first time we patterned), and the beads both centered on the target. But this time, it patterned very close to 90% on top, and 10% on bottom!! Ah! The only thing that was different from the first time we patterned was we used AA heavy target loads. What is going on?! You can imagine how frustrating this is... We do reload by the way. Can you recommend a way to somehow get the pattern lower? Hueco

March 17, 2000, 01:33 PM	#2
Al Thompson Staff Alumnus Join Date: May 2, 1999 Location: South Carolina Posts: 3,611	The reason is pretty simple - the heavier load is slower and dwells in the barrel longer. The longer dwell time has the shot exiting the barrel when it is higher in it's recoil arc. The same thing happens with rifles and pistols. Faster projectiles strike lower than heavy projos, relative to the point of aim. I am under the impresion that trap shooters like higher patterns.. The guys in my club have their guns with the center of the pattern a foot above point of aim at 30 yards. Giz

March 17, 2000, 02:07 PM	#3
Hueco Senior Member Join Date: December 7, 1999 Posts: 561	I thought it could be the same thing that you mentioned. And yes, high is good -- but this is absurdly high! I'll load some lights and get them patterned -- that will fix it most likely. Thanks!! Hueco

March 17, 2000, 04:13 PM	#4
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	Is the change affecting your hitting the clays? If so, you might consider a slip-on butt-pad. Remember all our discussions about length of pull, and the effect on where you hit? A longer stock would make you shoot a bit lower, and thus lower the center of your pattern, would it not? Something to consider... Regards, Art

March 17, 2000, 11:22 PM	#5
Hueco Senior Member Join Date: December 7, 1999 Posts: 561	Goodness yes it is affecting it! Otherwise I wouldn't mind much at all. Your solution is a good one Mr. Eatman -- in theory. Problem is, Dad is smaller than me. I actually do need a longer butt-stock. But he needs a shorter one. I will try tailering a few rounds up to shoot low. After that, I guess I might have to shim the butt-stock/reciever joint. Thanks! Hueco

March 19, 2000, 11:55 AM	#6
Dave McC Staff In Memoriam Join Date: October 13, 1999 Location: Columbia, Md, USA Posts: 8,811	I'd suggest getting another shotgun,Hueco, instead of switching over the stock constantly. FWIW, I'm a big guy,and I can shoot Daughter's 870 Youth model with its 12 1/2" pull OK, tho not quite as good as a standard stock. On shimming, I've done it with folded aluminum foil. Remember, dropping the stock takes the recoil further from straight line, so you'll feel it a little more. BTW, have you tried shooting trap with those high hitting loads to see if they break clays? Might be what you need. Also, switching to larger beads will lower impact a bit, that may work better for you than shimming the stock.

March 24, 2000, 08:47 PM	#7
Hueco Senior Member Join Date: December 7, 1999 Posts: 561	Dave...it is already shooting high -- why would I try high-hitting loads? Anyway, I am not simply shooting under the bird about a barrel width -- works great. It's come out nicley in fact, I can see the target and where it is going. In high wind this is great because I can see the minor coarse variations! Today, I shot my best ever, I just held low. I see no reason now to get it to shoot a pattern lower. Hueco Also, we did get another one! An 835...we both love it!! [This message has been edited by Hueco (edited March 24, 2000).]

March 25, 2000, 07:55 AM	#8
Dave McC Staff In Memoriam Join Date: October 13, 1999 Location: Columbia, Md, USA Posts: 8,811	I'm glad you're now happy with it, Hueco. Sometimes what seems to be a problem isn't.

March 25, 2000, 05:10 PM	#9
Hueco Senior Member Join Date: December 7, 1999 Posts: 561	Well, yes! Dad and I went back again today to shoot some more. We believe (have yet to pattern it though), the 835 might be shooting too high also -- shots that were held under do well. WE were joking that we wre most likely the ONLY two trap shooters who hold under the bird. But hey, just as long as they are breaking, I don't care where I have to hold!! Hueco

March 26, 2000, 01:11 PM	#10
Dave McC Staff In Memoriam Join Date: October 13, 1999 Location: Columbia, Md, USA Posts: 8,811	Hueco,if you're busting an appropriate number of birds,patterning holds few surprises. patterning will enable a fine tune to be done tho. Good luck and good shoooting...