QLA Flunked, Yes It Did

[ronlaughlin]

Two rifles came with, to the hills this morning. The Optima, and another Omega. This is the third different Omega shot these past two days; it is the one that was used to 'burst' pop. First the Omega was shot three times, then the Optima. W209 primer was used in both rifles, as was Art' (Flounder) home cast conicals, a wad, and 60g Blackhorn.

One can see that a bullet fired by the Omega nearly, completely missed the paper, and the three shots look like they came from a shotgun.

 

[flounder]

Oofda.

 

[ronlaughlin]

Art, surely you don't think the problem is your casting? Remember 4 year ago when you sent those 499g, your first casting? They scattered the same as these, from that old X7. What i did then was cut the OLA off of that rifle.

After i cut the QLA off, here is what i wrote back then

when i arrived in the hills, rain seemed imminent, so i didn't take long placing the target at 48 yard, and loading the X7 with 100g BH, 300g Deep Curl, crush rib sabot, and W209 primer. The aim was the lower bull for all shots taken today. Two shots were taken using the Deep Curl; they are the 2 holes in the lower target.

Without taking time to adjust the scope, the rifle was loaded 3 times with Art' bullet, 85g BH, and W209 primer. The holes dyed green are these shots. Then a move was made out to 100 yard. By now it had begun raining, so the rifle was loaded and fired with Art' bullet 3 times without delay. These are the other 3 holes in the upper target. That uses all the 499g Art cast bullet i had.

 

[flounder]

Those conicals shoot good out of my White's and Knight's so I don't think it would be the casting, at least I hope not. :shock:

 

[Underclocked]

I would certainly trust Art's castings to be good conicals. I think if you remove the QLA from this Omega you will see decent groups with those same conicals. Did you try them in the Optima?

 

[Hatchet Jack]

I have read on several threads about people cutting the QLA off the end of their barrel. Just curious to know how that helps with accuracy.

 

[WV Hunter]

I have read on several threads about people cutting the QLA off the end of their barrel. Just curious to know how that helps with accuracy.

Because on some rifles the qla and the bore of the rifle are not properly aligned, thus it creates a negative affect when shooting full bore bullets. As you can see on Ron's...the QLA significantly impacted his accuracy. Sabots typically shoot fine.

 

[Muley Hunter]

Why does the QLA not centered only affect conicals? Why doesn't the pressure imbalance affect a sabot too?

 

[jsmuddydogs]

I'm not sure I understand this post. From what I'm reading is the OP shot one load with a light powder charge and got horrible results so he should chop off the end of his barrel? I would think dropping or increasing the powder charge might show a sweet spot.

If the bore isn't true all the way down why would it effect conicals and not sabots?

 

[WV Hunter]

Why does the QLA not centered only affect conicals? Why doesn't the pressure imbalance affect a sabot too?

That is a good question Muley and one that's above my knowledge level. Maybe it has something to do with the plastic sealing with the barrel, but I don't know for sure. I'm sure someone smarter than me will give you the answer

 

[BuckDoeHunter]

Why does the QLA not centered only affect conicals? Why doesn't the pressure imbalance affect a sabot too?

This interests me too.

This post has some pics illustrating the problem with conicals.

viewtopic.php?t=23029

My best shooters (with sabots) do not have a QLA, I wish none of them did.

 

[sendit]

I don't quite understand these post either. How is it that the QLA is determined to be off?
Is the concentricity measured from the bore's ID or the OD of the barrel? There can be fairly large differences between the two. The counterbore needs to be concentric to the bore, if not then there is a chance of the interference with the bullet and QLA.
I am guessing that the muzzle is recrowned after the QLA is chopped off?
Getting a good crown is a bit more troublesome in a deeply counterbored muzzle over one that is flush and easy to get to.
What are the conditions of the crowns in the QLA? The exact end of the muzzle(crown) is the last thing the bullet touches as it exits the barrel. It needs to be free of any defect and perfectly perpendicular to the bore. The condition of the crown would be suspect to me. The QLA/counterbore not being concentric with the bore is also suspect. . Both can be repaired/fixed without removing the QLA. Just my thoughts......

 

[Grouse]

I don't quite understand these post either. How is it that the QLA is determined to be off?
Is the concentricity measured from the bore's ID or the OD of the barrel? There can be fairly large differences between the two. The counterbore needs to be concentric to the bore, if not then there is a chance of the interference with the bullet and QLA.
I am guessing that the muzzle is recrowned after the QLA is chopped off?
Getting a good crown is a bit more troublesome in a deeply counterbored muzzle over one that is flush and easy to get to.
What are the conditions of the crowns in the QLA? The exact end of the muzzle(crown) is the last thing the bullet touches as it exits the barrel. It needs to be free of any defect and perfectly perpendicular to the bore. The condition of the crown would be suspect to me. The QLA/counterbore not being concentric with the bore is also suspect. . Both can be repaired/fixed without removing the QLA. Just my thoughts......

Your a smart man!!

 

[sabotloader]

sendit

Usually it is not a crown issue, the way TC bores their barrels the bit does not always not always come out centered on the end of the barrel. It is also a less expensive way to create the bore. Then to hide the bore a QLA is drill into the muzzle that is center on the barrel. For appearance sake this looks much better than have a bore that is off-center in the barrel. The fact that the bore is off-centered a little bit really does not hurt accuracy at all. It is the appearance that would create a problem with the public.

This is the front view of a QLA - from this view the QLA is centered on the barrel and looks very good...



This is the rear of the cut QLA just after the crown in the bore. If you look carefully you can see that the actual bore is off-center with the QLA.



This is that same bore with the QLA cut of and re-crowned. Again looking care fully you can see that the bore is slightly off-centered. The barrel is a little thicker under the sight. This little bit of off-centering - then the addition of the QLA can cause problems with a full bore conical. TC really does not hide this fact at all they will tell you that the rifle was built to shoot sabots.



After Txhunter completed this operation/modification his rilfe performed very well in Colorado with full bore conicals.

 

[ronlaughlin]

I'm not sure I understand this post. From what I'm reading is the OP shot one load with a light powder charge and got horrible results so he should chop off the end of his barrel? I would think dropping or increasing the powder charge might show a sweet spot.

If the bore isn't true all the way down why would it effect conicals and not sabots?

If you look at the OP you can see the first shot, and the second shot are 12" apart, and this is at only 50 yard. It may be possible that one could improve this by juggling the powder charge, but myself, i cannot imagine one can make this bullet in this rifle work good, by just changing the charge.

This exact same rifle was accurate enough to hit a pop can at over 200 yard using a bullet in a sabot.

 

[ronlaughlin]

I don't quite understand these post either. How is it that the QLA is determined to be off?
Is the concentricity measured from the bore's ID or the OD of the barrel? There can be fairly large differences between the two. The counterbore needs to be concentric to the bore, if not then there is a chance of the interference with the bullet and QLA.
I am guessing that the muzzle is recrowned after the QLA is chopped off?
Getting a good crown is a bit more troublesome in a deeply counterbored muzzle over one that is flush and easy to get to.
What are the conditions of the crowns in the QLA? The exact end of the muzzle(crown) is the last thing the bullet touches as it exits the barrel. It needs to be free of any defect and perfectly perpendicular to the bore. The condition of the crown would be suspect to me. The QLA/counterbore not being concentric with the bore is also suspect. . Both can be repaired/fixed without removing the QLA. Just my thoughts......

The QLA is determined to be off, because the rifle won't shoot conicals.

The same thing happened about 4 years ago when i shot some of Art's home cast in my X7. The rifle scattered Art's bullets just like this rifle did. What i did to that rifle is explained in the third post in this thread. What i did to that rifle was cut most of the QLA off, saving just about 1/32" of QLA, so i wouldn't have to worry about re crowning the rifling.

Cutting the barrel off was far far easier for me than trying to repair the QLA.

The photo is cropped from the photo in the third post in this thread. It shows the target at 100 yards, shot 4 years ago, using Art's home cast conical. Conicals shot by the X7, after the QLA was mostly cut off. Cutting the QLA off turned a 12" group at 50 yard into a 2" group at 100 yard. Cutting the QLA off was a good thing to do. That rifle felt better to me with the barrel cut off. The rifle was as accurate shooting bullets in sabot, as it was before removing the QLA. The rifle was easy to load without the QLA. The rifle was my favorite, and it was shot so much, it developed a loose spot in the barrel. When it was no longer accurate, i was sad. Even though it doesn't shoot good any more, i bet it would still shoot conicals more accurately than a brand new Omega.

 

[JStanley]

I did the exact same thing to my omega as Ron and it became almost almost as good a conical shooter as a White. I cut all the QLA off and carefully recrowned it. I think of a non concentric QLA the same as a badly boogered crown on any other rifle (when it comes to full bore bullets). The post BuckDoeHunter links to has great graphics showing the asymmetrical escape of gases for conicals.

 

[flounder]

Pretty much sums it up for me. I had a few t/c rifles with the misaligned qla. I guess I was squeamish about cutting off the qla so I sold them and bought knights and white rifles. That worked too.

 

[toytruck]

Sabotloader, I don't recall (correct me if I'm wrong) T/C saying their rifles were meant for saboted bullets only. When I bought my first T/C's before the QLA was introduced they offered the Maxiball and MaxiHunter conicals along with saboted bullets, (remember the "breakaway sabot"), for all their rifles.

I tried to get a Encore barrel without the QLA, but T/C reps told me they didn't offer those or any other barrels any longer. I'm better off in the long run as I found my White rifles and said so long to T/C. I still have my .54 Renegade, no QLA, and will be keeping it (killed my first ML buck with it).

 

[sabotloader]

Sabotloader, I don't recall (correct me if I'm wrong) T/C saying their rifles were meant for saboted bullets only. When I bought my first T/C's before the QLA was introduced they offered the Maxiball and MaxiHunter conicals along with saboted bullets, (remember the "breakaway sabot"), for all their rifles.

I tried to get a Encore barrel without the QLA, but T/C reps told me they didn't offer those or any other barrels any longer. I'm better off in the long run as I found my White rifles and said so long to T/C. I still have my .54 Renegade, no QLA, and will be keeping it (killed my first ML buck with it).

I believe you are correct - pre QLA days they would shoot conicals very well... Today even some of them do still with a the QLA but I think the larger majority of them will not. Also remember TC did not build their own barrels for a very long time, they were contracted from various barrel companies. When they did start and then when they chose the method of boring the barrel they started using the QLA. At that point TC declared their rifles were sabot shooters. And were not designed for conicals.

I wish I could remember the name of the method that they (TC) uses - my mind is just to dang old...