Mortar tube diameter

[kmosmen]

So this is my first year shooting 1.3 fireworks.

I just purchased a quantity of 3 inch and 4 inch diameter HDPE tubes. They arrived yesterday and my concern is that their internal dimensions are 3/16 of an inch narrower than their listed diameter. Is this going to be a problem?

Thanks!

[kmosmen]

Anyone? I would love advice before I start building my racks!!!

PLEASE?! :)

Thank you

[Dmkaz]

So this is my first year shooting 1.3 fireworks.

I just purchased a quantity of 3 inch and 4 inch diameter HDPE tubes. They arrived yesterday and my concern is that their internal dimensions are 3/16 of an inch narrower than their listed diameter. Is this going to be a problem?

Thanks!

With HDPE, there's no such thing as a '3" and 4" tube'. You should be shooting 3" out of DR17 which has an ID of 3.03" and 4" out of DR21 which has an ID of 4.0". If the size is off by a marginal amount, you should be fine. The size shells you're going to get fluctuate in size a bit anyway.

[kmosmen]

Thanks Dmkaz.

The tubes were advertised as such but upon receipt, I measured them and they were as listed. There is obviously some variation and tolerances in manufacturing and maybe some distortion from storage but more than one tube measured 3/16th" less than 3" and 4"....not the 3.03" or 4" of the DR17 and DR21 respectively. This is my concern. However, not knowing the details of these tubes and how they are sold commercially before being cut.....I guess that as long as they ARE DR17 and DR21 tubes to begin with, I should be okay. My other concern is that when asking of the outside diameter, I was told something different as well. The seller said that they were 3.6" and 4.6" when I measure them much less.

Thanks again!

[Dmkaz]

Thanks Dmkaz.

The tubes were advertised as such but upon receipt, I measured them and they were as listed. There is obviously some variation and tolerances in manufacturing and maybe some distortion from storage but more than one tube measured 3/16th" less than 3" and 4"....not the 3.03" or 4" of the DR17 and DR21 respectively. This is my concern. However, not knowing the details of these tubes and how they are sold commercially before being cut.....I guess that as long as they ARE DR17 and DR21 tubes to begin with, I should be okay. My other concern is that when asking of the outside diameter, I was told something different as well. The seller said that they were 3.6" and 4.6" when I measure them much less.

Thanks again!

If they are commercial DR17 and DR21, then you should be fine. Tolerances do vary a bit as we both mentioned. I shoot 3"/4" out of fiberglass that widely varies and haven't found a shell that was super snug or didn't fit yet. Since with larger shells it's all thin quickmatch going to the lift, less problems arise if things are off a bit. I have had many 1.75" fiberglass tubes that will not fit next to anything in them because they're made *exactly* 1.75" and shells usually have visco down to the lift making them a hair too big. I moved exclusively HDPE for 1.75" (DR11) for this reason.

[Rocketshooter]

Many times the tubes are slightly egg shaped. Did you measure from different angles?

[kmosmen]

Thanks Rocketshooter. Yes, I measured all around a few tubes and consistently got the same dimension. What I should do is measure the bottom of the tube with the plug. The seller stated, in an email, that he sells these without problem so I should be good. I was just worried that after picking up my 1.3 order, I will have fit issues then be stuck!