What are the largest diameter .177 pellets

[bezzer]

Can't see the point of 7 fpe, what do you use it for? be over the 6 allowed for a lot of indoor disciplines and not really high enough for outdoor shooting at longer ranges. Higher power would force the pellet skirt more into the rifling depending on the hardness, thickness of the skirt.

[Rich]

Try H&N FTT. They are usually a tighter fit than Exacts.

edit: forget Bisley Magnums at 7 fpe.

[32:1]

My best barrels are non-choked and I get the same, hardly any resistance on pushing through but the pellet will expand when fired !

Id try a few samples and see if one comes good


Chris

[Shed tuner]

RWS superdomes are large

[noz1]

Never forget that the head sizes are NEVER EVER as stated on the tin, regardless of the brand of pellet!
I also find that many barrels appear to be bored, hammered? on the big size as well.

This subject has been covered many times before, I think.

[Otley]

Thanks for the replies - I'll try some Superdomes.

[nurek]

My best barrels are non-choked and I get the same, hardly any resistance on pushing through but the pellet will expand when fired !

Id try a few samples and see if one comes good


Chris

^ exactly what Chris says... the pellet skirt will expand once it has some air behind it

[hmangphilly]

^ exactly what Chris says... the pellet skirt will expand once it has some air behind it

Is there any available evidence to support this theory please ?

[nurek]

Is there any available evidence to support this theory please ?

I don't have any theoretical evidence, but I think it's self explanatory, higher pressure behind pellet + friction resistance, the soft metal skirt will expand as it's moving (if it has place to expand)?

Do you think otherwise?

I have done a test where I have squashed a pellet skirt and measured the velocity, as expected it was lower, however the skirt 'opened' up. Probably more pronounced in a springer due to higher pressure... I only shoot spring guns.

As you work with barrels, you could do an experiment, where you push a pellet through a barrel (hence 0 pressure on skirt) and see how the skirt is deformed, and fire one, if the markings on the one that has been fired are deeper, the skirt has expanded.

[hmangphilly]

I don't have any theoretical evidence, but I think it's self explanatory, higher pressure behind pellet + friction resistance, the soft metal skirt will expand as it's moving (if it has place to expand)?

Do you think otherwise?

I have done a test where I have squashed a pellet skirt and measured the velocity, as expected it was lower, however the skirt 'opened' up. Probably more pronounced in a springer due to higher pressure... I only shoot spring guns.

As you work with barrels, you could do an experiment, where you push a pellet through a barrel (hence 0 pressure on skirt) and see how the skirt is deformed, and fire one, if the markings on the one that has been fired are deeper, the skirt has expanded.

That's exactly what we did . We could see no noticable difference .

It only works with an unchoked barrel of course

I'll try find the pics

[32:1]

Is there any available evidence to support this theory please ?

Recently there was a thread and it showed a pellet before and after firing, It looked like an ftt or accupell, the difference was very noticeable indeed, I wouldn't of thought they were effected that much, post was by BigAl who is the barrel guy. Not sure if it was on here of the r7oc

Chris

[Lol Moore]

Is there any available evidence to support this theory please ?

https://photos.app.goo.gl/tpdLyAwW6voL8ua5A

[hmangphilly]

https://photos.app.goo.gl/tpdLyAwW6voL8ua5A

Thanks Lawrence .
What does this show ?

I see grooves formed by the lands in both the skirt and the head .
I do not see any sign of contact to the bore in the section between these grooves .
This is the part of the pellet that is believed to be blown out to make a seal with the bore . Not happening on this pellet , which looks like it has only been pushed / rodded through a barrel .

Ok found a couple pics of a fired and retrieved from down range pellet , i'll have to get help posting the images , but check the portion of pellet that is believed to be blown outwards and drag along the wall of the bore ......

[RobF]

Can't see the point of 7 fpe, what do you use it for? be over the 6 allowed for a lot of indoor disciplines and not really high enough for outdoor shooting at longer ranges. .

What indoor disciplines have a power limit?

[trick cyclist]

Possibly try something with a softer skirt, perhaps some AA Diablo? With the lower energy available, you want a head that will fit on the lands of the rifling, but not be too indented, otherwise you will waste to much of that precious energy. A soft skirt that fits into the rifling should provide a seal with the minimum of friction I would have thought?