Quick Study, Dressing and Seating Pellets

[Guest]

I shot pellets from the tin, pellets whose skirts were rounded with a pelseat (dressed), pellets which were not dressed but were seated using the pelseat, and pellets which were both rounded with the tool and seated. I shot 25 pellets in each category.

I wanted to discover if rounding the skirts and seating them to a uniform depth made a difference in the muzzle velocity which might improve consistency. I expected to see more of a difference than I see here but 25 pellets within each category is a large enough sample to see any trends. There was about a 30% improvement in standard deviation when skirts were rounded with the tool. Skirts are obviously very important.

Stated simply this data shows that round skirts are more important than seating the pellets to a consistent depth. It shows that there is questionable efficacy for seating pellets to a consistent depth and that some muzzle velocity is lost when you do that.

Why? I suspect that seating to a consistent depth should also ensure the pellet is square within the bore and that the seating tool does not damage skirts or change the angle of the head WRT the axis of the pellet.. My seating tool probably needs work. I believe it was Motorhead who showed a picture of a skirt/seating tool which was machined to fit the base of the pellet. At the time I thought it was a "problem seeking a solution", it looks like I was wrong about that. I'll revisit the tool I make and rerun the test in a few days.

Seems counter-intuitive to me but this is what I got.

Rifle was a new HW-98 which has less than a tin of pellets through it.

Pellet was JSB Exact .20 cal, ~13 grains

 

[bltefft]

Are you reporting velocities of pellets based on how you treated them? What do you mean by "Dressed", "Seated", "Dressed and Seated?

 

[sidepass]

Are you reporting velocities of pellets based on how you treated them? What do you mean by "Dressed", "Seated", "Dressed and Seated?

Curious minds are waiting.

 

[bandg]

Are you reporting velocities of pellets based on how you treated them? What do you mean by "Dressed", "Seated", "Dressed and Seated?

Curious minds are waiting.

No kidding. Exactly what was done?

 

[Guest]

Are you reporting velocities of pellets based on how you treated them? What do you mean by "Dressed", "Seated", "Dressed and Seated?

Oh sorry, my bad. I shot pellets from the tin, pellets whose skirts were rounded with a pelseat (dressed), pellets which were not dressed but were seated using the pelseat, and pellets which were both rounded with the tool and seated.

The intent being to discover if rounding the skirts and seating them to a uniform depth made a difference in the muzzle velocity which might improve consistency. I expected to see more of a difference than I see here but 25 pellets within each category is a large enough sample to see any trends.

 

[bandg]

Interesting that both "dressed and seated" and "seated" showed lower velocity than "from the tin" or "dressed". Dead air space from the seating depth??? Something else???

 

[dizzums]

changing the pressure would effect actual 'pellets' more than anything .. their actual 'starting point' in relation to the port lands and grooves though im sure affects things as does its diameter in relation to the bore to start with .. but dressing the skirt doubt it does much.. when ~3000psi hits the skirt it flares into the rifling .. thats the idea .. if its alittle deformed doubtful it will make much difference when that pressure hits it unless its just really beat up ...

 

[FrankinFairfield]

Someone with tooooooo much time on his/her hands.

They are adult toys.

 

[bltefft]

Looks like the "plain old pellets" out of the tine had higher velocities than any of the others, what about accuracy?

 

[elh0102]

One problem with this kind if exercise is, nothing counts except the target. SD, ES, etc. do not consistently define accuracy, at least not to a statistically significant degree. 

I spent years engaged in centerfire and rimfire BR competition. And that is the most demanding of exacting preparation. It finally wore me out. Now I just shoot. If the targets are good, I did well, if not, it was obviously bad pellets! Why work to remove my best excuse?

 

[Chuck-in-Ohio]

Thanks for devoting the time to test, compile and post your findings.



Interesting and helpful!

 

[davelarson]

Nothing wrong with eliminating all the factors that get in the way of what we are all looking for! Accuracy! Thanks for sharing your findings. As far as having way too much time on our hands, what an awesome way to spend some time! With a rifle shooting for accuracy. It’s what I look forward to every day. And it always makes me grin. We are so lucky to have these guns available. Our back yards are shooting sanctuaries lol!

 

[Solo1]

I think it would depend alot on the type of pellet also. I have jsb 10.34 that shoot 940 ( thin skirt) h&n 10.6 that go 928 and h&n 10.6-4.52 that go 908 The 4.52 are most consistent on target and also seem easier to shoot well and this is without changing anything else 

 

[Guest]

Looks like the "plain old pellets" out of the tine had higher velocities than any of the others, what about accuracy?

They do. I believe they shoot tighter groups when I dress the skirts. I did a study on only that a few years ago and that was what it showed. There are probably two things that dressing skirts does for you; first it ensures that every pellets skirt is not out of round when you load it and second it flares the skirt outwards a bit and ensures a better seal around the forcing cone as the pellet is driven into it by pressure striking the skirt and swaging it down as it engraves. That's what I THINK. I have no proof that is correct.

 

[AirShot]

Over the years I have conducted similar tests, it all depends on the rifle barrel and how the breech was finished off at the factory. Some results were like yours and other barrels were completely different. Some barrels like expanded skirts while some didnt....the real conclusion here is to check with each and every barrel on each and every gun. No two are identical no matter how close tolerances are held !!

 

[Bigragu]

Nothing wrong with eliminating all the factors that get in the way of what we are all looking for! Accuracy! Thanks for sharing your findings. As far as having way too much time on our hands, what an awesome way to spend some time! With a rifle shooting for accuracy. It’s what I look forward to every day. And it always makes me grin. We are so lucky to have these guns available. Our back yards are shooting sanctuaries lol!

Love your outlook on life and our luxury of being able to own and shoot these toys in the privacy of our own home. Others in other areas of the world, not so fortunate.

To CORNPONE, thanks for taking the time and posting up your findings. This hobby truly is about experimentation. As an example, take a look at what all Ernest has done with his experiments on different parts, pieces, and combinations. As a result, the new M3 now bears the fruits of his efforts. 

 

[bandg]

changing the pressure would effect actual 'pellets' more than anything .. their actual 'starting point' in relation to the port lands and grooves though im sure affects things as does its diameter in relation to the bore to start with .. but dressing the skirt doubt it does much.. when ~3000psi hits the skirt it flares into the rifling .. thats the idea .. if its alittle deformed doubtful it will make much difference when that pressure hits it unless its just really beat up ...

Obviously SOMETHING made a difference. Some would like to know. Some prefer to remain.....(insert descriptor here). Either is OK.

Nothing wrong with eliminating all the factors that get in the way of what we are all looking for! Accuracy! Thanks for sharing your findings. As far as having way too much time on our hands, what an awesome way to spend some time! With a rifle shooting for accuracy. It’s what I look forward to every day. And it always makes me grin. We are so lucky to have these guns available. Our back yards are shooting sanctuaries lol!

Love your outlook on life and our luxury of being able to own and shoot these toys in the privacy of our own home. Others in other areas of the world, not so fortunate.

To CORNPONE, thanks for taking the time and posting up your findings. This hobby truly is about experimentation. As an example, take a look at what all Ernest has done with his experiments on different parts, pieces, and combinations. As a result, the new M3 now bears the fruits of his efforts.

Exactly. Good effort at testing and it might be helpful to some. Others can prefer to "just shoot". Only yourself to make happy in each case.

 

[Guest]

One problem with this kind if exercise is, nothing counts except the target. SD, ES, etc. do not consistently define accuracy, at least not to a statistically significant degree. 

I spent years engaged in centerfire and rimfire BR competition. And that is the most demanding of exacting preparation. It finally wore me out. Now I just shoot. If the targets are good, I did well, if not, it was obviously bad pellets! Why work to remove my best excuse?

That's true as far as it goes. An ES of 48 on an average velocity of 688 fpe changes POI at 40 yards by 0.4 inches (1 MOA). I like the excuse though . Somewhere along the way I just got tired of wondering why my groups were bigger than I wanted. So I study.

I got five tins of Barracudas in yesterday so I'll probably duplicate the study with them. Maybe it will help me quantify something else I did not know.

I really do like the excuse though ... I blame in on the wind, myself

 

[Guest]

Over the years I have conducted similar tests, it all depends on the rifle barrel and how the breech was finished off at the factory. Some results were like yours and other barrels were completely different. Some barrels like expanded skirts while some didnt....the real conclusion here is to check with each and every barrel on each and every gun. No two are identical no matter how close tolerances are held !!

I believe this is true. I am hoping that I can find something that is more or less universal. It will probably take a while to gather all the data.

 

[elh0102]

One problem with this kind if exercise is, nothing counts except the target. SD, ES, etc. do not consistently define accuracy, at least not to a statistically significant degree. 

I spent years engaged in centerfire and rimfire BR competition. And that is the most demanding of exacting preparation. It finally wore me out. Now I just shoot. If the targets are good, I did well, if not, it was obviously bad pellets! Why work to remove my best excuse?

That's true as far as it goes. An ES of 48 on an average velocity of 688 fpe changes POI at 40 yards by 0.4 inches (1 MOA). I like the excuse though

. Somewhere along the way I just got tired of wondering why my groups were bigger than I wanted. So I study.

I got five tins of Barracudas in yesterday so I'll probably duplicate the study with them. Maybe it will help me quantify something else I did not know.

I really do like the excuse though ... I blame in on the wind, myself

Obviously, I was kidding around a bit with my response, but with a grain of truth. Yes, an ES of 48 with that pellet, velocity, and distance, is enough to remove it from the precision accuracy category, at least by most folks' definition. The amount of preparation one can execute in this sport is virtually endless. And, there is a time in your duration in it, that all this study and experimentation is very interesting, educational, and just fun. That is probably where you are at this moment, so I wish you all the best in achieving your goals. It can be very satisfying. Based on age, health, and time spent in the sport, I get a lot of pleasure now from just shooting. If the pellet hits, great, if not, well, I've got plenty of pellets and I'll eventually find the target!