ART BARREL DAYSTATE RW HP AND JSB PELLETS

Thinking out loud....when reloading for center fire rifles you often see an increase in accuracy having the bullet seated so that it is either touching or 'jammed' into the lands of the rifling as opposed to having it 'jump' into the rifling when fired. Could this be the same phenomenon here?

Guy’s, Do yourself a favor And read the whole post! Start to finish! Probably answer some Q’s! I mentioned all this Earlier...

Edosan, Nomo:

I have a recently purchased ( from AoA) RW Safari in .25 caliber. It shoots ok, but not as accurate as I was hoping, so I have been wondering about this thread and your findings on JSB pellets. I will have to check my JSB 33 and 25g pellets to see if they are flat or deep based skirts. 

My preset Daystate factory power settings with 33g are 947 FPS on high power, and around 865-875 FPS on Medium. It shoots the 25g right at 900 FPS on medium. Accuracy is good, but not great at 100 yards after about 5 outings. I don't have the programmer to tune and right now am not interested in buying it just yet either.

Q. Do you think Daystate is aware of the pellet probe issue with regard to being perhaps a bit too small in length, based on your mutual findings? If not, should they be aware of the issue some of you are seeing? Should they design either an adjustable pellet probe or a longer version?

We can use an Allen wrench or another home made device to push the pellets farther into the chamber, but that's not a workable long term solution in my view.

Thoughts?

OK thanks.

I'm thinking that JSB is going to keep making inconsistent sized and/or shaped pellets no matter what anyone says or does, so I guess maybe what you are saying is that "it's not on Daystate to fix inconsistent pellet sizes and shapes with building a longer pellet probe."

Understand what you are saying, but it's really unfortunate because if your testing reveals that the deep base pellets are more inaccurate, then you almost have to sort/size and inspect every tin if you want to achieve some type of consistent accuracy. Alternatively, and as you pointed out, you can use an Allen wrench to push the pellets further into the chamber. But, if you use a magazine, this doesn't work if you have deep base pellets correct?

Do you think the base depth affects the balance point (Head to skirt) of the pellet? Therefore, the different balanced pellets prefer different speeds to stabilize them? I’m certainly no expert but merely thinking out loud.

This is my take on the pellet dimension issue, first most guns are not overly sensitive to inner skirt depth dimensions? Most will be more sensitive to weight or head size, general shape or hardness of the lead, etc. etc. etc. what I found was that I trying to eliminate All variables in my R.A.W. for 25m competition And my RW as well, I was finding accuracy Issues between lots of jsb’s trying to get consistency and the underlying reason why this was Happening? in doing so I looked at all the dimensional differences between what shot very accurately and did not? in the end “out of desperation” I found the inner skirt depth or “well” played a major factor in accuracy! That was my hypothesis anyway... I have two very accurate guns and both utilize a pin style probe to seat pellets into the barrel also these guns have aTP within the barrel proper, unlike a Thomas or USFT! and as you see in my earlier post I made a crude seater to try and prove this to myself, but let me say in no way will this crude device be precise enough to test for the specific depth’s required for every pellet/barrel combination, this would require infinite adjustability and precision to properly test for ultimate accuracy! Not to mention very, very time consuming! now I did find that accuracy “appeared“ to be increased By seating Pellet deeper into the bore, the shallower the inner skirt well the further into the barrel the pellet was seated. Also I’m sure every gun sensitive to this phenomenon maybe for many different reasons like, barrel harmonics, TP air flow inconsistencies? so many variables to account for!, ( Just to be clear your gun may act the opposite Deeper skirt well better accuracy? ) JUST REMEMBER NONE OF THIS MAY APPLY TO YOUR GUN OR INTENDED USE!, And also let me say I probably have “NO IDEA” what the hell I’m talking about...

Joe

Before someone jumps on me about my RAW, it’s a BM-500 with the thimble, so yes ”technically” The TP is not in the barrel proper, but believe it behaves similar to TP cut directly into the barrel? Want to add both the Raw and RW have LW poly barrels! Interesting side note I have a.177 RW that does not really seem to care? I’ve tested two different lots of 16.1’s different well depths, 13.4 both redesigned and original, and here’s the kicker the 10.3 jsb’s shoot fantastic!!! Haven’t chronographed these yet but have to believe they in access of 900fps? So It comes back to every gun acts differently And you can’t blindly expect your gun to only shoot Accurately with the shallow inner skirt well? Must test...

edosan....Thanks for the tip. I made a pellet seater tonight out of an allen wrench. It should seat the pellets about 2mm deeper. I'll try it out with the single shot tray this coming weekend (I hope).

Joe, Edosan

Thanks for the additional information and insights. I can see now that this is more complicated with other variables to consider as you both mention. Regardless, we all benefit from your sharing of information/ testing; and insightful theories as we strive for improved accuracy.

Tom

This is indeed a general problem for pin probes that seat the projectile just in front of the TP. Since some pellets 'feature' a long hollow base they won't be seated past the TP in that case and thus will not bump up their skirt in the same way during a shot but will also get a small burst of air inbetween the head and skirt.

For the highest accuracy I would indeed suggest a pin probe with changeable pin length. Or use a hollow tube like FX uses for seating since this works on the edges of the slugs and pellets. Downside of the hollow probe is that it blocks a bigger portion of the entrance hole and thus decreasing the flow capabilities a.k.a. restricting a bit of power.

Maybe we just need a retractable pin inside the probe with adjustable seating depth Use the pin for seating the pellet or slug and retract it before shooting. Gives you maximum flow and thus no disturbances from a probe. Or even better, have a hollow tube for best seating without tilting and retract it before shooting. Since this is a public forum, did I just kill a potential patent here ? 

This is indeed an industry-wide “problem”. Or the pellets just need a more consistent shape....

The WAR rifles had a bolt that was solid flat faced and then you retracted it into a slot. Here's some pics on here you can see

https://www.airgunnation.com/topic/wicked-air-rifle-warp-30cal/