Spent some time today at the range experimenting with headspace tweaking. I think I found some sweet spots. Each bull was shot with a different headspace length.
Thomas Air Headspace tweaking, not the kind between your ears
- Thread starter igolfat8
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So, my Thomas has a pellet seater... I am understanding your suggesting the depth to which i "seat" a pellets skirt into the breech, does indeed matter?
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Seating depth matters....but I don't see big differences on the low power guns. You can see significant differences on the higher powered guns like Tims.
Changing lot numbers of pellets will require you to start all over when looking for optimum.
Mike
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That makes sense. fortunately i shoot what i have and only discard obviously damaged pellets. Never taken the time to weigh wash lube sort and oh my, now measure my pellets length.
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@cavedweller , Consider this that some pellets have deep skirts and others shallow skirts. When you have your pellet pusher adjusted for the deep skirts then switch to shallows the shallow skirt pellet‘s head will be seated much deeper into the leade or possibly started into the rifling. It may or may not shoot better but as Mike says you have to start all over to find the searing depth that yields the highest accuracy potential.
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For the low power units have you found that the redesigned monsters like to be seated deeper than the regular monsters? I can't get the redesigned to shoot well at all (low power) but have not messed with seating depth. On the regulars shooting low power it seems that they don't like to be seated any deeper than where my thumb would do it, any deeper and it seems to not do good things but just slightly, nothing obvious as demonstrated here.
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Headspace is definitely not the right term. We aren’t cutting a max depth for a cartridge. But it definitely made me look at the topic. Thought there might be pressurized cartridge airgun involved and that would be cool to read about. Seating depth is important for more than just accuracy. I’ve seen crazy ES numbers with incorrect seating depths.
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On its own, sure... LOL
In PB terms that would equate to bullet seating depth or jump (ogive to lands).
Now if we were talking about knitting using firearm terms would not be confusing (very little to no crossover), AG & PB's share too many things so using PB terms for a somewhat similar (terms/vocabulary) but different process will likely confuse some people.
Seating depth (even though it is also a PB term) would be the most appropriate for what this post is about.
Headspace (ok) or seating depth (better) works for me and it got me to click...and I learned something too!!
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I would not recommend any space between a pellets head and the rifling. So since there will never be space involved, depth is more appropriate. If someone is jumping a pellet into the rifling with great success, I would love to see the leade. It would have to be exquisite.
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I had a 24" LW made for my mrod some years back that had no leade, just a curb and that was even drilled to deep. H&N 21.14 wouldn't touch the rifling at battery. Crazy fliers, returned for a refund.
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This is a topic that is IMO that gets overlooked too often. Thanks for the reminder. I have a heavily modified disco that shoots .257 cast bullets. This rifle has an adjustable probe and I use that to get the bullet depth correct. Never changed on my pellet rifles , but I do always check that the pellets is pushed past the transfer port on every rifle I own.
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Hi igolfat8,
This has got me thinking... I just did a mini review of the .177 AEA 13.7g pellet in the 30-Yard Challenge thread.
I've always felt that I got more consistent results (and perhaps shot strings) with the shorter length 8.x and 10.3g pellets. I don't get traditional "fliers" so much with the longer 13.4/7 grain - I get what I'll call "droppers" - a pellet shot at a similar velocity to others that drops significantly lower from a target shooting perspective. Example:
Questions:
#1: Could it be that longer pellets are more subject to "droppers" because their longer cavities are more likely to have depth variances significant enough to cause a low shot?
#2: Would using a pin probe, instead of a pellet probe, help to eliminate this issue (if in fact its an issue).
I'm not a pellet sorter/weigher - just shoot straight from the same tin when shooting targets. Another assumption would be that shooting all targets from the same tin of pellets is advantagous - as pellets from the same tin should be more uniform than the same make/model pellet from different tins/lots?
-Ed
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I have a <12 FPE Thomas BR.
During pellet testing the two best pellets were the H&N Baracuda FT 9.57 grain, 4.51 diameter and the MEISTERKLUGEN 7.0 grain pistol wad cutter.
If inserted into the chamber deep enough to touch/engage the rifling, both pellet's 5 round group size opened up.
For depths between flush with the breech face and touching the rifling, it didn't seem to matter, the group size remained consistent.
So I set the depth of the pellet probe to insert a pellet till the skirt is just inside the breech face so depth and centricity can be verified easily by eye and therefore be consistent shot to shot.
During pellet testing the two best pellets were the H&N Baracuda FT 9.57 grain, 4.51 diameter and the MEISTERKLUGEN 7.0 grain pistol wad cutter.
If inserted into the chamber deep enough to touch/engage the rifling, both pellet's 5 round group size opened up.
For depths between flush with the breech face and touching the rifling, it didn't seem to matter, the group size remained consistent.
So I set the depth of the pellet probe to insert a pellet till the skirt is just inside the breech face so depth and centricity can be verified easily by eye and therefore be consistent shot to shot.
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