Pellet diameter

[BenjiHunter]

You read a lot about different size pellets.
Bigger is better in some,like a Webley.
Does it really matter much if they are ( In .22),
5,5. 5.52 or 5,53.
Shouldn't the skirt expand to the size of the bore if you have enough oomp in the gun?

[TorqueMaster]

It's more about the head size, and how it rides on the rifling.  Some guns are picky about head size.  Generally speaking, in my experience, loose in the bore is bad, and so tight you have to really jam it in is bad.  I notice both issues with Crosman CPHPs.  JSB and H&N feed very consistently.

The skirt should be larger, and seal pretty well when inserted, and yes, likely swell when fired.

Any pellet marked "5.5" could be 5.50 or 5.55, maybe even 5.45, it doesn't inspire confidence they will be of a consistent size.   I trust the better brands to be more consistent if they are just labeled "5.5."  I have seen some 5.50 pellets advertised as "5.5" just because the retailer didn't bother to add the extra zero.

And you've probably seen the posts -- just because it says "5.53" surely doesn't mean they will all be 5.53, and they may not even average 5.53.   I like to think the manufacturer took *some* effort to at least try to keep them close to the same size, even if it isn't exactly what's shown on the tin.   

[BenjiHunter]

The thing I have noticed is that the rifeling shows on the skirt and not the head.
So is the head really riding on the barrel rifeling? Every shot I have made in some soft material show rifle marks on the skirt.

[Bayman]

The sizes are for head size. Every barrel is different. I find my Weihrauchs to better with snugger fitting pellets. Within reason. Head sizes are relative to the manufactures. H&N FTTs in 4.51 have to be pushed into my guns. Meanwhile 4.52 JSB Exacts fall out of the breech if I'm not careful. I've also had 5.54 FTTs fit tighter than 5.55 as well as 4.51 tighter than 4.52 FTTs. Still somehow there's a logical difference in the chrono and sometimes the targets.

I buy mixes of sizes because I have a few guns and occasionally work on other people's guns, so it's nice to have a variety. Sometimes there's no difference sometimes it's a big difference. 4.53 Exacts half the group size of 4.52 Exacts in my HW95.

[JPSAXNC]

Pushing pellets through the barrel, I like to see just enough marking on the head of the pellet to see that it is touching the rifling, and feel that it is still making contact as it leaves the muzzle.

[nced]

You read a lot about different size pellets.
Bigger is better in some,like a Webley.
Does it really matter much if they are ( In .22),
5,5. 5.52 or 5,53.
Shouldn't the skirt expand to the size of the bore if you have enough oomp in the gun?

I have almost no .22 cal airgun experience (shot .22 half of a season and reverted back to .177) but I have a different opinion about .177 cal "pellet sizes". I found that if the pellet is a "loose fitter" in the leade when loading it can/will be a "flier" when shot. I'm of the opinion that as long as the pellet head is large enough to be "swaged in the leade" when loading (require some pressure to seat) each pellet will start down the bore the exact size and group well. The problem I had with "pellet fit" was when shooting "straight from the tin" with pellets having various pellet head sizes regardless of the claimed head size. A perfect example of this are the 9 tins order of supposedly 4.52mm JSB Exacts I bought a few years ago. During one field target match I attended with my Beeman R9 I had two "dry fires" (shots with no pellet in the leade). I would have had a 3rd if I didn't see the pellet flip out of the leade when re-latching the barrel after loading. That started my "measuring pellet heads" to determine consistency and this is what I found with those JSB Exacts. There were some that actually measured 4.52mm however the large percentage was a variety of smaller pellets with quite a few of a 4.58mm size and one at 4.57mm...........

Further testing the smaller sizes in my R9 explaines why there were a lot of "loosies" in the leade and those with a 4.48mm heads were indeed "possible flipper outers" when re-latching the barrel.

The exact opposite was the now discontinued die lot marked and dated Crosman Premiers from the 1250 count cardboard box. I used those pellets straight from the box for years and almost all with a few exceptions fit snug in the leade and were my "go-to" pellet. After measuring the JSB Exacts I measured the CPLs and found that they were very consistent with rather large heads. I did have a case (4 boxes) of die #7s years ago with an abnormal amount of peewees (135 out of 1250) but sorted out the rest were accurate however that was an anomaly.

When I bought a new .177 HW95 a few years ago I found that evidently HW changed their .177 cal barrel specs because the boxed CPLs were "sore loading finger tight" so I made a couple pellet head sizers, one sized CPL heads to 4.48mm for the new HW95 and another to size the pellet heads to 4.52mm for the R9. Just for grins I lapped out the 4.48mm sizer to put out CPLs with 4.50mm heads and found that thet were accurate from both the R9 and HW95 yet a shooting session with the HW95 didn't leave me with a sore loading finger tip.........




Anywhoo, perhaps the air pressure from a PCP can "pellet skirt blow out" a pellet skirt to fit the bore but it seems to me that the variation/severity of the "pellet skirt blow out" needed to seal the bore there would also be variations in air pressure behind the pellet after "sealing" the bore. I'm only guessing here and I could be mistaken however if the pellet head/skirt is "swaged to size" simply by loading the pressure behind the pellet would be consistent. LOL....that's assuming power plant is supplying consistent pressure i.e. no abnormal dieseling in the case of a piston gun.

[ezman604]

Moved to Pellets All Caliber Discussion Gate.

[BenjiHunter]

I took a closer look at the pellets and they have rifle marks on the head. My mistake.😉